VFP-62 "Eyes of the Fleet" and the Bay of Pigs Invasion

Over the course of the Second World War, photoreconnaissance in the US Navy progressed from rudimentary handheld photography from whatever aircraft was available to reconnaissance variants of carrier fighters equipped with cameras in fuselage bays. The reconnaissance mission was carried out usually by the fighter squadrons in the carrier air wing (which were still called carrier air groups back then) and in the years after the war, small groups of combat-seasoned photo recon pilots were usually attached to carrier air groups but no standard training, syllabus or even squadron existed for the reconnaissance mission. That all began to change in 1948 when Fleet Air Service Squadron THEE formed a photographic detachment at NAS Norfolk, Virginia. On 8 January 1949, 13 officers and 88 enlisted personnel gathered to form Composite Squadron SIXTY-TWO (VC-62) at Norfolk, with a sister squadron, VC-61, formed on the West Coast at NAS Miramar, California, to serve the Pacific Fleet. The squadrons were tasked to train and perform the photo reconnaissance mission. The first aircraft of the units were photo variants of the Bearcat and Corsair- the Grumman F8F-2P (the P suffix designating a recon variant) and the Vought F4U-4P and -5P. Though specialized for the recon mission, that's a loosely used term since the aircraft carried a single camera in a fuselage bay and the pilots were still considered fighter pilots and VC-61 and VC-62's training regimen still required proficiency in gunnery, rocketry and bombing missions with extra emphasis on navigation. 

A VFP-62 F2H-2P Banshee aboard the USS Franklin D. Roosevelt
(Wikipedia)

Of the two squadrons, VC-62 would soon become famous. The unit was transferred from Norfolk to NAS Jacksonville and converted to the McDonnell F2H-2P Banshee which was a quantum leap in performance over the Bearcats and Corsairs as not only was the Banshee jet powered, but its extended nose bay housed multiple cameras that could photograph targets from over 40,000 feet. In 1953, VC-62 added the swept wing Grumman F9F-6P Cougar to its existing fleet of Banshees. Camera technology also progressed in this time to allow sharper and better quality photos from aircraft moving at much higher speeds than piston-engined aircraft. The arrival of the jets also meant that the pilots no longer had guns to shoot back- the recon variants of the jets were unarmed, requiring the use of speed, maneuverability and sharp mission planning to get home with the photos. On 2 July 1956, VC-62 was redesigned VFP-62 and VC-61 became VFP-63. Two years later, VFP-62 got one of the finest naval photo reconnaissance aircraft in the form of the Vought F8U-1P Crusader. 

A VFP-62 F9F-6P Cougar overflies the USS Essex
(Wikipedia)

The Crusader wasn't just fast, it also had the latest in state of the art camera technology in the -1P recon variant. At the speed of the Crusader, especially at low levels, the images would have been blurred, but the four cameras of the -1P Crusader had what was called IMC (Image Motion Compensation). A set of avionics boxes with controls in the cockpit coordinated the aircraft's speed and altitude with the camera equipment. During a photo run, a vacuum sucked the film frame against a moving shuttle- when the shutter opened, the shuttle would move the film frame in the opposite direction of flight at a speed that canceled out the forward speed of the Crusader for that brief moment. When the shutter closed, the vacuum released the film frame and the next frame entered the shuttle. This process took place with each of the Crusader's four cameras multiple times in a second depending upon the target, the aircraft's speed and altitude, and ambient lighting conditions. The IMC electronics also made sure the frames overlapped the ground to insure a required level of coverage of of the target. 

In 1958, the same year as the conversion to the F8U-1P Crusader, VFP-62 moved to NAS Cecil Field outside of Jacksonville as it had outgrown its Jacksonville base. It was an unusually large squadron compared to most Crusader fighter squadrons on account that it sent detachments of carrier air wings- a typical photo detachment might be three aircraft with 35 officers and enlisted men. The squadron could have multiple detachments deployed worldwide at any given moment. 

A VFP-62 F8U-1P Crusader tanks from an A4D-2 Skyhawk
(Wikipedia)

On 1 January 1959, the revolutionary forces of Fidel Castro defeated Fulgencio Batista's regime in Cuba, putting the island nation square in the communist sphere of influence. Needless to say, having a Soviet client state just 90 miles from American shores would greatly influence the foreign and defense policy of both the Eisenhower and Kennedy administrations. John F. Kennedy won the 1960 presidential elections against Richard Nixon on a strong anti-Castro platform, campaigning that Nixon, as Eisenhower's vice-president, was weak on Cuba. Unfortunately for Kennedy, this put him in a position after entering office of accepting the plan for the invasion of Cuba by US-trained Cuban exiles at a location called the Bay of Pigs. On 18 April 1961, a force of 1,400 Cuban exiles landed ashore at the Bay of Pigs as the Cuban Expeditionary Force (CEF) with plans to start a counter-revolution against Castro. Kennedy was keen to limit the appearance and extent of American involvement and the CIA-trained CEF force had its fleet of Douglas B-26 Invader aircraft cut in half as part of that effort. The young president wanted the CEF to look like a home grown force than a US-backed force to prevent a superpower confrontation. The operation was doomed from the start and when it became clear that the CEF was in over its head against Castro's forces the following day, Kennedy ordered a secret photo assessment of the situation on the ground at the Bay of Pigs. 

VFP-62 had three F8U-1Ps as part of Detachment 41 assigned to the USS Independence which was in the area for contingency operations should US air support be needed (which it was but was never authorized). Det 41's commander was ordered to paint over any military markings and even the maintenance stencils were overpainted in gray. Roman numerals I, II, and III, were painted inside the wheel wells to tell the aircraft apart as they were completely sanitized of any exterior markings. The Crusaders were identified as "Gray Ghost" and then "One", "Two", or "Three" during flight operations. They conducted a series of flights over the Bay of Pigs which confirmed that the CEF was about to be overrun by Castro's forces. It was hoped that the low level overflights of the area might give Castro's forces pause that the CEF might be defended by US airstrikes and give the beleaguered exiles time to regroup, but this wasn't to be the case and the CEF was roundly defeated with those not killed taken prisoner. 

A VFP-62 F8U-1P Crusader prepares to launch from the USS Independence
(Wikipedia)

The USS Independence and its carrier air wing were awarded the Armed Forces Expeditionary Medal for its clandestine operation, but even after the disaster at the Bay of Pigs had passed, VFP-62 was requested to remain in the area to keep an eye on Cuba. Up until the Cuban Missile Crisis in October 1962, the squadron would make periodic flights to Cuba, mostly staging out of NAS Cecil Field. Flights of two aircraft would then "pretend" to making practice approaches to NAS Key West and dash to Cuba at low level. Other missions had two Crusaders appear as a flight transiting to Guantanamo Bay and then dash down at low level before recovering at Homestead AFB in Florida. 

VFP-62's missions would soon take on added urgency as October 1962 approached. But that's a subject for a future article here at Tails Through Time! 

Further reading: 

Vought's Not-So-Fearsome F6U Pirate

The First American Covert Overflights of the Soviet Union

The U-2's Antecedent: The Martin RB-57D Canberra

Taiwan's Secret Recon Voodoos

Project Palladium: Testing Soviet Radars

Source: Blue Moon Over Cuba: Aerial Reconnaissance during the Cuban Missile Crisis by Capt. William B. Ecker USN and Kenneth V. Jack. Osprey Publishing, 2012, pp 33-50.

A Cat of a Different Sort: The Grumman Ag-Cat

Crop dusting expanded considerably after the Second World War with a surplus of pilots, aircraft and engines. Most crop dusting operations used the Boeing/Stearman Kaydet training biplane as it was rugged to deal with the ham fisted flying of students and it was cheap being war surplus as the US military modernized its training fleets in the postwar period. Though plentiful and relatively easy to maintain, a fully loaded Stearman for crop dusting was in most cases underpowered. One of the qualities that made the aircraft so ideal for training was that it required a lot of coordination to minimize its yaw tendencies. It wasn't unusual for a Stearman student to find operational combat aircraft less demanding to fly! That's not to say it was a difficult aircraft in the training environment, but if you were to add a heavy load of chemicals and associated spray equipment, then the Stearman was definitely a handful for crop duster pilots who were flying just a few feet above the ground and then having to climb to avoid treelines and whatever obstacles surrounded most agricultural fields. In 1956, two members of Grumman Aircraft's preliminary design group, Joe Lippert and Arthur Koch, had been touring the Gulf Coast talking to oil industry executives and operators on their requirements for proposed amphibian they were considering. They had a second aircraft in mind as well, a purpose-built crop duster, but the amphibian was their priority at the time of their visit to the Gulf Coast. What Lippert and Koch found was that there was a broad range of needs by the oil industry that they weren't sure a single design could meet all the demands they discussed with prospective customers. Shelving the amphibian project, they then visited farming communities and observed crop dusting operations with considerable interest. Discussions with crop duster pilots revealed some of the problems pilots faced with the near-ubiquitous Stearmans that were the bulk of the crop dusting fleet of the day. While Grumman was not alone in its considerations of a custom-designed crop dusting aircraft, they certainly chose a different design philosophy than other aircraft manufacturers like Piper and Cessna took in their crop dusting designs. 

The Smithsonian's Gruman Ag-Cat
(NASM Udvar-Hazy Center)

Lippert in particular was fascinated with how crop duster operations were getting war surplus radial engines for only $25 to replace the existing worn out Continental R-670 seven-cylinder radial engines for their Stearmans. He astutely realized that the best approach for Grumman was a design that used the 220-hp radial engine as they were inexpensive and plentiful on the aftermarket. This would make acquisitions costs more reasonable and potential owners and operators already had experience operating and maintaining the R-670 engine. Lippert and Koch went back to Leroy Grumman and presented their preliminary specification for what would become the Grumman Ag-Cat. However, Grumman was tied up with a lot of military business in the later half of the 1950s and Grumman told the two men that the new project would have to carried out on a shoestring budget. An empty hangar was secured as a workshop and design space along with tooling that was to be scrapped that they thought might be of use. The entire engineering team for the aircraft consisted of only eight people, two of which were Joe Lippert and Arthur Koch. They borrowed craftsmen from the production floor as needed based on who was available- most of these craftsmen were on the verge of retirement but their skills dating back from the 1920s and 1930s would prove valuable to the Lippert and Koch. While the number of craftsmen working varied based on who was available, it usually averaged about thirty individuals. With the craftsmen working right next to the engineers and draftsmen, a tight-knit group that hearkened back to the Grumman's early days formed. 

Unusually for an aircraft program, the design and build of the Ag-Cat began simultaneously on 30 October 1956. Some of the workers came in on weekends and evenings on their own time to help with the project- after all, the last Grumman biplane was the F3F from the 1930s, so there was considerable interest among the "old hands" at Grumman in the Ag-Cat project (which had yet to get the Ag-Cat name at the time). The fuselage mock up was built in Joe Lippert's garage much to his wife's consternation. Ideas from the mock up then went to the hangar in the morning for incorporation in the aircraft as it came together. To keep things simple, a welded tube fuselage was used with removable aluminum panels to allow the interior to be washed out of any chemical residue from crop dusting. The two wings were staggered with the lower wing 35% aft of the top wing to give the aircraft very benign stall characteristics. This way one wing stalled before the other which insured the pilot would always have some level of control in a stall situation. The four wing panels- left and right top and bottom wings, were all interchangeable which eased maintenance and production costs. The aileron on a top wing panel became a flap if that wing panel were used on the lower wing. The nose sloped downward to improve the pilot's vision during low level flying and the airspeed indicator and engine tachometer were put right at the pilot's eye level to avoid having to look down at the instrument panel. The fuselage structure around the cockpit was designed to absorb a 40G crash- given that 10% of crop duster pilots crashed each year of their careers, making the aircraft survivable in the event of a crash was to be a prime selling point- in fact, from the first delivery in 1959, nine years elapsed before the first Ag-Cat crash. The chemical hopper was installed in the fuselage ahead of the cockpit right at the center of gravity to prevent there being any shifts in the center of gravity as the load was expended. The hopper had a 217 gallon capacity for liquids or 1,200 lbs for dry product. The price was established at $12,995 without the engine and propeller, $13,995 if a power plant package was factory installed. 

N10291, the Grumman Ag-Cat prototype
(Wikipedia/Rene Francillon Collection)

The first flight took place on 27 May 1957, just seven months after design/fabrication of the prototype, N10291, began! Lippert and Koch requested that all the workers who worked on the project bring their wives to the first flight- as many of them had worked additional hours on top of their existing jobs on the project, they thought that the wives should see "the other woman" in their husbands' lives!

With a successful first flight that revealed no major issues, the second prototype joined the test program a month later. Grumman himself invited crop duster pilots from around the country to try out the prototypes and every single one was enthusiastic about the aircraft's handing and tight turning capability given that most crop duster pilots that stalled did so during turns to make another pass. The two prototypes were then taken on a nationwide tour by Lippert and Koch with over 150 pilots trying out the aircraft. One of the crop duster pilots that tried out the aircraft, Dick Reade, suggested the name Ag-Cat to the Grumman team as it was in line with Grumman's naming of its fighter aircraft with feline names (Dick Reade's name is below the cockpit of the Ag-Cat on display at the National Air & Space Museum's Udvar-Hazy Center). While on tour in Texas, Joe Lippert began to take flying lessons and on the day he earned his pilot's license, the first thing he did was try out the Ag-Cat- one of those few occasions where an aircraft's designer got to fly their own aircraft- common in the early days, but increasingly rare as aircraft grew in complexity and performance. 

Leroy Grumman had planned on building the Ag-Cat at the Bethpage facility on Long Island in the event that military sales slowed, but this wasn't to be the case and space was lacking for the production of the Ag-Cat. Grumman had the entire production sub-contracted to Schweizer Aircraft in Elmira, New York, who had the production space and the experience in building welded tube aircraft from their long line of gliders. The first production Ag-Cat was delivered in 1959- Schweizer would build 1,730 Ag-Cats from Grumman until 1980. In 1981, Schweizer purchased the design rights outright from Gulfstream (which was the spin off of Grumman's civilian aircraft business) and would build another 617 Ag-Cats until production ended in 1995. Over its production life, more powerful engines and even turbine power was offered which allowed even greater load carrying capability. In 1995, the Ag-Cat Corporation of Missouri purchased the design rights from Schweizer and a further five Ag-Cats were built before they went bankrupt. A large Ag-Cat operator in Arkansas then bought the design, but I haven't been able to determine who currently holds the design rights to one of the most iconic agricultural aircraft. I did come across an online article from 2011 in the Columbus Telegram in Nebraska about an individual named Jared Storm who owned an agricultural flying service and was in negotiations at the time about relaunching Ag-Cat production at David City Municipal Airport in Nebraska (93Y), but haven't found anything further from that news item. If any of my readers has any information, please do add it in the comments section of this article. 

Further reading: 

The Humble Birth of Grumman Aircraft

C.E. Woolman and the Founding of Delta Airlines

The Birth of the Gulfstream Series of Aircraft

Hatching the Grumman Goose

An Aircraft Manufacturer Goes Into the Boat Business

Sources: Ironworks: The Story of Grumman and Its Aircraft by Terry Treadwell. Tempus Publishing, 2000, pp 160-164. The Smithsonian National Air & Space Museum's entry on the Ag-Cat (http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A20080395000). 

The Humble Birth of Grumman Aircraft

Leroy Grumman (Time Magazine)

In October 1920, the head of the Loening Company, Grover Loening, had been supervising the construction of a two-seat naval floatplane at two locations- at Loening's own plant at 31st Street on the East River in mid-town Manhattan and at the Naval Aircraft Factory in Philadelphia. It was in Philadelphia that Loening convinced one of the Navy's test pilots to resign his commission and join his company. That young 25-year old naval lieutenant was Leroy Grumman. The young Grumman rose quickly to the top ranks of Loening's company and by 1924 Loening had hired two other talented individuals to support Grumman- Jake Swirbul and Bill Schwendler. Loening's company prospered right until the 1927 when Lindbergh's solo flight across the Atlantic sparked the imagination of American business which was already riding a bull market in Wall Street. Though well-run, Loening began to falter and in 1928 Grover Loening sold his company which was to be absorbed by the Keystone Aircraft Company which at the time was building a twin-engine bomber for the US Army Air Corps. In less than a year, Keystone itself was purchased by Curtiss Wright. Under the terms of the sale, Loening's Manhattan factory would be shut down and all the employees were assured employment if they moved to Keystone's main facility in Bristol, Pennsylvania.

Leroy Grumman and his two closest friends, Jake Swirbul and Bill Schwendler, weren't happy about having to move to Pennsylvania as they had settled in the New York City area and had families that would have to be moved. So in 1929 the trio decided they'd form their own aircraft company and stay in the New York City area. Since Grover Loening and his brother were barred from forming another aircraft company as part of the terms of the sale, they decided that investing in Grumman's fledgling enterprise would be the next best thing. Their first act was to hire Loening's treasurer who also happened to be from a prosperous New York family that offered to invest with Grumman as well. In contrast to the businesses of the day, however, Grumman decided that control of the company would rest only with a few individuals and to not canvas Wall Street for further investors. It proved to be a wise move with the Wall Street crash just over a month away. 

Grumman then set about to recruit the thirty most skilled employees at the Loening plant. His years of service under Loening endeared him to many of the Loening workers and all asked, with the exception of one or two, threw their fate into Grumman's hands. In addition, Grumman, being a financially cautious individual, decided that his new company would only seek the business of the US military, preferably the US Navy given Grumman's background as a naval aviator and their long history of doing business with the sea service during their employment with Loening. In order to fund their day-to-day operations, they would repair existing Loening amphibians at a rented facility in Long Island. 

On 5 December 1929, Leroy Grumman and his five founding associates met for the first time and the following day the Grumman Aircraft Engineering Company was born. Much of the company's initial capital came from Grumman's severance pay from Loening. Jake Swirbul's widowed mother worked for a wealthy Long Island family that so much of her that they lent Swirbul enough money to become the first vice-president of Grumman. A few months later in March 1930, the rest of the tiny company's employees were allowed to purchase stock (On the eve of the maiden flight of the Grumman F-14 Tomcat, those employees' initial investment over 40 years had multiplied by a factor of 7,700!). 

Their first design proposal was for the US Navy, which at the time had a two-seat scout biplane, the Vought O2U Corsair. The Corsair could be fitted with floats for operation from cruisers and battleships or it could be fitted with landing gear for operation from aircraft carriers. Grumman's proposal was for a new float that was not only lighter and stronger than the existing main float used on the Corsair, but it would also incorporate a fully-retractable landing gear to allow true amphibious capability. In 1930, fully-retractable landing gear were a novelty- on the Loening amphibians, the landing gear simply swung upward out of the way but what Grumman and his team proposed was a streamlined arrangement in which the gear would be fully retracted into the sides of the central float. 

Vought O2U with the Grumman-design center float (Wikipedia)

The Navy was intrigued by this modification of its O2U scoutplanes, and asked Grumman for a demonstration. Many in the Navy were skeptical that a float lighter than the existing float could be stronger, let alone be strong enough to accommodate a full-retractable landing gear. But Grumman's design was an early pioneer in monocoque construction in which the skin of the float carried a good portion of the stress loads and as such, didn't need a heavy internal framework that was the standard in aircraft construction of the day. The Navy paid Grumman $33,700 for two such prototype floats for testing at the naval yards in Anacostia in Washington, DC. The floats would be attached to Vought O2Us that would be launched from test catapults as that was the most stress anticipated on such a float arrangement. The landing gear was manually operated, but was designed so that either mechanical or hydraulic power could be added.

On the day of the flight tests, the Navy couldn't find an observer willing to sit in the second seat of the modified scoutplane. Many thought Grumman's float would either crumple up on launch or collapse on landing either on land or on water. Not wanting to delay the flight tests, both Leroy Grumman and Jake Swirbul both volunteered to sit in the observer's seat on different flights to prove their faith in the monocoque design. The day's test flights were of course successful and Grumman walked away with his first Navy contract for what was called the Grumman Model A float. In addition, the Navy had asked Grumman the possibility of using the retractable landing gear on its single seat carrier fighters. Grumman offered to go one better and on February 1930 began work on what would be come the first Grumman fighter, the FF-1. Grumman's landing gear design would go on to be used on not just the FF-1, but also the F2F and F3F biplane carrier fighters and on the F4F Wildcat used in the Second World War. 

Source: The Grumman Story by Richard Thruelsen. Praeger Publishers, 1976, p17-41.

C.E. Woolman and the Founding of Delta Air Lines

C.E. Woolman (Minnesota Public Radio)

Collett Everman Woolman was born in Indiana in 1889 and was raised in the academic environment of Champaign-Urbana, Illinois, where his father taught physics at the University of Illinois. Woolman's interest in aviation began at an early age when he and his friends appropriated every clothesline in his neighborhood to build a giant passenger-carrying kite which fortunately for history, crashed before anyone tried to take flight in it. As a freshman, he even built a crude airplane which had to make a forced landing on his university campus. In his sophomore year of collge at the University of Illinois, he learned of the first aviation world meet to be held in Reims, France, and the ambitious Woolman managed to get a job tending a herd of 800 travelling calves to get to France. On his return, he helped pioneer aviator Claude Grahame-White overhaul a rotary engine in the passenger steamer's cargo hold in preparation for an airshow in Boston. 

He graduated in 1912 from the University of Illinois with a bachelor's degree in agriculture. That's right, farming. The legendary founder and head of Delta Airlines studied agriculture in college, hardly the field to propel him into aviation, but in those days, aviation as a business and industry hardly existed and was more the realm of half-cocked mad scientist types to be shunned by the general population. In fact, if you wanted to look up Glenn Martin's aircraft company in Los Angeles in those days in the phone book, it was listed under "Amusements"! With a fresh degree in agriculture, Woolman moved south to farm various locales in Mississippi before becoming the manager of a 7000 acre plantation in northern Louisiana. 

In 1913 he joined the extension department of Louisiana State University at Baton Rouge as an agricultural sciences instructor who travelled out to farmers to pass on the latest techniques. In 1914 the US Congress passed the Smith-Lever Act which formalized the extension cooperative system in which universities would reach out to farmers to formally educate them on the latest developments in agriculture. With this new law, the young C.E. Woolman became LSU's first extension agent in Lousiana and based his operation in Monroe, Louisiana. 

Travelling throughout Louisiana, he not only met with farmers and plantation owners but also consulted with financial institutions on investing in agriculture as well as liasing with the agricultural scientists back at the LSU campus. It was during this time that the boll weevil infestation was ravaging the US cotton crop. A chemical had been developed which was effective against the boll weevil; calcium arsenate was a dry powder which worked well, but was cumbersome and inefficient when applied from the ground. 

The federal government had experimented with US Army planes in rudimentary crop dusting efforts, but a grant was given to an entomologist by the name of Dr. Bert Coad at the US Department of Agriculture's Delta Laboratory in Tallulah, Louisiana. Coad had difficulty finding an airplane that possessed a good load carrying capacity to carry enough calcium arsenate powder to dust an entire cotton field. Coad hooked up with a small company called Huff-Daland which was trying to market a military training biplane. Struggling for cash, Huff-Daland eagerly cooperated with Bert Coad in his crop dusting trials.

Huff-Daland Duster at the National Air & Space Museum
(Smithsonian Air & Space Museum)

Given Woolman's job with LSU's agricultural extension, he observed many of Coad's trials with interest. Encouraged by Woolman's favorable assessments of the effectiveness of aerial crop dusting against the boll weevil, Coad tried to get more federal grant money to expand the enterprise. Woolman had enthusiastically spread the word to area farmers that there was a new weapon against the boll weevil and soon Coad found he didn't have the resources to meet the demand. But the US Department of Agriculture saw Coad's trials as only an experiment and failed to provide more resources. 

In 1923, the vice president of Huff-Daland happend to stop by Tallulah, Louisiana, on his way to Texas to demonstrate a Huff-Daland trainer to the US Army. There he ran into Coad and Woolman at the airport and found their work intriguing and thought it would make for a great commercial opportunity with the right amount of investment. He convinced Huff-Daland to set up a crop dusting division in northern Louisiana and he put Coad in charge. But Coad wasn't the best of salesmen and he asked Huff-Daland to hire C.E. Woolman as it's head of sales. Huff-Daland Dusters was originally based in Macon, Georgia, with the bulk of their original business being the spraying of peach orchards. However, by 1925 the company moved to Monroe, Louisiana, with the promise of local investment that Woodman had secured. Coad's former laboratory in Tallulah was close by and Woolman's work with the farmers there brought them a ready-made clientele. Woolman, in that classic Southern genteel style he would become famous for, convinced local business leaders in Monroe to invest in Huff-Daland Dusting Company and by the mid 1920s, Woolman had expanded the dusting operation to include Texas, Arakansas, California, North Carolina and even a contract to do crop dusting for the Peruvian government. In a few short years, Huff Daland Dusters would have one of the largest private fleets of aircraft in the United States, even more than some of the airlines of the day.

Delta's first logo (Delta Flight Museum)

Within a few years, Woolman himself would buy the entire dusting operation from Huff-Daland while Huff-Daland Aircraft itself moved to Pennsylvania and was renamed Keystone Aircraft, one of the pioneering aircraft companies of the day. Woodman wanted a simple name preferably with five letters and it was his long time administrative assistant Catherine Fitzgerald, who suggested the name "Delta". Given its long time service area of the Mississippi Delta region, the name was perfect and the triangle was not too dissimilar to the Huff-Daland Dusting Company logo. One of Delta's first non-dusting contract came from the Army Corps of Engineers who wanted aerial surveys done of the levees along the Mississippi River after some disastrous floods in 1927. Woodman likely was considering starting an airline around that time, a federal airmail survey passed through Monroe and he had been looking at a proposed air mail route that connected Shreveport, Monroe, Jackson, Meridian, Tuscaloosa, and Birmingham. In 1929, he even went as far as got advice from a Minneapolis-based airline (Northwest) who offered him suggestions on operating a passenger-carrying airline. However, Delta's finances at the time weren't in a position to get the Ford or Fokker trimotor airliners used by the major airlines of the day. As luck would have it, in a small town not far from Monroe was a businessman named John Fox who had just started a local air service that concentrated on taking people up for joyrides in Travel Air biplanes. Fox had ordered a larger aircraft, a high-wing monoplane with a six-seat enclosed cabin Travel Air S6000. Fox and Woodman met in 1929 and hit it off well given their mutual aspirations of starting an airline. Delta purchased the assets of Fox Flying Service in exchange for Delta stock which made John Fox the biggest Delta shareholder. Fox was named an officer of the company by Woodman and moved to Monroe to help Woodman get their airline off the ground.  Delta Air Service carried its first passenger from Dallas, Texas, to Monroe, Louisiana in on 17 June 1929. Though Delta's agricultural operations would dominate for a while longer, it was a humble beginning for a Southern farmer and his airline.........

Historical Tangent: Thomas Huff and Elliot Daland started their company in 1920 as Ogdensburg Aeroway Company in 1920 in Ogdensburg, New York. They soon became the Huff Daland Aero Company and in 1924 their chief designer was James S. McDonnell (yes, *that* McDonnell that would go on to establish McDonnell Aircraft in St. Louis during the Second  World War). Thomas Huff sold his share of the company in 1926 and it was acquired by a securities firm who invested a significant amount in Huff Daland and moved the operation from New York to Bristol, Pennsylvania and renamed it Keystone Aircraft. Keystone merged with Loening Aircraft in 1928 and the following year Keystone-Loening was taken over by Curtiss Wright. The Loening plant on the East River in New York City was closed by Curtiss and operations transferred to Bristol. A handful of Loening workers and management, though, all New Yorkers, elected to stay and form their own company to stay in New York. The leader of the group was none other than Leroy Grumman. Yes, *that* Grumman!

Sources: Delta: The History of an Airline by W. David Lewis and Wesley Phillips Newton. University of Georgia Press, 1979, pp 1-24. Delta: An Airline and Its Aircraft by R.E.G. Davies. Palawdr Press, 1990, pp 8-13. 

Refining Anti-Submarine Warfare: The Grumman AF Guardian

Grumman XTB3F Guardian prototype
(San Diego Air and Space Museum)

By 1944, the United States was already laying down plans for the invasion of Japan and if the stiff resistance in the island hopping campaign across the Pacific was any indication, the Japanese were far from defeated and planners expected the worst may yet to come. Navy torpedoes delivered by Grumman TBF Avengers were notoriously unreliable and required a relatively slow approach of 120 mph during their drops at low level. Navy torpedo research languished in the years before the Second World War and torpedo bomber crewman paid the price in their lives. Wartime urgencies caused a reinvestment of torpedo development by the Navy. New air-launched torpedoes in the works could be dropped at higher speeds and further stand-off distances from enemy warships, but by this point in the war, in order to take advantage of the new designs, something with twice the engine power of the venerable Avenger was needed. The first design Grumman submitted for a new carrier-borne torpedo bomber was for the large XTB2F. With two Pratt & Whitney R-2800 Double Wasp radials, the XTB2F was a big aircraft with a maximum takeoff weight of nearly 43,000 lbs which was 8,000 lbs heavier than the maximum takeoff weight of a late model B-25 Mitchell medium bomber! The XTB2F reached the mock up phase before the program was canceled in June 1944 as it was simply too large of an aircraft for the Essex-class fleet carriers. 

The XTB2F mockup before the program cancelation
(Wikipedia/Grumman Archives)

Under the G-70 in-house designation, Grumman offered several variations of a new single-engined design, some of which were mixed-propulsion designs with a big radial engine (either the Wright R-3350 or the Pratt & Whitney R-4360) and a jet engine in the rear fuselage for extra speed on the target runs. When it became clear the R-3350 and R-4360 radials wouldn't be ready for the planned production schedules for what was designated the XTB3F, the Navy asked Grumman for a redesign with the more widely available Pratt & Whitney R-2800 engine which was the same engine used on the B-26 Marauder and P-61 Black Widow. A Westinghouse J30 would be installed in the rear fuselage- the J30 was the first all-American jet engine to run and was only the second production axial-flow engine in the world after the German Junkers Jumo 004. Using the R-2800 engine only cost the reconfigured XTB3F 30 mph of speed which was acceptable to the Navy. Despite the ending of the war by this point, the Navy still wanted the XTB3F, now named Guardian, as a replacement for the Avenger and on 23 December 1946, the prototype aircraft made its first flight. 

As designed, the J30 turbojet in the rear fuselage of the aircraft had 1,330 lbs of thrust and was fed by air intakes in the leading edge wing roots that fed ducts that ran to the engine. During ground test runs, the intake ducting wasn't big enough and strong enough to handle the mass flow to the J30 and would collapse. The engine was only run on ground tests and never used during the flight test program. Ultimately the intake duct problems resulted in the engine being removed and would be absent from the production Guardians. 

With a spacious weapons bay for the Navy's latest torpedoes, the Guardian also had two 20mm cannons in each wing as well as provisions for underwing bomb racks and rocket launchers. Most remarkable about the Guardian, though, was its size. It was the largest single engined piston aircraft to be operated from an aircraft carrier and was 2/3 the size of a Douglas DC-3. In fact, its production maximum take off weight was nearly that of a DC-3! The big R-2800 radial up front was canted down slightly to improve pilot visibility in the carrier approach pattern and it was also canted 3 degrees to the right to help offset the torque of the big engine. It's large tail was to help its stability in low altitude regimes but it did make the Guardian difficult to handle in a crosswind. 

AF-2S and AF-2W hunter/killer team
(San Diego Air and Space Museum)

On the day following the Guardian's maiden flight, the Navy imposed a stop-order on the program to give funding priority to the Douglas AD Skyraider and Martin AM Mauler programs which were also capable of dropping torpedoes and as optimized attack aircraft, were more flexible than the Guardian not to mention smaller in size. It might have been end of the Guardian had it not been for the rapid postwar expansion of the Soviet Union's submarine force. Navy carrier forces needed a specialized anti-submarine aircraft and the XTB3F Guardian best fit that need. As a result, in January 1947, the Navy redesignated the Guardian as the AF (this would be a whole topic for a complete article on how the Navy consolidated the scout, bomber and torpedo roles in the new "A for Attack" designator). Given the state of the art of anti-submarine warfare of the time, though, a single AF Guardian couldn't carry both the necessary detection equipment and weapons, so the Navy brought back the hunter-killer team concept that had worked well during the Battle of the Atlantic were Avengers hunted U-boats and were assisted in their attacks by F4F/FM-2 Wildcats. One Guardian would be equipped with the AN/APS-20 radar in a large under fuselage radome and this would be the AF-2W "hunter". The other Guardian of the pair would be the AF-2S "killer". In operational service, the AF-2W was nicknamed "Guppy" while the AF-2S was nicknamed "Scrapper". 

Interestingly the AN/APS-20 radar started out as a crash program to give the Navy its first airborne early warning aircraft to warn of incoming Kamikaze attacks. Fitted to an Avenger designated the TBF-3W under Project Cadillac, the first AEW Avengers were in Hawaii conducting carrier qualifications when the war ended in 1945. The radome and radar installation on the Guardian was for all intents and purposes, pretty much just moved over from the TBF-3W to the AF-2W. With the J30 engine and its intake ducting gone, space was available for the radar and electronics on the AF-2W and more fuel on the AF-2S. 

Production was launched in October 1947 with an order for 23 early examples which would be devoted to operational testing as well as further flight testing. The first operational examples were delivered to the fleet in September 1950 with VS-24 being the first ASW squadron to get their Guardians. The first carrier qualifications took place that November and in December 1950, VS-24 embarked on the USS Palau (CVE-122) on the Guardian's first operational cruise. Now imagine an aircraft as heavy as a DC-3 that's just 2/3 the size of a DC-3 operating off the decks of escort carriers like the Palau! While a tough and reliable aircraft, a significant number of AF Guardians were involved in deck accidents. Most deck crews were used to handing aircraft half the size of the Guardian and one ASW squadron commander got so frustrated at the incidence of handling accidents just moving the Guardian on the carrier that he required a pilot to be present and in the cockpit if needed when an AF was being moved, even if it was just in the hangar deck!

Operationally, the AF hunter/killer team would form a protective ASW screen around the carrier battle group with the idea to detect and attack any submarines as far away from the carrier as possible. During the Second World War, the protective ASW screen was handled primarily by destroyers and destroyer-escorts- with the arrival of the Guardian, aircraft could now provide the ASW screen for the task force. Guardian teams would fly up to 500 miles out from the carrier with the AF-2W "Guppy" flying a search pattern using its radar to either detect a surfaced sub or a snorkel. Once detected, the "Guppy" would summon the AF-2S "Scrapper". Once in the area, the AF-2S had it's own pod-mounted radar under the right wing (and a search light under the left wing if it was needed at night) to prosecute the attack using vectors from the "Guppy". A periscope sight aft of the wings in the belly was used to release depth charges. If needed, the "Scrapper" could come back around and use rockets and bombs to finish the job. Late model Guardian "Scrappers" designated AF-3S were fitted with magnetic anomaly detection (MAD) gear to improve the chances of note just detecting a sub but sinking it. 

A total of 386 Guardians were built and from 1945 to 1954, it was the US Navy's premier front-line carrier-based ASW aircraft. Of that nine year span, only three of those years was the Guardian truly operational as part of anti-submarine squadrons at sea. Its replacement, also from Grumman, the S2F Tracker, would combine the hunter and killer roles in the same aircraft and the design of the Tracker was heavily influenced by the canceled XTB2F, the design that was replaced by the AF Guardian. Of all the Guardians built, five survived and were used by Aero Union as 800-gallon capacity water/retardant bombers against forest fires from 1957 to 1974. That final year the US Forestry Service instructed its water bomber operators that single engined aircraft could no longer be used. Most were scrapped but a single Guardian was saved and restored to its original configuration and is now on display at the Naval Aviation Museum in Pensacola, the last of its breed in existence. 

Sources: Ironworks: The Story of Grumman and Its Aircraft by Terry Treadwell. Tempos Publishing, 2000, p150-154. "Grumman's Guardian" by Budd Davison. Flight Journal, September 2011.

The Douglas F6D Missileer

The F6D Missileer's resemblance to the F3D Skyknight is apparent

In 1957 the US Navy issued a specification for carrier-based fleet defense fighter that could loiter for long periods of time at long distances from the carrier. In addition, the aircraft had to be able to engage enemy aircraft at 100 nautical miles with a powerful onboard radar and long-range air-to-air missiles. Under the assumption that enemy aircraft were to be destroyed at well beyond visual range, dogfighting capability was not necessary and the need for long endurance dictated a subsonic design. Six hours was the specified endurance for this fighter and in turn this meant a large fuel load. The complex radar systems planned called for a three-man crew, with the pilot and co-pilot on each side of the radar intercept officer, this way both of the flying crew man could share some of the same displays with the radar intercept officer (RIO). 

There were four components to 1957 concept for fleet air defense that would be issued to industry for submissions. The first, of course, was for the aircraft itself, which was awarded to Douglas Aircraft Company in 1959 for what was designated the F6D Missileer. But in addition, a contract was awarded to Westinghouse for the AN/APQ-81 radar that would be used by the F6D to track and engage enemy aircraft. The third component was a contract awarded to the Bendix Corporation for the large AAM-N-10 Eagle missile. What is little-known about the F6D program was the fourth component, for an advanced airborne early warning aircraft to search out targets for patrolling Missileers. This contract would go to Grumman Aircraft which resulted in the W2F Hawkeye (later redesignated E-2 Hawkeye) with its advanced AN/APS-125 radar which could scan an area 400 miles in diameter and cue several F6D Missileers. 

Overall configuration of the F6D Missileer

The F6D itself resembled a scaled-up version of the Douglas F3D Skyknight twin-seat all-weather/night fighter. The nose section was quite bulbous to house the Westinghouse AN/APQ-81 radar and the three man crew were seated side-by-side in a cockpit that resembled that of the Grumman A-6 Intruder. Two non-afterburning Pratt & Whitney TF30 turbofans were mounted on each side of the fuselage just under the unswept wings. At the time, the use of a turbofan engine in a combat aircraft was a new concept and the TF30 was selected for its fuel economy. Since the Missileer didn't have to be supersonic, there was no need for a heavy and fuel-hungry afterburner. 

The Westinghouse AN/APQ-81 radar would have been the most advanced radar of its day using pulsed-Doppler technology years before the first production pulse-Doppler radars would enter service. The radar had a maximum range against large aircraft of 120 miles and could track as many as eight targets at once. The radar could also send mid-course corrections to the Eagle missiles. 

Overall configuration of the AAM-N-10 Eagle missile

The Bendix AAM-N-10 Eagle was the first of the four components from the 1957 fleet defense concept to be awarded. A large solid rocket booster would boost the Eagle to Mach 3.5 after launch on a loft trajectory for maximum range. After the booster was jettisoned, the Eagle's own sustainer motor ignited and further accelerated the missile to Mach 4.5. The use of a loft trajectory gave the Eagle missile a range of 160 miles and on final approach to the target, the missile's own onboard radar system (based on the radar used on the Bomarc surface-to-air missile) switched on. The Eagle could be armed with either a conventional or nuclear warhead.

Despite the advanced nature of the technology used in the F6D Missileer program, many quarters in the Navy fundamentally opposed the concept, arguing that once the Missileer had fired its six Eagle missiles, it was left vulnerable and unable to defend itself as it lacked any other armament and its large subsonic size precluded any evasive maneuvers. Once firing its missiles, the Missileer faced a long return flight to the carrier to refuel and re-arm. In 1960, the building opposition within the US Navy won out and the F6D Missileer program was canceled along with the Westinghouse AN/APQ-81 radar and what was becoming an enormously complex AAM-N-10 Eagle missile. The cost of developing the missile itself was estimated to be more than the aircraft development cost. 

However, the development of the Grumman W2F/E-2 Hawkeye continued and the aircraft is still in production today, albeit with more advanced radar systems, and is perhaps sole remaining legacy of the ambitious, but flawed, F6D Missileer program. 

Source: American X & Y Planes: Volume 2; Experimental Aircraft Since 1945 (Crowood Aviation Series) by Kev Darling. The Crowood Press, 2010, p60-61. Photos: Wikipedia, various internet forums.

Flying High This Past Week: 5 April-12 April

A continued thank you to all my readers and visitors with a special shout out to those who have added comments. When I first started this blog in 2009, the articles were really just short paragraphs on some part of aviation history I had come across in my reading that I wanted to share. Those posts were daily- a trip through the archives shows that to be the case- but as my family grew, there was less time to do daily posts, so I shifted over to more detailed articles that were posted every several days which is the current format. I have been considering adding shorter articles that would be on a more frequent basis or as a filler in between the five day interval of my longer articles. I certainly don't think it will be daily, but I'd like to have more frequent additions to the blog that at least dovetail with my current work and family obligations. We'll see, stay tuned for what I come up with. In the meantime, my more in-depth articles will continue to be posted here every five days. Without further ado, here's what's been getting a lot of hits in the past week here at TAILS THROUGH TIME:

• The Development of the Boeing Flying Boom: Quite obviously the most recent article usually tops our weekly round up and my most recent posting on how Boeing came up with the flying boom for aerial refueling certainly continues that trend. What I found most fascinating out of my reading for that posting was not just Boeing's process for determining the best positioning for aerial refueling, but that at one point Boeing considered for commercial jetliners as well.  
•  The Early History of the Air Line Pilots Association, ALPA: The previous article to the one on the Boeing flying boom still continues to get plenty of hits! The early history of Northwest Airlines is weaved into the early history of ALPA as the founder of the union, Dave Behncke, was Northwest's first pilot and flew its first passengers in 1927. The early history of ALPA gives us a good look at the state of the airline industry in the 1920s which was just on the cusp of making the leap into greater technologies led off by the Boeing 247 and Douglas DC-3. Despite the landmark in aviation history those aircraft were, flying for many professional pilots was still a hazardous profession in the years prior and many airline heads of the day tried to do what they could to stamp out ALPA in its early days. Fortunately a strike at a small airline that ran between St. Louis and Chicago thrust ALPA into the national spotlight and won it friends in high places.
• Vought's Not-So-Fearsome F6U Pirate: The Pirate was the first of setbacks that put Vought on the ropes as a fighter manufacturer for the US Navy. A series of misfortunes, the significant of which was its weak Westinghouse J34 engine, hit the program and by the time the F6U was ready for service, it was quickly overshadowed by superior aircraft like the McDonnell F2H Banshee and the Grumman F9F Panther. Some believe Vought over-compensated for the failures of the F6U Pirate with its next fighter, the F7U Cutlass. But they most certainly hit it out of the park with their third try that resulted in the F8U Crusader. 
• The A-6E TRAM: Making the Grumman Intruder More Lethal: The A-6E was the first major design upgrade of the Intruder over the A-6A that was introduced into combat in Vietnam. Many of the advances of the A-6E were in the miniaturization of its electronics and that created an opportunity to utilize the space created to add full all-weather/night attack capability in the form of TRAM- Target Recognition Attack Multi-Sensor.
• Lockheed's Own L-1000 Jet Engine: Believe it or not in the waning days of the Second World War, Lockheed was developing its own jet engine that, when compared with the current state of the art in jet turbines of the day, was quite advanced. The L-1000 would have had the service designation J37 had it been launched into production in 1947. 

The next article goes up later tonight, it will cover the origins and history of the barrier airborne early warning patrols over the Pacific and Atlantic that extended out the US radar fence from the continental United States to try and provide as much lead time as possible for a Russian bomber attack. Stay tuned! 

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

The Grumman A-6E TRAM: Making the Intruder More Lethal

The patch worn by A-6 Intruder crews. Note the radar and TRAM sensor symbolism

The main variant of the Grumman A-6 Intruder to fight in the Vietnam War was the first production version, the A-6A. The next two variants, the defense-suppression A-6B and the night attack-optimized A-6C, were just modifications of the basic A-6A variant and both the B and C versions served in only small numbers given their specialized roles. The next variant was actually the tanker version, the KA-6D. With the experience of combat, the Navy went ahead with the A-6E variant in 1968 which improved upon the deficiencies of the A-6A and replaced many of the 1950s-era systems with more modern equipment. With combat experience in the skies of Southeast Asia and over ten years of technological advancements, the A-6E was a major upgrade in capability, reliability and maintainability over the A-6A, with newer engines, a digital nav/attack system, a single multi-mode radar (the A-6A had two radars, which is why the Intruder had such a portly nose), and built-in test equipment that allowed the bombardier/navigator (B/N) to test the avionics before takeoff. On 22 September 1972, VA-85 "Black Falcons" embarked aboard the USS Forrestal were the first unit to take the new A-6E on an operational cruise. 

However, the navigation system of the new A-6E proved to be a weak spot and a few short years after the A-6E deployed with the fleet, CAINS (Carrier Airborne Inertial Navigation System) was added to the Intruder. Using the Litton AN/ASN-92 which was the same INS system used on the Grumman F-14 Tomcat and Lockheed S-3 Viking, an Intruder B/N literally plugged the aircraft's INS into the aircraft carrier's navigation systems to get a quick and very accurate initial fix before departing on a mission. But the most dramatic improvement to the capabilities of the Intruder came about at the same time as CAINS. At the time, there were a number of Intruder combat veterans assigned to the Office of the Chief of Naval Operations (OpNav) and with the Naval Air Systems Command. They spent their time getting upgrades and improvements pushed out to the Intruder fleet like CAINS.

A-6C TRIM. Note the prominent ventral gondola for the sensor.

One of the officers, Lieutenant Commander Lyle Bull, was working in the Aircraft Requirements Directorate of OpNav and decided to see what he could do to make the Intruder a full-capability all-weather/night attack aircraft that they had always dreamed about in Vietnam. During the war twelve A-6As were converted into the A-6C which had a large ventral gondola that housed the TRIM (Trails/Roads Interdiction Multi-Sensor) unit that had a FLIR and low-light TV (LLTV) unit for night attack missions over the Ho Chi Minh Trail. Large and aerodynamically bulky, TRIM also suffered from the relatively primitive state of the art in sensor technology at the time. Bull decided that TRIM was a good starting point for an improved system for the A-6E. This improved system became TRAM- Target Recognition Attack Multi-Sensor. In his position with OpNav, Bull had seen the state of the art in infrared technology and made the astute observation that there was space in the Intruder for an internal installation- because, as he put it, "Pods and sailors are not compatible". In the A-6A there was a separate search radar and a track radar in the portly nose- with the A-6E, a new Norden unit combined the functions into one radar and there was now space where the track radar used to be in the lower portion of the nose section. Bull had figured out that a 400-pound installation would fit perfectly into the space. 

In briefing his superiors on what TRAM could do for the A-6E, he pointed out that unlike TRIM which could only search and identify targets, TRAM would also incorporate an internal laser designator to mark targets for the new generation of laser guided bombs under development. Combined with the advances in sensor technology, an A-6E TRAM had a drastically improved bombing accuracy with miss distances of less than 10 feet, while today routine, such accuracy was stunning in the 1970s. However, in the lean funding environment following Vietnam, money for the R&D for TRAM had to be raided from other Naval Air Systems Command programs. Bull's superior, Rear Admiral Donald Davis, authorized $15 million in initial funding with the warning that the funding came from other programs which mean Bull wouldn't be liked- "They'll be after your ass, so watch yourself", he warned. 

A-6E TRAM prototype. Note the compactness of the installation.

Both Hughes and Texas Instruments agreed to develop competing designs for TRAM and Grumman readily agreed to handle testing and integration. Both systems were broadly similar differing in sensor details. TI had the advantage having developed the TRIM sensor during Vietnam- however, Hughes' design proved to better in testing and it was selected for the TRAM contract. As part of the TRAM integration, Grumman took the opportunity to upgrade the radar so it was better integrated with the TRAM sensor along with a new intertial navigation system. TRAM B/Ns would remark on the ease and simplicity of operating the laser designator. 

The A-6E TRAM prototype made its first flight at Grumman's Calverton facility on Long Island on 22 March 1974. With only a year of systems integration testing, Bull's system proved to be winner and the Navy began to procure TRAM units for the A-6E fleet. The first production A-6E TRAM flew on 29 November 1975 with VA-42 "Green Pawns" at NAS Oceana getting the first examples on 1 December 1975. Combined with CAINS, by the early 1980s the entire A-6E fleet was flying the most lethal Intruder variant yet and by that time, a Direction and Ranging Set (DRS) and Airborne Moving Target Indicator (AMTI) were added to the aircraft. This all made the A-6E TRAM Intruder the most accurate all-weather attack aircraft in the fleet if not all of the US forces. It would culminate with the A-6E TRAM being responsible for 85 percent of all the laser designations and LGB drops during Desert Storm. 

Source: Intruder: The Operational History of Grumman's A-6 by Mark Morgan & Rick Morgan. Schiffer Publishing, 2004, p131-133.

The Bell L-39 Swept-Wing Demonstrator

The Bell L-39 making a simulated carrier approach.

Following the end of the Second World War, captured German aerodynamic research had indicated the high-speed benefits of swept wings and many designs under development in the mid to late 1940s were revised to incorporate swept wings- two such examples being the North American F-86 Sabre and the Boeing B-47 Stratojet. While the USAF might have been enthusiastic about the benefits of swept wings, the US Navy still had its reservations- the Bureau of Aeronautics (BuAer), the Navy organization tasked with the development and support of naval aircraft, had concerns about the low-speed handling characteristics of swept wings as it was this particular flight regime that was critical in flight operations aboard aircraft carriers. While there was no questioning the high-speed benefits, the Navy didn't have the luxury of long runways to land at high speeds. To determine the scope of the problem, BuAer solicited bids from industry for a swept-wing flying demonstrator to explore the low-speed handling qualities of swept wings. Grumman tendered two proposals, one based on a modified F4F Wildcat as well as an all new aircraft that would have allowed wings of differing sweep to attached to the fuselage. Bell submitted a modification of its P-63 Kingcobra which won the contract as it offered lower development costs using two P-63 aircraft. The aircraft would be designated L-39. In those days, the Navy designated its research aircraft with a letter denoting the manufacturer followed by the manufacturer's model number- as exemplified by the more well-known D-558 Skystreak and later Skyrocket- "D" for Douglas, Model 558. In the case of the L-39, "L" was Bell Aircraft's letter designation and the swept wing demonstrator had the company designation Model 39. The design had really only a tangential relationship to the P-39 Airacobra (more on this in a bit). 

The wings were basically P-63 Kingcobra outer wing panels that were modified to be swept to 35 degrees and attached to an unswept center stub section. This was done for aerodynamic balance purposes. The wings were further modified with slats which could be positioned before flight either open or closed. Because of the wing modifications, the landing gear was non-retractable, but since BuAer was more interested in low speed landing, this was of no consequence. Two L-39s were built, differing only in the size of the slats.

The swept outer panels attached to an unswept center section.

The first L-39 was ready to fly only 10 weeks after the go-ahead from the Navy and made its first flight on 23 April 1946. The initial set of flight tests showed some handling issues that were easily resolved with further modification to the first aircraft- namely a fuselage extension aft of the wing to increase the moment arm of the tailplane to provide more pitch authority, a ventral fin for stability, and to shift the center of gravity rearward more, the original four-bladed P-63 propeller was replaced with a lighter three-bladed unit from a P-39 Airacobra (and thus the only real link between the P-39 and the L-39). The second L-39 demonstrator was completed with the additional modifications and joined the flight test program.

It was quickly determined that the swept wing with the slats closed possessed entirely unacceptable stall characteristics- namely it was abrupt and caused the aircraft to roll to one side. However, if the wing were slatted, then the stall characteristics become acceptable. Simulated carrier approaches and landings were made by both BuAer test pilots and even Corky Meyer, Grumman's chief test pilot (as Grumman was in the process of designing swept wing aircraft for the Navy). Handling and stall characteristics in the low speed regime around the carrier were quickly determined to not be an issue as long as the swept wing were slatted and the L-39 flight test program concluded in August 1946.

Close up of the L-39's wing slats.

One issue that did come up during the L-39 test program was that swept wings needed a responsive power source in the carrier landing pattern. On aircraft there is a relationship between power required for flight and airspeed. As the airspeed decreases, the power needed also decreases, but it then reaches a point due to drag that the power needed starts to go up even as the airspeed decreases. This is called the "back side" of the curve. In carrier aircraft, they are flown on this backside because the approach to the deck must be at as low as a speed is possible. On a propeller-driven aircraft, power can be immediately applied to halt the aircraft from settling in the approach and striking the ramp. But swept wings had a steeper "back side" and early jet engines took time to spool up. And it would be jet engine development that would later dog the Navy's aircraft programs in the 1950s. But more on that in a later post!

Source: U.S. Naval Air Superiority- Development of Shipborne Jet Fighters 1943-1962 by Tommy H. Thompson. Specialty Press, 2008, p69-73.