26 June 2015

The Daring Rescue of a Downed Pilot at the Battle of A Shau Valley

Major Bernard Fisher, first USAF Medal of Honor recipient of the Vietnam War
In 1961 the CIA, in cooperation with the US Army Special Forces teams, began to set up a network of surveillance camps along the borders of South Vietnam to monitor North Vietnamese infiltration of South Vietnam. Located primarily in the remote highlands of South Vietnam, the special forces camps were manned by a mixture of US Army special forces personnel, South Vietnamese special forces personnel, and paramilitary units recruited from the indigenous populations of the area like the Montagnards. By 1962 the US Army assumed full responsibility for the special forces camps. In 1966, one of these special forces camps was the scene of one of the most daring rescues of downed American pilot in the Vietnam War. High up in a remote area of the northwest corner of South Vietnam just two miles from the Laotian border was the special forces camp in the A Shau Valley. If there was a more remote camp that was nearly inaccessible elsewhere in South Vietnam, the A Shau Valley would have given them a run for the money. With steep jungle covered mountains ascending to over 7,000 feet and constant storms during monsoon season, the aerial resupply of the A Shau Valley camp was challenging even under the best of conditions. It had an approximately half-mile long dirt airstrip that sat astride the triangular-shaped fort that served as the special forces base camp. But the camp lay astride three major infiltration routes off the Ho Chi Minh Trail into South Vietnam- one route ran westward from the valley towards the main axis of the Ho Chi Minh Trail and two routes ran eastward towards the city of Hue and the heavily populated areas of the South Vietnamese coast. In early March of that year, two regiments of the North Vietnamese Army set up positions in the mountains above the camp in preparation of an assault. A flak trap was set up in the heights over the camp with 37mm anti-aircraft cannons. On 9 March at 0400, the assault began with a mortar bombardment on the camp with NVA sappers punching holes in the camp's defensive perimeter. An estimated 2,000 NVA soldiers squared off against 360 South Vietnamese and Montagnard soldiers led by 17 US Army Special Forces troops.

Due to poor weather with only 400-foot ceilings (in a valley surrounded by 7,000 foot mountains), the first air support didn't arrive until mid-morning when a USAF AC-47 Spooky gunship arrived over the area in poor weather conditions. On its third pass at low altitude, the NVA flak trap caught the gunship and it crashed into a mountainside. The crew of six survived, but three were rescued thanks to the heroic actions of two of the crew to defend the crash site until they could be rescued. Captain Willard Collins and 1st Lt. Delbert Peterson posthumously earned the Air Force Cross for defending the survivors before they were killed by NVA troops. Two Cessna O-1 Bird Dogs attempted to land on the dirt strip to fly out some casualties, but the heavy enemy fire only allowed them to fly out one wounded special forces soldier. Later that afternoon, the Marines sent two Sikorsky UH-34Ds into the area to evacuate the wounded. One helicopter was shot down but managed to crash land inside the camp perimeter. Its crew was picked up by the other helicopter before it had to withdraw under the thick overcast. That night under cover of darkness a USAF Sikorsky CH-3E managed to land in the camp and fly out 26 causalities. The following morning the NVA pressed their attack against the camp again, managing the penetrate the defensive perimeter. In the pre-dawn darkness, a Marine A-4 Skyhawk two-ship responded and one of the pilots managed to make a low level bombing pass before coming around to strafe the area with the Skyhawk's 20mm cannon. Lt. Augusto Xavier failed to pull out of his strafing run in the limited visibility conditions and crashed into one of the mountains around the camp. He was posthumously awarded the Silver Star. Nearly 200 close air support sorties were mounted that day despite poor weather to keep the camp from falling into NVA hands.

With the arrival of daylight, USAF Major Bernard Fisher (call sign "HOBO 51") from the 1st Air Commando Squadron led a flight of A-1E Skyraiders in 800-foot overcast ceilings to try and assist the defenders of the A Shau Valley camp. Fisher's wingman took 37mm cannon hits to his engine and had to return to base. A second pair of USAF A-1E Skyraiders arrived on scene, led by Major D.W. "Jump" Myers (call sign "SURF 41") from the 602nd Air Commando Squadron. The Skyraiders pressed their attacks as close to the camp as possible to keep the perimeter from falling. Making strafing passes on the NVA troops pushing on the camp perimeter, Myers was hit on his third pass and his Skyraider caught fire. He elected to crash land on the camp's dirt runway and Major Fisher flew along side to give him steering directions as Myers' windscreen got covered in oil when the engine got hit. Myers successfully crash landed his Skyraider on the dirt strip and immediately got out before his Skyraider exploded and took cover in a ditch next to the runway. A team from the camp tried to get to Myers to bring him inside the camp perimeter, but the NVA fire in the area was too heavy to effect a ground rescue. Orbiting above and dodging enemy fire, Fisher directed the other Skyraider pilots' fire to protect Myers and buy time for the inbound rescue helicopter. When he found out a rescue helicopter would take about 20 minutes to reach the area due to the weather conditions, Major Fisher elected to try and land on the strip to rescue Myers himself. 

With debris from the battle as well as Myers' destroyed Skyraider littering the runway, Fisher had to abort his first landing attempt and swung around to land the other direction on the runway. One of the pilots in the area described the scene as like "Flying into Yankee Stadium with everyone in the bleachers firing at you with machine guns!" Fisher managed to land on the runway and in the midst of the heavy fire, taxied back up the runway searching for Myers. Since his Skyraider was the side-by-side two seat version of the A-1, Fisher spotted Myers who sprinted for the aircraft from his hiding place. Fisher had already unharnessed himself thinking that Myers was wounded and needed help when he found the pilot already scrambling up his wing to the cockpit. Fisher grabbed Myers and quite literally threw him into the cockpit headfirst with Myers yelling "You dumb son-of-a-bitch, now neither of us will get out of here!" With Myers scrambling to get himself seated and harnessed into the cockpit, Fisher wheeled the A-1 around and kept the Skyraider in ground effect until he had the speed climb up through the overcast and over the mountains to safety at their base at Pleiku.

Fisher on the left and Myers on the right after the rescue flight
Remember that group of special forces that got pinned down trying to rescue Major Myers? They were able to escape and get back inside the camp perimeter as all the NVA guns that had them pinned down were focused on trying to shoot down Major Fisher's Skyraider.; When his aircraft landed back at its base, the aircraft had 19 holes from ground fire sustained during the rescue flight. Fisher was unlikely Skyraider pilot- he served in World War II as a sailor and on return to the United States, joined the ROTC while in college. He only finished three years at the University of Utah before he was commissioned to fly for the USAF. He had earned his wings flying Convair F-102 Delta Daggers in Europe and Lockheed F-104 Starfighters for the Air Defense Command stateside. He volunteered for combat duty in Vietnam, getting assigned to fly Skyraiders with the 1st Air Commando Squadron at Pleiku. At the time of his epic rescue flight, he had been flying combat missions in the A-1 for eight months. The day prior to his rescue of Major Myers, he earned a Silver Star flying combat missions over the same special forces camp in the A Shau Valley! 

On 19 January 1967, he was awarded the Congressional Medal of Honor for his rescue of Major Myers. This is the citation: 
For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty. On that date, the special forces camp at A Shau was under attack by 2,000 North Vietnamese Army regulars. Hostile troops had positioned themselves between the airstrip and the camp. Other hostile troops had surrounded the camp and were continuously raking it with automatic weapons fire from the surrounding hills. The tops of the 1,500-foot hills were obscured by an 800 foot ceiling, limiting aircraft maneuverability and forcing pilots to operate within range of hostile gun positions, which often were able to fire down on the attacking aircraft. During the battle, Maj. Fisher observed a fellow airman crash land on the battle-torn airstrip. In the belief that the downed pilot was seriously injured and in imminent danger of capture, Maj. Fisher announced his intention to land on the airstrip to effect a rescue. Although aware of the extreme danger and likely failure of such an attempt, he elected to continue. Directing his own air cover, he landed his aircraft and taxied almost the full length of the runway, which was littered with battle debris and parts of an exploded aircraft. While effecting a successful rescue of the downed pilot, heavy ground fire was observed, with 19 bullets striking his aircraft. In the face of the withering ground fire, he applied power and gained enough speed to lift-off at the overrun of the airstrip. Maj. Fisher's profound concern for his fellow airman, and at the risk of his life above and beyond the call of duty are in the highest traditions of the U.S. Air Force and reflect great credit upon himself and the Armed Forces of his country.
Fisher was the first USAF Medal of Honor recipient of the Vietnam War. He finished his tour in Vietnam on the Skyraider with 200 combat missions. His unit, the 1st Air Commando Squadron, had a 40% casualty rate amongst its pilots as they did a lot of low level close air support flying in support of the special forces camps in some of the most inhospitable parts of South Vietnam. He returned to the Air Defense Command until his retirement as a colonel in 1974, having flown the McDonnell F-101B Voodoo. He took up corn and alfalfa farming with his wife in rural Idaho. Every year since his rescue, each March 10th, D.W. Myers called Bernard Fisher to wish him well until Myers died in 1992. Myers' daughter kept up the ritual for another 22 years, calling Fisher on March 10th herself to wish him well. In 2008, the University of Utah awarded a diploma to Bernard Fisher 57 years after he was last a student there in recognition for his achievements and decorated military career. In 2010, the Boise Rescue Mission was established as a homeless veterans' transitional program with Fisher's help and its motto is Fisher's quote after he rescued Myers: "When a man is down, you don't leave him there." Colonel Bernard Francis Fisher flew west on 16 August 2014.

Fisher's A-1E Skyraider at the USAF Museum
You can see Bernard Fisher's A-1E Skyraider today as it has been restored and wears the colors and markings as it looked on the day of his Medal of Honor Mission at the National Museum of the United States Air Force in Dayton, Ohio.

As for the fate of the special forces camp in the A Shau Valley after Fisher's rescue flight? By late afternoon on 10 March 1966, the decision was made to evacuate and abandon the A Shau Valley camp. Sixteen UH-34D helicopters along with six UH-1Es, all from the Marine units HMM-163 and VMO-2 respectively, flew into the valley with 200-foot overcast for the evacuation. Two helicopters were shot down but their crews managed to lead groups of camp soldiers out of the area on foot, evading the NVA units that were closing in on the camp. The NVA flak trap was so intense that three Marine F-4B Phantoms, two A-4 Skyhawks, two UH-1s and three more UH-34D sustained damage. The following morning a second evacuation flight managed to get the rest of the personnel out of the camp. The Marine helicopter squadron HMM-163 needed to have 21 of its 24 UH-34Ds replaced. Interestingly, one of the UH-1s involved in the evacuation of the rest of the personnel from the special forces camp was flown by Brigadier General Marion Carl of the US Marine Corps. Carl was the Marines' first ace of the Second World War and before Vietnam he was a decorated test pilot. Despite his rank as the commander of the 1st Marine Brigade in Vietnam, he often flew combat missions in both helicopters and jet fighters much to the chagrin of his superiors!

Sources: Above and Beyond: The Aviation Medals of Honor by Barrett Tillman. Smithsonian Institution Press, 2002, pp 218-221. Assault from the Sky: US Marine Corps Helicopter Operations in Vietnam by Dick Camp. Casemate Publishers, 2013, pp 64-79. Photos: USAF Museum

21 June 2015

Captain Joseph M. Reeves: Leading Carrier Aviation From Experiment to Fighting Force

Captain Joseph Mason "Bull" Reeves, USN
In writing this particular article for TAILS THROUGH TIME, I had wrestled with how best to title the subject on Captain Joseph Reeves as the father of carrier aviation. He certainly wasn't the first, and he most certainly wasn't the only pioneer in the field. Anything I came up with sounded to complicated from "Father of the Modern Carrier Flight Deck" to more esoteric things I'm too embarrassed to share here on this blog. When he assumed command of the US Navy's sole aircraft carrier, the USS Langley (CV-1) on October 1925, he wasn't there to break new ground, but to learn more about what aviation could contribute to naval operations and in the process, forged carrier aviation into a fighting force that shaped military operations in the Second World War and beyond. On that day in 1925 when he set foot aboard the Langley, there was no dispute as to carrier aviation being part of naval operations as it had been so in various capacities going back to the First World War. I think what is interesting about Captain Reeves' role in the development of carrier aviation stems from the fact that in those days, he was one of the foremost battleship tacticians of the day. Nicknamed "Bull" from his days playing football as a midshipman at the US Naval Academy, Reeves' appointment to command the Langley and by extension, all of naval aviation in the 1920s, comes from a background based on two factors. The first one was his own time as the head of the Tactics Department of the Naval War College. It was there he came to be known for his innovative tactics and being uncharacteristically forward-thinking for an officer of his stature. His time working on naval tactics exposed him to the potential of aviation in future naval operations and he himself once did admit that despite having a "Big Gun" battleship background, he saw the submarine and the airplane as possibly being decisive in the next war, he just didn't know which one. The Chief of Naval Operations (CNO), Admiral Edward Eberle, had served with Reeves on the battleship USS Oregon and was well aware of his innovative thinking when he selected Reeves to command the Langley. Perhaps the CNO wanted someone in charge of aviation who could creatively make something of the whole enterprise. 

That same year Reeves assumed command of the USS Langley, a very public dispute had broken out between Rear Admiral William Moffett, the chief of the Bureau of Aeronautics (BuAer), and Rear Admiral William Shoemaker, the head of the Bureau of Navigation (BuNav). At the time, BuNav was in charge of personnel matters for the entire Navy. Moffett, taking it as his personal mission to nurture and grow naval aviation, felt that aviation personnel should be the responsibility of BuAer rather than BuNav. After all, in Moffett's eyes, only aviators knew what was best for other aviators. While this important administrative dispute was going on within the halls of power of the Navy, the CNO's selection of Captain Reeves was one of careful selection to avoid ruffling any feathers at either BuAer or BuNav- after all, Reeves had a respected reputation as a tactician, he was a trained engineer, and he came from the battleship side of the Navy. Commanding the Langley as a politically sensitive post and it probably helped Reeves that he was seen by BuNav as an acceptable choice. A law, however, passed in 1921, stipulated that all aviation units of the US Navy, including aircraft carriers (of which there was only one, the USS Langley) had to be commanded by naval aviators. Reeves wasn't a pilot and naval aviation was so new to the Navy that there weren't any senior officers in aviation with the qualifications, time served, and rank to fill aviation command billets. The most senior naval aviator, Commander John Towers, didn't have the qualifications to command the Langley- in fact, Towers wouldn't make captain for another ten years! So BuAer created a special course for naval aviation observers at NAS Pensacola to train senior officers in the basics of flight for postings to aviation units until there were enough senior aviation officers in the ranks. As a prerequisite to Reeves getting to command the Langley, he had to complete the naval aviation observer course at Pensacola, which he did the month prior to assuming command of the Langley in San Diego. 

The Navy's first aircraft carrier, USS Langley (CV-1)
When he took command of the USS Langley, the pace of operations on the converted carrier (it was once the collier USS Jupiter before a flight deck was built atop the hull, giving the Langley its nickname "Covered Wagon") reflected the experimental nature of carrier operations. For a whole month, Reeves observed shipboard operations both below decks and on the flight deck. He was rather surprised that the Langley's air wing was composed of only eight aircraft. But he took notes, made observations and then in November 1925, he gathered the officers of the carrier and its air wing to a meeting at NAS North Island and bluntly told all of them "They had no conception of either the capabilities or limitations of the air force". He fired off a long series of questions to his officers about carrier operations like "What is the most efficient way of launching planes?" or "What is the maximum interval between planes in a scouting screen?". He then told his men to their surprise he didn't know the answers either "But unless we can answer them, we are of little use to the fleet." Reeves' questions came to be called "A Thousand and One Questions" and his men sought to figure out each one. As each one was answered, it went into what would become the textbook of naval aviation. It was Reeves' mission statement- the USS Langley and her air wing would become a school before becoming an air force of use to the fleet.

From his time as a tactician at the Naval War College, Reeves was quite familiar with English engineer Frederick Lanchester's N-Square Law when it came to defining the relative power of opposing forces- the combat effectiveness of a military force is proportional to the square of its numerical strength multiplied by the fighting value of its individual units. The fighting value was determined by training and Reeves would relentless drill the Langley's crew and air wing and make sure the ship participated in as many fleet exercises as possible. The numerical strength aspect was solved by getting as many aircraft as possible on the Langley. If the crew could launch and recover aircraft quickly and efficiently, then the carrier could support a much bigger air wing than its current paltry complement of eight aircraft. His first order of business was to increase the Langley's air wing to fourteen. No one thought it was possible, but Reeves' order stood and on the first day of fleet exercises, VF-2 managed to launch six aircraft quickly and get a second group of six airborne right after that- after all, the day would come that a carrier would have to defend itself against air attack and its aircraft were its own best defense. 

In the months that followed, Reeves trained the Langley crew and air wing hard. He pushed them endlessly to increase the tempo of flight deck operations as a carrier was useless if its planes weren't in the air. He steadily increased the air wing of the Langley as well and frequently took charge of flight operations himself, acting as the "Air Boss". In less than six months, he had twenty aircraft operating routinely off the Langley's small deck, quite a feat given that prior to his command, there were only eight aircraft in the air wing. Before he took command, it was customary to let a plane land and then lower it to the hangar deck before allowing the next plane to land. This was time consuming and Reeves pushed his men to orchestrate their movements on the flight deck. As each plane landed, it was disengaged from the arresting gear and pushed forward to the bow to make way for the next aircraft. A collapsible barrier was used at the midpoint of the flight deck to protect the parked aircraft forward. Working with his executive officer (XO), Commander John Towers, Reeves worked out a system of specialized groups of deck crew- each group was assigned a specific task on the flight deck- arresting gear, releasing tail hooks, fueling aircraft, arming aircraft, and more. To delineate their roles to each other, Reeves and Towers had each group wear colored shirts. The blue shirts moved aircraft forward, the brown shirts were crew chiefs, the purple shirts were in charge of refueling, and so on. The yellow shirts were the plane directors, the elite of the flight deck crew. The yellow shirts orchestrated all the action of the other groups and movement of aircraft on the deck. Hand signals were developed to make communication clear and concise over the roar of aircraft engines. Once all the aircraft landed, they were all pushed aft for fueling and rearming to prepare for the next launch cycle. A subset of the plane directors were assigned the role of flight control officers who used a checkered flag to signal each pilot to firewall the throttles and race down the deck for takeoff. By increasing the speed of the launch and recovery cycle, the Langley made more use of its air wing- it was a force multiplier. 

A Curtiss F6C Hawk of VF-2 embarked on the USS Langley
In preparation for the fleet exercises in the summer of 1926, Reeves had all the squadrons under his command (two fighter squadrons, three observation squadrons, one utility squadron and one torpedo/bombing squadron) train together as an integrated air wing. Changes and improvements to operating tactics were to be shared amongst all the squadrons as it was important that each unit know the strengths and limitations of the other squadrons of the air wing. Befitting his nickname of "Bull", Reeves pushed his men to turn around aircraft faster on the deck and further reduce launch and recovery times. By this point, it wasn't unusual for the Langley's air wing to have 24 to 30 aircraft, quite a feat compared to just a year prior. Reeves would stand on the deck during each launch and recovery cycle with a stopwatch. Only 15 seconds were to elapse between each launch and only 90 seconds were to elapse between each landing. And even that was too long for him! By the time of the summer fleet exercises, VF-1 had conducted 127 takeoffs and landings in a single day. Just a year prior that might have been VF-1's sum total of takeoffs and landings for an entire month! As far as Reeves was concerned, he was abiding by the old adage "Fight like you train, train like you fight". The increased pace of operations increased the proficiency of his men from the pilots and deck crew to the crew in engineering spaces that kept the ship operating. 

When the USS Langley and her air wing set sail for the fleet exercises in the summer of 1926, many of Captain Reeves' "A Thousand and One Questions" had been answered and formulated into naval air doctrine. But one question nagged him that summer and that was how to sink ships. He had seen level bombing in action during his naval aviation observer course in Pensacola and he felt that was a useless endeavor as bombsights were inaccurate, targets had to be more or less stationary and they definitely shouldn't be shooting back. Torpedo bombers were still limited in their carrying capacity and no one was keen on the idea of a low, slow approach to an enemy warship for a torpedo launch. 

The solution of course, would be dive bombing and it came from one of Reeves' officers, Lt. Commander Frank Wagner, the skipper of VF-2. But that's going to be a topic for a future blog posting- so stay tuned! 

*As a historical aside, in 1893 when Joseph Reeves played football at US Naval Academy, he was advised by a physician he had to give up football or risk a kick to the head which could kill him. Reeves then went to a local shoemaker and had a protective helmet made out of leather and mole skin so he could play in the Army-Navy game. He is considered one of the inventors of the football helmet.

Source: Destined for Glory: Dive Bombing, Midway, and the Evolution of Carrier Air Power by Thomas Wildenberg. Naval Institute Press, 1998, pp 24-36. Photos: Wikipedia, US Navy

16 June 2015

American Automates Reservations and Ticketing, Part Two: SABRE

SABRE terminals at American's terminal at JFK Airport
Part One of the story of how American Airlines moved to automate the passenger reservations and ticketing process looked how things were handled manually until the development with the Teleregister Corporation of the Reservisor System which was subsequently upgraded to a more capable system called Magnetronic Reservisor. Charles Amman, an analyst with American Airlines who was tasked by chairman C.R. Smith to improve the process, had delineated that there were three steps to making an airline reservation- the first step was to determine seat availability for a given flight, the second step was to then adjust the seat inventory to that a given flight didn't get oversold, and the last step in the process was to connect the passenger's name and information to that reservation to issue a plane ticket. Magnetronic Reservisor was one of the earliest distributed data processing systems to try and automate as much of that three step process as possible. The system could perform the first two tasks, but it took a second system developed by IBM called Reserwriter to complete the third step. Between the second step in Reservisor and the third step in Reserwriter, there was still a need for manual intervention and this was time-consuming. In 1958, it could take Magnetronic Reservisor up to three hours to complete that three step process outlined by Charles Amman! Things weren't going to get easier not just on account of the growth of passenger traffic on American, but the impending 1959 inauguration of Boeing 707 jet services. The speed of jet aircraft would, quite simply, outstrip the speed at which the Reservisor/Reserwriter system could process reservations and issue tickets.What C.R. Smith wanted was an automated system that could perform all the three step process in near-real time. 

How that was solved, though, requires us to take a step back a few years from the year 1958. In October 1952, the United States Air Force and IBM initiated the development of SAGE (Semi-Automatic Ground Environment), an integrated set of radar, surface to air missile batteries, and interceptor aircraft all tied together by digital computers and long distance telephone lines. At the time of the inception of SAGE, there was only one digital computer in existence, the Whirlwind at MIT. Very quickly, the SAGE project would eclipse the Manhattan Project in terms of size and complexity as much of the technology had to be developed to develop the world's first integrated air defense system. IBM would win the contract in April 1953 to develop the computers that would be the core of SAGE. As SAGE would tie together all the assets of the joint US-Canada North American Air Defense Command (NORAD), it was absolutely necessary for SAGE to be able to update and process data in real time so air defense units could respond rapidly to any threats. It was also necessary that SAGE be reliable.
The IBM 7090 mainframe was developed from the SAGE FSQ-7

Called Whirlwind II by IBM but AN/FSQ-7 by the USAF, the FSQ-7 was the world's first production digital computer weighing 275 tons with 919 miles of cable, 50,000 vacuum tubes, 7,300 pluggable units and 170,000 diodes. The computer consumed 3 megawatts of power and required 100 operators. The FSQ-7 was the brains of SAGE. The magnetic core of the FSQ-7 had 256 kilobytes of memory and was supported by 150 kilobyte magnetic drum as well as 4 tape drives each holding 100 kilobytes of data. One-hundred fifty consoles displayed data on circular CRT screens that used light pens to interact with the screen information. With the light pens, operators could tag radar tracks and issue commands to air defense units. Each of the 24 SAGE director centers built across the United States had a large multistory hardened concrete structure housing two FSQ-7 computers- one running and the other one operating as back up to the first. Each of the director centers were then linked not only to each other but to also as many as 100 air defense units by long distance telephone lines. SAGE was the single most expensive defense project until the development of the ICBM. The first direction center went online at McGuire AFB in New Jersey in November 1956. Today we'd call computers like the FSQ-7 a mainframe computer and in fact, the FSQ-7 is the progenitor of all modern mainframe computers used today. Much of what IBM learned in the development and implementation of SAGE led to the development of their first business mainframe computers, the IBM 7090 being an development of the FSQ-7. But at the time, IBM had spent much of their time working with the US military and were lagging behind their competitors in getting real-time data processing technology for commercial and business applications. 

One day on an American Airlines flight in 1953, two men sitting next to each other struck up a conversation that sprang from a realization they shared the same surname, Smith. One man was Blair Smith, an IBM sales executive who was bemoaning IBM's late entry into the business world and how much he needed to make a sale. The other man was none other than American's chairman, C.R. Smith, who bemoaned the monumental challenge the airline faced with the limitations of Reservisor with the inevitable arrival of faster jet aircraft. When the flight landed at New York La Guardia, Smith invited the IBM executive to tour the Reservisor nerve center located at the airport. It wasn't long before American and IBM entered into a partnership for a new, more advanced system that would be much more capable than Reservisor/Reserwriter. American's specifications for the new system were demanding given the technology of the day: 
  1. Be able to maintain at least 40,000 passenger reservations in real-time (this would be approximately 9 times what Reservisor was capable of handling).
  2. Be able to support 83,000 phone calls each day (Reservisor could handle only 15% of that load).
  3. Be able to retrieve flight information and seat availability within 3 seconds 90 percent of the time.
  4. Be able to support remote operations with at least 100 locations nationwide.
  5. Be able to record and access passenger information (what Reserwriter was doing already but it was a separate system).
  6. To have the capacity in the future to send and receive messages to other airlines.
American reservations agents at SABRE terminals
Nothing of this capability had ever been done in the business world before and this was where IBM's experience with the USAF in developing SAGE paid off. SAGE was the only existing distributed network computer mainframe system that could do data processing in real time. Partnership with American was just the break into the business world IBM needed for its mainframe computer systems. After his fortuitous meeting with C.R. Smith, he informed the head of IBM, Thomas Watson, who astutely realized many new technologies that IBM was developing based on its SAGE experience were just what would meet American Airlines' stringent specifications. IBM code-named the project SABER (Semi-Automatic Business Environment Response). Discussions between IBM and American continued for approximately two years under a memorandum of understanding that defined SABER as a joint project. American Airlines even set up its own department of software programmers to work with IBM to create the operating system to be used by SABER. On 18 September 1957, IBM submitted the formalized SABER proposal to C.R. Smith and the board of American Airlines which quickly approved the joint venture. Smith saw seat inventory and rapid booking and ticketing as not just an important business function but also both a customer service function and a marketing advantage for American- many other airlines were working on getting similar systems to SABER, but not all of them were as advanced and as scalable as SABER. In the same year that the Boeing 707 inaugural flights for American Airlines were flown in 1959, the project was expanded to include future upgrades as technology allowed, one of which was the ability to request seats on other airlines and to be scalable and support upgrades that would increase speed to near real time. That same year, one of Smith's subordinates came across an ad in a magazine for the Buick LeSabre and suggested that the project name be changed slightly to SABRE as it had more marketing panache. 

Advertisement showing how the SABRE network worked.
The first two IBM 7090 mainframe computers were installed in a data center in Westchester County north of New York City in 1960 on a trial basis and the system was an immediate success. The SABRE terminal had a display that agents would slide coded cards into that would then query the mainframe on possible flight options. A series of buttons on the left of the card allowed individual flights to be queried on seat availability and a modified IBM electric typewriter (that became the iconic IBM Selectric typewriter as a stand alone unit) allowed the agent to enter passenger information into SABRE much like what IBM's earlier system, Reserwriter, did for the airline. SABRE terminals were quickly installed throughout American's network, from city ticketing offices to airport check-in counters. By 1964, SABRE had completely taken over all the reservations and ticketing functions from the Reservisor system. With 10,400 dedicated long distance telephone lines for SABRE, the system became not just the largest single user of telephone lines in the United States but the largest civilian data processing system in the entire world when it became fully operational in 1964. 

Typical SABRE terminal
The Transport Workers Union wasn't happy with SABRE, though. The union was concerned that jobs would be lost with the automatic functions of the system and C.R. Smith promised that not one employee would lose his or her job in the transition from Reservisor to SABRE. This was perhaps a bit coy on Smith's part as the reservation agent force at American had the highest turnover rate in the airline so it was just a simple matter of not replacing normal losses via attrition. Switching to SABRE would end up saving American a very significant 30% in labor costs overall. But this wasn't the only area American won out, there was obviously the competitive advantage as SABRE was considerably faster than competitor airline systems which gave American the edge in customer service. Flights no longer had to be undersold and there would come to be a greater degree of utilization of American's fleet as it was SABRE generated reams of data on passenger loads, peak flights, seasonal variations and more. Even more significant, it allowed the airline to keep track of its most loyal customers. 

But as much as an advantage as SABRE was for American Airlines, all that data the system generated from thousands of passenger bookings, fare transactions, was accumulating faster on tape reels in SABRE facilities than American's own people could review it. Data processing is one thing; data analysis, on the other hand, is using that data to optimize the business and in the mid-1960s, that was still an emerging field in the airline industry. For the first few years SABRE was operational, American was content to sit on its own laurels, but it wasn't long before IBM turned its SABRE experience into a new business as it extended the technology to other airlines. It wasn't long before American's competitors had systems of their own with IBM mainframes. Rather unusually given American's history of innovation in the industry, SABRE wasn't given the same priority by C.R. Smith's successors at the helm of the airline. That would change soon enough when American hired an aggressive, astonishingly detail-oriented former TWA executive as its new chief financial officer in 1973. 

That man was Robert Crandall. His background and passion for detail would turn SABRE into a competitive weapon that would make American Airlines one of the world's most dominant airlines for a good twenty years. But as always, that's a blog posting for another day here at TAILS THROUGH TIME! 

Further reading:

Source: Hard Landing: The Epic Contest for Power and Profits That Plunged the Airlines into Chaos by Thomas Petzinger. Times Business/Random House, 1996, pp 60-63. Waves of Change: Business Evolution Through Information Technology by James L. McKenney, Duncan C. Copeland, et all. Harvard Business Press, 1995, pp 106-153.  Valkyrie: North American's Mach 3 Superbomber by Dennis Jenkins and Tony Landis. Specialty Press, 2005, p53-54. SABRE: How American Airlines Reconfigured the Airline Industry Ecosystem by Taylor Cornwall, Daniel Kane, David Rader, Tomas Garcia, Lacey Farrell and Pablo Navarro. Presentation, Tuck School at Dartmouth accessed at http://faculty.tuck.dartmouth.edu/images/uploads/faculty/ron-adner/22SABRE_Report_FINAL.pdf Images: Wikipedia, American Airlines C.R. Smith Museum, IBM, Sabre.

11 June 2015

A Watershed Moment in Close Air Support: The 1927 Battle of Ocotal

Major Ross Rowell, USMC
Less than a year had elapsed in Nicaragua since the last civil war and American intervention (1912-1925) ended when liberal and conservative factions in the unity government broke into open rebellion on 2 May 1926 with conservative factions representing the Managua government. On 24 January 1927, the 400 Marines arrived in-country at the request of the government as events proved beyond Managua's ability to control. Accompanying the initial group of Marines was the Marine Observation Squadron VO-1M, led by Major Ross Rowell. In the years following World War I, Marine aviation was very much a lean force, so much so that Marine aviators like Rowell had to be temporarily assigned to the Army to get flight training. Rowell's tour of duty with the US Army began in 1923 at Kelly Field in San Antonio, Texas. There he was assigned to the 3rd Attack Group, an Army squadron that had been established in 1921 to specialize in ground attack. The unit had experimented with a variety of aircraft during this period which were to have been designed for the role of ground attack (and distinct from long-range bombing) on the battlefield, but most designs were wholly inadequate for the roles envisioned by the Army unit. The unit ended up experimenting with the De Havilland DH-4B for ground attack as the aircraft was plentiful, available, and had been used by the British in the ground attack role in the First World War. Using the DH-4B, the unit experimented with dive bombing, which to be more accurate was more glide bombing- the distinction being that glide bombing involved descents of about 45 degrees while dive bombing was quite a bit steeper, approaching 70 degree or more. British experience in the First World War had shown that steep attacks greater than 45 degrees were needed to attack ground positions and while ground attack in the First World War never proved decisive, the seeds of the idea had been planted and were being sown further by the unit that Major Ross Rowell was assigned to. Their DH-4Bs were modified with underwing racks that could hold 10 small bombs. The aircraft was less than suitable for the role and the unit's work had concluded that attacking aircraft would be exposed to hostile fire during its attack that the mission would be of little use. 

Despite the inadequacy of the DH-4 biplane, Rowell held the opposite view as a result of his time with the Army in San Antonio. Given the number of interventions the Marines were conducting in the 1920s, Rowell was convinced that an aircraft making a steep glide or dive attack would be useful for close air support in the small guerrilla wars that the Marine Corps were being committed to throughout Latin America during the interwar period. Upon his return to the Marines from his tour with the Army, Rowell was given command of Marine Observation Squadron One (VO-1M) based at North Island in San Diego. VO-1M had just returned from the Marine intervention in Santo Domingo and based on their experience there, was designated the aviation asset to accompany Marine expeditionary forces being sent overseas. As such, Rowell instructed the pilots of VO-1M in glide and dive bombing based on his experiences with the Army's 3rd Attack Group in Texas. He relentlessly trained his men against simulated ground targets as well as seaborne targets. In February 1927, VO-1M was given orders to deploy to Nicaragua to support the Marines there that landed the previous month. By the end of February, Rowell had the unit's DH-4B biplanes flying a variety of missions ranging from observation and reconnaissance, shuttling messages amongst the various Marine garrisons in the country, and supporting assaults against the rebels who called themselves Sandinistas after their leader, Augusto Cesar Sandino. Prior to the arrival of VO-1M, most air missions during the civil war were flown by the Nicaraguan Air Service which didn't amount to much- two converted civilian Laird Swallow biplanes flown by mercenary pilots that dropped dynamite on the Sandinistas. Needless to say, it wasn't terribly effective and for the most part, the Sandinistas ignored the aircraft until VO-1M arrived. 

Marine DH-4B. Note the Ace of Spades logo of VO-1M. 
On 17 July 1927, a large Sandinista force of 800 men attacked the small Marine outpost at Ocotal near the Honduran border about 125 miles from the capital, Managua. Defending the outpost were 37 Marines and less than 50 Nicaraguan National Guard. The attack opened at 3:00am and it wasn't until 10:15am in the morning that the Marine HQ in Managua became aware of the attack after a Marine patrol overflew Ocotal and saw the gunfire. Major Rowell mustered five DH-4Bs which were crewed by two and bombed up to fly to Ocotal. Since there was no other Marine force in the area that could be delivered to the area in time on account of distance and Nicaragua's primitive transportation network, it was Marine air or nothing to save the garrison at Ocotal. Arriving over the garrison, Rowell circled the area to assess the situation. At the time, radios were supplied to VO-1M, but their were so heavy given the technology of the time, it was easier to remove the radios and trade that weight for fuel and bombs. The beleaguered Marine garrison laid out colored panels to give Rowell and his pilots indications of where the Sandinistas were located. Being 125 miles from their base in Managua, the fuel situation didn't lend itself to extended loitering by the DH-4Bs and to make matters worse, thunderstorms were approaching the area. Rowell organized his pilots into a bombing column that was single file and he made the first diving attack from 1500 feet, released a some bombs and then pulled out at 600 feet with the other four aircraft in the column following suit against targets he'd marked with his own bombs. Since the Sandinistas' previous exposure to air attacks were minimal, the Marine attacks drew little if any ground fire. In fact, the Sandinistas weren't even taking cover. Rowell astutely realized this fact and had his men fly lower for greater accuracy, diving from only 1000 feet and pulling out at only 300 feet. During their dives, the pilots fired the forward gun to add to the firepower and in the pull out, the observer in the rear seat would strafe as well with their trainable gun, effectively suppressing any potential ground fire. The Sandinista attack on the garrrison was broken as they retreated in the countryside taking approximately 25% casualties from the air attacks. Major Rowell would earn the Distinguished Flying Cross for leading the attack to save the Marine garrison at Ocotal.

It was a watershed moment in the history of military air power and close air support- the 1927 Battle of Ocotal was the first time that an ground unit facing a numerically superior enemy was saved solely by aerial intervention. It was a lesson not lost by the Marines in particular. During the time period and well into the Second World War, Army doctrine manuals discouraged close air support out of a fear of friendly fire casualties while the Marine Corps were quite the opposite in seeing air support as an integral part of ground force operations. It was also the first time that steep diving attacks were used in combat effectively. During his time at North Island in San Diego, Rowell had made friends with a number of naval aviators of the Pacific Fleet would were soon to make their own mark on the history of military aviation with their use of dive bombing. But as always, that will be the subject of a future post on this blog!

Historical aside: VO-1M was formed in 1919 as First Division, Squadron 1. Following the intervention in Santo Domingo, the squadron was redesignated VO-1M. Prior to the Battle of Ocotal, the squadron was redesignated again as VO-8M. In 1934, as part of the reorganization of Marine aviation, the unit was reorganized and was routinely sent to sea aboard aircraft carriers to participate in exercises. In 1941 the unit was moved to Hawaii with their first monoplane, the Vought SB2U Vindicator, along with a redesignation to VMSB-231 (Marine Scout and Bombing Squadron 231) and was embarked on the USS Lexington when Pearl Harbor was attacked. In 1942 the squadron transitioned to the Douglas SBD Dauntless and participated in actions at Guadalcanal and later in the war got the Vought F4U Corsair for the Marshall Islands campaign. They were deactivated in 1962 after long serving as a Marine reserve unit. They were brought back in 1973 to become an AV-8A Harrier unit and fly the AV-8B Harrier II today as VMA-231 "Ace of Spades"- the Ace of Spades logo used on VO-1M's DH-4s in Nicaragua are still the unit emblem today.

Source: Strike From the Sky: The History of Battlefield Air Attack, 1911-1945 by Richard P. Hallion. Smithsonian History of Aviation Series, Smithsonian Institution, 1989, pp 71-75. Photos: USMC, Wikipedia.

06 June 2015

The Macchi-Castoldi Line of Italian Fighter Aircraft

Mario Castoldi, one of the great unheralded designers of WW2
In a lot of ways the development and history of the Macchi-Castoldi series of fighter aircraft used by the Regia Aeronautica during the Second World War parallels that of the Supermarine Spitfire. Unlike many other contemporary fighter aircraft, both lines of fighters weren't derived from earlier fighter designs but sprang from the design work of the elegant racing seaplanes of the 1920s and 1930s and both fighter lines were developed and refined continuously during the course of the war to improve their performance. The Spitfire was born from the Supermarine Schneider series of racing seaplanes designed by Reginald Mitchell. The Macchi-Castoldi series of fighters were the products of Italian engineer Mario Castoldi and his work on the Macchi racing seaplanes that were Schneider Trophy winners as well. Castoldi joined Macchi in 1922 with his first winning racing seaplane design being the Macchi M.39 that won the 1926 Schneider Trophy. Castoldi spent three years working on his ultimate racer, the Macchi M.C.72 that was planned to retake the Schneider from a series of British wins with Reginald Mitchell's designs. Though the M.C.72 didn't complete in a race due to not being ready in time, in 1934 it set a world speed record of 440 mph that still stands to this day for piston-engined seaplanes. For comparison, the world speed record at the time for landplanes was held by the Hughes H-1 with a speed of 352 mph. Castoldi began work on his first fighter aircraft based on his racing seaplane designs when the Hawker Hurricane and Supermarine Spitfire started their flight test programs. Castoldi, however, was handicapped from the start with a lack of a suitable engine like the Rolls-Royce Merlin that wasn't just only a powerful engine but being a liquid cooled inline engine, could be installed in a low drag nose cowling. The only engine that had the power Castoldi wanted was the Fiat A.74 twin-row fourteen cylinder radial developing 870 hp. In addition, the Regia Aeronautica had very stringent visibility demands from the cockpit and this required a hump-backed fuselage which along with the Fiat radial engine, eliminated any of the clean lines that would have belied its racing aircraft origins. The design was entered into the "Program R" competition for a fighter aircraft that had two hours' endurance and twin 12.7mm machine guns. Designated the M.C.200 Saetta (Arrow), it first flew on 24 December 1937. 
M.C.200 Saetta
Proving to be a highly maneuverable aircraft with good ground handling due its wide spaced landing gear (something that always bedeviled both the Spitfire and Bf 109 on account of their narrow track landing gear), the M.C.200 lacked the elegance of the Spitfire but was an impressive performer capable of 500mph in a dive and a quantum leap over the current Regia Aeronautica fighter aicraft, the Fiat C.R.42 Falco biplane. The M.C.200 was declared the winner against the other entrants in 1938 and ordered into production with deliveries beginning in 1939. Thoroughly conventional in its design and construction, the M.C.200 was unique in having its ailerons interconnected with the wing flaps so that they drooped slightly during takeoff and landing to improve field performance. When the first M.C.200s were delivered to the pilots of 4 Stormo (Wing), the pilots were resistant to giving up their Falco biplanes and felt that the enclosed cockpit would delay their egress in an emergency. Castoldi switched to a partially open cockpit design as a result of pilot demands. The pilots of 1 Stormo were more accommodating of the new monoplane fighter, though, as those pilots had participated in the Spanish Civil War and took little convincing that monoplane fighters were the wave of the future. Initial operations had uncovered some unpleasant spin characteristics that had to be rectified with a modified wing and this delayed operational capability further. Only 29 Saettas were in service by the time World War 2 broke out in September 1939 as a result. Interestingly, Italy did solicit export orders for the Saetta and did get a contract for 12 aircraft from Denmark! They were ordered for the Danish Naval Air Service but the order was never finalized after the German invasion of Denmark on 9 April 1940. Two months later when Italy entered the war there were 156 Saettas on strength with the Regia Aeronautica. The M.C.200 Saetta was to have participated in the invasion of France, but another unpleasant quirk was found with high speed stalls. Again the wing required modification and the Saettas went into action over Malta against the Hawker Hurricane. Though slightly slower, the Saetta could hold its own against the Hurricane and proved just as sturdy. Saettas would see extensive service flying escort missions on strikes against Allied shipping in the Mediterranean and were also sent to the Balkans, North Africa, and even participated in Operation Barbarossa on the Eastern Front. 
M.C.201 prototype

M.C.202 Folgore in North Africa

As the development of the M.C.200 Saetta proceeded in 1938, Castoldi was asked to work on a modified Saetta that would use the new Fiat A.76 radial that produced 1,000 horsepower. Castoldi refined the M.C.200 design with an aerodynamic clean up that dropped the hump-backed fuselage and featured an enclosed cockpit for drag reduction. Designated M.C.201, it wasn't enough of an improvement over the production M.C.200 to warrant changing production. Contributing to the termination of the M.C.201 program was Castoldi's next design which was much more promising, the M.C.202 Folgore (Lightning). The Folgore was more of what Castoldi wanted in a fighter design as it featured the German Daimler-Benz DB 601 liquid cooled inline engine that also powered the Messerschmitt Bf 109. With the slimmed down airframe of the M.C.201 and its enclosed cockpit combined with the powerful and low drag DB 601 engine, the M.C.202 Folgore was an instant winner from the time it made its first flight on 10 August 1940. It evoked the lean lines of Castoldi's pre-war racing seaplanes and much of the Saetta production jigs and tooling could be used with sped its introduction into service. Early Folgores used imported DB 601 engines before Alfa Romeo was license-building the DB 601 as the R.A.1000 developing 1,175 hp. The Folgore's empennage was identical to the Saetta and the wings were also identical apart from the installation of fuel tanks in the inboard sections. Armament was basically the same and rather light compared to contemporary aircraft, but some Folgore variants also included an additional pair of wing mounted machine guns and one production batch had underwing fairings for 20mm cannons. The first Folgores went into action with 1 Stormo on 25 November 1941 in Libya. In battles over North Africa, the Folgore gave good account of itself being more maneuverable than both the Hurricane and Spitfire. The M.C.200 Saettas were soon relegated to ground attack missions as the Folgore became the Regia Aeronautica's primary fighter aircraft. Despite this, however, the Saetta remained in production due to production issues with Alfa Romeo on the DB 601 engines. Like the Saetta-equipped units, Folgore squadrons were sent to the Eastern Front but in smaller numbers than the Saetta. 
M.C.205 Veltro in RSI markings
Castoldi wasn't resting on his laurels with the Folgore, though, as he continued to refine the design further and on 19 April 1942 the M.C.205V Veltro (Greyhound) first took flight. While looking very similar to the M.C.202 Folgore, the Veltro used the more powerful Daimler Benz DB 605 engine that produced 1,475 hp. In fact, the Veltro prototype was a Folgore that had been modified to take the DB 605 engine. Like the transition from the Saetta to the Folgore, the transition from the Folgore to the Veltro was relatively easy as much of the same production equipment could be used. Early M.C.205V Veltro aircraft had the same armament as the Folgore before the production standard became two wing-mounted 20mm cannons and the 12.7mm twin guns on the top of the nose. The M.C.205V Veltro went into action for the first time in June 1943 during the Battle of Pantelleria- with the surrender of Axis forces in Tunisia, the Allies prepared for the invasion of Sicily but first had to secure the small island of Pantelleria as well as the rest of the Pelagie Islands of Lampedusa, Linosa, and Lampione. The Veltro then went into action defending Sicily during Operation Husky in July 1943. Despite the fact that the Veltro could easily hold its own against the P-51 Mustang, they were overwhelmed by the sheer size of the Allied invasion force. When the Italian government capitulated on 8 September 1943, the Regia Aeronautica was a shell of its former self with only 33 M.C.200 Saettas, 53 M.C.202 Folgores, and 35 M.C.205V Veltro fighters in serviceable condition along with a variety of other aircraft. But the Macchi-Castoldi fighters were the crown jewels of the Regia Aeronautica and the Germans had no intention of respecting the Italian Armistice. Only 23 Saettas and 6 each of the Folgores and Veltros were able to make it to Allied airfields to become part of the Allied-supported Co-Belligerent Air Force. Most of the fighters were either destroyed by their Italian crews or taken in by the Repubblica Sociale Italiana (RSI) that held out in northern Italy determined to continue fighting with the Germans. 
M.C.205N Orione
Castoldi had always considered the Veltro an interim design, though, as he again refined the design further to make full use of the performance of the DB 605 engine. The new design was the M.C.205N Orione (Orion) and while it used the same empennage that was used on the Saetta, Folgore and Veltro, the fuselage was slimmed down for drag reduction and the wing span increased. Four 12.7mm guns were mounted in the forward fuselage- two on the upper nose just like on the prior Macchi-Castoldi fighters but a second set were mounted in fairings on the fuselage sides above the wing roots. Like the Bf 109, the Orione featured a nose-mounted 20mm cannon. The second Orione prototype replaced the 12.7mm guns near the wing roots with a 20mm cannon in each wing. The first Orione made its first flight on 1 November 1942 and the second Orione flew on 19 May 1943. The Italian government afforded production priority to the Veltro as it could use existing jigs and tooling while the Orione would need new tooling. It had also been decided at this point that the successor to the Veltro would be the Fiat G.55 Centauro as it showed more promise at high altitudes where American bomber aircraft operated.

M.C.206. Only one prototype built, but destroyed before flown
This wasn't quite the end of the Macchi-Castoldi line, though. Always refining his designs with several parallel concepts in the works, the successor to the M.C.205N Orione was the M.C.206. Being the consummate engineer, Castoldi set out to improve upon the deficiencies of the M.C.205V Veltro and the M.C.205N Orione. Still using the DB 605 engine, a single M.C.206 was nearly complete when it was destroyed in an Allied bombing attack in the spring of 1944. The more powerful DB 603 engine that was used on the Focke Wulf Ta 152 spurred Castoldi to revise the design again with the M.C.207 which had it been built would have been the ultimate Macchi-Castoldi fighter. With 1.700 hp available, the M.C.207 was a larger aircraft with four 20mm wing cannon. Work began on the M.C.207 prototype, but it was never finished before the war ended in 1945. 

The ultimate Macchi-Castoldi, the M.C.207. Prototype started, never completed
While the quantities of the Macchi-Castoldi fighters were modest compared to other fighter aircraft of the Second World War, the fighters were well-regarded by the Allies as adversaries. The Italian aircraft industry was never fully mobilized on war footing and this was one factor that was detrimental to Italian fortunes in the war. Germany proved to be a less than ideal ally through it all, often holding up deliveries of Daimler Benz engines, failing to provide requested assistance to the Italian aircraft industry. In addition, many skilled Italian workers in the industry were forcibly moved to work in German aircraft factories. Mario Castoldi retired from aviation with the end of the war in 1945, passing away in 1968. 

Source: Famous Fighters of the Second World War by William Green. Doubleday and Co, 1975, pp 71-83. Images: Wings Palette, Wikipedia, World of Warplanes forum.

01 June 2015

American Automates Reservations and Ticketing, Part One: Reservisor System

C.R. Smith knew reservation systems had to keep up with jet speeds
In the early days of the airlines, the reservations and ticketing process was all done by hand at a central office with a ledger that was passed among agents who recorded reservations and erased ones that were canceled. As airlines grew in the early 1930s with the introduction of larger aircraft like the Boeing 247 and in particular, the Douglas DC-3, a single book was obviously impractical so multiple ledgers for each flight was kept in a large lazy-Susan with the reservations agents sitting all around. As they took incoming calls, they retrieved the ledger for that particular flight. The books had to be frequently reconciled so that more seats weren't sold than available and even for small airlines, this process of inventory reconciliation was time consuming on top of the fact that it had to be done multiple times through the day. Books soon gave way to large chalk boards and reservation offices had to get bigger in size to not only accommodate every larger boards to display the seat inventory for each flight, but to also accommodate the increasing numbers of personnel to keep the system running. As agents took calls, they filled out cards that were then taken clerks to the other agents who maintained the boards. Supervisors watched the boards and in the case for large airlines, they would have to use binoculars or opera glasses to view the data. A typical reservations office for a large airline might be sixty agents taking phone calls with forty additional clerks and agents who maintained the boards and conveyed data back and forth. It was a personnel intensive and time consuming process become progressively more cumbersome as airlines added more flights and larger aircraft. The first systems in place were called "Request and Reply"- agents took calls and then passed a message to "Inventory Control" who were the agents who maintained the boards. The message went back to confirm that the seat was available and reserved and a third message confirmed the reservation. So even the most rudimentary system in use needed three messages and even in those days, the airlines were the biggest users of telephone lines in the United States. In 1939, the Boston reservations office for American Airlines had determined that until a flight was 80% sold, it was possible to sell seats freely without having to get a reply from inventory control. This streamlined the process as message volumes were cut in half. When a flight was 80% full, agents in inventory control sent out a stop-sale and any further sales on those flights required confirmation from inventory control. This system was called "Sell and Report" but became "Request and Reply" for any flight over 80% booked. Despite this, the airline still had to reconcile seat inventory as well as get out ticketing information to the airports. Clerical mistakes were common and it wasn't unusual for business traveler to book two flights just in case.

Typical reservations center with status boards (this one is Pan Am's)
In 1943 a system analyst with a background in electronics and communications, Charles Amman, joined American Airlines and was tasked to find a better solution. Running the military's Air Transport Command during the war, C.R. Smith astutely saw not just a postwar boom in air travel but the arrival of faster and larger aircraft that would hopelessly encumber the manual system. Amman had determined there were three key steps in the reservations process: determine seat availability, adjust the seat inventory, and record the passenger's name. Amman met with several manufacturers of adding machines and electromechanical equipment of the day and every single one thought what American wanted was impossible- too many variables to adjust in real time was simply beyond what the technology of the day could accomplish. Amman even pared down the requirements to just the first two steps in the reservations process, determining seat availability and adjusting the seat inventory but even this was too daunting for companies he approached. Amman had C.R. Smith's support to try and come up with an in-house solution. A series of tall cylinders with each representing a flight on a given day were filled with marbles. Each marble represented an available seat. An agent would use a cash register like device to select a flight to make a reservation. This sent an electrical signal to the cylinder that represented that flight and a hatch dropped one marble out of the cylinder. If a reservation was canceled, a marble was electrically released back into the cylinder. adjusting the seat inventory automatically. Amman's machine was bulky and impractical for an airline the size of American, but it demonstrated the principles of a solution.

An early Reservisor terminal
Amman's mock up convinced the Teleregister Corporation to sign on the develop the reservations system for American. Originally a division of Western Union, Teleregister was set up in 1948 as separate company and produced the stock ticker units used by stock brokers. This gave them the experience in remote data transmission that could be applied to the American reservations project. American called the system "Reservisor" and the first pilot system was a massive room of switches, relays, and plugs called "The Brain" which was installed in the Boston reservations office in 1946. Electrical relays replaced the marbles and cylinders of Amman's mockup with the agents using a smaller device that looked like the early adding machines used by accountants. "The Brain" replied on the agent's terminal if space was available- a green light meant space was available for booking, an amber light meant the flight was sold out. A one year pilot of the Reservisor at the Boston office showed two hundred additional passengers could be booked each day with twenty less personnel. C.R. Smith, back in the executive suite after serving as head of the Air Transport Command during the war, was excited about the possibilities of expanding the Reservisor system across American's network. But the Reservisor as it was still encountered delays as it only solved the first two parts of the reservations process- determining seat availability and adjusting seat inventory. Passenger names for the tickets were still taken down by hand and there was still a stop-sale system in place as agents were responsible for manually inserting control plugs into the proper parts of "The Brain" when a flight reached 80% full. But the Reservisor as it was was a quantum leap over what American had done before and because the airline wanted accuracy and reliability, Teleregister incorporated redundancy into the Reservisor system. The challenge at that point wasn't just addressing the last step of the reservations process but to also speed up the system and increase its memory capacity as the airline not only grew but added faster aircraft like jets. Recognizing that there was a sales advantage to a faster system, Amman also wanted an upgrade to Reservisor that would allow an agent to recommend an alternate flight should a passenger's first choice of flight be booked. What he wanted was for Reservisor to be able to not just store increasing amounts of flight information, but to also be quick to allow agents to easily query the system to find out seat availability on alternate flights. He had been following developments in computer memory and settled on what was called drum memory for Reservisor. 

Magnetronic Reservisor. Note the smaller terminal and drum memory units.
The drum was a large metal cylinder coated with a ferromagnetic material and a row of fixed read-write heads along the long axis of the drum. Each read-write head had its own track on the drum. It was a precursor to the hard disk platters of today which have a moving read-write head that moves across a spinning disk. In drum memory, each track on the circumference of the drum had its own read-write head. Drum memory is what replaced the relays and switches of "The Brain" of the first version of Reservisor. The new upgraded Reservisor was called the Magnetronic Reservisor and first went into operation in 1952 at American's reservations office at New York La Guardia Airport. The system had a response time of one second and the drum unit could hold data for 1,000 flights up to 10 days in advance. Four years later, a larger unit was installed in the West Side of New York City that had a half-second response time and could store data for 2,000 flights up to 31 days in advance. Amman redesigned the West Side reservations center of American Airlines to take advantage of the new Magnetronic Reservisor with 362 agents to take phone calls, each with their own terminal. Forty additional agents were devoted just to handling reservation requests from travel agencies and large business accounts. Another 140 agents acted as liaisons between the reservations center and the other reservations offices, airport stations, and airline operations center. Forty supervisors oversaw the West Side center that averaged 4,500 phone calls a day. 

Close up of the drum memory units. The wires ran to the read-write heads.
Despite the advances of the 1956 version of the Magnetronic Reservisor, Amman worked with IBM on the last step in the reservations process, connecting passenger information with the reservation. In 1956, the Reserwriter went into operation after testing in Buffalo. The Reserwriter basically read keypunched cards that represented passenger information and then automatically sent messages via teletype to the main reservations offices. Messages could go back and forth between the two systems (albeit manually) and for the first time for the airline, agents didn't have to be in the main reservation offices to book flights. By 1958, Reserwriter terminals were in key locations across the country in American's network. Despite the success of the whole system, it still suffered with errors on account of the number of individuals still required to make the system work. Approximately 8% of reservation transactions at American were in error despite the advances in the system. Passengers who benefited the most from the Reservisor system were those flying into and out of the largest of American's destinations. The Reserwriter terminals at outlying locations helped, but because manual action was needed to move information between Reserwriter and Reservisor, it was prone to error not to mention still time consuming. For example, a round trip reservation between Buffalo and New York La Guardia required 12 people, 15 distinct steps and could take as long as three hours. Passenger growth at American meant that over an eight year period from 1950 to 1958, the number of passengers flying on American per reservations employee had dropped from 5,100 to 3,100. Simply adding employees wasn't a solution in C.R. Smith's eyes. The transaction error rate meant the airline had to undersell a flight to avoid overselling a flight during times of peak volume. American would be taking delivery of its first Boeing 707s in 1959. This meant that a transcontinental flight was faster and could move more passengers- the airline's flagship DC-7 services moved 80 passengers across the United States in 10 hours but the 707s promised to move 112 passengers across the nation in just 5 to 6 hours. Smith was worried that the new jets would overwhelm the existing system. What American needed to keep up with the jet age was reservations system that moved just as fast, preferably in real-time and with as little manual intervention as possible. Charles Amman's original reservations problem from 1953 was still an issue that lurked in the background- determine seat availability, adjust the seat inventory, and record the passenger's name. Only now, it had to be done in real time if it was to keep up with jet aircraft. 

That solution will be the subject of a future post on this blog, so stay tuned! 

Source: Hard Landing: The Epic Contest for Power and Profits That Plunged the Airlines into Chaos by Thomas Petzinger. Times Business/Random House, 1996, pp 57-60. Waves of Change: Business Evolution Through Information Technology by James L. McKenney, Duncan C. Copeland, et all. Harvard Business Press, 1995, pp 97-106. Images: Wikipedia, American Airlines C.R. Smith Museum