28 May 2016

CHECK SIX: The F-4 Phantom's F3H Demon Roots

With yesterday being the 58th anniversary of the F-4 Phantom II's maiden flight, here's some interesting trivia. There is actually a continuous line of evolution from the McDonnell F3H Demon to the F-4 Phantom (which was designated F4H when it first flew). This photo is of the full scale mock up of the main missing link that connects the F3H Demon to the F4H Phantom. In 1953, the McDonnell team headed by Herman Barkey was looking at ways of extending the Demon's viability and expanding its versatility. McDonnell had the in house designation F3H-X for the design as it was considered an evolution of the Demon. 

F3H-C "Super Demon": This design was first, it was powered by a single J67 engine. The J67 was to be have been a license-built version of the Rolls Royce Olympus. No J67s were ever built in the US and the Navy wasn't keen on an unproven engine. 

F3H-E: This was different enough from the Demon that it was given the Model 98A designator. It was also powered by the J67 but had a bigger wing than the Demon and had a level stance on the ground instead of the nose-high stance of the Demon.

Full scale mock up of the F3H-G design

F3H-G (Model 98B): This one had twin J65 engines, a license built British Sapphire engine like that used on the Hawker Hunter. It had lateral intakes that looked more like the Phantoms and exhausts that looked also more like the eventual Phantom design. The Navy was attracted to twin engines for safety. The wing was also further enlarged from the F3H-E. It had four 20mm cannon and had an impressive external stores capability. 

F3H-H: This was was the F3H-G but with two of the then-new and promising GE J79 engines. 

Model 98C: Delta winged version of the F3H-G/98B with J65 engines. 

Model 98D: Delta winged version of the F3H-G/98B with J79 engines. 

F3H-J (Model 98E): Similar to the 98C/D, but with an even larger delta wing. 

Model 98F: Recon version of the 98C. 

Tail section of the F3H-G mockup showing the two different engine sizes-
The J79 was on the right side, the J65 was on the left side.
Barkey's team decided the F3H-G/98B was the most promising of the designs and built a full scale mockup, but one side was sized for the J65 engine and the other side sized for the J79 engine. On 19 September 1953 McDonnell submitted the design as an unsolicited proposal to the Navy. Though impressed with the design, the Navy had already ordered the Grumman F11F Tiger and Vought F8U Crusader for its supersonic fighter needs. The Navy, however, encouraged Herman Barkley's team to refine the design to meet an all-weather attack requirement. This design was submitted to the Navy in 1954 and two prototypes were ordered as the AH-1 which had four 20mm cannon and eleven weapons stations. 

F4H full scale mock up showing the originally
planned trapeze launchers for the Sparrow missiles.
The following year the all-weather attack program was canceled and McDonnell was asked to redesign the AH-1 into a two-seat interceptor with a single centerline station for a 600-gallon fuel tank and AIM-7 Sparrow capability. The J65 engine was dropped from contention when the Chief of Naval Operations selected the J79 engine for the new aircraft which would be designated F4H Phantom II. 

And the rest is history! 

Further reading: 

21 May 2016

CHECK SIX: KLM Becomes the First European Airline Postwar to Serve America

21 MAY 1946: Seventy years ago today, KLM Royal Dutch Airlines was the first European airline postwar to launch scheduled services to the United States with the arrival of a KLM Douglas DC-4 at New York Idlewild Airport (today's JFK Airport). The aircraft was PH-TAR "Rotterdam". After the end of the Second World War, KLM's long-haul fleet consisted of former military Douglas C-54 Skymasters, the military transport derivative of the DC-4. To augment this fleet, right after the war, KLM ordered four DC-4s and PH-TAR was one of these four aircraft. It was delivered to KLM on 12 April 1946 and flew the first US services just five weeks later.

PH-TAR "Rotterdam" arrives in New York City
(KLM Royal Dutch Airlines)
This newsreel clip is in Dutch, but the images are wonderful even for us non-Dutch speakers!

Further reading: 

18 May 2016

CHECK SIX: The Douglas DC-7


Douglas launched the DC-7 program at the prodding of C.R. Smith of American Airlines who wanted a competitor to TWA's Lockheed Super Constellations for the first transcontinental nonstop services. American's requirement even called for the same engines as the Super Constellation, the Wright R-3350 Turbo Compound (the DC-6 used the Pratt & Whitney R-2800 Double Wasp) radial. Douglas didn't think there was a market for such an aircraft, but Smith ordered 25 of what would become the DC-7 for $40 million which pretty much covered Douglas' development costs. To save time and make the most of the $40 million, the DC-7 was a stretched DC-6 with Wright R-3350 engines. The DC-7 was slightly faster than the Super Consellation and could under *ideal* conditions (which was rare) do a nonstop transcon in under 8 hours. 

The first variant of the DC-7 was good for transcon runs but was no better than the DC-6 for oceanic routes. That first variant went exclusively to US operators- American (34), United (57), Delta (10), and National (4). American Airlines inaugurated its own nonstop "Mercury Service" DC-7 flights between Los Angeles and New York Idlewild on 29 November 1953. As the DC-7 had a higher cruising speed than the Super Constellation, the eastbound LA-New York run was made easily in 7 hours, 15 minutes (a fact not lost upon American's marketing department, hence the name "Mercury Service"), but the westbound run from New York to LA couldn't be made within 8 hours. Despite over a dozen modifications to the DC-7s made by American's engineers which included tweaks of the Wright R-3350 radial engines to squeeze every bit of horsepower out of the engines, the DC-7s still couldn't beat the prevailing winds. American's pilot union repeatedly pointed this fact out, but C.R. Smith's influence in Washington left the issue unaddressed by federal regulators. In the following year, federal regulators adjusted the time limit to allow the flight to be made legally and American's DC-7s blocked in at 8 hours, 15 minutes on a westbound nonstop.

The next DC-7 variant was the DC-7B which had uprated engines and more fuel tanks in the engine nacelles which made oceanic crossings possible. Pan American launched its own transatlantic services in the summer of 1955 and South African Airways was finally able to fly Johannesburg-London nonstop.

The final DC-7 variant had longer wings and a stretched fuselage, the DC-7C "Seven Seas". The fuel capacity of the Seven Seas allowed full westbound nonstop transatlantic capability, something that the DC-7B couldn't routinely perform. 

There was a DC-7D which would have Rolls-Royce Tyne turboprops (same engine as the Vickers Vanguard) and a swept back vertical fin, but it never made it off the drawing board as Donald Douglas decided jets were the way to go and development of the DC-8 was given priority. 

Further reading: 

(Photos: Vintage Ad Browser, California Classic Forums)

14 May 2016

CHECK SIX: The Rollout of the Boeing 367-80

14 May 1954: The rollout at Boeing's Renton Field facility of the aircraft that would change jet transport, the Boeing 367-80. Bill Boeing was 72 at the time and had long since divested his holdings in the company he founded, but he was present at the rollout of the the Dash 80 and Boeing's wife, Bertha, christened the aircraft with champagne while the Renton High School band played "Wild Blue Yonder", the USAF theme. I always thought this Boeing photo was cool- it's the Boeing president at the time, Bill Allen, showing the 367-80 to Bill Boeing. 

Allen bet the company on Dash 80, investing $16 million of the company's money to gear up for production tooling before having an order from either any airline or the US Air Force. 

But then again, taking a bold risk was something the company did three times undeniably in its history. The first time was in 1934. Boeing president Claire Egdtvedt proceeded with the Boeing 299 without any orders or contracts from the US Army Air Corps for a four engined bomber- the 299 is better known as the B-17 Flying Fortress. When Egdtvedt took his gamble on the 299 prototype, he asked his friend for guidance- who happened to be Bill Allen, who at the time was the company lawyer.

Almost twenty years later Bill Allen found himself in the same position when he launched what become both the KC-135 Stratotanker and the Boeing 707 with the Dash 80 prototype. 

And about 10 years later, Bill Allen was fishing in Puget Sound with Pan American chairman Juan Trippe when Trippe pressed Allen on building a jumbo-sized jetliner- legend has it that Trippe asked Allen "Would you build it if I buy it?" and Allen responded "Would you buy it if I build it?" and by the end of the day, the Boeing 747 was launched on a handshake. According to aviation author Robert Gandt, Allen thought to himself the 747 "would be the perfect swan song if he could step down knowing that he had launched the world’s mightiest ship of the sky. It would secure Boeing’s future well into the century. Or it could ruin Boeing".

Further reading: 

10 May 2016

CHECK SIX: The Vought V-173 "Flying Pancake"

In the 1930s while at Vought, aeronautical engineer Charles Zimmerman advocated a unique discoid aircraft layout that was a form of a lifting body that became known as a “flying pancake”- such an aircraft would have low drag and high structural strength. The Vought V-173 was built as a proof of concept aircraft that first flew 23 November 1942. The large 16-foot props turned opposite each other, driven by Continental A-80 four-cylinder 80-horsepower engines on each side of the cockpit. The props turned in the opposite direction of the wing vortices, in effect nearly canceling them out which resulted in a significant drag reduction. The low aspect ratio wing-fuselage was rigid and generated a lot of lift that made the V-173 very maneuverable and gave it excellent low speed handling characteristics. High-speed, maneuverability and good low speed handling got the US Navy’s attention and Vought got the contract for a fighter version called the XF5U. Though the XF5U never flew (it was five times the weight of the V-173 and would have been an impressive carrier fighter), the V-173 made 190 test flights with its last flight on 31 March 1947. It resided in long term storage with the Smithsonian before it was restored by Vought volunteers here in North Texas and is now on display at the Frontiers of Flight Museum at Love Field. 

Further reading: 

Photo: JP Santiago

09 May 2016

CHECK SIX: The Area Ruling of the Cessna Citation X

If you look closely at the aft fuselage by the engine nacelles of the Cessna Citation X, it’s pinched in quite considerably to conform with supersonic area ruling, the same reason supersonic fighter jets have “coke bottle waist” mid-fuselages- If you were to plot the cross sectional area of an aircraft from nose to tail, the ideal curve on such a graph would be a smooth elliptical curve. But in most aircraft, the wings, tail, or engine nacelles make that curve “bumpy”- so you can take away some fuselage area by the wings. In the Citation X, the fuselage is pinched in to compensate for the engine nacelles increasing the cross-sectional surface area which is what transonic area ruling- if you didn’t there would be a big increase in drag. The pinching also creates a more constant width channel between the nacelle and fuselage- this keeps air from speeding up locally and then slowing down, which would cause it to become turbulent, also increasing drag (that kind of drag is called interference drag). If you’re going to cruise at Mach 0.92, you’ll need every trick in the aerodynamics book!

Further reading: 

Photo: JP Santiago

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
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
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
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
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"
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
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.