04 May 2016

A Giant Ahead of Its Time: The Lockheed R6V Constitution

Before the start of the Second World War, Pan American Airways was the world's biggest operator of large ocean-going flying boats with the Boeing 314, Martin M-130 and Sikorsky S-42 in the fleet that spanned Pan American's worldwide network. However, the airline recognized that the pace of development in aviation technology meant that landplanes would be the dominant airline aircraft of the future. Pan Am worked with Boeing to bring the Boeing 307 Stratoliner to fruition (the world's first pressurized airliner). But with the start of the war for the United States in 1941, Pan American's operations were shifted to support the war effort and in this capacity the airline solicited the US Navy for the construction of a true heavy-lift landplane transport. This was finalized with the US Navy, Lockheed, and Pan American in November 1942 with what became the Lockheed Model 49 Constitution. 


The R6V Constitution on final approach at Moffett Field in California
(Wikipedia/US Navy)
The requirements issued by the Navy as suggested by Pan American were for a range of 5,000 miles, 17,500 lb payload at 255 mph at 25,000 feet cruising altitude. A year later on 1 November 1943 the contract was formally issued to Lockheed. Pan American's engineers led by their head engineer, Andre Priester, worked alongside Lockheed's engineers and their head, Willis Hawkins (he also designed the Constellation and later on would work on the F-80 Shooting Star, F-104 Starfighter, and the C-130 Hercules). The fuselage of the Constitution was a double deck, double lobed cross-section design with the large wing passing through the mid-fuselage between decks. With a fully-pressurized double-deck, the Constitution could carry up to 204 military passengers but the normal complement would be 168 passengers. Pan American's plans were for 51 passengers on the lower deck and 58 passengers on the top deck. Cargo doors were installed on the lower deck and the wings were deep enough to allow mechanics to access the four radial engines in flight for maintenance. The Constitution was also the first large transport aircraft to have multi wheel main landing gear bogies (four wheels to each main landing gear). 

The wing itself was based on the layout and structure of the wings used on the Constellation and the P-38 Lightning. Four 3,000 horsepower Pratt & Whitney R-4360 28-cylinder Wasp Major engines drove four bladed props. Unusually, the upper surface trailing edge root of the wings could hold RATO units to shorten takeoff runs. There were three units in each wing- they were fired when the landing gear retraction sequence started. As the landing gears took 14 seconds to retract, the RATO units burned for 15 seconds.

Takeoff using the overwing integral RATO units
(San Diego Air & Space Museum)
Since the Constitution was a low-priority project during the war, it wasn't until well after the war ended in August 1945 that the aircraft was completed. Though standard for today's design work on modern airliners, Lockheed used a full-scale hydraulic and electrical systems test rig that today would be known as an "iron bird". The system was loaded so the hydraulics and flight control systems would "experience" loads similar to what would be found inflight and were invaluable in letting the Constitution's test pilots get familiar with the large aircraft. The first flight came on 9 November 1946 and after the first 44 flight hours of testing the Constitution was found to be significantly underpowered. More powerful versions of the R-4360 Wasp Major were installed that theoretically produced 3,500 horsepower, but in practice even these engines could only garner 2,900 to 3,300 horsepower and that was with water injection and bypassing the superchargers on takeoff. As a result, use of the integral RATO units was commonplace. 

To keep Pan American interested in the project, Lockheed proposed the civilian version of the Constitution be powered by Wright 5,500 horsepower Typhoon turboprop under development, but by this point Pan American had thrown its lot with the Boeing Stratocruiser and bowed out of the Constitution program. Designated XR6O-1 by the US Navy, the first Constitution underwent a full year of flight testing at NAS Patuxent River, Maryland. The second XR6O-1 made its first flight on 9 June 1948 and unlike the first aircraft, the upper deck was fitted out for VIP passenger service with 92 seats while the lower deck was fitted out to carry as much as 40,000 lbs of cargo. Dual spiral staircases at each end of the cabin provided access to the upper deck from the lower deck and passenger entry was via the nose gear well which was large enough to allow airstairs to be pulled up just in front of the nose gear. 

The Constitution on static display during an open house at San Francisco Airport
(San Francisco International Airport/FlySFO.com)
In February 1949 the second R6O (the X prefix was dropped) was commissioned into service at NAS Moffett Field, California, with the fleet logistics support squadron VR-44. Soon joined by the first R6O, the Navy embarked on a series of publicity flights across the country, using the Constitution to not only transport personnel and materiel, but also to stimulate interest in naval aviation. The R6O carried one and a half times more cargo than the next biggest Navy transport, the Douglas R5D (C-54 Skymaster/DC-4). In 1950, the two R6Os were redesigned R6V; in the Navy's aircraft designation system used prior to 1962, "V" stood for the Vega Division of Lockheed that had built the PV-1 Ventura and PV-2 Harpoon in the Second World War- the "O" of Lockheed was dropped as it could be confused with the number zero and "V" took it's place as the Lockheed designator code. They were reassigned to VR-5 for expanded operational duties that included flights to Hawaii and Alaska. With a total of 3,760 flight hours between the two aircraft, in 1953 the R6O Constitutions were retired and placed in storage at NAF Lichtfield Park, Arizona. The aircraft were offered to the airlines on a proposed five-year lease, but no interest came about. 

The first Constitution ended up in Las Vegas as a promotional billboard for Alamo Airways at McCarran Airport and plans were floated to move the aircraft to the Strip to be part of a casino. However, the plans were never materialized and when Howard Hughes acquired the property that the aircraft sat on, he also gained ownership of the aircraft and had it scrapped in 1970. The second Constitution ended up in Opa Locka, Florida, where it was to be sold to a German businessman who wanted to use it for a restaurant in Barcelona, Spain. The deal fell through and the aircraft mysteriously caught fire which gutted the interior but spared the exterior. After several years of legal wrangling, the aircraft was scrapped in 1979.

Further reading: 

The Convair Model 6: A Jumbo Jet Before Its Time
Pan American and the Boeing 314 Toilet Scandal
The Cadillac of the Constellation Line

Source: Lockheed R6O/R6V Constitution (Naval Fighers No. 83) by Steve Ginter. Ginter Books, 2009.

29 April 2016

The American V-1 Program 1944-1950

Beginning in 1942, Allied intelligence began a systematic analysis of the Fiesler Fi 103 flying bomb better known as the V-1. Analysis of crashed test articles combined with photoreconnaissance and intelligence collected by agents within occupied Europe led the United States in particular to restart its flying bomb programs in 1943 that had laid dormant for the most of the Second World War on account of what was felt to be beyond the current state of the art. In 1944, Northrop was contracted to begin development of the first US flying bomb, designated the JB-1. Running parallel to the Northrop effort was the reverse-engineering of the V-1 using 2,500 lbs of salvaged V-1 parts that had been provided by Great Britain. The parts arrived at Wright-Patterson Field in Dayton, Ohio, on 13 July 1944 and the US Army Air Forces directed the engineering staff there to build 13 copies of the V-1. Quite remarkably, the USAAF technical staff completed the first copy in just three weeks! To put the scope of the success of the Allied intelligence effort and the work the Wright-Patterson Field team into perspective, the first German V-1s struck Britain on 12-13 June 1944. By the end of the following month, the USAAF had its first copy of the V-1 and they had test fired the reverse-engineered pulse jet engine. A memo from the technical team responsible to General Henry Arnold, head of the USAAF, recommended mass production at the earliest opportunity- however, General Arnold and his advisors were well aware of the V-1's inaccuracy and despite reservations that production of an American V-1 would divert crucial wartime resources and manpower from battle-proven weapons, it was felt that if the guidance of the V-1 could be improved, an American version might be useful. 

The Republic-Ford JB-2 differed from the V-1 in minor details
(USAF/Wikipedia)
Republic Aviation was tasked with producing the American V-1 which was designated JB-2 with the first of the thirteen USAAF copies arriving on 8 September 1944 from Wright-Patterson Field. The USAAF ordered 1,000 JB-2s from Republic. The Ford Motor Company was tasked with producing the JB-2's pulse jet engine which was designated the PJ31. With Republic's resources nearly all committed to the production of the P-47 Thunderbolt, the company subcontracted the airframe assembly to Willys-Overland, the same company that built the Jeep. With Ford responsible for engine production, the Jack & Heintz Company of Cleveland which had been building aircraft electrical components and autopilots as a subcontractor was given responsibility for the JB-2's control system. Alloy Products of Wisconsin was given responsibility for the fuel tanks and pressure vessels used in the JB-2 while the Northrop was contracted for the JB-2's launch sled. The booster rockets that actually propelled the JB-2 off the ground were contracted to Monsanto. 

By the end of September 1944, the USAAF revised its initial order for 1,000 JB-2s to 1,000 JB-2s *per* month with a target goal to reach that rate by April 1945. The first JB-2 launch took place at Eglin Airfield in Florida on 12 October 1944- just three months had elapsed since start of the German V-1 campaign against London and the first American copy had made its first flight! Flight testing was also carried out at Wendover Field in Utah at the same time that the B-29 Superfortress unit that dropped the atomic bombs, the 509th Composite Group, was a tenant at Wendover training for their special mission. The flight tests didn't go too smoothy- by the first week of December, there were two successful flights out of ten launches. 

JB-2 air launch from a B-17 at Eglin Army Air Field in 1944
(USAF/Wikipedia)
Northrop's own flying bomb design, the JB-1, made its first launch in December 1944 but crashed after launch. (The JB-1 will be the subject of its own later article here at Tails Through Time.) With the the early failures of the JB-1 and problems with its jet powerplant, the USAAF decided to continue with the development of the Northrop design but production and operational priority went to the JB-2. Despite issues with accuracy in the flight tests at Eglin and Wendover, the USAAF leadership pushed for an increased production rate for the JB-2 to at least 3,000 per month. On 14 January 1945, General Arnold ordered another 75,000 JB-2s with the ability to launch 100 per day by September and 500 per day by January 1946 in anticipate of the invasion of Japan. On the next day, the JB-2 program got the same priority that was given to the B-29 Superfortress program. 

Despite the enthusiasm from the USAAF leadership, theater and operational commanders were skeptical of the JB-2. The generally poor European weather that was interfering with the strategic bombing campaign, however, offered perhaps some utility for the JB-2 as it wasn't dependent on clear weather- a view supported by Sir Trafford Leigh-Mallory, the head of the Royal Air Force and commander-in-chief of Allied air forces for the Normandy invasion as well as General Carl Spaatz, head of US Strategic Air Forces Europe. Spaatz, however, was a bit more measured in his support for the employment of the JB-2. He felt that it was more a harassment weapon that could be used when bad weather precluded a strategic bombing mission and outlined his planned use at 300 JB-2s per day only 10 days out of the month. But General Spaatz was very specific that operational employment of the JB-2 could not interfere with heavy bomber operations and he personally expressed concerns to General Arnold regarding the JB-2's cost-effectiveness given its inaccuracy. 

The JB-2 flight test program centered primarily on improving the weapon's accuracy. The first successful flights in the fall of 1944 showed an average error of eight miles at a range of just over 120 miles, not much better than what the Germans were averaging in their own V-1 campaign. The next step by the USAAF was to install radio guidance control in the JB-2. Using a radar beacon and remote control, it was thought the JB-2's accuracy could be improved. However, continued flight tests showed in 20 flight tests with the new guidance system, the JB-2's average error was no better than it was before with preset controls. Things did get better though- by war's end, the JB-2 with preset controls was averaging 5 miles error over a range of 150 miles and 1/4 mile error over a range of 100 miles with radio guidance. 

The biggest stumbling block to the operational deployment of the JB-2 in Europe in 1945, believe it or not, was logistical. The sheer numbers of JB-2s needed competed with other munitions production and it was estimated by some in the War Department that just transporting the JB-2 and its associated equipment to Europe would take up nearly 25% of Allied shipping capacity in the Atlantic. Brief consideration was given to moving JB-2 production to Europe, but there simply wasn't the production capacity anywhere else but the United States to produce the numbers of JB-2s planners envisioned using. 

With the end of the war in Europe, JB-2 production numbers remained in flux as planners debated what was needed for the planned invasion of Japan. By this point, however, the production and logistical concerns for the mass deployment of the JB-2 had exhausted the initial enthusiasm for the weapon. Production was halted initially at the end of January 1945 but then reinstated at a lower rate. By the time of the Japanese surrender, 1,385 JB-2s had been built when production was terminated.

Concurrent with the USAAF testing, the US Navy worked on a navalized version of the JB-2 that would have been launched from specially-modified LSTs and escort carriers during the invasion of Japan. Fifty-one JB-2s were requested by the Navy for its own testing program in September 1944 when production was launched. While airborne launches from B-17 Flying Fortresses were done during testing at Eglin Field, the Navy planned to launch JB-2s from Consolidated PB4Y Privateers as well. Navy planners, however, didn't expect operational capability with the JB-2 (which was called the Loon by the Navy) until August or September 1946. The first Navy Loon launch was on 7 January 1946 with the Secretary of the Navy approving the conversion of two submarines for Loon operations in March 1946. Conversion of the USS Cusk (SS-348) began in January 1947. The Cusk entered the history books on 18 February 1947 as the world's first missile submarine when it made its first Loon launch...which ended in failure after only 3.5 miles of flight. The Cusk finally had its first successful launch on 7 March 1947 after five tries. Submarine launch had become the Navy's focus for the Loon program with the USS Carbonero (SS-337) also modified for the program and by 1949 finally carried out a firing from a surface ship, the test ship USS Norton Sound. In March 1950, the Navy terminated in the Loon in favor of the more promising Regulus cruise missile. 

The USS Cusk fires a JB-2 Loon
(US Navy/Wikipedia)
With the US Air Force becoming independent in 1947, the JB-2 program was reactivated in March 1948 at Holloman AFB in New Mexico as part of a program for the development of missile guidance systems and seeker technology. Work using the JB-2 benefitted the later Matador cruise missile program with the JB-2 program winding down by 1949 with test airframes successfully being flown remotely and skid landed for recovery. A joint effort with Eglin AFB also used the JB-2 as a target drone for the development of gunsights. Interestingly "Flakzielgerät 76" was the German cover name for the V-1 during its development which loosely translates as anti-aircraft target device.

Further reading:

British Defenses Against the Summer 1944 V-1 Bombardment
Regulus: The US Navy's First Operational Nuclear Missile
CHECK SIX: Ships Damaged or Sunk by the Yokosuka MXY7 Ohka

Sources: The Evolution of the Cruise Missile: Comprehensive History from the V-1 and V-2 to the Tomahawk and Snark by Kenneth P. Werrell. Air University Press/USAF, 1983, pp 79-85. V-1 Flying Bomb 1942-1952: Hitler's Infamous Doodlebug (New Vanguard No. 106) by Steven J. Zaloga. Osprey Publishing, 2005, pp 39-41.








25 April 2016

CHECK SIX: The USS Wasp (CV-7)

The USS Wasp in 1940
(Wikipedia)
The Wasp (CV-7) was a scaled down Yorktown-class carrier and a product of the Washington Naval Treaty. After the Yorktown and Enterprise were built, the US still had 15,000 tons allowed for an additional carrier under the treaty. Since the Navy wanted as big an air wing as possible on the Wasp despite the ship being about 25% smaller than the Yorktown class, a number of torpedo protection features were omitted from the design that would have protected her stores and machinery spaces. The carrier also had less armor protection topside. Her machinery was less powerful than even the Independence-class CVLs. The Wasp's machinery was capable of 75,000 shaft-horsepower. The Yorktown's power plant could do 120,000 shp, the Essex-class had a power plant capable of 150,000 shp and that of the Independence-class CVLs could do 100,000 shp.

The Wasp had the first deck edge elevator- it was a T-shaped platform to accommodate the tailwheel at the top and the mainwheels on the cross part. Though instead of running vertically on side rails, articulated arms moved the elevator in a semicircular path from the hangar deck to the flight deck. 

The deck edge elevator of the USS Wasp with a Vought SB2U Vindicator
(National Museum of Naval Aviation/Wikipedia)
The Wasp was commissioned on 25 April 1940. Her final sea trials took place on 26 September 1940 and was afterwards assigned to the Atlantic Fleet with the homeport at Norfolk, Virginia. One of her earliest assignments were experiments to see if Army aircraft, in this case Curtiss P-40 Warhawks, could be flown off the carrier. Interestingly while on Neutrality Patrol in the summer of 1941, the Wasp participated in the search for the German cruiser Admiral Hipper. With the declaration of war in December 1941, the Wasp's first tasking was in the Caribbean to intercept any French warships which were feared to be under Vichy control and would attempt a breakout to reach France. With carrier losses in the Pacific after the Battle of Coral Sea and the Battle of Midway reducing the US Pacific fleet to only three carriers, the Wasp was urgently transferred from the Atlantic Fleet to the Pacific Fleet. It was participation in the Guadalcanal campaign with the USS Saratoga and the USS Enterprise that the Wasp would be lost. 

The design omissions to meet Washington Treaty stipulations would prove fatal in 1942 when she was torpedoed during the Guadalcanal campaign by the submarine I-19. Early war inexperience with damage control was also a factor in the Wasp's sinking. I-19 fired six torpedoes- three hit the Wasp in the area of its fuel bunkers and magazines with disastrous effect. The fourth torpedo hit the escorting destroyer USS O'Brien, the fifth and six torpedoes missing. Thirty-five minutes after being hit, Captain Forrest P. Sherman gave the order to abandon ship. She later had to be sunk by one of the escorting destroyers. Of her air wing, 45 aircraft went down with her, but of the 26 aircraft that were airborne at the time of the attack, all but one were recovered aboard the USS Hornet. 193 men died with 366 wounded.

The Wasp ablaze shortly after the three torpedo hits
(Wikipedia)
Further reading: 


24 April 2016

The Grand Daddy of the Bell Helicopter Family: The 1942 Model 30

I had posted an article this past November on how a self-taught engineer, Arthur Young, got Bell Aircraft into the helicopter business. Young had demonstrated to Larry Bell himself the stability and controllability of his model helicopter designs. From my November 2015 article: 
On 3 September 1941, Young arrived at Bell's Buffalo plant and was taken to a hangar where P-39s were prepared for delivery. Bell ordered the personnel in the hanger to stop work and move the P-39s outside to give Young room for his demonstration. Not only did Young fly a successful demonstration for Larry Bell, he also reviewed with Bell films showing his previous design efforts and showed him his notes on the design process he had developed to solve the problems of vertical flight. Bell was enthralled by Arthur Young and wanted to hear Young's ideas on a full-size piloted helicopter design. In a matter of weeks they reached an agreement where Young would come to Buffalo and work for Bell in developing a new helicopter based on his designs. Young assigned his patents to Bell Aircraft and Larry Bell funded the development of two full-sized helicopters. Young wanted two aircraft in case one crashed and Bell insisted that the second prototype be a two-seater so he could go on a ride!

Though Bell had established a $250,000 budget for Arthur Young and the design and fabrication of a full-scale flying helicopter prototype, the demands of the war effort meant that just about anyone and everyone who worked at Bell was assigned to one of the three shifts that were running around the clock building aircraft. Larry Bell was under the impression that Young would produce manufacturing drawings while Young was under the impression that he would design *and* build the helicopter prototypes. Young had successfully argued that plans couldn't be drawn until more was known about vertical flight through experimentation and test flying. The original agreement was clarified and amended to provide for the construction of two prototypes which would be designated the Model 30. Larry Bell, however, not understanding the nature of helicopter flight himself, would only agree to the fabrication of flying prototypes if Young could assure him that if the engine quit, the helicopter wouldn't drop out of the sky, killing its pilot. Young took one of his remote controlled models, attached an egg to it, and with Larry Bell watching, turned off the electric motor and the model autorotated smoothly to the ground without breaking the egg!

The Birthplace of Bell Helicopter in Gardenville, New York
(Bell Helicopter)
It was decided that a work space separate from the main Bell plant in Buffalo was needed and a vacant Chrysler car dealership building in Gardenville was secured for Young's use. However, since Young had to agree to not place additional burdens on Bell's engineering staff, Young did most of the engineering work himself with his assistant, Bart Kelley (who had been working for Young even before Young joined Bell). Skilled tradesmen and a few draftsmen were sent to Gardenville from the Bell plant- at any given point during the three year development program, Young only had 24 to 32 workers at his disposal. Using one of Young's flying models as a pattern which was scaled up six times, the first Model 30 helicopter was designed and fabricated in just six months starting in June 1942 and was named "Genevieve"- the name never caught on, as everyone referred to this helicopter as "Ship 1". 

The single-seat fuselage was made of plywood and welded tubing with magnesium sheet covering the tail boom. The rotor blades (32 feet in diameter) were made of a composite sandwich of balsa and fir wood with a stainless steel leading edge for reinforcement. A 165-horsepower Franklin flat-six piston engine was used as the power plant. Franklin engines were light aircraft engines used in a variety of light aircraft at the time. The engine was mounted vertically under the rotor mast. Since no one at Bell knew how to make a helicopter transmission, one of Arthur Young's model's transmission was scaled up for the Model 30. 

Ship 1 with its original "spider legs"
(Airwar.ru)
Ship 1 was rolled out of the Gardenville facility on 18 December 1942. It initially had four long spidery legs for its early flight test program that began with its maiden flight on 29 December 1942. Since the program didn't have the budget for a test pilot, Arthur Young himself made the first flight! When Bell's chief test pilot, Robert Stanley, wanted to have a go at the Model 30, he over controlled it and crash landed it. As a result, Bell assigned the Model 30 its own test pilot to work with Arthur Young and prevent further mishaps. Easily repaired, the Model 30 prototype continued its flight test program and experimentation which allowed Arthur Young and his small team to refine the rotor head and transmission design while work began on the second helicopter, designated Ship 2. 

In September 1943, the project's test pilot, Floyd Carlson, was attempting the first autorotation landings when Ship 1 landed hard and crashed a second time. Despite having sustained more damage than the first crash, Ship 1 was rebuilt as Ship 1A but Ship 2 was quickly finished and picked up the Model 30 flight test program in the fall of 1943. As had been agreed upon initially between Larry Bell and Arthur Young, Ship 2 was a two seater with an enclosed cabin as opposed to the open single seat cockpit of Ship 1. With a two seat flying prototype, Bell formally notified the company's board of directors that they had a flying helicopter prototype in testing and that it would be Bell Aircraft's goal of getting into the helicopter business in the postwar period. It was around the end of 1943 that Larry Bell got his wish to ride in a helicopter when Floyd Carlson took up for a short hop around Gardenville. The expanding flight test program with Ship 2 made it a local celebrity with locals lining the fences to catch sight of it in flight. On 4 July 1944, the rebuilt Ship 1 as Ship 1A gave a flight demonstration to thousands of spectators at Buffalo Civic Stadium. With two helicopters in the flight test program, it was inevitable that Bell would be asked to fly rescue flights with the Model 30. 

The two seat Ship 2
(Toronto Aviation History)
On 5 January 1945, Bell test pilot Jack Woolams was injured bailing out of an early model P-59 Airacomet jet fighter. Though injured, Woolams walked a mile deep snowdrifts to reach a farm house in Lockport, New York. With the roads in the area closed due to the heavy snowfall several days earlier, Floyd Carlson flew a physician in Ship 2 to the farm house where Woolams was treated, preventing the need for amputation of his frost-bitten feet. On 14 March 1945, Floyd Carlson was asked again to assist with a rescue and he flew Ship 2 to save two fishermen who had been stranded on an ice floe in Lake Erie for 21 hours. He flew out, picked up the first fisherman, brought him to shore and then went back for the second one. Amusingly the fishermen had insisted on bringing the fish they caught with them, but Carlson refused on the grounds there was no room and Ship 2 couldn't handle the extra weight!

Ship 3, the unauthorized helicopter
(Aviastar.org)
In January 1945, Arthur Young and his growing Gardenville helicopter development team decided to build a third Model 30. Though not authorized by contract, they had figured out they had the parts and sufficient funding to proceed, though they did it quietly starting in January 1945 since it was an unauthorized project. It was decided that Ship 3 would be a two-seater like Ship 2, but it would incorporate all the lessons learned in the design, fabrication and flight testing of Ship 1A and Ship 2. It was only when Ship 3 made its first flight on 20 April 1945 that its existence was revealed to Larry Bell and the company's management. While most company managers might have been upset with this sort of activity, the Gardenville team explained that Ship 3 would bring Bell Aircraft much closer to its goal of entering the civilian helicopter market as it embodied all the lessons learned from the past three years. 

To say that Ship 3 would bring Bell Aircraft closer to entering the civilian helicopter market would be an understatement- Ship 3, in effect, was the prototype for Bell's first success in the postwar market for any aircraft design in its portfolio- the iconic Bell Model 47 helicopter. 

But that's a story for a future article here at Tails Through Time! 

Further reading: 

Arthur Young Gets Bell into the Helicopter Business

Sources: The Bell Helicopter Textron Story: Changing the Way the World Flies by David A. Brown. Aerofax Publications, 1995, pp 19-39. "Bell Model 30 Ship 1A Genevieve" at the Smithsonian National Air & Space Museum.

22 April 2016

CHECK SIX: Chikuhei Nakajima and his Aircraft Company


So here's something from the "Persons in Aviation History that Don't Get Enough Attention" Department- this is Chikuhei Nakajima, the founder of the Nakajima Aeroplane Company in Japan. Prior to World War II, there were three dominant aircraft manufacturers in Japan- Mitsubishi, Kawasaki, and Nakajima. Both Mitsubishi and Kawasaki were capitalized from their founding by government contracts for military aircraft. Nakajima, on the other hand, was the only major Japanese aircraft company of the time that not only was independent of any other industry (both Mitsubishi and Kawasaki were divisions of per-exisiting industrial corporations), it also was privately capitalized on account of its success with flying its aircraft on air mail routes within Japan. 

Nakajima was a former naval officer with a background in engineering. While he was still in the Navy, in 1912 he spent time in the United States as a student and observer of naval aviation. He spent time studying aircraft manufacturing with Curtiss Aircraft and even learned to fly during his time with the company. When he returned to Japan, he left the Imperial Japanese Navy and started Nakajima Aircraft in December 1917. His business connections helped him raise capital- while Mitsubishi and Kawasaki's aircraft manufacturing was funded by military orders, Nakajima focused on civilian designs that could fly air mail routes in Japan. By 1924, Nakajima was also designing and building his own aircraft engines. In 1931 he retired with his younger brother taking over the company. 

By the end of the war, only Mitsubishi had built more aircraft for the Japanese war effort than Nakajima. By the terms of the surrender agreement and subsequent military occupation of Japan postwar, aircraft companies were forbidden from aircraft development and production. This wasn't so bad for companies like Mitsubishi and Kawasaki which were diversified. Nakajima had to be dissolved, but many of its managers and engineers stayed together in smaller ventures until 1950 when they formed Fuji Heavy Industries. 

The Fuji T-1 jet trainer was Japan's first indigenous jet aircraft following World War 2 when aircraft production was allowed to resume. Fuji builds trainer aircraft for the JASDF and is a subcontractor for several US aerospace companies, but you all might know Fuji more from their automobile division, Subaru. Many of the Nakajima engineers who couldn't work in aviation after the war turned their attention to Japan's then-fledgling automobile industry. Subaru has been such an important part of Fuji Heavy Industries that the Subaru logo in 2003 became the official logo for Fuji itself.

Further reading: 

(Photo: Wikipedia)

19 April 2016

Nakajima's Demon: The Ki-44 Shoki

Throughout World War 2 the standard practice of all of the major powers both Allied and Axis in introducing a new combat aircraft into operational use was that use in combat followed an extensive flight test and pre-production development period. One of rare exceptions to this established practice came with the Nakajima Ki-44 which was christened "Shoki" (Demon) by its pilots. And it wasn't on account of its performance against Allied aircraft- the first pilots to fly the Shoki in combat gave it that name out of disdain for an aircraft that represented a new philosophy in fighter aircraft for the Imperial Japanese Army Air Force.

The Nakajima Ki-44 Shoki's Allied code name was "Tojo"
(San Diego Air and Space Museum Collection)
Until the Ki-44 Shoki (codenamed "Tojo" by the Allies) came along, the prevailing wisdom in Japanese fighter aircraft design was to put maneuverability as the prime design objective- all other considerations were secondary, which to quite an extent explained the relative lack of significant armor protection for fighter pilots, as that would have added weight to the aircraft and adversely impacted maneuverability.

Nakajima had been exploring the ideas of trading off maneuverability for increased speed as far back as the mid-1930s after the experience of the brief border war with the Soviets in which the Polikarpov I-16 savaged the IJAAF by using its superior speed and diving abilities to avoid close combat with the more maneuverable Japanese fighters and conduct hit-and-run attacks. Based on the experience, Nakajima's engineers contracted the services of two French engineers from the Dewointine aircraft company to develop the Ki-12 experimental fighter that in 1935 was more modern and faster than anything else the IJAAF was fielding but it remained experimental as it was deemed too radical for the established fighter design philosophy of the day.

The lead engineer at Nakajima just prior to the outbreak of the Second World War was Professor Hideo Itokawa (who later would become the father of the post-war Japanese space program and have an asteroid named for him in honor of his contributions to space science) revisited the ideas behind the Ki-12 experimental fighter by using a short-span wing which would make for a faster fighter that if highly-loaded, could also be a stable gun platform at high speed. His work is what resulted in the Ki-44 Shoki- a powerful radial engine but a comparatively stubby wing with much higher wing loading that other Japanese fighters.

By 1940 there was a greater willingness in the IJAAF for new ideas and it was decided by the Japanese High Command that the Ki-44 Shoki prototypes would be combat tested before going into production. On 15 September 1941 the IJAAF created an evaluation squadron called the 47th Dokuritsu Hiko Chutai (Independent Air Squadron) equipped with the seven prototype Shoki fighters that were quite literally handbuilt by Nakajima. The initial plans were to combat test the Shoki prototypes in China, but with Japan's declaration of war in December on the Allies, the so-called "Kingfisher" Chutai and its seven prototypes were sent to Malaya for use against the British. The Shokis ranged across the peninsula as the invading Japanese forces pushed the British southward to Singapore, scoring victory after victory on hapless British fighters.

By early 1942, Nakajima began work on 40 pre-production Shokis which had improved armament and other modifications such as a combat flap that was a modified Fowler flap that could be extended rearward with little deflection to improve the lift from the Shoki's stubby wings. As production kinks were being worked out, the Doolittle Raid in May 1942 laid bare the vulnerability to the home islands to Allied air attack and the 47th Chutai was recalled from Malaya for home defense duties where its speed and rate of climb made it a natural bomber interceptor. The last pre-production Ki-44 Shoki was delivered in October 1942 and by the end of 1942, the Imperial Japanese Army Air Force formally accepted the Shoki for operational use- after the prototypes had been in combat for nearly a year!

The Shoki's performance led it to be used primarily in the defense of the Home Islands
(Hasegawa)
In the fall of 1944 the last of the 1,225 Ki-44 Shoki fighters was delivered to a home defense unit. By that point in the war, the Shoki was used primarily with reasonable success against the B-29 Superfortresses that were ranging all across the home islands. After the war, the Nationalist Chinese operated the Shoki against the Communists, who themselves had their own Shoki squadrons which were flown by Japanese mercenary pilots. The last Shokis used by the People's Liberation Army Air Force were retired in the early 1950s. No Shokis survived to this day, but a college in Xian, China, has a wing center section. 

Further reading:


Source: Air Enthusiast, Volume 3, Number 1 (July 1972), "Nakajima Demonology: The Story of the Shoki" by William Green, managing editor, Gordon Swanborough, editor. Pilot Press Ltd, 1972, p17-25.

14 April 2016

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: 


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.

12 April 2016

CHECK SIX: Ships Sunk or Damaged by the Yokosuka MXY7 Ohka

Hasegawa model kit box art showing a G4M releasing an Ohka
(Hasegawa Models)
The Yokosuka MXY7 Ohka ("Cherry Blossom") kamikaze flying bomb was conceived by Ensign Mitsuo Ohta of the 405th Kokutai of the Imperial Japanese Navy. He was considering how to overcome the dense anti-aircraft defenses of Allied warships. His design solution, aided by students from the University of Tokyo, was for a rocket propelled kamikaze aircraft that would be flying too fast in its terminal approach to the target to be shot down. He submitted his ideas to the IJN for consideration and his proposals were refined further by engineers at the IJN's Yokosuka Naval Air Technical Arsenal which resulted in the MXY7 design which was essentially an anti shipping missile with a 2600 lb warhead with a kamikaze pilot as its guidance system. 

The Ohka had three rocket engines which could be ignited at once or in sequence. Dropped by the Mitsubishi G4M "Betty", the Ohka had a range of approximately 23 miles and had a terminal approach speed between 580-620 mph, significantly faster than piston engined kamikazes. 

The Yokosuka arsenal would build 155 Ohkas while the Kamisagura Air Arsenal would built over 600 Ohkas. It was planned to debut the Ohkas at the Battle of Leyte Gulf, but the ships transporting the Ohkas to the Philippines were sunk enroute. The Ohka's operational debut would be in the Battle of Okinawa with mixed results:

12 April 1945: USS Mannert L. Abele, destroyer, sunk by one, possibly two Ohkas.
12 April 1945: USS Jeffers, a destroyer converted to a minesweeper, damaged.
12 April 1945: USS Stanly, a destroyer, damaged.
4 May 1945: USS Gayety, a minesweeper, damaged.
4 May 1945: USS Shea, a light destroyer coverted to a minelayer, damaged.
11 May 1945: USS Hugh W. Hadley, a destroyer, damaged.

Interestingly, the captain of a support vessel who witnessed the sinking of the USS Mannert L. Abele had this to say: "It is difficult to say what it was that hit the DD 733. This officer personally saw what appeared to be two (2) planes orbiting in a northerly direction from the DD 733, and then suddenly, what appeared to be, one plane, accelerated at a terrific rate, too fast for us to fire at. This plane dove at an angle of approximately 30 degrees, starting at about four miles [7.5 km] away. Since we had no air search radar, the above statements are merely my own conclusions."

That captain's report was the first to indicate that the Ohka was operational. 

Further reading:


09 April 2016

The WW1 French Fighter That Got More Fame Than It Deserved: The Nieuport 28

Aviation author Peter Bowers once said of the Nieuport 28 biplane fighter of the First World War "The French Nieuport 28....is unique in aviation history for having achieved a considerable degree of fame that it didn't really deserve." The penultimate Nieuport biplane fighter design was rejected by the French for front line service and that might well have been the end of the story for not just the aircraft but the Nieuport company as well had it not been for the American Expeditionary Force's need for a fighter aircraft as the better SPAD biplane's production was devoted to filling the needs of the French Air Service. Since it was available, it would be the Nieuport 28's claim to fame to be the first combat aircraft to wear American colors into the First World War. 
This N.28 wears the "kicking mule" emblem of the 95th Aero Squadron. The kicking mule is still used by the 95th Reconnaissance Squadron that flies the Rivet Joint.
(USAF Museum)
The story of the Nieuport 28 (N.28C-1 was its company designation, but for brevity reasons I'll just refer to it here on out as the N.28) begins with the formation of an aircraft company by Edouard and Charles Nieuport in 1909, at first devoted to producing aircraft components like engine ignition systems. Both brothers were pilots and began working on their own monoplane designs which were contemporaries of the more famous Blériot XI design that made the first air crossing of the English Channel on 25 July 1909. After a series of prototype designs, the Nieuport brothers reorganized the company in 1911 to focus more on their own aircraft designs as Nieuport et Deplante. Edouard was killed while flying that year and with the help of aviation-minded investors, the company was renamed Société Anonyme des Établissements Nieuport with the remaining brother, Charles, heading the company before his untimely demise also while flying later that year. Swiss engineer Franz Schneider, who would become more famous for his German designs in the First World War, briefly held the post of chief designer at Nieuport until he left for Germany in 1913. French engineer Gustave Delage took over in January 1914 and began work on a sesquiplane racer- not a true biplane as the lower wing was much narrower than the top wing. For lightness, Delage used only a single spar in each wing and used a "V" brace for the wing struts, the apex of the "V" being on the lower "half" wing. By the time the First World War had broken out, Delage's racing aircraft design became the Nieuport 10 fighter which in turn was developed into the faster Nieuport 12 fighter. The V-strut and sesquiplane layout would be the pattern of a series of further developments of the Nieuport fighter over the course of the war. By 1917, the current design was the Nieuport 17- though light and maneuverable, it couldn't deal with the latest crop of German fighters as it was underarmed (it only had a single machine gun when twin guns were pretty much the air combat standard by that point) and the single spar sesquiplane structure wasn't strong enough for extended air combat with the latest German designs. It was painfully obvious that Gustave Delage's design layout had reached its limits. 

With the French Air Service considering the SPAD S.VII fighter, Delage set about to create a better Nieuport fighter and broke with his long-standing design tradition by adopting a true biplane layout with conventional two spar wings and a twin machine gun armament with the Nieuport 28. With a longer fuselage but keeping the same cross section, the N.28 looked sleeker than previous Nieuport designs. Both the upper and lower wings now had two spars for strength and the chord of the lower wing was slightly less than that of the upper wing with Delage abandoning his favored sesquiplane layout. In contrast to the angular wing tips of his previous designs, the N.28 had rounded elliptical wingtips with conventional two strut wing braces attached to the spars, again, breaking with the V-strut configuration of his past designs (which were sometimes referred to as "V-Strutters"). Because of the narrowness of the fuselage, the twin Vickers 0.303 machine guns were offset- one left of center ahead of the pilot and the other nearly on left fuselage side. This was the result of the original N.28 prototype having only a single gun offset to the left ahead of the pilot. The need for a second gun meant that the fuselage was too narrow for two guns side by side ahead of the pilot, the second gun was offset to the left and below of first gun. 

Eddie Rickenbacker and his N.28. Note the offset guns and the Hat-in-the-Ring emblem
still used to this day by the 94th Fighter Squadron which flies F-22s from Langley AFB.
(Wikipedia)
In keeping with past Nieuport designs, a rotary engine was used from either the Gnome or Le Rhone engine manufacturer. To keep the engines lightweight, they lacked carburetors and could not be throttled down- as a result, the N.28 had what was called a "blip switch" on the control stick that would briefly turn off the engine when power needed to be reduced, such as landing. The Le Rhone rotary engines were a bit more flexible and could be throttled between 900 to 1250 rpm, but even at the lowest setting it was still too much power for the N.28, so the "blip switch" was still necessary regardless of the engine type installed. Later engines would feature additional switches that could cut out certain cylinders on the engines to reduce power, but these systems would prove to be continual maintenance headaches. The late model Gnome engines boasted 100 hp which for the N.28 was a lot of power, but to keep engine weight down, the engine cylinders had only a single valve instead of the traditional two valves and as such, were referred to as "Monosoupape" engines which worked not unlike a two stroke engine. Unfortunately this was very wasteful when it come to fuel consumption and incompletely burned fuel posted a constant engine fire hazard for N.28 pilots. 

While the engine issues alone might have been enough cause for the French Air Service to reject the N.28, the performance gains offered were eclipsed by the SPAD S.XIII which became the standard French fighter of the period. That might have been the end of the Nieuport story at that point had it not been for the arrival of the American Expeditionary Force in France. Lacking a suitable fighter aircraft of their own, the Americans turned to the French for the SPAD S.XIII, but all of SPAD's production was committed to French needs and none were available for the AEF. The French offered the N.28 which wasn't ideal but it was better than nothing and Nieuport would build 297 N.28s for the AEF. 

The introduction into service was lackluster at best. The First Pursuit Group assigned the N.28 to four of its squadrons- the 27th, 94th, 95th, and 147th Aero Squadrons. The 95th AS arrived first to the front in February 1918, but the N.28s were delivered without guns! To boost morale and show that that the Americans were ready for action, Major Raoul Lufbery, a veteran of the Lafayette Escadrille of American volunteers, led unarmed patrols over the front lines the following month. It was an inauspicious start to American air combat operations that the first fighters in action lacked armament. On 14 April 1918, the 94th's sister squadron, the 95th Aero Squadron, made its first armed patrol with three N.28s- with the flight lead aborting due to weather, the other two pilots, Lt. Reed Chambers and Lt. Eddie Rickenbacker, decided to press on with their patrol. Returning to the airfield, two German fighters were overhead, apparently lost above the fog. The second patrol launched with Lt. Alan Winslow and Lt. Douglas Campbell and they downed the two Germans, Winslow scoring the first victory for the AEF and Campbell (soon to become the first American ace) getting credit for the second German by forcing it to crash land.

In the weeks of air combat that followed, the Americans found the N.28 had other short comings besides its troublesome rotary engine. During extended dives, the upper wings tended to shed their fabric covering, often taking the wing ribs forward of the forward wing spar with it. Several American pilots were lost due to the wing failures. Even Eddie Rickenbacker nursed home a crippled N.28 when he lost most of his upper wing's fabric. By the time Nieuport had a fix for the problem, adequate SPAD S.XIIIs became available and the Americans quickly converted to the superior SPAD fighter in July 1918. After the last N.28s were built for the AEF squadrons, Nieuport switched over to license production of SPAD fighters in an ironic twist. By August 1918, the last N.28s were phased out from the AEF in favor of the SPAD. 

Despite the shortcomings of the N.28, the Americans maintained a favorable win-to-loss ratio, the most appreciated quality of the N.28 being its maneuverability. The kill ratio was about 3:1, respectable given the shortcomings of the N.28 and the relative inexperience of the American pilots early on. By the time the four squadrons had converted to the SPAD, the kill ratio had slipped to 1:1 on account of there being more veteran German pilots in combat than earlier in the N.28's combat career. 
An N.28 flies off the turret platform of either the USS Oklahoma or USS Pennsylvania
(US Navy)
Following the First World War, about 50 N.28s that did not see combat service over France were shipped to the United States and used by the US Navy as gunnery observation aircraft. Small fly-off platforms were built atop some battleship turrets and the light weight and rapid acceleration of the N.28 allowed them to be operated off these platforms. Flotation gear and hydrovanes were fitted that allowed the N.28s to be recovered from water landings. 

Further reading: 


Sources: Profile Publications No. 79: The Nieuport N.28C-1 by Peter Bowers. Profile Publications, 1966. National Museum of the US Air Force, Wikipedia. 

07 April 2016

CHECK SIX: Trans World Airlines Goes All-Jet


As the sun rose on 7 April 1967, history was made as TWA became first US airline to go all pure-jet, having retired its Constellations and Starliners the night prior. The last TWA passenger Connie service was Flight 249 JFK-Philadelphia-Pittsburgh-Columbus-Louisville-St. Louis. The next day the last one flew to storage in Kansas City where there were 35 other Super Constellations and Starliners awaiting their fate. The night of 6 April, ground service crews put a booklet in all the seat back pockets of the TWA passenger aircraft titled "Props Are For Boats". 

The introduction of the Boeing 727 and Douglas DC-9 accelerated the Constellation retirement which by the 1960s were relegated to short haul domestic routes and some cargo flying. Two Connies soldiered on after 7 April on cargo-only duties, though. From the introduction of the Lockheed Constellation with TWA's dramatic 1944 delivery flight to Washington flown by Howard Hughes to its retirement to the 1967 retirement from passenger service, the Constellation family served TWA for 23 years with over 140 examples. 

Within two years, by 1969, Trans World Airlines had surpassed the iconic Pan American in the number of passengers carried across the Atlantic. 

Further reading: 


(Photo: FlyerTalk Forums)