By Tommy H. Thomason

Monday, June 27, 2011

Scooter!

It took longer than we hoped, but Scooter! is in the last stages of the publishing process and should be available in the fall. This is the final cover:

It is being published by Crecy Publications in England (Home Page), distributed by Specialty Press (Home Page) in the United States and available for advance order from Amazon, HERE.

See HERE for an example illustration that I posted a year ago.

Sunday, June 19, 2011

A Brief, F4U Corsair-oriented History of Navy Color Schemes and Markings

One of the useful aspects of the Vought F4U Corsair's long career is that it can be used to illustrate three decades of U.S. Navy color schemes and markings. With the exception of two schemes, one arguably and the other definitely experimental, it lasted from the "yellow" wings of biplanes of the 1930s through to the change to gull gray and white in the mid 1950s.

n.b. Federal Standard 595 was first issued in March 1956 to provide a reference for "Colors Used in Government Procurement." The colors are identified by five-digit numbers but no names. Before that, there was Federal Specification TT-C-595 issued in January 1950 that identified colors by four-digit numbers. It was preceded by  an Army/Navy Aeronautics Bulletins that identified colors by three digit numbers and names. For some, this will be a gross oversimplification of aircraft color specification history but it's not my specialty.

The XF4U-1 flew for the first time on 29 May 1940. In conformance with the exterior color scheme at the time, metal surfaces were painted with aluminized lacquer and fabric surfaces were finished with alumininized dope except for the upper surface of the wings (including the ailerons), which was painted Orange Yellow so an airplane could be easily spotted if ditched in the ocean. (It would float because like most Navy airplanes of the era, it was equipped with flotation bags in the wing.)
Note that the national insignia is a blue circle with a white star encompassing a red circle and that the propeller tip has bands of blue, yellow, and red.

The first scheme that the F4U missed (the first production airplane did not fly until mid 1942 and the prototype doesn't appear to have been repainted) was an overall Light Gray scheme with white markings that marked the prewar change to low visibility in early 1941 as illustrated by this Grumman F4F Wildcat. It also added the national insignia to the sides of the fuselage and removed it from the upper right and lower left wings.

The single shade of gray approach was short-lived and replaced with a Blue Grey over Light Grey scheme for carrier-based airplanes on 20 August 1941. On 5 January 1942, the national insignia was reinstated on the upper right and lower left wings.

Note that the red centers have been removed from the national insignia as of 15 May 1942 in order to avoid confusion with the Japanese red rising-sun markings. (The original scheme, which did not appear on the first production Corsairs, also had red and white rudder stripes that somewhat detracted from the camouflage effect and were removed by the same directive. For more details, see http://tailspintopics.blogspot.com/2012/12/early-world-war-ii-usn-paint-and.html)

In January 1943, the U.S. Navy released a specification that replaced the simple Blue Gray over Light Gray camouflage scheme scheme with a complex one that employed counter-shading and counter-shadowing. Four colors were used: Semigloss Sea Blue on upper surfaces, non-specular Sea Blue on the wing leading edges, non-specular Intermediate Blue Sides, and non-specular Insignia White on the lower surfaces. Four-place national insignia were again decreed on 1 February 1943 in order to further minimize the likelihood of confusion with Japanese six-place markings.

It took some time for the Navy to repaint delivered aircraft and probably a month or more for the contractors to develop and switch over to color schemes in accordance with the specification. For example, VF-17, which was working up for combat, was still flying Corsairs in two-tone gray scheme with six-place national insignia when carrier qualifying aboard Charger in March 1943.

However, by the time that Bunker Hill was available for shakedown of its air group in July 1943, VF-17 had F4U-1s that had been repainted by the Navy rework/repair facility at Norfolk, Virginia in their version of the new multi-color scheme. (Click HERE for background on it.)
(National Archives 80-G-205087 via Jim Sullivan)

The addition of white bars with a red surround of the national insignia was decreed on 28 June 1943. At least one VF-17 F4U-1 received the change in time to participate in the pilot qualifications and proficiency operations on Bunker Hill in July.

 In August, VF-17 reequipped with factory new (and factory painted) F4U-1As for their departure on Bunker Hill to the Pacific. In September 1943 the red surround was ordered to be replaced by blue, again due to reduce the potential for confusion with the Japanese markings. (It had already been deleted in the Pacific by an edict on 31 July 1943.) Note the difference in demarcation between the upper and side colors on the repainted airplanes above and this one.
This VF-17 Corsair, BuNo 17640, is marked with 1 and "Big Hog" for the squadron commander, Tom Blackburn, who is fourth from the left. (The dark patches behind the "1" are reportedly repairs of bullet holes made when one of his pilots mistook his airplane for a Japanese fighter.)

The complex multi-color scheme was eventually replaced by an overall gloss Sea Blue one by a directive issued on 26 June 1944.
(F4U-1D on Essex July 1945 via Jim Sullivan)

This provided a direct comparison of the Sea Blue and Insignia Blue, although neither may be accurately represented here.


It was eventually suggested, probably by Grumman, that the Insignia Blue surround of the national insignia was redundant and should be eliminated on all-blue airplanes. It was reportedly deleted well before the official authorization to do so was issued in June 1946. A red bar was added in January 1947 to reinstate all the colors of the U.S. flag.

Although no Corsairs were involved in the experimental (and again short-lived) unpainted approach of the early 1950s (click HERE for a brief discussion), there was an F4U-1A created from various wrecked Corsairs by Service Squadron 11 of Marine Aircraft Group 11 based at Espiritu Santos (Vanuatu). However, it appears to be not unpainted but instead have been given an aluminum paint finish. "Sally" was marked on the cowling.
 (Photo provided by Jim Sullivan.)

The Corsair lasted long enough in service, as the AU-1 attack version, to be repainted light gull gray (36440) and white in accordance with the change introduced on 23 February 1955. This one was assigned to Aircraft Engineer Squadron-12 at Quantico, Virginia, circa 1957, to provide training for air-to-ground controllers.

New soft-cover Corsair books well worth your consideration have been published recently: Jim Sullivan has completely rewritten and re-illustrated his F4U Corsair In Action published by  Squadron/Signal Publications. Is is a very good summary of the various versions with many previously unpublished photos.

Rafe Morrissey and Joe Hegedus have authored The Vought F4U Corsair: A Comprehensive Guide, SAM Publications. As you might guess from the title, it provides more detail (and more than twice as many pages) as Jim's monograph, including coverage of the kits and decals that had been produced at the book's publication.

Saturday, June 11, 2011

The Navy and Liquid-Cooled Engines

Although the Navy effectively ended deployments of airplanes powered by a liquid-cooled engine in the late 1920s, that wasn’t the end of its interest and involvement in the technology. Its racers were powered by liquid-cooled engines up through 1930. The Navy funded development of the Wright H-2120 engine from 1933 to 1936 (click HERE). In 1938, the Navy’s Bureau of Aeronautics included the Allison-powered FL-1 Airabonita in its competition for a new high-performance fighter.*

 In 1940, the Navy began funding the development of Lycoming’s 2,200 hp H-2470 engine and in June 1941, BuAer contracted with Curtiss for the F14C to be powered by that engine. Pratt & Whitney’s even bigger H-3730 also received Navy funding for a time

At some point in World War II, the Navy acquired an Allison-powered early  P-51, 41-37426, from the Army Air Force.  It was one of a production lot of Mustang Mk 1As that were ordered by the RAF, some of which were taken instead by the Army Air Force. It was assigned BuNo 57987.

None of the post-1930 programs resulted in an operational aircraft—or engine for that matter—but the F14C (which flew with an air-cooled Wright R-3350) was only the penultimate effort. In a 21 March 1944 memorandum to BuAer, the Deputy Chief of Naval Operations (Air), Admiral J. S. McKain, asked for what proved to be the final evaluation of the technology:
1. It is requested that the Aviation experimental program be subjected to a study and review.
2. It is considered that experiences of the war and the present trend of design within the Navy may point to the necessity of reefing our sails and. departing on a new tack.
3. The weights and physical measurements of our newer airplanes are increasing rapidly with the result that we shall soon be forced into reduction of carrier complements. To obtain increased performance the natural and logical step has been an increase in power. However, the direct result of this has been larger engines presenting greater frontal areas with correspondingly larger fuselages to accommodate them.
4. Possibly we have reached the place in the development of the air-cooled engine where we should sever our many years of allegiance and look to a design of aircraft incorporating liquid cooled in-line power plants.
5. The size and weights of our projected designs is ample evidence of the fact that our engineers must concentrate on smaller and more compact aircraft with which to do the job at hand. If the liquid cooled in line engine represents the step necessary to achieve the results, we should then be spending some of our time and money on development of that article.

That direction proved controversial within BuAer, but it was not without supporters. The performance of the North American P-51 Mustang had impressed some. As a result, BuAer agreed to request proposals for a liquid-cooled engine powered fighter, as well as one powered by a combination of a liquid-cooled and jet engines. In July 1944, BuAer Military Requirements stated that the Navy’s next fighter should have a Vmax of at least 425 mph at sea level and 475 mph at a critical altitude of 25,000 feet. It would be able to climb to 30,000 ft. in five minutes. Its combat radius should be 300 miles in the escort version, 75 miles in the interceptor version. Either version should be able to remain in the air for six hours.

In August, Boeing, Grumman, Curtiss, Ryan, and McDonnell all informally declined an informal invitation to propose a liquid-cooled engine powered fighter, either because they sensed that the Navy wasn't serious about liquid-cooled engines or realized that the performance requirements were beyond challenging. In the event, only North American submitted a proposal, in October 1944; Vought responded with a design study that concluded “that other types of power plants were more suitable for future fighters.”

The North American proposal was based on its P-51H, the culmination of its effort to improve on the P-51D, focusing on a better rate of climb and roll. The Army had ordered the P-51H into production in April 1944. It was very similar in appearance to the P-51D but was slightly longer, with an elongated ventral cooling installation, and very different in detail.

The NAA-133 was to be powered by a Merlin V-1650-11 engine planned for the stillborn P-51L. The wing was redesigned to increase the wing area by 10 square feet (an increase in wing chord of about three inches since the wing span was not changed), substitute larger and slotted flaps, and incorporate wing folding. The ailerons were enlarged and hydraulically boosted. The landing gear was strengthened and an arresting hook and catapult hook added. The Mustang’s fuselage fuel tank was deleted and the wing fuel capacity was reduced to 150 gallons. The elimination of the fuselage tank allowed for a smaller horizontal tail while maintaining adequate longitudinal stability. The reduction in internal fuel capacity was to be offset by the addition of 50-gallon tip tanks when required. Here is the North American drawing of the P-51H with the NAA-133 changes shown in red:
(The NAA-133 fin and rudder are depicted with dashed lines although they are as depicted on the relatively crude North American three-view provided to BuAer.)
In November 1944, doubtless as part of this evaluation, a minimally modified P-51D was evaluated aboard Shangri-La by Bob Elder after shore-based trials.

As tested, rudder control power and the tail hook attachment were marginal. Elder stated that the rudder was on the stops at 82 mph in approach configuration and the hook structure strength limit was reached at 90 mph. As a result, he had to approach at 85 mph: “Fortunately the little lady exhibited marvelous speed control characteristics and even though operating at near minimum margins of directional and lateral controllability (limited by torque) wave-offs could be executed by judicious application of power.” He reported that visibility during approach was no problem: “Some of the radial engine fighters of that era, notably the F4U and F6F with cowl flaps open, had even more restricted forward visibility and I simply made a turning approach almost to touch-down as was the practice at the time.”

The November 1944 BuAer report on the North American proposal concluded that the NAA-133 failed to meet the desired performance by a wide margin, which wasn't a big surprise to BuAer's engineers, although it was superior to the F8F-1 and the F2G-1. The tip tank option was judged to be inferior to the use of conventional drop tanks. The engine-related “serious disadvantages… for carrier use” were:
(a) Increased vulnerability inherent in any liquid-cooled arrangement over air-cooled types.
(b) Increased maintenance because of addition of radiators and aftercoolers.
(c) The airplane as presented will possess the poor ditching characteristics of the P-51 series airplanes.
(d) Introduction of liquid cooled type will increase logistic problems, and necessitate an additional training program.

Fortunately, North American had also submitted a proposal, NAA-134, for a jet-powered fighter based on the P-51.
 The Navy ordered it as the FJ-1 as part of its initiative to enter the jet age.

The Air Force’s P-51H flew for the first time on 3 February 1945. However, only 554 were built before production was terminated in November 1945 as part of the draw down following the end of World War II and realization that all future fighters would be jet propelled.

For much, much more on the P-51H (although nothing on the NAA-133) see the excellent monograph by David McLaren published by Steve Ginter (http://www.ginterbooks.com/AIRFORCE/AF209.htm).

For more on the P-51D carrier trials including pictures, see Mustang: The Story of the P-51D Fighter by Robert W. Gruenhagen.

*For more on liquid-cooled versus air-cooled engines and the Bell Aircraft FL-1 Airabonita, see my FL-1 monograph also published by Steve (http://www.ginterbooks.com/NAVAL/NF81.htm).

Most of the above material is derived from the research of Ryan Crierie, who generously shares his hard-won information.

Modelers will find more information on the Seahorses HERE.

Wednesday, June 1, 2011

United States Naval Aviation, 1919-1941

I was very pleased recently when the mailman delivered a copy of United States Naval Aviation, 1919-1941: Aircraft, Airships, and Ships Between the Wars from its publisher for me to review.


This is a large format (8.5” x 11”) soft-cover 352-page book with encyclopedic coverage of the subject. (According to the publisher, the content includes 605 photographs and 40 color profiles.) A brief synopsis of the history of each of the major mission types, e.g. attack, fighter, patrol, etc. is provided ahead of each section describing each aircraft designed for that mission. As near as I can tell, every Navy, Coast Guard, and Marine Corps airplane that flew during that period—however briefly or ignominiously—is represented by a Lloyd Jones three-view drawing, a picture (sometimes two or three), technical specifications, and a description of its development and service career. Even walk-ins, like the Republic NF-1, a navalized P-35, are included, as well as gliders and the OP-1 autogyro. The same coverage is provided for airships and ships, albeit with only a side view instead of a two-view or three-view. Ship coverage includes those only peripherally associated with aviation.

Appendix 1 covers foreign aircraft and airships; Appendix 2 covers racing and experimental aircraft. Only photographs are provided in these appendices. Appendix 3 is the always useful summary of the designation systems for ships and aircraft. Appendix 4 is a listing of the type and quantity of Navy, Coast Guard, and Marine aircraft extant in December 1941. The glossary and index are also comprehensive.

Disappointments are few and more than offset by its usefulness as a one-stop source of information on the ships and aircraft described in the title. The only color included is for a set of profiles of some of the more well-known airplanes. I'd have rather had plan views of the carrier decks, preferably to the same scale. I wish the paper used were a bit higher quality although the reproduction is good enough.

Buyers should also be aware that the rear cover promises a bit more than the book delivers in terms of an in-depth discussion of “naval treaties, fleet tactics, government programs, leadership and organization.” The coverage is not significant in that regard, basically an introduction six-pages long including large photographs, but that does not detract from the book’s value to the reader interested in the aircraft and ships of the period.

The publisher is McFarland and Company, Inc. Their web site is www.mcfarlandpub.com, The phone number to order the book is 800-253-2187. It's also available from Amazon but at no discount from the list price of $45.

McFarland provided me with a review copy but I’d have bought it anyway.