The marking of the 81st Sentai was based on the numbers "8" in the middle and stylised "1". In the first chutai the 81 was white surrounded by red, in the second chutai the 81 was red surrounded by white as shown above and the third chutai had a yellow 81 surrounded by red. (Artwork: Devlin Chouinard)
On September 20, 1941 the 16 Dokuritsu Chutai (Independent Company) equipped with two chutai of reconnaissance aircraft was renamed the 81 Sentai (Regiment).
Initially the 81st had six Mitsubishi Ki-46 "Dinah" and 20 Mitsubishi Ki-15 "Babs" in its strength and was based in Zhangde (present-day Anyang, Henan province) in North China.
In the middle of November, 1941, the unit left its base and arrived in Pnom Penh via Nanking and Canton to participate in the Malay Peninsula Operations with the 3rd Hiko Shudan (Joint Air Group).
From December 8, the unit was based either in Sungei Petani or Alor Setar in Malaysia performing reconnaissance flights keeping truck of the enemy movements.
By January "Dinah" of the unit were flying over Singapore reporting the status of the defences, helping the ground units in their attack preparations.
Their next contribution was helping the Army parachute units in their airborne operations in Sumatra and Palembang. Parachute unit officers flew with "Dinah" of the 81st over Palembang constantly reporting on the weather and enemy positions. During the actual operations on February 15, 1942 two "Dinah" of the 81st reconnoitre the area to observe the progress of the parashute landings.
On May 1st the unit was left with only six "Dinah" and one "Babs". Starting from that month one chutai was assigned to the Burma theatre to participate in the operations in that area. Aircraft of the chutai flew well inside India and as far as Kunming in Yunnan province, southwest China and also participating in the operations of the 7th Hikodan (Air Brigade).
In December a third chutai was organised and in January 1943, the 81st Sentai was based in Hlegu airfield in Burma (Hlegu).
On April 2 the 1st Chutai of the 81st Sentai became the 2nd Chutai of the 10th Sentai and relocated to Wewak in Papua/New Guinea.
In this most interesting NARA photo a Mitsubishi Ki-21 "Sally" of the 81st Sentai is seen under a camouflage net on the left of the photo next to a 14th Sentai "Sally". The 81st mainly operated Ki-46s and Ki-15s so this "Sally" is either a liaison aircraft or perhaps modified for reconnaissance missions. Location is Lakunai airfield, Rabaul, New Britain, January 26, 1944. Note the harbor of Rabaul in the background full of ships but also the Nakajima J1N "Gekko" and the various installations.
In January 1944 unit strength was 20 airplanes with equal number of pilots but from the beginning of March ten airplanes were in Hlegu, an unknown number in Heho airfield also in Burma (Heho) and from these two bases the 81st Sentai participated in the Imphal operations with the 5th Hiko Shidan (Air Division).
By the end of April, elements of the 8th Sentai were incorporated into the 81st bringing the total strength of the unit to 30 airplanes and 27 pilots.
From 1945 the 81st with its remaining airplanes and pilots performed reconnaissance missions over a very wide area covering Burma, the Andaman Islands and South-West China until the end of the war.
This NARA photo the tail of a shot down "Dinah" belonging to the 81st Sentai in the C.B.I. theatre in 1944 excellently shows the shape of the tail marking. Any more details about the location etc?
Luca Ruffato sent this most interesting comment (grazie tante):
I have the following 81st Sentai losses for 1944:
16 January: Capt KURIYAMA shot down 70 miles east of Dohazari (India). I think this is the likely candidate for the NARA photo.
28 April: Capt OHATA shot down near Imphal.
6 July: WO TOMIZUKA shot down near Indaw.
22 July: Capt MORI failed to return from Myitkina-Bhamo area.
Hope this helps,