Mike Melvill's Early Days with Burt Rutan

Mike Melvill in the cockpit of SpaceShipOne

On 21 June 2004, Mike Melvill piloted SpaceShipOne past the edge of space, becoming the first commercial astronaut in aviation history. Melville and his wife, Sally, were Burt Rutan's very first employees when they moved out to California in 1974 to join Rutan in his business. But Melvill is nothing like the 433 individuals that preceded him into space. I think Dave Hirschman's article for the June 2013 issue of AOPA Magazine "The Unlikeliest Astronaut" put it best in the following paragraph: 

Unlikeliest astronaut. Mike Melvill doesn't fit the typical military-trained, academically overachieving astronaut profile. The South African native failed a math course and never finished high school. He raced motorcycles and became a machinist at 17. He married his childhood sweetheart, Sally, and they emigrated to the United States in the late 1960s. He became a U.S. citizen in 1972, and his motivation to fly was a dislike of airline travel—not a dream of exploration.

To understand how Mike Melvill's unlikely career in aviation is inextricably linked with that of Burt Rutan, we have to step back a bit and take a look at Burt Rutan's first aircraft design, a homebuilt piston pusher he called the VariViggen. Rutan began the design work on the VariViggen in 1963 while he was still an undergraduate at California Polytechnic State University. He would graduate in 1965 third in his class with a degree in aeronautical engineering and soon landed work at Edwards AFB as a civilian flight engineer. Living in Lancaster at the time he was working at Edwards, Rutan began construction of the VariViggen in his garage in 1968 after five years of doing his own model experiments with subscale models and wind tunnel testing that basically was Rutan mounting design iterations of the VariViggen to a test rig he built that could be clamped to the luggage rack of his station wagon. Using his day job experience as a flight test engineer, he was able to use these tests to refine the VariViggen's configuration before starting assembly. Around the time he was ready to start taxi testing the VariViggen, he left California in 1972 and took a job with Jim Bede's aircraft company in Newton, Kansas, as the director of development for the BD-5 homebuilt aircraft. In his spare time, he prepared the VariViggen for its taxi and flight tests with the help of some of Bede's engineers and employees. He made the VariViggen's first flight in April that year and embarked on a nine-week flight test program before flying the aircraft to the 1972 Oshkosh Air Show, demonstrating the aircraft to the experimental homebuilt aircraft community and selling the blueprints for pilots to build their own VariViggen. He returned to California in 1974 and formed the Rutan Aircraft Company. 

The Rutan VariViggen

It was there at Oskhosh in 1972 that Mike Melvill met Burt Rutan and purchased a set of blue prints for the VariViggen. Melvill was a machinist with a gift for tinkering working for a tool and die company in Indiana that specialized in industrial box cutting machines. Traveling all over to customers, Melvill figured if he learned to fly, traveling for business would be much more enjoyable than just a series of tedious waits in airport terminals across the country. He began working on his own Nesmith Cougar aircraft (a high wing homebuilt design from the 1950s) which was 2/3 finished before he sold it off and picked up another Cougar which was 90% completed. That second Cougar was the one Melvill was flying for four years before he met Rutan at Oshkosh. 

Melville liked the VariViggen design as it accommodated two people and three suitcases easily. With his wife's support, they bought a new house in Indiana that had the room for Mike to build his own VariViggen. Melvill can tell you exactly how much time it took him to finish his VariViggen- "Three years, one month, twenty-two days". He had followed Rutan's blueprints exactly until he got to the landing gear retraction mechanisms. Melvill didn't like the design and with a tool and machinist background, redesigned the system to his liking, fabricating his own parts at work. Melvill's VariViggen was the first one built aside from Rutan's and that made Rutan a regular visitor to see the construction progress. One day, when Rutan was visiting, he found out Melvill's wife was a bookkeeper (and a pilot in her own right as well) and that she worked at the same company as her husband. Rutan offered both of them the opportunity to come to California and work for him. The story goes that Rutan was more in need of his wife's accounting skills than Melvill's piloting and machinist skills:

"I need her worse than I need you!"

Melvill and his wife are one of the ten original owners of Rutan's company, Scaled Composites and his first employees as well. Melvill still has his VariViggen with 4,200 hours on the airframe. He would go on to become Rutan's main test pilot and the general manager of his company with his wife as the head of human resources. Being Rutan's main test pilot, Melvill was the pragmatist counterpart to Rutan's dreams and often Rutan talked with Melvill several times a day about his ideas. Most of the time Melvill would be first person to know what new ideas Rutan was contemplating. From the same AOPA article: 

“He came into my office almost every morning,” Melvill said. “He would say something like, ‘I think we’ve developed the technical expertise to build a twin, or a jet.’ But I’ll never forget the day he said he thought we had the technical expertise to fly an aircraft into space. It was something I’d never considered. We were doing a credible job with airplanes that flew about 200 miles an hour—but to get to space, we’d have to fly at Mach 3. It seemed too ambitious to seriously contemplate, and I was intimidated.”

Source: The Complete Guide to Rutan Aircraft, Third Edition by Don & Julia Downie.TAB Books, 1987, pp35-48. "The Unlikeliest Astronaut" by Dave Hirschman, AOPA News and Video, 1 June 2013. Photos: Wikipedia, EAA.

How the Shuttle Orbiter Lost Its Jet Engines

The McDonnell Douglas design with a large flyback booster

As design work by various aerospace companies began on the Space Shuttle program in the late 1960s, it was a given that the Orbiter would have its own jet engines. Having its own air breathing engines offered three advantages- they would allow atmospheric flight testing much like any other aircraft was tested and pilots could practice landings in the run up to an orbital mission. The engines also facilitated ferry flights, repositioning the Orbiter amongst various facilities (landing, launch, overhaul, etc.). Having its own jet engine propulsion also gave the Orbiter cross range capability upon return from orbit. Some designers envisioned the Orbiter rendezvousing with a tanker for additional jet fuel. But in the ascent and in orbit, jet engines and fuel for those engines was dead weight that subtracted from potential payload. Even if designers went with an Orbiter design that was unpowered on its landing, the 1970 and 1971 design studies prominently featured a fully reusable two stage Space Shuttle with a big flyback booster that would have to have its own jet engines. Some of the designs for the flyback booster were massive with a need for as many as twelve jet engines. Soon the design of the flyback booster itself began to take on technical challenges that rivaled that of the Orbiter design itself. The weight of up to twelve jet engines and the necessary jet fuel cut into the payload of liquid hydrogen and liquid oxygen for the booster's rocket engines. Many of the flyback booster designs would need approximately 150,000 lbs of jet fuel (for comparison, a Boeing 777-200ER has a fuel capacity of roughly 300,000 lbs). Consideration was then given to using liquid hydrogen as fuel for the jet engines which would cut out the need for jet fuel tanks. In June 1970, NASA issued contracts to GE to study the feasibility of using liquid hydrogen in the F101 engine being developed for the B-1 bomber. Pratt and Whitney also got a similar contract to study the use of liquid hydrogen fuel in the F401 engine, the planned naval derivative of the USAF's F100 engine planned for the F-15 Eagle. Both companies showed that liquid hydrogen fueled jet engines saved about 2500 lbs of weight per jet engine compared to conventionally-fueled jet engines. The weight savings was modest at best. 

A typical high-key to low-key unpowered approach to landing

At the same time these studies were going on on how to save weight with Orbiter and flyback booster-mounted jet engines, with NASA there was a group at the Flight Research Center at Edwards AFB where unpowered landings were routine for many high speed research aircraft going back to the X-1 (the X-15 program being the most recent one at the time) and the graduates of the co-located Aerospace Research Pilot School had as a requirement that students demonstrate proficiency in unpowered landings using the school's Lockheed F-104 Starfighters which were throttled down to idle for the practice sessions. Even more demanding were the unpowered landings made by the lifting body program aircraft that lacked wings and derived their lift from their tubby fuselage designs. Regardless of what sort of aircraft was used, USAF test pilots and the NASA-FRC pilots used what was called "energy management" where they traded altitude for airspeed on the descent and used turns to bleed off speed in preparation for final approach. The first step in unpowered landings was the arrival at the "high key" which was high above the touchdown point. From the high key, a gradual 180 degree turn was made that allowed speed reduction and descent to the "low key" which was usually abeam the touchdown point. From the low key, the turn continued allowing more speed to bleed off and the descent to continue until lined up for final approach. If at any point the speed was excessive, speed brakes or gentle S-turns could be used to get down to the necessary airspeed. The lifting body pilots found that on final approach, diving at the runway touchdown point 15 degrees or more improved their accuracy as the speed improved the stability and the speedbrakes could be used to moderate the speed build up on final approach. An assessment by one of the experienced lifting body pilots in September 1970 showed that in 30 landings on a 10,000 foot runway from altitudes as high as 90,000 feet and speeds as high as Mach 2, the dispersion of the landing points was only 250 feet. 

However, the astronaut office in Houston at the Manned Spaceflight Center headed by Deke Slayton felt that unpowered landings for the Orbiter were too risky. Slayton was concerned that the test pilots were more proficient at unpowered landings than his astronauts would be, especially if they were returning from a 7-10 day orbital mission. The astronauts' views carried considerable weight for good reason and it took the USAF to swing the design work in favor of unpowered landings. 

I had posted previously that the Space Shuttle program's development phase was taking place during a period of budget austerity. One of the keys to navigating the budgetary climate of the day was to be sure to secure as much political support as possible since Congress determined the program budget. But in 1970 the program had some close calls, narrowly avoiding funding cuts in both the House and Senate. The Air Force offered to lend its support as it saw opportunity in the Shuttle program to launch heavy reconnaissance satellites. But NASA had baselined the Orbiter design at the time with a 25,000 lb payload to orbit. The USAF wanted to put its heavy reconnaissance satellites into polar orbit and the Orbiter needed a payload capacity of 40,000 lbs. That much payload weight into polar orbit (and unable to take advantage of the Earth's rotation for additional boost) was equal to a 65,000 lb payload launched for the Kennedy Space Center. NASA informed the USAF that the payload had to be baselined at 25,000 lbs due to the weight of the jet engines and their fuel. But it was apparent from the Congressional battles that NASA needed a strong ally like the USAF, so the jet engines were dropped from the Orbiter design and that allowed the payload capacity to orbit to meet the USAF requirements. 

The idea of onboard jet engines didn't end, though. NASA shifted towards the idea of removable kit that could be used for flight testing, ferry flights, and for return from orbit if the payload wasn't maxed out. This also coincided with the 1971-1972 time frame when the flyback booster was dropped as too much of a technical risk and the Space Shuttle began to look more like its final design- an Orbiter with an external tank and solid rocket boosters in what was called the TAOS configuration- Thrust Assisted Orbiter Shuttle. The significant weight savings by going to a TAOS configuration also helped cut development risk as there was a considerable amount of experience already with solid rocket boosters and large external tank structures to hold cryogenic fuels. 

The test pilots at NASA-FRC persisted in their opinion that jet engines were completely unnecessary in the Orbiter design. They had their long experience of over 10,000 unpowered landings since the X-1 program as their proof, but the astronauts insisted that the Orbiter was a much bigger aircraft than many of the X-planes. Another round of tests then were held by NASA-FRC, this time using their B-52 Stratofortress carrier aircraft. Set up in a high drag configuration with the engines at idle, pilots successfully and accurately landed the B-52. NASA-FRC then got some lifting body pilots who had never flown anything as big as the B-52 and had them fly the bomber through a simulated unpowered landing using energy management. They were able to land successfully and when the same pilots were asked to land the B-52 using a conventional powered low angle approach, none of them were able to do so. The test pilots the FRC even brought into two United Airlines pilots to fly the B-52 in simulated unpowered landings and they had no issue doing so, reporting that such landings were much easier than conventional landings. The test pilots then followed up the B-52 tests with the same tests using NASA's Convair 990 which could simulate the Orbiter aerodynamics on landing. 

The final iteration of a jet-engine powered Shuttle Orbiter (from the Dennis Jenkins book)

NASA finally got agreement to go to exclusively unpowered landings on return from orbit for the Shuttle Orbiter, but the jet engines still didn't go away. At the time of Rockwell's award in 1972, the Orbiter design featured two engines that deployed from the payload bay and two more engines that could be mounted on struts. Less than six months later, the Orbiter design dropped the internally mounted jet engines completely and they were to be mounted as a kit on the flat underside when needed for flight testing and ferry missions. It finally took the ferry range to kill the engines completely from the Orbiter design. The Orbiter was similar in size to a Douglas DC-9 but had twice the weight. It had a lot of drag since it wasn't optimized for atmospheric flight and the delta wing was highly loaded. With five jet engines mounted in pods on the underside and tank of jet fuel in the payload bay, the Orbiter had a ferry range of only 500 miles. With Space Shuttle sites across the nation and contingency fields overseas, a 500 mile range was simply unacceptable. NASA looked at aerial refueling during ferry, but this added complexity to a design that was already experiencing cost overruns. In February 1974, NASA deleted the jet engine requirement completely. As a result, both for flight testing and ferry flights, the Orbiter would need a carrier aircraft, but fortunately that was a lot more straightforward a development process!

The Buran analog with its four AL-31 jet engine nacelles

Interestingly in the Russian Buran Shuttle program, there was an aerodynamic test analog designed OK-GLI that made 25 atmospheric test flights with four Lyulka/Saturn AL-31 jet engines mounted in nacelles in the aft fuselage. A fuel tank sat in the payload bay. The AL-31 is the jet engine that is used on the Sukhoi Su-27 Flanker. Nine taxi tests and 25 test flights were made using the Buran analog from December 1984 to December 1989. The engines were used to takeoff and then were throttled back on the descent to landing. All of the flight testing took place at the Baikonur Cosmodrome. The operational Buran, however, would not have jet engines at all and the Antonov An-225 Myria was developed as the carrier aircraft to ferry the Buran orbiter. 

Source: Development of the Space Shuttle 1972-1981: History of the Space Shuttle, Volume Two by T.A. Heppenheimer. Smithsonian Institution Press, 2002, pp85-92. Space Shuttle: The History of the National Space Transportation System- The First 100 Missions by Dennis Jenkins. Specialty Press, 2008, pp187-192. Photos: NASA, Wikipedia, Dennis Jenkins. 

Major General Keith B. McCutcheon, Father of Modern Close Air Support

Major General Keith "Frank" McCutcheon, USMC

Here's another face virtually unknown to aviation history but very important- this is Marine Corps Major General Keith B. McCutcheon, the architect of modern close air support as we know it. During World War II, most air strikes against targets on the battlefield were called "direct air support" or DAS against preplanned targets with no guidance from the boots on the ground. Even the air strikes in support of the island hopping campaign in the Pacific were DAS-type missions.

In 1942 the Marine Corps began experimenting with ALPs- Air Liason Parties, who were specially trained Marines who used radios and smoke markers to direct pilots to targets. In 1943, they made their combat debut on the island of Bougainville during the Solomon Islands campaign. But their use was limited and faced strong operational opposition from the Army. In fact, the Army's operational manual at the time recommended against close air support for fear of friendly fire casualties. 

Army resistance to CAS doctrine eased in 1944, when Lieutenant Colonel Keith McCutcheon formalized the training of the Marine Corps ALPs. He pulled together all that had been written about the use of the ALPs in at Bougainville and developed a formal curriculum and training plan. Any Marine aviator that was performing CAS missions had to prove their abilities through intensive training under McCutcheon's close eye. At the time, the Marines were working with the Army's 1st Cavalry Division clearing Luzon of Japanese forces. His commanding officer, Colonel Clayton Jerome, asked him to come up with a way of using close air support to cover the 1st Cavalry Division's left flank. His operational experience at that point was flying combat missions in the Dauntless dive bomber in support of Marines during the liberation of the Philippines. Despite what appeared to be limited experience, McCutcheon had a keen sense of the needs of the infantryman, he considered the pilots in his charge Marines first and aviators second. In a short period of time, McCutcheon and his staff wrote five training manuals and eleven supplements for pilots on close air support doctrine and the training even applied to ground personnel attached to the ALPs. McCutcheon wanted everyone from the pilot in the cockpit to the radioman on the ground to thoroughly understand each other's jobs and abilities before going to combat. Over 500 men from Marine Air Group 24 and the Army's 37th Division were trained in just two months in the midst of the Philippine campaign from October to December 1944. The improved ALPs went into operational use for the first time during Marine Corps action on the main Philippine island of Luzon in February 1945.  

McCutcheon himself as head of Marine Air Group 24 flew combat missions in the Douglas SBD Dauntless who had their targets called in by ALPs in radio-equipped Jeeps moving with ground units. As a result, during the battles on Luzon, McCutcheon's SBD pilots quickly gained a reputation for lethal accuracy in the battlefield.

McCutcheon's methods were further refined during the Korean War with not just ALPs but also airborne ALPs we know know as FACs- Forward Air Controllers. In Korea, the FACs were usually North American T-6 Texans. By the time of the arrival of Marine Corps A-4 Skyhawk and F-4 Phantom units in Vietnam in the spring and summer of 1965, the squadrons were organized into Marine Air Groups (MAGs)- a Marine Air Group was made up usually of one type of aircraft and was tasked to fight at least 90 days in support of a Marine brigade. Several MAGs formed a Marine Air Wing (MAW). And in Vietnam in 1965, MAW-1 was headquartered at Da Nang AB and led by none other than Keith McCutcheon himself.

As the commanding general of Marine Air Wing 1, McCutcheon protected his air assets with zeal to keep them from being subordinated to the USAF and US Navy. Despite numerous "official" moves to strip the Marine Corps of their autonomy, in practice, 70% of Marine CAS missions in Vietnam were in support of Marines and controlled by Marines.

In 1970 McCutcheon was to get his fourth star as but was unable to assume his final post as Assistant Commandant of the Marine Corps due to ill health. In recognition of his distinguished career and what he did for Marine aviation, Congress passed special legislation to have McCutcheon listed as a retired full four star general anyway. He got his fourth star on 1 July 1971 and passed away from cancer less than two weeks later. He was laid to rest at Arlington National Cemetery.

Source: Frank B. McCutcheon: Crusader for US Marine Corps Close Air Support, Command and Control by Julie M. La Point, USMC Command and Staff College, 2002. Case Studies in the Development of Close Air Support by B. Franklin Cooling. DIANE Publishing, 1990. Photo: Wikipedia

Task Force 38's Unheralded Contribution to the Fall of Japan

Some of the carriers of TF38 at their anchorage on the eve of Phase One

Contrary to common belief, the dropping of the atomic bombs on Hiroshima and Nagasaki didn't make the invasion of Japan unnecessary. In fact, the invasion of Japan began on 1 July 1945 when Task Force 38 left its anchorage in the Philippines to begin Phase One of Operation Olympic, the invasion of the southernmost of the Home Islands, Kyushu. The amphibious landings on Kyushu were set for November 1945 and Kyushu would then be used as a base of operations for Operation Coronet, the invasion of Honshu and the capture of Tokyo set for the spring of 1946. By this point in the war, the US Navy's Fast Carrier Task Forces had eclipsed the Imperial Japanese Navy's Kido Butai (Mobile Strike Force) of the first half of the Pacific War as the most powerful naval strike unit of the war. Phase One of Operation Olympic was for the powerful Task Force 38 to conduct raids on the Japanese Home Islands in preparation for the November landings. Commanding TF38 would be Admiral William "Bull" Halsey and Vice Admiral John S. McCain. TF38 was made up of Task Groups, each group centered around 5-6 aircraft carriers supported by 2-3 battleships, cruisers and 2-3 destroyer squadrons. Halsey flew his flag aboard the battleship USS Missouri while McCain had his flag on the newest Essex-class fleet carrier, the USS Shangri-La. (the prior link will take you to a detailed order of battle for TF38). In concert with the US Army Air Forces' B-29 Superfortress offensive, TF38's aircraft would be hitting pinpoint targets that the B-29s were unsuited to go after- airfields, harbors and dockyards, coastal shipping and transportation chokepoints. 

Once within striking range of the Home Islands on 10 July, the sailors and airmen of the TF38 awaited the kamikaze onslaught and expected fierce air resistance over the target areas. To their surprise, they literally had air superiority over even Tokyo with little effort. The Japanese were expecting the landings in October and saw no use in fighting the growing number of American aircraft attacking the Home Islands, instead they chose to stockpile and husband their airpower for use to defend against the expected landings. The aviators of TF38 turned their attention to coastal targets around Kyushu, but the pickings were slim. With intelligence reports indicating a far better target would be the coal industry on the northern Home Island of Hokkaido, TF38 moved north to disrupt Japanese industry by going after its power source. The factories on Honshu, the main island, got over 80% of their coal from Hokkaido in the north. Disrupting the rail lines on Hokkaido would further hamper the transport of coal from the mines southward. On 14 July alone 850 sorties were carried out against various targets in Hokkaido from airfields, rail lines and harbors. Many of the harbors were crowded with merchant ships who were trying to avoid the minefields that had been sown by the B-29 Superfortresses. 

Turning into the wind off the coast of Japan, July 1945

It was during the strikes on Hokkaido that the Navy discovered the Achilles heel of the Japanese industry. As there were no bridges or tunnels linking Hokkaido to Honshu at the time, they relied on train ferries to move coal cars from the port of Hakodate on Hokkaido across the Tsuguru Strait to the port of Aomori on Honshu. In the 1920s as Japan's industrialization increased, four 3,400 ton ferries were built that could carry 25 rail cars across the Tsuguru Strait. Larger ferries were built in the late 1920s that could carry up to 43 rail cars. A dozen of these ships were the only way to move coal from the mines in Hokkaido to the factories in Honshu. Eight of the ferries were sunk by TF38's aviators and an eighth was forced aground. The air wing of the USS Essex alone accounted for four of the precious train ferries. Coal shipments were quickly moved by the Japanese to smaller coastal merchantmen, but they were inadequate for the task and they were just as much targets for the prowling aircraft of TF38 as the train ferries. The effect was dramatic- in just two days, the amount of coal available to factories on Honshu dropped by a staggering 80%. 

The contribution by targeting the train ferries presented the Navy's brass with a dilemma. For most of the Pacific War and the years prior carrier aviation strategy centered around attacking and sinking the enemy fleet at sea, but the carrier strikes against the coal industry of Hokkaido showed that hitting unglamorous targets like train ferries contributed for more to the war effort. This would have a great influence on one of the task group commanders of TF38, Rear Admiral Arthur Radford. In the postwar period, Radford served as the Vice Chief of Naval Operations, Commander of the Pacific Fleet and Chairman of the Joint Chiefs of Staff. In those various capacities he consistently pushed for a strong naval aviation arm. 

Source: Whirlwind: The Air War Against Japan 1942-1945 by Barrett Tillman. Simon & Schuster, 2010, pp 199-202. Photos: US Navy

A Short History of the Groundbreaking Williams FJ44 Engine

The Williams FJ44-3 engine. The fan is 23 inches in diameter

The Williams FJ44 engine of the CitationJet family has a fascinating history as it's based on the F107 turbofan used on American cruise missiles like the ALCM and the Tomahawk. Williams International started out with marine turboshafts and APUs before getting into small turbofan engines. Sam Williams and his namesake company would rise to prominence in the aviation industry with miniature turbofans but his real dream was a civilian turbofan for general aviation. In the 1980s Williams envisioned a new class of turbofans based on the F107 design that would allow for a new class of general aviation aircraft that were jets half the cost and size of current bizjets with the field performance and economy of turboprop twins. 

Sam Williams believed so much in his FJ44 engine design that development continued through the 1980s in the absence of any launch order or production application. Keep in mind that this class of engine had never been used in general aviation and Williams International had never made a civilian production jet engine. Through the 1980s, Williams lobbied numerous general aviation manufacturers about his concept for a light jet aircraft and how he had a superbly economical engine to make such an aircraft feasible. The first manufacturer to agree was Rutan's Scaled Composites who flew the Triumph in 1988. Rutan's design never entered production but it did mark the FJ44's first flight. The next manufacturer to agree to use twin FJ44s was Swearingen in its SJ30 design- even though the aircraft flew, Swearingen and the SJ30 have passed through many ownership changes serial production has yet to occur. Williams' big break came with the third manufacturer- Cessna was looking for an efficient and higher performing successor to its iconic Citation line and launched the Cessna 525 CitationJet family in 1992 with a very substantial order of Williams FJ44 engines, vindicating Sam Williams' dream.

Sam Williams

The FJ44 is a joint venture between Williams International and Rolls-Royce and was the company's first civilian engine and first manned aircraft engine. Simplicity and reliability were key to this new class of aircraft and as such, the FJ44 engine has only 700 parts total, 1/4 that of many other bizjet powerplants. The Cessna CitationJet series was the first production application for the FJ44 engine. It wasn't enough to have a simple engine, it also had to have performance and basing the FJ44 on the F107 cruise missile engine gave the FJ44 that foundation. In fact, the F107 that the FJ44 is derived from was such an impressive accomplishment that it won the Collier Trophy- it has 1/10th the weight of the Pratt & Whitney JT8D engine but has the same specific fuel consumption and thrust-to-weight ratio. That performance pedigree translated over well into the FJ44 and it made the engine successful. On the Cessna CitationJet series, the economy and performance of the new engine made the new jet a leap in performance over the Citation 500 series it replaced. While aerodynamic improvements are part of the equation, the FJ44 engine's performance and economics are a large contributor. Compared to a Citation 500 at an identical mid-cruise weight, the CitationJet goes 13% farther with 17% less fuel and it does this 40% faster than the original Citation with the FJ44s having a lower thrust output than the JT15Ds used on the first Citations.

There are four engines in the FJ44 family. The lowest powered one was the first one, the FJ44-1 and it powers the Cessna CJ1 and CJ1+ of the CitationJet family and is also used on the Cessna Citation M2 as well as the Swedish jet trainer Saab Sk60. It has a thrust rating of 1900 to 2100 lbs. The FJ44-1 series first flew in 1988 and went into production in 1992. 

The second engine in the family is the FJ44-2 and is based on the core and LP turbine of the FJ44 paired up with a larger fan and new compressor section for increased thrust. Its applications include the Cessna CJ2, the Beech/Raytheon Premier I,  and the latest incarnation of the SJ30 design, Syberjet SJ30. Two of Rutan's designs fly with the FJ44, the Scaled Composites Proteus and the Virgin Atlantic Global Flyer that Steve Fossett flew around the world in solo nonstop in 2005. It's also used on two re-engining programs for the Citation 500 and the Learjet 25. The FJ44-2 has a thrust rating of 2300-2400 lbs thrust and went into production in 1997.

The next engine in the family is the FJ44-3 which has a new fan and compressor section for an increase in thrust rating to 3000 lbs. It powers the Cessna CJ2+ and CJ3+ and is used in Nextant's re-engining and remanufacture program of the Beech 400 as well as on a re-engining program for later Citation 500 variants. It went into production in 2004. 

The top end member of the FJ44 family is the FJ44-4 with an increase in thrust to 3600 lbs with a larger fan and enlarged compressor. It also features a dual-channel FADEC for more efficiency. It powers the Cessna CJ4 along with the Beech 400XPR remanufacture/upgrade program for the Beech 400. The engine will also power the upcoming Pilatus PC-24 jet. 

There is also a scale down of the FJ44 engine, the FJ33, which went into production in 2004 and has a thrust rating of 1000 to 1900 lbs. The fan is only 19 inches in diameter and it powers the Diamond D-Jet and the Cirrus Vision. 

Unlike other manufacturers of small jet engines, the FJ44 has no turboprop derivative and there are no turboprops in the Williams portfolio. This is a reflection of Sam Williams' philosophy that given time and technological progress, light turbofans like the FJ44 will displace turboprop engines for most civilian aircraft applications. The FJ44 is one of the landmark engines of aviation history and Sam Williams has earned honors for creating an engine that gave rise to a whole new class of general aviation aircraft.

Source: The History of North American Small Gas Turbine Engines by Richard A. Leyes and William A. Fleming. American Institute of  Aeronautics and Astronautics/Smithsonian Institution Press, 1999, pp383-429. Williams International http://www.williams-int.com/. Photos: Williams International

Discord at the 1944 Chicago Conference and the Formation of ICAO

Adolf Berle, FDR's aviation advisor

Early in the Second World War, the Allied powers were already giving consideration to the commercial importance of aviation in a postwar world. In 1941, Secretary of State Cordell Hull placed a brilliant diplomat and lawyer under him, Adolf Augustus Berle, in charge of aviation affairs. Berle soon became President Franklin D. Roosevelt's primary advisor on commercial aviation affairs. Berle saw the postwar potential for aviation threatened by two factors- on one hand were what he thought were outdated imperial notions espoused by the British and on the other hand were ruthless commercial interests typified by Juan Trippe, the chairman of Pan American Airways. Given his legal background, Berle sought to construct a legal framework to govern aviation commerce worldwide and keep powerful political interests and business interests in check. By 1943, Berle had Roosevelt's approval to forge ahead with an international conference to be held before war's end to start laying down the ground rules for postwar commercial aviation. His concepts were for what today would be called "open skies". By the 1943 Quebec Conference, Prime Minister Churchill and President Roosevelt had on their agenda the discussion of postwar aviation policy in addition to the primary discussion of war strategy. At their meeting, Roosevelt established that open skies would be the United States position on postwar commercial aviation and the wheels were set in motion for an international aviation conference to be held the following year in Chicago. 

British aviation interests were forwarded by Max Aitken, Lord Beaverbrook. During the war as Minister of Aircraft Production he was instrumental in streamlining and increasing the efficiency of British aircraft production to meet wartime needs. Britain saw aviation as the key to retaining its Empire with far flung bases in its many dependencies and Commonwealth nations that would rival the American network of bases. However, many in the British government saw that despite wartime production demands, the American aviation industry still managed to design and build civilian aircraft as well as hold the technological lead in bomber designs that would undoubtedly influence postwar airliner designs. Combined with the already legendary ruthlessness of Juan Trippe at Pan American Airways, the development of postwar British aviation policy became one of protectionism- safeguard the economic livelihood of the British aircraft industry, maintain the British Empire and use British Overseas Airways Corporation (BOAC) as the primary means of maintaining the aviation links of Britain's far flung empire. 

With the Americans and the British certain to dominate the upcoming 1944 Chicago Conference, a third party emerged that would have great influence as well, and that was the Canadians. During the Second World War, Canada was of strategic importance in that it sat astride not just the North Atlantic sea lanes to support the war effort in Europe, but it also had key landing fields that formed the western terminus of the North Atlantic air routes to Europe. As long as aircraft were unable to cross the Atlantic non-stop, Canada was a necessity in the any postwar discussion. Led by the chairman of Trans-Canada Airlines (TCA, which later became Air Canada), Herbert Symington, the Canadians not only presciently saw the North Atlantic air routes as lucrative in the postwar period, but they also saw themselves as conciliators between the American and British viewpoints. Lacking Britain's extensive aviation industry and far flung empire, in general the Canadians tended to lean towards the United States' position of open skies. In the run up to the 1944 Chicago Conference, Canadian diplomats were already playing the part of honest broker between the Americans and the British. 

Given the time, it's obvious the Axis powers weren't invited. The Soviets were invited but early on they made it clear they were dead set against any internationalization of commercial aviation. As far as Josef Stalin was concerned, any air traffic within their vast nation would be their sole domain only and would only connect with other airlines at specific points. 

With the formation of the United Nations in October 1945, the Americans formally invited all the signatories to the UN charter to the Chicago Conference in November to discuss postwar aviation policy. Initially the Soviet Union agreed to send a delegation but backed out of the conference the day before it opened. The only nation not present in Chicago besides the Soviet Union was Saudi Arabia. 

Lord Swinton, head of the UK delegation

Adolf Berle led the American delegation at Chicago and Herbert Symington led the Canadian delegation. Curiously, Lord Beaverbrook didn't attend and instead sent one of his deputies, Philip Cunlife-Lister, the First Lord of Swinton, as head of the British delegation. He had just been appointed as the new Minister of Aviation though his prior experience in aviation paled in comparison to his superior, Lord Beaverbrook. Unfortunately for the British, they didn't place the priority on the Chicago Conference that the Americans and Canadians did. Even some of the British delegation present failed to attend any of the sessions where more specific discussions took place. 

At the opening of the conference, Berle outlined the five freedoms of the air: 

1. Freedom to fly over a nation (today we'd call this overflight rights).

2. Freedom to land in a nation but without picking up passengers or freight (today we'd call this a technical stop).

3. Freedom to fly passengers and freight from the home nation to another nation.

4. Freedom to fly passengers and freight from another nation back to the home nation. 

5. Freedom to fly passengers or freight of a another nation between any two intermediate points (today we refer this as Fifth Freedom rights or cabotage, a contentious issue in commercial aviation).

The first two freedoms weren't too contentious and for obvious reasons- there was no economic benefit or harm to the involved parties. But invoking its protectionist stand, Swinton pushed for a system of quotas in relation to the third and fourth freedoms to prevent what he thought would be postwar flood of American airlines starting services to British cities. France, Australia, and New Zealand supported Swinton's quota system where service frequencies and the number of passengers would be tightly controlled to prevent domination by the Americans. Key to the quota system was "escalation" which was supported by the British aircraft industry- as they were able to recover from wartime production and shift to production of airliners to rival American designs, the quotas would be gradually relaxed as the British (and any of their supporters) got onto a more competitive footing. 

The American delegation led by Adolf Berle wouldn't have any of it. It was clearly apparent to the attendees that Adolf Berle and Lord Swinton had a genuine dislike of each other and it was up to Herbert Symington and the Canadians to try to bridge the divide. The Canadians proposed a less stringent system that tried to take into account both American and British positions. It was at this point with both the Americans and British unwilling to give ground that a series of errors in communication would harm British interests. Lord Swinton contacted Lord Beaverbrook for further instructions but he was unavailable. When Beaverbrook called back, Swinton blew him off due to the hour with the classic quote "Max, go to hell, it's three o'clock in the morning here!" Beaverbrook then sent a telegram stating "You may abandon escalation." To the relief of the attendees, the British announced their concession to go with the Canadian proposal on regulating the third and fourth freedoms. After their announcement, a second telegram from Beaverbrook arrived "Before 'abandon', insert 'not'", but it was too late as Swinton told Beaverbrook "A British delegation does not go back on its word."

With agreement now on the third and fourth freedoms (which today we know as bilateral air agreements), the conference moved on to the hot button topic, that of Fifth Freedom rights. Again, the British refused to budge from their protectionist position and Prime Minister Churchill himself made it known that Fifth Freedom rights were unacceptable. President Roosevelt himself tried to convince Churchill to yield, saying "It has been a cardinal point in American policy throughout that the ultimate judge should be the passenger and shipper."Churchill pushed for an adjournment of the Chicago Conference to a later date, but Roosevelt insisted that it would continue until an agreement was reached. Herbert Symington, leading the Canadian delegation, supported the Americans and they also insisted that the conference would continue until an agreement was reached. Soon the Latin American nations joined the American resolution. The crucial swing came when the Dutch, keenly aware the British restrictions threatened KLM Royal Dutch Airlines, joined the Americans along with other European nations. Only New Zealand, France, and Australia supported the British. Churchill still refused to budge and Roosevelt continued his own intervention with Churchill, even to the point of assuring him that American airliner designs would be as readily available to British airlines as they would be with American operators. One of the American delegates, Ralph Damon, who was president of American Airlines (and later would be a long time head of TWA) even went as far to offer the British fifty Douglas DC-4s if they would at least compromise. 

The ICAO flag

The Dutch delegation with the support of the Canadians put forth a compromise in which the first two freedoms were explicitly recognized (something that was already the case anyway), the third and fourth freedoms would be subject to individual review between the involved nations, and the fifth freedom was essentially tabled for later discussion. While Adolf Berle was bitter at the failure of his dream of open skies, he did get his legal framework. At the conclusion of the conference, the International Civil Aviation Organization (ICAO) was set up under the aegis of the United Nations as a means for nations to exchange and maintain aviation regulations. The headquarters would be in Montreal-this was a compromise from the Canadians once again, with Britain and France wanting ICAO based in Europe and the Americans wanting ICAO based in the United States. The first president of ICAO was an respected American aeronautical engineer, Edward Warner, who would serve at the head of ICAO until his retirement in 1957. Today the ICAO has the Edward Warner Award given to for meritorious accomplishment in civil aviation. 

ICAO is the true legacy of the 1944 Chicago Conference. It created a mechanism for not just the exchange of regulations and safety advances in aviation but also a means for the standardization of the protocols and procedures in civil aviation worldwide. The Freedoms of the Air continue to be a contentious issue with open skies agreements coming only after considerable struggle amongst the signatory nations. Most remarkable has been the transformation of the United States from being an advocate for open skies to being protectionist of the domestic airline market with not just restrictions on cabotage but also foreign investment in US airlines. 

Source: Empires of the Sky: The Politics, Contests, and Cartels of the World Airlines by Anthony Sampson. Random House, 1984, pp 62-71. Photos: Wikipedia.

The Industry Cooperation in the Lockheed Electra Investigation.

The outboard nacelle- the Achilles heel of the Lockheed Electra

In my previous blog entry, I had discussed how subcontracting was a way of building goodwill between aerospace competitors, the example from I talked about was in reference to the Space Shuttle program. However, even aside from financial incentives, there have been times in aviation history that corporate rivals have cooperated beyond that of a joint venture and one unheralded example of such cooperation was the extensive investigation into the loss of two Lockheed L-188 Electras shortly after the type went into service. The first loss was on 29 September 1959 when Braniff International Airways Flight 542 went down near Buffalo, Texas, on a flight from Houston Hobby Airport to Dallas Love Field. The second loss was on 17 March 1960 when Northwest Airlines Flight 710 went down near Tell City, Indiana, on a flight from Chicago Midway to Miami. 

The cooperation of Lockheed's competitors began after the Braniff crash. A Dallas warehouse was used to reassemble the wreckage as part of the investigation. Using a chicken wire frame, pieces were added in a gigantic jigsaw puzzle from October into November. In January 1960, the investigators with the Civil Aeronautics Board (CAB) were no closer to determining the cause of the loss of Braniff 542 and invited representatives from Eastern Airlines and American Airlines, both operators of large Electra fleets, along with NASA to join the investigation. The following month Lockheed invited engineers from Boeing, Convair, and Douglas to review what had been done so far in the investigation. But the loss of the second Electra when Northwest 710 went down shook the airline and aviation industry as aircraft like the Electra were the leading edge of the jet turbine age that would revolutionize air travel. There was near unanimous sentiment in American aviation that the cause of the loss of two Electras in passenger service had to be found and rectified for the good of the entire industry. 

NASA immediately put its resources at Lockheed's disposal (the decision to ground versus speed restrict the Electra will be subject of a future post for this blog). Allison, the maker of the Electra's engines, initiated its own flight test program with its own company Electra. Boeing and Douglas made their resources also available to Lockheed- with both companies fielding their own advanced jetliner designs for the day, helping Lockheed determine the cause of the Electra crashes was vital to confidence in both the Boeing 707 and the Douglas DC-8. With Lockheed engineering staff getting pulled from various projects to the Electra investigation, Boeing's chief Bill Allen dispatched his own engineers and his best aerodynamicists from Seattle to assist Lockheed in Burbank. The investigation and any fix needed had a name- Lockheed Electra Achievement Program, or LEAP. To everyone involved, it became Operation LEAP. 

Part of Operation LEAP was the use of a specially instrumented Electra that was flown by Lockheed and government test pilots over the Sierra Nevada range looking for mountain wave turbulence that would shake the test aircraft as no airliner had ever before been punished in-flight. Lockheed had actually pioneering the methods for testing inflight loads on structures back in 1949 that became the industry standard in flight testing. Sixty nine flights into the rough air offered a clue- the load instruments noted that the outboard nacelles were taking a rougher beating than expected. Flutter of some sort became the suspect cause- every aircraft has some degree of flutter, the air moving over various parts and imposing loads can cause them to vibrate and if unchecked, those vibrations increase in amplitude until structures fail. Aircraft structures are designed in part to dampen these oscillations. 

With flutter as the suspect, Douglas had sent over to Lockheed a vane exciter that was basically an actuated vane mounted on the wingtip that could move quickly to induce flutter in the wings. Even in smooth air, the vane exciters could really dole out some punishment to the wing structure. Douglas had used the device in the DC-8 flight test program and put them at Lockheed's disposal. The devices in combination with the rough air flight testing showed the outboard engine nacelles were the source of the flutter and a review of the wreckage from the Braniff and Northwest crashes showed that the outboard nacelle structure in combination with the wing structure allowed an obscure type of flutter called "whirl mode"- in short, gyroscopic movements of the propeller caused oscillations in the nacelle which were then transferred to the wing which caused the wing to fail. 

Though commercial rivals, Boeing and Douglas were only keenly aware that Lockheed was well respected in the business and its engineering and design methods were top notch. Much of how Lockheed went about the design and testing of the Electra wasn't all that dissimilar to how Boeing and Douglas went about the design and testing of their jetliners. If there was something Lockheed had missed, then it was something that left their designs  and the processes used open to question as well. 

On 12 May 1960, Lockheed chairman Robert Gross announced the cause of the loss of Braniff 542 and Northwest 710 as unstable whirl mode. Think about the technology of that day as this was well before computer modeling was available. Now think about the time frame- Braniff 542 went down at the end of September 1959. Northwest 710 went down in the middle of March 1960. And by the middle of May 1960 the cause had been identified. It's one of the great herculean efforts of American aviation that an obscure flutter mode was found to be the cause in just seven months. That amazing time frame wouldn't have been possible if Lockheed didn't have the cooperation of its commercial rivals as well as NASA, Allison, and the airline operators of the Electra. 

Source: The Electra Story: Aviation's Greatest Mystery (Bantam Air & Space Series No. 9) by Robert Serling. Bantam Publishing, 1962, 1991. Illustration: Flight Simulator X screenshot.

Rockwell Builds the Shuttle by Farming Out the Work

The Grumman Shuttle Orbiter design

On 26 July 1972, NASA announced that Rockwell International had been selected as the prime contractor for the Space Shuttle (specifically the Shuttle Orbiter) after an intense competition with Lockheed, Grumman, and McDonnell Douglas. Each contractor proposal also had to detail management of the complex program as well as its technical aspects and the lengthy proposals then went to a specially convened selection board at NASA which evaluated each submission. The top two proposals belonged to Rockwell and Grumman and showcased the effect that a good management proposal could have in winning the competition. From a technical standpoint, NASA scored the Grumman proposal the best, with Rockwell's orbiter design coming in second. Rockwell's submission, however, impressed the NASA selection board with its management system. With the cost overruns on several military programs like the Lockheed C-5 Galaxy on everyone's mind, Rockwell's management proposal stressed cost controls for what was to be the biggest aviation contract in years. With a technical design not much more inferior that the Grumman design, Rockwell was awarded the contract. 

In the industry slump as Vietnam was winding down, the Orbiter contract was a very big prize for any firm that could clinch the award. At the time of the selection, Rockwell had 6,200 employees in their Space Division and with the award, plans were in place to hire as many as 16,000 by 1975. Priority would given to anyone who had worked on the Apollo program. Despite the buoyant mood at Rockwell, things were considerably more glum at the losing contenders, Grumman, Lockheed, and McDonnell Douglas. Grumman had been a mainstay of the US space program from its early days, best known for its work on the Apollo Lunar Module. Company officials made plans for Grumman to be out of the space business by December 1972 along with the attendant layoffs. 

McDonnell Douglas (via McDonnell) had built the Mercury and Gemini spacecraft and was in the midst of winding down its work as the prime contractor for Skylab. The company was also suffering from a downturn in the world commercial aviation market that was affecting most greatly its Douglas DC-9 program. 11,000 layoffs were planned at McDonnell Douglas by 1973.

While Lockheed didn't have as prominent a role in the US manned spaceflight program in the 1960s as McDonnell Douglas or Grumman, their expertise in high speed flight as well as thermal protection systems was unparalleled in the industry at the time. 

Rockwell, however, recognized two realities that came with winning the Shuttle Orbiter contract. The first one was the limitations of its in-house expertise. Quite simply, Rockwell would need other aerospace companies for their skills and expertise to bring the Orbiter to fruition. The second reality was a bit more prosaic but nonetheless vital. Keep in mind that in the early 1970s there was an atmosphere of budget austerity and NASA was no less exempt from financial realities than any other government agency at the time. Subcontracting work on the Orbiter to other companies in effect would spread the footprint of the endeavor across the districts of multiple Congressional representatives who would be routinely voting on NASA's budgetary allocations for the Space Shuttle program. Subcontracts were a common way as well in the industry of building goodwill- by farming out work to competitors and keeping them active and in business, today's winner might one day become tomorrow's loser on a another program and could hope for subcontract work from a rival. 

Rockwell planned to subcontract at least 53% of the work on the Shuttle Orbiter and this had NASA's blessing as a means of preserving the American industrial base for spaceflight. Just weeks after winning the contract as the prime, Rockwell was already conducting seminars across the nation for potential subcontractors. By March 1973 Rockwell began selecting subcontractors for the program with NASA's approval. Grumman would work on the delta wing, McDonnell Douglas got the OMS (Orbital Maneuvering System), Fairchild Republic got the vertical fin, and the Convair Division of General Dynamics got the mid-fuselage/payload bay. Rockwell would be responsible for the nose and crew compartment as well as the aft fuselage that would house the three Rocketdyne SSME (Space Shuttle Main Engine) packages. Lockheed would get the External Tank while Thiokol got the contract for the SRB (Solid Rocket Booster). 

By the summer of 1975, 34,000 workers across 47 states and a broad host of companies across the American aerospace industry were working on the Space Shuttle program. The peak would be in 1977 with 47,000 workers. The post-Vietnam slump, the Space Shuttle program was very much the crown jewel of the US aviation industry. 

Source: Development of the Space Shuttle 1972-1981: History of the Space Shuttle, Volume Two by T.A. Heppenheimer. Smithsonian Institution Press, 2002. Illustration: Aerospace Projects Review

Saving Lockheed for Christmas and Beyond: Carl Squier

Carl Squier

I had written this article a year ago for Christmas but I think it's worth reposting given this is Christmas Eve. There are a lot of folks in aviation little known to history but whose actions footnotes of the time set the stage for larger events in history. Carl Squier is one such individual- the 13th licensed pilot in the United States, in 1917 he became an Army pilot and flew in France in the first World War and became a long time friend of American ace Eddie Rickenbacker.

In 1928 he became the VP of the Eastman Flying Boat company after a career barnstorming after he returned from the Western Front. That year Eastman was bought by the Detroit Aircraft Company and they sent him to California to manage a struggling subsidiary they had just also acquired, Lockheed Aircraft in Burbank. While running Lockheed for the parent company, he found himself a home in aviation and became a patron of the employees at the Burbank plant.

With the stock market crash and the Great Depression, Detroit Aircraft went bankrupt and it dragged Lockheed into the red. No one was sure if Lockheed would survive. A few days before Christmas, he sent the employees home early from the Burbank plant and at the exit, handed each demoralized employee a ten dollar bill (a hearty sum in those days) and wished them a Merry Christmas. All one-hundred ten employees of Lockheed Aircraft went home that evening with ten dollars, all from Carl Squier's own savings which he emptied for his employees. The following January he mortgaged his own car and home to make payroll for the employees. When Lockheed finally succumbed to bankruptcy a few months later, Lockheed only had three employees- his secretary, an accountant, and a stock clerk who doubled as the night watchman for the Burbank hangar of the company.

Squier so believed the Lockheed name was too good to pass into history and the people he came to lead too good to abandon, he convinced an investor, Robert Gross, Gross' brother Courtlandt, three other men, and what he had left of his own savings to purchase Lockheed's remaining assets. Gross wanted to run an aircraft company of his own and in 1932 the group purchased what was left of Lockheed for $40,000. In the bankruptcy courtroom that day sitting in the back was none other than Allan Lockheed himself, who on his way out told Gross "I hope you know what you're doing". With a shoestring staff led by a young engineer they recruited, Hal Hibbard, Lockheed came back to life with its Lockheed Model 10 Electra.

Hal Hibbard and Robert Gross would go on to build Lockheed into one of the giants of American aviation, but it all started with the passion, generosity, and salesmanship of Carl Squier. It was said that if it wasn't for Carl Squier, there wouldn't be a Lockheed. He retired in 1956 as the VP of sales and flew west in 1967.

Source: The Electra Story: Aviation's Greatest Mystery (Bantam Air & Space Series No. 9) by Robert Serling. Bantam Publishing, 1962, 1991.

The Coming Kamikaze Threat in World War II We Never Faced

The USS Callaghan, the last Allied ship sunk by kamikazes.

As the American fleet began to become proficient at meeting the kamikaze threat during the Second World War, night time was usually a period when sailors got a respite from the waves of suicide attackers- the vast majority of kamikaze attacks that took place were during the daylight hours. At night the fleet could repair damage from the day's attacks, sailors could get some rest, and ammunition and supplies for the next day's battles could be stocked. By the time of the invasion of Okinawa in April 1945, the Japanese were already in full swing preparing the Home Islands for the anticipated Allied invasion. Operation Olympic was the code name for the invasion of the southernmost of the Home Islands, Kyushu, and it was scheduled for November 1945. The size of the invasion fleet would dwarf not only what was used at Okinawa, but it would also dwarf the Allied landings at Normandy on D-Day in 1944. Approximately just over 2,700 ships and landing craft participated at Normandy; the invasion of Kyushu would have required over 4,000 ships. In twelve days, over 300,000 American troops came ashore at Normandy; on the beaches of Kyushu during Operation Olympic, it was planned that the same number of American troops would storm ashore in just the first *three* days. Therefore in Japanese defense planning for the defense of Kyushu, called "Ketsu-Go", kamikazes were a key part of disrupting the Pacific Fleet Amphibious Force/Task Force 51. Little known to most, though, is that the planned kamikaze threat would have been of a level of ferocity and technique not widely faced by the US Navy in the Pacific War. 

Through most of the war, the kamikaze threat consisted of primarily front-line aircraft. However, the submarine blockade of Japan made getting strategic materials like the ores used in metal increasingly difficult. Bauxite, for example, is an ore that is the main source of aluminum and the Japanese aircraft industry's main source for bauxite were open pit mines near Singapore. As early as 1943 thoughts began to shift towards the use of wood in new aircraft designs and the Germans had even provided the Japanese with plans for the De Havilland Mosquito, the Royal Air Force's "Wooden Wonder". Mosquito components that had been captured were even shipped to Japan aboard the Imperial Japanese Navy submarine I-29, but it was sunk in July 1944 near Japan. While the Japanese were aware of wood's natural radar defeating properties, any consideration at this point in using wood in aircraft designs was more a practical matter with the ore shortages; any benefits against Allied radars was seen rather remarkably as a secondary and less important benefit. 

Yokosuka K4Y1, probably the type that sank the Callaghan.

By the time the Battle of Okinawa was winding down, "Ketsu-Go" was in full swing on Kyushu and a key part of the defense was the use of massed kamikaze attacks. But the state of Japanese aircraft industry was in disarray with the B-29 attacks and the ongoing ore shortages. In July 1945 to meet the required numbers of kamikaze aircraft, all of the training units were converted to kamikaze units which added thousands of experienced pilots but over 5,000 antiquated biplane trainers made of wood and fabric. But again, at this point in the war, no one in Japan had realized that an elderly biplane trainer was a lot harder to spot on radar- plans at that point were to offset the slow performance of the biplane aircraft by shifting the kamikaze attacks to the night time, the traditional sanctuary period for the American fleet. However, somewhere in the Japanese command structure connected all the dots- on the night of 28 July 1945, the Fletcher-class destroyer USS Callaghan was on radar picket duty off the coast of Okinawa. In a time before the advent of airborne early warning aircraft, radar picket destroyers patrolled the edges of the fleet to search for inbound kamikazes. On this night, an elderly biplane floatplane, most likely a Yokosuka K4Y1 trainer, was warded off on its first pass, but it came around undetected for a second pass and struck the destroyer, sinking it with the loss of 47 sailors. The following night, another elderly biplane struck another radar picket, the USS Cassin Young- though not sunk, 22 sailors were killed and the ship had to withdraw from action for repairs. A third destroyer, the USS Prichett, was aiding the stricken Callaghan, was very nearly sunk by another elderly biplane on a kamikaze mission.

Yokosuka K5Y biplane trainer.

The destroyers had difficulty on downing the attackers for three reasons- it was night, not the usual time kamikazes attacked, secondly, the wood and fabric biplanes were difficult to spot and track on radar, and lastly the wood and fabric construction threw off the proximity fuses of the anti-aircraft guns- the proximity fuse's sensor that triggered the detonation of the round was optimized for metal aircraft; against the old wood and fabric biplanes, the proximity fuzes detonated the round too late, or in some cases, not at all. The action that night against those three radar picket destroyers changed thinking on the role of the 5,000+ elderly biplane aircraft that were going to be used as kamikazes for "Ketsu-Go". Here was an unexpected weapon that could counter the American technological advantages in radar and proximity-fuzed shells fired by anti-aircraft guns. American intelligence analysts had seen the massive change in the air forces of Japan in the summer of 1945 and were well aware of Japanese interests in wood, but it hadn't occurred to the Navy that this was a possibly game-changing combination that would have threatened initial phases of Operation Olympic. It was assumed that fuel shortages would keep most Japanese aircraft grounded and this misconception was reinforced by the increasing lack of air action against the B-29 raids and that US warships even managed to get close enough to the Home Islands to shell coastal targets without getting attacked. In fact, the Japanese had stockpiled fuel just for the use of the kamikazes in "Ketsu-Go". 

Tachikawa Ki-17 trainer aircraft.

At Okinawa, only one of the US Navy's carrier air wings was trained and equipped for night combat, that being Night Air Group 90 embarked aboard the USS Enterprise. By November 1945, only one additional night air group would be available for Operation Olympic, giving only 50 aircraft to defend the invasion fleet at night against well over 5,000 night kamikazes that would have been difficult to spot on radar, using the mountainous terrain of Kyushu to mask their approaches to the invasion fleet, and be of a construction that would probably render a large portion of the proximity-fuzed shells ineffective. 

It is perhaps a blessing that the Japanese surrender following the atomic bombings of Hiroshima and Nagasaki took place. The kamikaze plans for "Ketsu-Go" alone would have well resulted in significant casualties on the shores of Kyushu, but instead history is left with the USS Callaghan as the last Allied ship to be sunk by kamikazes- and that night on 28 July was a small preview of the storm facing the US fleet in the waters of the Home Islands.

Source: Hell to Pay- Operation Downfall and the Invasion of Japan, 1945-1947 by D.M. Giangreco. Naval Institute Press, 2009, p125-137. Photos: Wikipedia.