On 14th December 1941, following the Japanese invasion of Thailand, the Thai government was coerced into acceding to a Japanese request to support its war effort by entering into a military alliance with Japan. The Royal Thai Air Force was reluctant but eventually agreed to co-operate with the JAAF by sending units into Northwest Thailand to support the Japanese Army campaign in Burma. As part of this agreement the Japanese undertook to provide Thailand with Type 97 (Ki-27) fighter aircraft and for the JAAF to begin teaching Thai pilots to fly this fighter at Don Muang airfield. An order for 12 Ki-27 Otsu fighters was placed with Mansyu Hikoki Seizo K.K. in Manchuria who were building the aircraft under licence. In Royal Thai Air Force service the Ki-27 was known as the Fighter Type 12 or ‘Ota’, after the Japanese city where the Nakajima plant was located. The new fighters were allocated to Foong Bin 16, the wartime designation of the 3rd Squadron of Kong Bin Noi 1 based at Don Muang, which was also partially equipped with the Curtiss Hawk 75N.
RTAF Ki-27 photographed post-war. The pre-war rudder stripes have replaced the charging elephant insignia on the tail but the wartime markings remain under the wings (via Edward M Young)
After re-equipment the squadron moved to Lampang to provide escort duties to the two attack squadrons of Kong Bin Noi Phasom 85 equipped with the Mitsubishi Ki-30 light bomber. The first mission of the Otas was flown on 6th February 1942 when all 12 aircraft flew escort to a force of nine Ki-30 bombers bombing Chinese positions at Loi Mwe in the Burma Shan States. Shortly afterwards allied attacks against Thai airfields necessitated a re-organisation to improve air defence and as a result Squadron 16 was re-assigned to patrol duties over Chiang Mai and Chiang Rai.
RTAF Ki-27 (via Edward M Young)
Most of the Ki-27 service in the Royal Thai Air Force was uneventful and no Thai pilots achieved ace status whilst flying the type. Squadron 16 continuing to fly patrols or escorts to unopposed bombing missions by the Ki-30’s and, following a tacit truce with China, their reconnaissance missions over the Shan States and Southern China. The Ki-27 was also somewhat eclipsed when the Japanese provided the Royal Thai Air Force with the more modern Nakajima Ki-43 Hayabusa “Oscar” Type 1 single seater fighter and a few of these found their way to Squadron 16, replacing the Curtiss Hawk 75N. As the Allied air offensive against the Japanese intensified, targeting airfields and installations in Thailand, the likelihood of encounters with Thai aircraft increased. In most cases the defending fighters, marked with the red flag and white elephant insignia adopted after alliance with Japan, were not distinguished as Thai and were reported as ‘Japanese’. In an encounter with B-24 bomber’s attacking Lampang on 21st December 1943 six Otas of Squadron 16 were reported as holding off from attack and veering away when fired upon by the bomber gunners.
RTAF Ki-27 in action against P-38's (Wanchai)
On the 11th November 1944 five Otas of Squadron 16 intercepted a force of US fighters conducting an interdiction mission against rail and airfield targets of opportunity in the vicinity of Chiang Mai. The American fighters were from the 51st Fighter Group and consisted of eight P-51 Mustang’s of the 25th Fighter Squadron with four assigned as low strafers and four covering them at a higher altitude, with a top cover of seven P-38 Lightnings from the 449th Fighter Squadron, 16 aircraft in all. The P-51’s had attacked a locomotive and shot up a single black coloured fighter on the airfield at Lampang. Shortly after noon the P-38’s flying at 18,000 feet called out five Japanese fighters. At about the same time 2nd Lt Henry F Minco flying P-51 44-10812 in the middle flight of Mustangs led by 1st Lt Roger R Vadenais called out three Japanese fighters above them and about 5 miles ahead. “Do you see them Vad?” he called out. Lt Vadenais spotted the enemy aircraft, ordered his flight to drop their wing tanks and led them in a climb to make a head on pass against the approaching Ki-27’s. The Ki-27’s passed through the P-51 flight and Lt Vadenais turned to pursue, firing at one of them and seeing its propeller break off before it rolled and dived away. This was possibly the aircraft of the Ki-27 leader Flight Lieutenant Chalermkiat who had to force land with a damaged engine. The Ki-27 was then strafed and destroyed on the ground by one of the P-51‘s. During this encounter Lt Minco called out “I see two below, am going after them.” and broke from Vadenais’ right wing in a dive. 1Lt Otto C Miller apparently pursued and shot down Chalermkiat’s wingmen Chief Warrant Officer (CWO) Nat Sunthorn, killing him, whilst Lt Minco might have damaged the aircraft of CWO Thara Kaimuk, wounding him and forcing him to crash land some distance from Lampang. During this combat at low level it appears that Lt Minco’s P-51 was either shot down (perhaps by ground fire), crashed accidentally (perhaps stalling in a turning fight) or was damaged badly enough during air combat for him to bail out. Rumours arose in early 1945 that he had attempted to bail out of his Mustang but had been killed landing in trees and that his body had been buried by local people. Whatever his fate he did not return from the sortie and was listed as missing in action. During the battle the P-38 pilots had heard an unknown pilot, possibly Minco, call out “I’ve got one trapped in the valley down here!”.
Witness Statement from MACR 10064 (NARA)
The P-38’s had also engaged the Ki-27’s simultaneously, with 1Lt Dale D Desper’s flight claiming one of the Ki-27’s shot down in the first head on pass. This was probably the aircraft flown by CWO Chuladit Detkanchorn who managed to bail out. The P-38 pilots then reported that they were attacked by four more Ki-27‘s from above. Pilot Officer Kamrop Bleangkam fired at a P-38 flown by 1Lt Richard D Conway, shooting out its port engine and claiming it as destroyed. But Lt Conway egressed safely from the fight and made an emergency landing on an airfield at Simao. PO Kamrop or another Thai pilot also fired at 1Lt Leonard W Flomer’s P-38, setting fire to his wing tip tank. Flomer called excitedly for help, angering Lt Desper who after driving off the Thai Ki-27 admonished Flomer for his lack of radio discipline. Desper then escorted Flomer back to Yunnanyi where both P-38’s landed safely. PO Kamrop’s Ki-27 was badly damaged in the fight, probably by Desper, and he too was forced to crash land.
Extract of MACR 10064 (NARA)
P-51 43-25244 flown by 1Lt Rudolph C Shaw of 26th FS, 51st FG is also the subject of a Missing Air Crew Report (MACR 10632) on the same day and the loss has sometimes been associated with this incident. However Shaw was on a bombing mission from Nanning to Laipin with four other P-51s and after strafing two sampans on a river east of Tawan, south of Chenglunghu in China, he was not seen again. His companions heard him calling on the radio that he was bailing out due to loss of fuel but his ultimate fate is unknown.
RTAF Ki-27 in action against P-51's and P-38's (Wanchai)
The P-38 pilots claimed three Ki-27’s destroyed (one each to 1/Lt Robert H Jones, and 2/Lt Grover W Stubbes and one shared by Lts Desper, Flomer and Frederick A Roll Jr) together with three probably destroyed. The P-51 pilots claimed two destroyed by Lts Miller and Vadenais and a quarter share for 1/Lt Clell H McKinney for the Ki-27 claimed jointly by P-38 pilots Lts Desper, Flomer and Roll. 2/Lt Henry F Minco, a 70 mission veteran, was not posthumously awarded any credit for a victory but it is clear that he was in combat with a Ki-27 and that all the Thai aircraft were shot down or forced down. During the combat two parachutes were seen, presumed both to be Thai pilots. It appears from the evidence that the Thai Ki-27 pilots damaged two P-38’s and possibly shot down one P-51. One of the P-38 pilots involved in this combat reported that the Ki-27‘s were “maneuverable as hell but slow as hell”. Subsequent records reveal that at least one of the Thai aircraft was made airworthy following the combat, possibly the Ota of F/Lt Chalermkiat.
Apart from a possible attack on a 7th BG B-24 flying a low-level railway sweep on 22nd March 1945 there were no other recorded combats for the Thai Otas. By April 1945 Squadron 16 had only four serviceable Otas from a total strength of eight whilst Squadron 15, operating the Ki-43, had a single Ki-27 on strength. By November 1945 only a single Thai Ota remained operational with Squadron 43 and the Ki-27 fighter had passed into history.
With special thanks to Ronnie Olsthoorn and Edward M Young for their kind contributions and assistance with this article.
'Aerial Nationalism - A History of Aviation in Thailand' by Edward M Young (Smithsonian Institution Press, 1995)
'The Forgotten Squadron - The 449th Fighter Squadron in World War II' by Daniel Jackson (Schiffer Military History, 2010)
'Air Power Under His Majesty's Bounty' (Edited RTAF, 2006)
Image credits: Ki-27 profile © 2013 Ronnie Olsthoorn; Photographs via Edward M Young; Ki-27 paintings 'Wanchai' via RTAF; MACR extracts NARA.