PART 6

THE F-6 AND RF-51 TACTICAL RECONNAISSANCE MUSTANGS

Photographic reconnaissance and mapping aircraft are critical assets to successful military combat operations. In the Second World War, there were fifteen aircraft specifically created for photographic reconnaissance and mapping duties. Some were armed, some were unarmed. But all were of the utmost importance to the war effort.

To meet this challenge, the US Army Air Forces procured a relatively large number of photographic reconnaissance aircraft that were designated with the prefix F for Photo (graphic). These photo-recce aircraft (as they were called) were created from attack, bomber and pursuit airplanes. Since the Mustang was a fast, well-armed pursuit airplane, the USAAF opted to procure a total of 481 tactical reconnaissance Mustangs up until VJ Day. For the most part, these Mustangs were manufactured on the Inglewood and Dallas production lines with special fuselage openings, behind which were specially built bays to house the cameras they carried. They were then sent to various modification centres (mod centres) for their respective camera installation processes. Since the Mustang was the sixth in the series of photo-recce aircraft, the first variant was designated F-6A followed by the F-6B, F-6C, F-6D and F-6K. All of the photo-recce aircraft were also known as ‘Foto Joes’. These various photo-recce aircraft included the Fairchild F-1, Beech F-2, Douglas F-3, Lockheed F-4, Lockheed F-5, North American F-6, Consolidated F-7, De Havilland F-8, Boeing F-9, North American F-10, Hughes F-11, Republic F-12, Boeing F-13, Lockheed F-14 and Northrop F-15. Of these, however, it was only the F-4, F-5, F-6, F-7, F-9 and F-13 that were most widely used.

It was a tactical reconnaissance Mustang that became just the second USAAF Mustang variant to be used in a combat situation. On 9 April 1943, a lone P-51-2-NA (41-37328) flown by Lt. Alfred C. Schwab Jr. of the 154th Tactical Reconnaissance Squadron flew an armed reconnaissance mission from its base in Tunisa, North Africa, whereby he successfully photographed the enemy-held Kairouan Aerodrome and returned without incident. This also marked the first time that a USAAF P-51 was used in combat. This P-51-2-NA and seventy-three others were re-designated F-6A-1-NA in late 1943. The first six P-51-2-NA Mustangs to arrive came to the 154TRS seven days earlier on 2 April 1943. On the next day during training manoeuvres near the base, one of the 154TRS P-51s crashed killing its pilot Lt. Howard Kenner. These P-51s, said to closely resemble Bf 109s by some, had yellow stripes painted on their outer wings to help identify them as USAAF Mustangs. (Although the first USAAF P-51 Mustangs to see operational service were with the 154th TRS, after only a few weeks, the aircraft were transferred to the 68th Observation Group, 111th Tactical Reconnaissance Squadron.)

The USAAF employed five versions of the F-6 tactical reconnaissance Mustang and these are now discussed:

F-6A-1-NA and F-6A-2-NA Mustang

NAA Charge Number NA-91

Original Date: 7 July 1941

The F-6A-1-NA airplanes began life as modified P-51 (Mustang MK.IA) airplanes originally designated P-51-1-NA and P-51-2-NA of which seventy-five airframes were reworked into photographic types as follows: two K-24 cameras installed; SCR-274N, SCR-535 and RC-32 filter radio equipment installed; auto signal discharger and control removed; AN-3089 signal lamp installed; provisions made for storage of signal pistol and cartridges; carburettor air filter installed; the British-type oxygen system modified to US standards and long-range oxygen system installed. Various other details were arranged for long-range ferrying flights and/or for crating to be shipped. And the standard P-51 armament of four 20-mm cannons was retained.

All of the F-6A airplanes except for the first one, were created at a modification centre where they were reworked into photo-recce aircraft. The first was modified in Inglewood and served as the pattern airplane. The F-6A airplanes were modified with the installation of two K-24 cameras – one behind the pilot’s seat pointed to the left rear of the airplane and one mounted in the tail section to be pointed by the pilot straight down or straight aft.

The production F-6A-1-NA aircraft included 41-37320 (1 P-51-1-NA), 41-37321 to 41-37339 (19 P-51-2-NA), 41-37353 to 41-37371 (19 P-51-2-NA), 41-37412 to 41-37420 (9 P-51-2-NA), 41-37422 to 41-37425 (5 P-51-2-NA), and 41-37427 to 41-37329 (3 P-51-2-NA).

The Dallas plant built 1,000 NA-124 P-51D Mustangs. This is the final P-51D built by NAA, P-51D-30-NT (45-11742), and the ‘000’ on the vertical stabiliser denotes this milestone. An additional ten were completed as NA-124 TP-51D-25-NT airplanes. The USAAF ordered 1,000 NA-124 P-51M Mustangs to be built in Dallas, Texas, following the Dallas-built P-51D production run. The contract for these was approved by the US War Department on 21 September 1944. Why the P-51M carried the same NAA Charge Number (NA-124) remains a mystery. Supposedly, one example of this airplane was built as the unique P-51M-1-NT (45-11743), but no photograph or proof of its manufacture has surfaced. The remainder of the P-51M production run consisting of 999 airplanes (45-11744 to 45-12742) was cancelled. The P-51M was to be very similar to the P-51D-30-NT but was to be powered by a Packard-built V-1650-9A Merlin engine without water injection that decreased its WEP or War Emergency Horsepower rating from 2,280 hp to approximately 1,720 hp. (Rockwell International via Chris Wamsley)

F-6B-1-NA Mustang

NAA Charge Number NA-99

Original Date: 23 June 1942

Originally designated P-51A-11-NA, 35 F-6B-1-NA airplanes were created from P-51A-10-NA airplanes. The F-6B was similar to the P-51A except for the installation of two K-24 cameras and its engine. Equipped with two K-24 cameras, the F-6Bs served primarily with the 107th and 109th Tactical Reconnaissance Squadrons of the 67th Tactical Reconnaissance Group of the 8th Air Force based at RAF Middle Wallop in Great Britain. This group was later deployed to France with the 9th Air Force at Le Molay in July of 1944.

F-6C-1-NA and F-6C-1-NT Mustang

NAA Charge Numbers NA-102 and NA-103

Original Dates: 26 August 1942 and 8 October 1942

The F-6C photo-recce Mustangs were all created from modified P-51B-10-NA and P-51C-10-NT airplanes, ninety-one in all, from seventy-one P-51Bs and twenty P-51Cs. These were similar to the P-51Bs and P-51Cs except for their two K-24 cameras and provisions for two K-17 or two K-22 cameras. These were also the first photo-recce Mustangs to be powered by the Packard-built V-1650 Merlin engines.

R F-51D of 82TRS at Johnson Air Base, Japan, named ‘Angel Face’. (National Museum of the USAF)

F-6D-25-NT and F-6D-30-NT Mustang 

Charge Number NA-124

Original Date: 14 April 1944

Under the NA-124 P-51D production programme, USAAF contract number AC 2400, Dallas manufactured seventy F-6D-25-NT and thirty-five F-6D-30-NT airplanes in the order as follows:

F-6D-20-NT Mustang

NAA Charge Number NA-111

Original Date: 3 May 1943

NAA produced thirty-one factory-built F-6D-20-NT airplanes at its Dallas, Texas, facility as part of its NA-111 programme under USAAF contract number AC 40063 officially implemented on 5 November 1943. These were manufactured as follows:

F-6K-5-NT, F-6K-10-NT and F-6K-15-NT Mustang

NAA Charge Number NA-111

Original Date: 3 May 1943

Under USAAF contract number AC 40063 approved on 21 July 1943, NAA built 163 F-6K airplanes on its Dallas, Texas, production line. These included:

Not all F-6s remained in service after the war, but the F-6D and F-6K versions did. On 11 June 1948, when the DOD reclassified a number of its aircraft, the F for Photo prefix was changed to RF for Reconnaissance Fighter. More appropriately, the number 6 was replaced by the Mustang’s proper number 51. Thus, the F-6D and F-6K became the RF-51D and RF-51K. While five versions of the photo-recce Mustang were employed in the Second World War, only these two variants would be used later in the Korean War.

F-6 Units in the Second World War and the Korean War

8th Tactical Reconnaissance Squadron (TRS); 10TRS; 12TRS; 15TRS; 20TRS; 22PRS; 22TRS; 33PRS; 34PRS; 45TRS; 67th Tactical Reconnaissance Wing (TRW); 68th Observation Group (OG); 82TRS; 107TRS; 109TRS; 110th Tactical Reconnaissance Group (TRG); 110TRS; 111TRS; 118TRS; 154TRS; 160TRS; 161TRS; 162TRS

Aerial Cameras

The F-6 and RF-51 series of tactical reconnaissance Mustangs employed four types of aerial cameras manufactured by the Fairchild Camera and Instrument Corporation. These included the K-17, K-18, K-22 and K-24 aerial cameras.

The K-17 Aerial Camera was the original all-purpose aerial camera. It was widely used for vertical mapping photography and all types of reconnaissance, intelligence and bomb damage assessment. It was also used for oblique photography. The basic camera used the trimetrogon mapping system. It was available with cone-shaped lenses of six, twelve and twenty-five in focal lengths. It had an interchangeable vacuum-back roll-film magazine providing up to 200 negatives of 9x9 in. It was automatically or manually operated. It featured exchangeable lens cones for Bausch & Lomb Metrogon lenses of six inch, twelve inch and twenty-four inch focal lengths respectively with F stops of F6.3, F5 and F6.

The K-18 Aerial Camera was designed for high-altitude photography requiring a large image size. Although it was designed for vertical mounting, it was also used for low-altitude oblique photography. It was equipped with a cone-shaped twenty-four inch focal length. Its negative size was 9x18 in. and it was manually or automatically operated. This camera was comprised of a single unit housing and a twenty-four inch focal length with an F stop of F6.

The K-22 Aerial Camera was equipped with a high efficiency focal plane shutter to cover a wide range of shutter speeds up to 1/800th of a second. It was the only Fairchild camera equipped with a focal plane shutter. It could take 200 exposures and was for electrical (fully automatic) operation only. This is a focal plane shutter camera with a 9x9 in. format using a range of lens cone options for adjustable six inch, twelve inch and forty inch focal lengths. The forty inch telephoto lens has three F stops (F5, F5.6 and F8); the six inch has one (F6.3); the twelve inch has one (F5); and the twenty-four inch has one (F6).

The K-24 Aerial Camera was the US- built version of the Williamson F.24 Aerial Camera that was the main air reconnaissance camera at the start of the Second World War used in early Mustangs. Its small 5x5-in. format, when fitted with the smaller of the full-length lenses, was too small for detailed photo interpretation, especially when the camera-carrying F-6s were forced to fly at much higher altitudes. The camera featured a cloth focal plane and used four focal lengths measuring four inches, five inches, eight inches and twenty inches.