Category And Colors

Under para. 5., T. O. 07-1-1 called out Spec. Nos. 98-24105 and 99-2050 for airplanes and lighter-than aircraft, respectively. Spec. 99­2050 will not be covered here as the AAF had no airships and very few balloons of any kind at this time. Interested readers will find full details of this spec, in the author’s work on the Air Service and Air Corps.

Spec. 98-24105-P was the current version of the spec., entitled “Marking for Airplanes and Airplane Parts”, issued on August 11,

1936. It covered very extensive requirements for markings on external and internal surfaces and parts of all airplanes. These included:

(1) Name plate to be placed in each airplane

(2) Serial number of the airplane

(3) Letters and numbers designating the manufacturer of the airplane

(4) Code markings giving a record of the materials used in the finish

(5) Date of manufacture of covered airfoils (fabric covered – author)

(6) Strut numbers

(7) Data card

The Douglas XB-19 was quickly camouflaged al the end of 1941, prior to flying to Wright Field on January 23, 1942. It was to be the largest aircraft ever to be Finished in dark olive drab and neutral gray. (Harry Gann)

Bell Airacobra Mk 1, AH621, in flight, shows how the Sky underneath has been brought too far up on the fuselage sides. (USAF via Gerry R. Markgraf)

Consolidated Model 32 Liberator II was one of 165 to be ordered by the RAF, with RAF serial numbers AL503/667. Ninety two of them were transferred to the Air Corps and used on the first trans-Atlantic transport service. Finished in the standard RAF night bomber scheme of dark green and dark earth on upper surfaces and night (black) on lower surfaces. It carries the Air Corps Ferry Command insignia on the rear fuselage. The USA flags denoted its neutral status. The number “76” on the fin is a shortened form of the RAF serial number, AL576. (USAF)

The following paragraphs cover the main external markings required on all AAF aircraft:

A. Color and style of markings. – Arabic numerals and letters made with black dope or black color-in-oil were to be used. Where black would not provide sufficient contrast, white was to be used.

B. Fuselage Markings – The following technical legend was to be stenciled on the left side of the fuselage, forward of the front cockpit. If the cockpit was in the nose of the fuselage, the markings were to be placed to the rear of the cockpit.

U. S. ARMY – {model designation)

AIR CORPS SERIAL No…………….

Crew Weight….. …..lbs.

The letters and numbers for the first two lines were to be not less than 3/4 inch, nor more than 1 inch high. All other lettering was not to be less than 7/16 inch high, nor more than 1/2 high.

C. Lower Wing Markings – the marking “U. S.ARMY" was to be painted on the lower surface of the lower wing or on the lower surface of the wings of monoplanes. The letters “U. S.” were to be painted on the right wing, and the word “ARMY" was to be painted on the left wing, with the top of the letters toward the leading edge of the wing. These markings were to be centrally located with respect to the wing outline. The letters were to be of the vertical type, 24 inches high and with strokes four inches wide.

No substantial changes in these marking requirements occurred until camouflage was called out for all combat aircraft in Spec. 24114, “Camouflage Finishes for Aircraft”, dated October 22, 1940. Their markings were to conform to Spec. 98-24105-P and amendments, except that the marking “U. S. ARMY” on the under surface of the wing was to be applied with blue, Shade 47 of Bulletin No. 41. All other exterior markings were to be applied with either red, black or blue, Shades 45, 44 and 47 of Bulletin No. 41.

This new release of the markings spec, grew to no less than twelve pages in length. The revisions included those for camouflage markings and were as follows:

All exterior markings on aircraft with camouflage finishes were to be applied with either red, black, or blue, shades Nos. 45,44, and 47 respectively, of Bulletin No. 41, of the same materials as the finish on the airplane.

Lower Wing Markings required that the marking “U. S.ARMY” was to be painted on the lower surface of the lower wing of biplanes or on the lower surface of the wings of monoplanes, except when the airplane was camouflaged, in which case the marking was not to be used. The letters “U. S.” were to be painted on the right wing, and the word “ARMY” on the left wing, with the top of the letters toward the leading edge. These markings were to be centrally located with respect to the wing outline. The letters were to be of the vertical type, 24 inches high and with strokes four inches wide.

Vertical Tail Markings required that each airplane should have a radio call number painted on its vertical tail surfaces. The number was to consist of at least four numbers, to be determined as follows: The first number was to be the last number of the year in which the airplane was manufactured, and the remaining numbers were to consist of the serial number of the air plane, using zero where necessary between the year designated and the serial number to make four numbers.

Example No. 1. – The radio call number of an airplane manufactured in 1942, having serial number 42-5434, was to be

25434.

Example No. 2. – The radio call number of an airplane manufactured in 1942, having serial number 42-7, was to be

2007.

Aradio call number was to be placed on each side of the vertical tail surface. Where more than one vertical surface was used the call number was to appear on the left exposed side of the left hand surface, and the right exposed side of the right surface. Each numeral was to be of the block type, the width two-thirds of the height and the strokes approximately one inch wide for each six inches in height. The distance between the numerals was to be equal to one-half the width of a numeral. The actual size of the numerals was to be such that the call number would be readily discernible from a distance of approximately 150 yards.

Uncamouflaged airplanes were to have the number on the vertical stabilizer surface. For light colored backgrounds, the numbers were to be black, and for dark backgrounds, the numbers were to be orange-yellow to chip No. 5 of Spec. 3-1.

Camouflaged airplanes were to have the number across both the vertical stabilizer and the rudder surfaces. For light colored backgrounds, the numbers were to be black Shade 44, Bulletin No. 41. For dark backgrounds, the numbers were to be red or blue, color shades Nos. 45 or 47 of Bulletin No. 41.

In reply to the Eglin Field suggestion on March 16,1943, that a clear varnish could be used as a substitute for the neutral gray camouflage, Mat. Com. (WF) on April 30,1943, stated that the practical considerations outweighed the theoretical advantages. It might be possible to save weight using such a varnish, but there was a tendency in painting to apply heavier coats of clear finishes than colored ones. Actual production figures on paint usage indicated that the possible weight reduction was extremely small.

Curtiss P-40-CU, 39-174, was the 18th P-40 built, and had managed to survive until April 10, 1943, most recently in the training role. It still has the “U. S. ARMY” under the wings, despite this being deleted from all aircraft in October 1942. (CSAF)

Lockheed P-38F-LO, 41-2308, is seen in dark olive drab and neutral gray finish which appears to have been overpainted with haze paint on the upper surfaces. However, it is fully armed and carries two rear-sloping yellow command bands on the rear booms. (USAF via Gerry R. Markgraf)

If both clear and camouflaged surfaces were smooth, Mat. Com. doubted that there would be any advantage of the clear finish over the camouflage paint. Mat. Com. also doubted that the clear finish would provide the same protection against corrosion that provided by zinc chromate primer, and the drying time of the clear varnish was longer than that of the presently used camouflage finishes. Due to these and other reasons (unstated), Mat. Com. recommended that the use of clear varnish should be reconsidered.

On November 3, 1943, HQ. AAF sent the following message to the VIII Ar Force Service Command:

Approved policy on camouflage is quoted in substance as follows: “No requirement exists for camouflaging any AAF aircraft except Night Fighters.

Night Fighters shall be painted with non reflecting type camouflage paint.

Camouflage paint will be eliminated from all production AAF airplanes subsequently produced except Night Fighters.

Navy type aircraft will be accepted with Navy camouflage.

Camouflage may be removed from existing AAF airplanes at the option of the Theater Commander or Commanding General under whose jurisdiction such aircraft operate in accordance with technical instructions issued by Commanding General Air Service Command.

Future production aircraft which require painting such as fabricated of wood shall be painted with aluminated paint”.

Above policy in no way prohibits Theater Commander if he desires from (retaining-sic) aircraft camouflage.

Western Proc. Dist. informed that camouflage would be removed from P-38s and B-29s, November 16,1943.

On November 16,1943, the Prod. Eng. Sect. (WF), informed the Western Proc. Dist., Los Angeles, that camouflage would be removed in production from P-38 and B-29s, but not from other aircraft until the Army, Navy, and Lease-Lend recipients could reach an agreement.

Material Command on January 13, 1944, directed Douglas to proceed with the deletion of camouflage on A-20G, A-20H, A-20J, and A – 20K aircraft, in accordance with their earlier letter dated December 8,1943. They told Douglas that a contract change would be initiated when Douglas told them the effective point of the change, and requested that Douglas expedite comments and date of the effective point. On January 17, 1944, Douglas advised Material Command by teletype that immediate results could be obtained by refinishing A-20 series aircraft in an aluminum color, as outlined in AAF tetter dated December 8, 1943. They had been unable to find any satisfactory stripping material that would allow them to delete camouflage without causing serious production delays. They requested permission to produce bare-mctal A-20 series aircraft, as requested in the letter dated December 27, 1943. The Douglas letter dated January 8, 1944, made no mention of eliminating primer on A-20 aircraft. Douglas’s effective point was contingent on an answer to the letter of December 27,1943, and upon receipt of allocations for AAF P-70, Moth and Mink aircraft a minimum of three months in advance of delivery dates. This was so that Douglas could make satisfactory arrangements for the deletion of camouflage with subcontractors. They concluded by requesting authority to proceed signed by an AAF contracting officer.

On February 8, 1944, Douglas received an air mail letter from Material Command, which stated that this letter was to be considered the final directive, superceding the letter dated December 8, 1943, for the deletion of camouflage on A-20 series aircraft. Douglas was directed to take immediate action to delete all exterior camouflage from subject airplanes without causing a delay in production. It went on to direct that prior to delivery, all A-20 aircraft allocated to Mink, Moth and those destined for conversion to P-70 airplanes would be camouflaged on exterior surfaces only, in accordance with present camouflage schemes. A primer coat of zinc-chromate primer was required on Mink, Moth and P-70 aircraft. All A-20 series aircraft delivered to the AAF were to be delivered without camouflage and other exterior coatings, except for Moth, Mink and P-70 aircraft.

This exchange concluded that started on December 8,1943, and serves to show the reasons for some of the typical delays and misunder­standings that arose in implementing new AAF policies on the production lines.

In the same October copy of the service bulletin, Douglas detailed how to prevent corrosion of the wing and nacelle skins due to exhaust gases. This had been found prevalent due to these aircraft being delivered in natural metal finish, rather than camouflage finish. (This became a problem on most post war piston-engined commercial transports and resulted in extensive painting of the affected areas – author).

Skin Treatment

CORROSION OF WING AND NACELLE SKIN DUE TO EXHAUST GASES

Excessive corrosion of wing and nacelle skin surfaces due to exhaust gases has been found on C-54 series airplanes delivered with natural rather than camouflage finish.

To eliminate this corrosion, the following procedure is recommended:

1. Remove oil and dirt from areas affected by wiping with rags saturated with wash thinner or suitable solvent. Wipe the surfaces with dry rags before allowing the thinner or solvent to evaporate completely.

2. Prepare the affected area for painting by using either of two methods, depending upon the severity of the corrosion:

a. If the corrosion is light or moderate, polish with Bon Ami in the normal manner. Other abrasives may be used, but care should be taken to see that they are not too severe.

b. If the corrosion is severe, smooth the surface of the metal by means of an abrasive cloth or sandpaper (no. 280 to 400 grit). Apply a hydrofluoric acid-gum tragacanth solution (see NOTE) with a paint brush and continue brushing to aid the etch­ing action. When the surface and pitted areas appear clean, remove the gum-acid solution with damp rags, flush thoroughly with water, and wipe dry.

CAUTION: Goggles, rubber aprons, and rubber gloves should be used when the gumacid solution is applied. Short-time con tact with the acid is not harmful if the acid is rinsed off immediately with plenty of water. The acid should not come in contact with areas or parts, particularly plated steel, other than specified. The landing gear should be covered with paper during this cleaning.

North American P-51B, serial unknown, aircraft no.261, of the 26,h FS, 51я FG, at one of the Fourteenth Air Force South China airfields. It had to be evacuated on November 19,1944, in Ihe face of a strung Japanese offensive. Aircraft is in standard camouflage and has two yellow hands, trimmed in hlack on the vertical tail and yellow wing tips, possibly yellow. The sharks teeth nose marking is in black, white and red. (USAF)

After the surfaces are thoroughly cleaned, apply one spray coat of zine chromate primer (Spec. AN-TT-P-656) to affected areas and allow to dry. Apply two spray coats of aluminized lacquer over the primer surfaces.

NOTE: To prepare the aluminized lacquer, add 2 parts of lacquer thinner (Spec. AN-TT-T256) to 3 parts of Du Pont No, 1234 clear lacquer. Add 6 ounces of aluminum paste (Spec. AN-Tr-A-461) for each gallon of thinned lacquer. The procedure should be repeated when subsequent cleaning of the surface removes the aluminized lacquer to the extent that the zinc chromate primer is exposed.

Two Dark Olive Drab and Neutral Gray, and one natural metal Martin B-26, drop their bombs in Italy, late 1944. Nearest aircraft is B-26C-45- MO, 42-107531. All are from the 441st BS, 320th BG, as shown by the yellow aircraft tail numbers. (USAF’ via Gerry R. Markgraf)

Boeing B-29-10-BA, 42-63393, aircraft “I", named “B-13 Rush Order”, of Ihe 462nd BG,58th BW, Twentieth Air Force, seen in China late 1944. (USAF)

Aluminized lacquer will be applied to the exterior areas affected on C-54B airplane AAF 43-17150 and all subsequent prior to delivery. Starting with C-54B airplane AAF 43-17163, the interior surfaces of the trailing edge of the center wing will have two coats of aluminized A and A lacquer (Army Specification 3-168) applied over the zinc chromate primer coating in production.

Boeing B-29-15-BW, of the 678th BS, 444th BG, Twentieth Air Force, flying over the Himalayan Mountains enroute to Japan on November 21, 1944. The lead aircraft is 42-6399, and has the squadron unit insignia on its nose. All aircraft carried the large black diamond above the serial number on the tail; the aircraft no. in white signified the aircraft number in the group. No.34 leads nos. 44 and 55 in this photo. A large yellow band with black diagonal stripes, around the fuselage behind the wing, indicates the 678th BS. (USAF)

Six Martin B-26s, one camouflaged and the rest natural metal, of the 441st BS, 320th BG, over Italy in late 1944, The most distant natural metal aircraft has invasion stripes under the fuselage only, probably a replacement aircraft from England. (USAF via Gerry R. Markgraf)

Douglas C-47A-40-DC, 42-24051, aircraft CN-N of the 73rd TCS, 434th TCG, leads others from that unit and the 74th TCS, 434th TCG, Ninth Air Force. They are on their way to drop supplies to the beleaguered troops in Bastogne, Belgium, December23,1944, Note the external supplies on rack under the fuselage and wings of the aircraft. Invasion stripes remain only under the fuselage. The lead aircraft still carries the factory applied medium green blotches and dearly shows the repainted blue outline to the 1943 insignia. (USAF)

Republic P-47D-6-RE, 42-74742, aircraft WZ-D bar, “Snafu”, of the 84th FS, 78th FG, Eighth Air Force, is seen after a belly landing at Duxford in England on December 15,1944. Nose checks are black and white, the name and the 90 mission markers are in yellow, code fetters white as is the band across the fin. The rudder is black- Note the large rear view mirror above the front screen. (USAF)

Boeing B-17F-40-DL, 42-3236, aircraft PY-3236 of a training group, starting up. Note its two-color top camouflage. Behind it are five more fi­ns, one P-51A, one Curtiss P-40, three P-47s, one B-25, one B-24 and one A-34. Location unknown, but is a major base with acres of concrete ramp and runways.

The diameter of the insignia will be standard size which is nearest to, but not greater than, 75 percent of height of fuselage at the point of application except that night fighter aircraft will have 25-inch insignia. The diameter of the basic blue circle should be not less than 20 inches or greater than 50 inches. These will be placed and maintained on each side of the fuselage near midway between the trailing edge of the wing and leading edge of the horizontal stabilizer, but may be moved to the rear (or forward) of the midpoint to avoid turrets or other plastic material. The insignia may extend over doors and emer­gency exits, but shall not extend over windows or openings which would change the insignia pattern. If the fuselage section, as described herein, is not large enough to accommodate the minimum size specified, the fuselage insignia may be placed on such other parts of the fuselage as will permit its being readily seen from the side. On aircraft assigned to AAF Training Command, if insufficient space is available for both the insignia and Field identifying numerals, the fuselage insignia may be omitted.

17. ORGANIZATIONAL INSIGNIA

a. The placing of organization markings or design (approved by the War Department as outlined in AAF Regulation 35-22) will be the responsibility of the organization itself. Depots will not be required to reproduce this insignia.

b. No specific locations are mandatory, but points between wing and tail surfaces on opposite sides of the fuselage are considered most desirable. In no case will size of insignia exceed 75 percent of height of fuselage at point of application. Similar airplanes in the same organization will have the same size insignia. If applied to other than smooth surfaces, insignia may be painted on the aluminum sheet and bolted or screwed securely to rigid members of the airplane.

The T. O. called for standard insignia to be used as required in Spec. 98-24102, or Spec. 24114 for camouflaged airplanes.

Spec. 98-24102-K was issued on November 1, 1935. As it so happened, this was also the last letter issue on this specification prior to World War II.

Although the design of the insignia on both wings and rudders remained exactly as before, several detail requirements were changed. For insignia on the wings, a new requirement was added that when the wing covering was both fabric and metal, the available chord length was to be that of the metal covered portion only.

This requirement was caused by the newer aircraft that were coming into service, which had metal covering over the forward portion of the wing and fabric on the aft portion. The effect of this was to effectively reduce the size of the national insignia as a proportion of the total wing chord, and this can be seen on many aircraft of the period. The requirement for the size of the available chord and maximum diameter and positions, remained exactly as before.

Stearman PT-13A al Randolph Field was one of ninety-two PT-13s and was used by the Stage Commander. Finished in the then standard trainer finish to Spec. 24113-A, it was nick-named the “Gray Ghost” or the “Washing Machine”, presumably as it was used when trainees either passed or washed-out in their primary training course.(USAF)

Fairchild PT-19s of an unidentified school squadron at Oakland in 1941. They are finished in the gloss True Blue and Orange Yellow trainer aircraft scheme per Spec. 24113-A. (William L. Swisher)

Ryan XPT-16, 39-717, at Wright Field forevaluation. This Is the first XPT-16, powered by a 125hp Menasco C4 inline engine. It was originally registered commercially as NC18907. Natural metal finish with insignia to Spec. 24102-K. This was the first monoplane primary trainer ordered by the Army.(Harry Gann)

For wings without ailerons, the requirements were changed so that the insignia was to be located on the metal covering tangent to the joint between the metal and fabric covering on wings where both fabric and metal were used for the wing covering.

The rudder design remained as before, with be seven red and six white stripes. It was also required that the surfaces of devices attached to the rudder, such as trim tabs, should be finished to blend with the adjacent surfaces of the rudder.

Amendment No. 2 to Spec. 98-24102-K, dated February 9, 1939 changed the insignia colors to conform to the new A-N Aircraft Color Standards (See Chapter 7).

Major changes were made in 1940 to the national insignia positions and placing, as a result of the decision to camouflage combat aircraft. Spec. 24114s requirements for insignia stated that one cocarde was to be applied on the upper surface of the left wing and one on the under surface of the right wing of the airplane. The design and dimensions of the wing cocarde were to conform to Spec. 98-24102. One cocarde was to be applied on each side of the fuselage midway between the vertical projections of the trailing edge of the wing and the leading edge of the horizontal stabilizer. If transparencies were located in this area, the cocardes could be moved forward or to the rear as directed by the Air Corps Procuring Agency.

Ryan PT-20A-RY, 40-2416, with a Kinner R-440-1 engine. This was the last PT-20A-RY of a hatch of 27 re-engined PT-20s. Natural metal finish to Spec. 24113-A, (Harry Gann)

The diameter of the circle for the fuselage cocarde was to be three-quarters of the length of the projection of the fuselage side. The design was to conform to Spec. 98-24102. All vertical tail surfaces, including the rudder, or rudders, were to be camouflaged and were not to have any insignia.

Insignia were to be applied with camouflage lacquer Spec. 14105 to metal surfaces, or with fully pigmented camouflage dope, Spec. 14106 to fabric surfaces. The colors were to conform to Bulletin 41 (see Chapter 7).

Thus, the newly camouflaged combat aircraft of the service had a completely revised placement of the national insignia. This was the first time that the service had used only one cocarde on the top and bottom of the wings, as suggested in McCook Field Report No, 1305 of 1920. (Although several more changes were to be made in the design of the national insignia in subsequent years, their position­ing has remained basically the same to date).

All non-combat aircraft, i. e. those which were not camouflaged, retained the cocarde and rudder stripes as specified in Spec. 98- 24102-K and amendments. Thus, the USAAF entered World War 11 with its combat and non-combat aircraft bearing national insignia in different positions. This was to be duly changed at a later date.

A conference was held by the Aeronautical Board in Washington, DC, on October 8,1942, to review the proposed ANA spec, for Insignia and Markings on aircraft exteriors.

It was agreed that the principal benefit from the standardization of insignia and markings on Army and Navy aircraft was that it would allow manufacturers producing aircraft for both services to put the same insignia in all aircraft. However, considerable variations existed between the markings applied for both services and their would be little or no benefits from standardization of markings such as serial numbers as each aircraft carried a different serial number, and it made little difference to the manufacturer to which part of the airplane it was applied. Standardization of squadron insignia would also confer no benefit to manufacturers as they were not applied until the

airplanes were assigned in service. Thus, it was agreed that standardization would be limited to the size and location of the national star insignia. The following agreements were reached:

a. There would be two insignia on the wings and two on the fuselage or hull.

b. The size and locations of the wing and fuselage insignia was decided.

The new spec, was finally released in March, 1943, as AN-1-9 (which see later).

Egiin Field issued another report in its continuing tests on camouflage, this one No. 3-43-47, dated May 4,1943. However, no copy of this report could be found at Eglin Field when requested by the author, so its contents remain unknown. However, no changes in the then current dark olive drab and neutral gray finish resulted, so it may be inferred that the results were basically negative.

AAF Bulletin No. 52, Aircraft Manufacturers’ Code Symbols, May 19,1943.

This Bulletin stated that the following manufacturers’ code symbols had been assigned to identify the aircraft manufacture and the plant in which the aircraft had been produced. These code symbols were to be added as a “suffix” to the present aircraft model designation, located on the aircraft as required in spec. 98-24105 (this list will be found in Appendix A).

Mat. Div. (Wash.) state that no definite recommendations for camouflage could be made throughout AAF due to conflicting theater needs, May 20,1943.

On May 20,1943, Mat. Div. (Wash.) forwarded to the Req. Div., OC&R (Wash.) the comments received in reply to the Dir. of Mil. Req. (Wash.) survey request dated March 24, 1943. Because of the conflicting replies received, Mat. Div, fell that no definite recommenda­tions could be made to the AAF as a whole. The Mat. Com. (WF) project on smooth camouflage was substantially complete; results were showing that it could result in increases of from 2 to 4 miles per hour in speed with no loss of camouflage effectiveness.

Removal of Camouflage Requested by “Urgent Secret” teletype. May 21, 1943.

The following “Urgent Secret” teletype was sent on May 21,1943, by the Commander, Eighth Air Force Bomber Command, England, to the Bomb Wing One:

It is considered advisable to remove the camouflage from all of our operational aircraft in order to gain additional speed coupled with less weight. It will require 30 gallons of paint remover and 200 man-hours per B-17 to accomplish this work. As the AFSC (Air Force Systems Command) will not be able to do this work for us due to shortage of personnel it is believed it will have to be accomplished by station personnel. It is planned to have this camouflage removal start on aircraft out for maintenance and repair and battle damage and gradually work towards fully operational aircraft.

This will possibly cause some of your formations to consist of half camouflaged and half uncamoutlaged aircraft at first but eventually they will all become uncamouflaged. It is realized that this will require an additional amount of labor and time on the part of our own personnel. It is believed the advantages to be gained will greatly outweigh this factor. Request your concurrence or non-concurrence in the above. Forward your reply by 1500, May 21, 1943.

If you are in concurrence with the above, this HQ.’s will take the necessary steps to furnish your command required material and personnel to provide camouflage coverings for your aircraft while in dispersal areas. Aircraft will not be stripped of camouflage until authority is granted by this HQ.’s.

The reply received on May 21, 1943, from the Commander, Bomb Wing One, Eighth Air Force, England, stated:

Concur in plan to remove camouflage from operational aircraft. Request this headquarters be furnished thirty (30) gallons of paint remover immediately so that comparative test can be made between a camouflaged airplane and one with the paint removed. Not desirable to start paint removal until satisfactory camouflage coverings are provided. Tests now being conducted in this wing on camouflage coverings for airplanes and coverings for dispersal points.