Texaco

One of the problems with basing jet airplanes on aircraft carriers was their lack of endurance. Roughly speaking, compared to a propeller-driven airplane a jet launched carrying more than twice as much fuel and yet had only half the endurance. As a result, carrier operations assumed that when jet airplanes were launched, they were going to be back in less than two hours. If the weather turned bad or the deck became fouled, things got awkward for jet pilots pretty quickly. If there had been any jets aloft in September 1953 during a joint exercise between the U.S. and Royal Canadian Navy's when the carriers involved were beset by fog, they would have all wound up having to ditch. The ability of a propeller-driven airplane to sip fuel eventually resulted in all the airplanes being recovered. For one account, click here.

The Navy initially utilized inflight refueling in 1953 to extend the range of F2H Banshees that were capable of carrying a tactical nuclear weapon but it was soon realized that it could be used to extend the endurance of a jet airplane if required. In September 1955, the Navy announced that all of its fighters in production would be equipped with a probe for refueling in flight. This dictate was extended to all carrier-based jets. Although new designs would have retractable probes, those on existing jets were scabbed-on contraptions that could be retrofitted to ones already delivered. The Douglas F4D Skyrays wound up with a probe mounted on the nose of an external tank.

Douglas developed a "buddy" store that could be carried on a standard pylon for refueling the jets. Its Model D-704 was based on the 400-gallon version of the bomb and tank shape it had developed for low drag. In addition to 300 gallons of fuel, it contained fuel transfer and hydraulic pumps driven by a nose-mounted propeller and a reel that could stream about 40 feet of hose with a drogue on the end. Fuel could be transferred at the rate of 200 gallons per minute.

This is an illustration of the very similar Sargeant-Fletcher refueling pod which replaced the D-704.

The popularity of the AJ Savage, the Navy's first nuclear bomber that could be landed aboard the carrier, increased significantly for Pacific carrier deployments when it was equipped with an inflight refueling capability.

However, the big AJ was still awkward to have on the ship and somewhat of an overkill for the purpose of providing one or two thousand pounds of fuel in extenuating circumstances around the boat. An airplane already in the air group was preferred. At the time, jets were not good candidates for the mission since they couldn't carry much more fuel than they needed for a standard deck cycle.

The tanker of choice in the late 1950s was therefore the AD Skyraider. It was just fast enough to refuel the jets (200 knots indicated was recommended but the AD could go as fast as 300 knots in a descent if necessary and could carry plenty of jet fuel in addition to its internal bag of aviation gasoline that was enough for a two-hour cycle time.

The disparity of speed performance isn't as apparent in the picture above because the F8U Crusader pilot could raise his wing for low speed flight. However, this F3H Demon pilot is hanging in there with only the slats out.

The AD had to be modified for the mission if more than the 300 gallons in the buddy pod were to be transferred. AD-6 BuNo 139744 and subsequent and all AD-7s were delivered from Douglas with the full tanker capability. Some earlier AD-6s and a few AD-4Bs (the nuclear-capable Skyraiders) were retrofitted with it. Two different configurations would be utilized, "basic" (near ship) and extended range. Both involved the use of 400-gallon drop tanks (the AD normally carried 150 or 300-gallon external tanks) that were modified with a fuel boost-pump kit.

In the basic configuration, jet fuel was carried in both 400-gallon drop tanks and the 300-gallon capacity refueling store, for a total of almost 7,500 lbs of giveaway fuel. The AD pilot would remain at a 145-nm station for 30 minutes using only its 380 gallons of internal fuel. (With the maximum amount of jet fuel on board, the AD was just under its maximum gross weight.)

In the extended range configuration, the left drop tank contained jet fuel and the right, aviation gasoline. The additional gasoline allowed the AD pilot to fly considerably farther out and for longer.  However, one or the other configuration had to be selected prior to flight and care taken to insure that the proper fuel was loaded in each tank. While jets could burn just about anything in a pinch (the first jet engines burned aviation gasoline), a piston engine would stop running completely if fed jet fuel, which was basically kerosene.

Thanks to Ed Barthlemes, my go-to guy for Skyraider stuff, for much of the above.

For a follow-on post, see http://thanlont.blogspot.com/2013/12/texaco-redux.html

The First Flight of Vought's XF7U-1 Cutlass

One of the discrepancies that I couldn't resolve before my F7U-1 monograph went to press was the frequently reported first flight date of 29 September 1948 versus a contemporaneous mention of a short flight on 27 September. In my F7U-1 monograph, I wrote "For some reason, (the XF7U-1's first flight on 27 September) only lasted six minutes." In the September 2013 issue of the Smithsonian Air&Space magazine, a letter by a Navy civilian flight test engineer Martin A. Snyder described the flight: "As soon as it lifted off the ground, it started to violently pitch nose up and down. We all were sure that the airplane couldn't fly. However, Baker managed to maintain a semblance of control, came around, and successfully landed. The airplane was towed to the hangar for inspection. We later found out that the longitudinal instability had nothing to do with the aerodynamics. The pitch trim control was a conventional thumb-operated slide switch on top of the control stick, and the switch had been wired backward: When the pilot wanted nose-up trim he got nose-down and vice versa."

I just talked to Martin on the phone and he sounds really sharp, not even allowing for his being 87 years old. I'm sending him a copy of my monograph in hopes that he can provide more information on the early flight test of the Cutlass.

Halcyon Days V

Once upon a time, when I was a preteen, I lived with my mother and stepfather in the Philippine Islands. He was assigned as the Assistant Public Works Officer at Naval Air Station Sangley Point, which was on a small peninsula located on the south side of Manila Bay adjacent to the town of Cavite. The runway had been built in early 1945, following the retaking of the area from the Japanese in World War II. It wasn't a very big air station, with almost 50% being the runway, taxiway, and parking areas...

Cdr T.L. Bigley USNR-TAR

In addition to having a runway, Sangley provided a base for Navy seaplanes that patrolled the area.

Cdr T.L. Bigley USNR-TAR 

Sangley provided tow-target services to ships and airplanes of the Seventh Fleet operating near Manila Bay.

 T.H.Thomason

Another valuable service was providing temporary parking at Sangley's west end for the air group of a carrier when it visited Manila Bay for R&R. This freed up the carrier's deck and hangar for maintenance and cleaning, in addition to providing more room for maintenance on the airplanes themselves, albeit al fresco in most cases.

Cdr G.W. Gregory Jr.

(When we first arrived at Sangley, there were many French Corsairs parked in the west end, having been ferried in from Vietnam following the fall of Dien Bien Phu in early 1954. A French aircraft carrier eventually showed up to take them away.)

Navy aircraft carriers would also offload airplanes at Sangley that were too badly damaged for repair aboard. These would come in by lighter for temporary storage until a ship came by that was headed back to the states.

I spent many happy hours watching the Cougars, Skyraiders, Banshees, etc. taking off and landing since the runway was only a few hundred feet from our house and no one seemed to care if I sat in the grass 50 feet or so off the taxiway. One memorable occasion was when Princeton parked many of its VS-21 S2Fs at Sangley in early 1956 for a week.

I made friends with one of the pilots and got to sit in an S2F with my mother.

Equally memorable was that I got to fly an S2F, a Turbo Firecat conversion with turboprop engines, almost 40 years later courtesy of the great folks at Conair. (See http://www.cascadeaerospace.com/products/Turbo%20Firecat/)

You probably haven't heard of NAS Sangley Point. While my stepfather was stationed there, NAS Cubi Point at Subic Bay was established and Sangley became a Naval Station in accordance with a treaty with the Philippines that stipulated there would only be one Naval Air Station, per se. It continued to be an active and important U.S. Navy base until it was turned over to the Philippine government in 1971.

Although I had been enamored with airplanes since I could remember, the two years at NAS Sangley between 1954 and 1956 (and one of the great airplane movies, The Bridges at Toko-Ri) convinced me that I wanted to be a Naval aviator, even if it did mean dying in a ditch in Korea. That, alas, was not to be because of my poor eyesight but I did the best I could under the circumstances.

Cannon vs. Machine Guns

One of the many interesting presentations at the Joint Fighter Conference held at NAS Patuxent River, MD in October 1944 concerned the Navy’s upcoming transition from the .50-calibre machine gun to the 20 mm cannon for fighter armament. It was given by Commander J.P. Monroe, head of the armament branch of the Bureau of Aeronautics.

A dive-bomber, the SB2C Helldiver, was the first U.S. Navy carrier based airplane to become operational with cannon, two replacing the four .50-caliber machine guns.

There were teething problems but none were serious relative to the perceived benefits of the larger round and firing mechanism. The Navy was also procuring the F4U-1C with four 20 mm cannon (the “C” suffix probably did not stand for cannon armament per se but was simply the next designation change letter; see http://thanlont.blogspot.com/2013/06/navy-aircraft-designation-suffixes.html).

Commander Monroe noted that, from a gun “horsepower” standpoint, one 20 mm cannon was equivalent to three .50-caliber machine guns. “The 20 will go through .75 inch of armor at 500 yards, while the .50 cal will go through only .43.” He also noted that the cannon barrel was not as susceptible to being damaged with long bursts like the machine gun’s.

There were disadvantages, of course. He noted that the time of flight of the 20 mm shell was longer, .75 second for 500 yards as compared to .62 second for a .50 caliber bullet. The 20 mm installation was also heavier, “one half as much ammunition for the same weight.” The standard of 400 rounds of ammunition for each gun (30 seconds) could therefore not be maintained so only 200 rounds of 20 mm ammunition could be provided per gun. Nevertheless, “The 20 is lethal enough to get far more results out of that 200 rounds than the .50 ever will get out of the 400 rounds.”

Only 200 F4U-1Cs were bought and the F4U-4 retained the six .50-caliber armament configuration, primarily due to ongoing reliability problems with the original Hispano-Suiza cannon. However, the problems were corrected so a handful of F4U-4s were produced with cannon as the F4U-4B (the suffix now designating an armament change, not built for the British) and cannon were standard on the F4U-5.

The Navy’s last propeller-driven fighter, the F8F Bearcat, was initially produced with only four .50-caliber machine guns. However, during production of the -1s, the armament was changed to four 20-mm cannon. The change was externally evident by the longer barrels and the bulges required over the chambers. The cannon were standard on the F8F-2 so no B suffix was required.

The Navy’s first jet, the McDonnell FH-1 Phantom, was produced with four .50-caliber machine guns. The North American FJ-1 Fury was delivered with six. However, the Navy's third jet fighter, the Vought F6U Pirate was armed with four 20 mm cannon, as were all subsequent Navy fighters up through the Vought F8U Crusader.

When the Navy procured the North American F-86 Sabre as a carrier-based fighter, it required the substitution of 20 mm cannon in addition to the changes required for operation to and from aircraft carriers. The armament change was evaluated in the one-off XFJ-2B BuNo 133756, the B suffix again denoting an armament change.

Note that the airplane had nothing in common with the two XFJ-2s other than F-86 parts. It was basically an F-86 with four 20 mm cannon, a Navy gun sight, and a modified windscreen.

The Air Force somewhat belatedly realized the need to transition to 20 mm, a change accelerated by combat experience during the Korean War.

The A-12 Avenger II Program: The End is Near

It's hard to believe that it has been more than two years since I last updated the status of the A-12 Avenger II program and its termination is still not yet complete from a financial standpoint. See http://thanlont.blogspot.com/2011/05/12-it-aint-over-until-its-over.html

For a prior post and links to four (!) more on the A-12 in this blog, see http://thanlont.blogspot.com/2011/01/gift-that-keeps-on-giving-final-chapter.html

The program was, of course, canceled back in 1991, but like Jarndyce v. Jarndyce in Dickens' Bleak House, it has lingered on as a lawyer's dream.

However, according to an online Aviation Week note dated 21 May 2013:

In a sign of movement in the epic legal battle over the A-12 Avenger II, the Obama administration is asking Congress to allow the Navy to accept a settlement in the case.

In a letter outlining amendments to the administration’s fiscal 2014 request for appropriations, the Pentagon is seeking legislation that would “authorize the Secretary of the Navy to accept and retain in-kind goods and services in lieu of monetary payment, for the purposes of a settlement of the A-12 aircraft litigation.”

More importantly for aviation history, the A-12 mockup has finally been moved to the Veterans Memorial Air Park in Fort Worth, Texas.

 Bill Spidle Photo

The Air Park is a nice little (and growing) aviation museum north of town and just south of Meacham Field with several aircraft on display outdoors. It's well worth a visit. See http://www.veteransmemorialairpark.com/home1.aspx

The full-scale mockup was displayed at an open house in 1996 at Carswell Air Force Base.

The mockup looks a lot better than I thought it would after more than two decades of storage, mostly outside, and hopefully the museum can refurbish it and provide a suitable venue for its display.

Navy Aircraft Designation Suffixes

Dana Bell has teamed up with Classic Warships to produce a series of Aircraft Pictorials on U.S. Navy Airplanes. Three have been published so far, covering the SB2U, OS2U, and F4F. See http://www.classicwarships.com/aircraft_pictorial/aircraft_pictorial.html

These are affordable, well-researched, copiously illustrated monographs. The production quality is excellent. Dana has spent a lot of time on what I call an Easter egg hunt in the National Archives, among other places, and found pictures, drawings, and information previously unpublished and that sometimes contradicts or expands on what we know about a particular airplane type.

Dana is currently sifting through boxes and boxes of 1940s documentation on the F4U-1 Corsair. One of his discoveries is that the F4U-1A designation of what the Navy called the "raised cabin" Corsair was never officially assigned. (There are more revelations but those will have to wait until this next Aircraft Pictorial is published.)

His assertion has generated some debate. After looking at some of my stuff that dates back to 1943 and 1944, I agree with Dana that the Navy did not officially recognize the raised cabin F4U-1 with a designation change.

In the process, I got interested in the Navy's use of letter suffixes to aircraft designations. As a result, I'm pretty sure that the early (through say, 1942) and subsequent meanings have been inadvertently conflated in a confusing way.  For example, in explanations in books and on line, you'll find that the letter suffix A stands for many different changes. After examining several examples and in particular relying on an explanation in Introduction to Naval Aviation (NavAer-80R-19) published in January 1946, it appears to me that up through about 1942 there were very few letter suffixes that were related to specific applications or capabilities. (One was P for Photographic.) "A" simply meant the first "minor modification not sufficiently important to change the modification number or where the airplane has been diverted to another service or for a special purpose".

It took a while to find an example of a "B" for a second minor modification that substantiated my thesis, which was the Consolidated NY trainer.

The above is an NY-2 modified with leading edge slats that was being evaluated by NACA in 1928. Consolidated Aircraft* won a 1925 Navy competition for a trainer that was then designated NY-1 (N for trainer, Y for Consolidated, no number between the type letter and the manufacturer letter because it was Consolidated's first trainer for the Navy). According to the interweb, the NY-1A was a modification for gunnery training with a machine gun mounted in the rear cockpit and the NY-1B was an NY-1 modified with the bigger wing and more powerful engine of the NY-2.

So in my opinion the suffix A originally didn't actually stand for amphibious (PBY-1A), armament (J2F-2A), target towing (JRF-1A), floats (TBD-1A), single-stage supercharger (F4F-3A), carrier-basing (SOC-3A), etc. It simply distinguished the modified airplane from the baseline one, like a dash number change signified a more significant change.

At some point early in World War II, however, the use of A appears to have acquired a specific connotation, possibly used only to differentiate a Navy airplane built for the Army, e.g. SB2C-1A. "B" similarly became associated with a Navy airplane that was to be provided to the British, as in F4F-4B. As a result, the first minor modification was now recognized with a "C" suffix and the second, with a "D". This led to the TBF-1C (wing guns and more fuel), the TBF-1D (ASB radar), SB2C-1C (cannon), F4U-1C (cannon), F4U-1D (multiple improvements), etc. Note that "C" did not, in this instance, stand for "cannon": it was a coincidence that the first minor change was to cannons. Thinking that D stood for droppable fuel tank in the case of the F4U-1D was even more fanciful; the F4U-1 had provisions for a droppable fuel tank.

Shortly after this philosophy change, however, mission-specific suffixes began to proliferate and the use of a generic suffix progression in alphabetic order beginning with C was abandoned.  One of the early additions was "N" for a "night" fighter (as an indication of the designation system development in progress at the time, the radar-equipped fighter version of the F4U-1 was designated F4U-2; the equivalent F6F-3 modification was the F6F-3N.) But I can't yet say whether a particular suffix used in the mid-1940s was the result of the alphabetical approach or the implementation of specific letters for particular mission capability modifications.  "C" was eventually used to designate a land-based airplane that had been adapted to be carrier capable but it's possible that the SNJ-3C was so designated because it was a first minor modification of this trainer. Similarly, "E" came to mean an electronic modification, but the TBF/M-1E might very well have simply been the third minor change of the Avenger.

Consistency in designations was not a Navy hallmark in any event. For example, the modification of the Douglas Devastator to add floats was designated TBD-1A. A similar evaluation of the Vought Vindicator was designated XSB2U-3...

Another divergence was the designation of successive variations of the North American PBJ, which for all intents and purposes was a US Army Air Forces B-25 Mitchell. Although the Navy did redesignate it as the first Patrol Bomber that they procured from North American (J), the suffix letter for major derivatives was consistent with the Army designations, e.g. the B-25H became the PBJ-1H.

*Consolidated Aircraft was merged with Vultee Aircraft in 1943 to become the  Consolidated Vultee Aircraft Corporation. After the war, the company adopted the brand name Convair. It subsequently was acquired by General Dynamics but as a named division. In 1994, GD eventually sold that portion of the division still based in San Diego to McDonnell Douglas Aircraft and the remainder that had been developing and building airplanes in Fort Worth, Texas to Lockheed.

F8U-3 Redux

I've written a couple of posts on the F8U-3 and a monograph for Steve Ginter.

http://thanlont.blogspot.com/2008/12/f8u-3-best-airplane-navy-didnt-buy.html

http://thanlont.blogspot.com/2010/08/best-f8u-3-monograph-now-available.html

The monograph is pretty good, if I do say so myself, but if in doubt you can read reviews of it on Amazon http://www.amazon.com/dp/0984611401 and then order it if it appeals

Whether or not you have the monograph, this is a pretty good Vought sales pitch for the airplane, emphasizing the fact that a radar operator wasn't necessary for the successful interception of an attack: http://www.texasarchive.org/library/index.php/F8U-3_Weapons_System

Unfortunately, the admirals didn't agree, opting for the two-seat F4H instead...