South Seas "Yo" 11073 Butai
Tokusetsu Kogekitai (Special Establishment Attack Unit)
Japanese Army Air Force (JAAF)

Background
During January 1943, the Japanese Army Air Force (JAAF) established the South Seas "Yo" 11073 Butai as a composite unit formed from the 5th Sentai (5th Flying Regiment) and Akeno Flying School under the command of Captain Sentaro Chiba from 5th Sentai. Also known as Tokusetsu Kogekitai (Special Establishment Attack Unit). This unit was an experimental unit to utilize cannon armed twin engine aircraft to intercept Allied bombers.

The unit had thirty-six personnel including twelve pilots and twelve planes including six Type 100 Command Reconnaissance Aircraft Ki-46 Shinshitei (Dinah) armed with 37mm cannon and six Type 2 Two-Seat Fighter / Ki-45 Toryu (Nick) armed with 37mm cannons. The unit had twelve pilots including six from 5th Sentai including Captain Sentaro Chiba, Captain Yoshitoshi Endo, WO Mitsugu Momotomi (Momodomi / Hyakutomi), MSgt Tadao/Toshio Furumori, Sgt Osamu Kadota and Cpl. Masaoki Mitsuwa. Plus six from Akeno Flying School: 2Lt. Sadao Honda, 2nd Lt Zenmatsu Wakamatsu, WO Ginji Sekiya, WO Tamotsu Motoyama, MSgt Hikoshiro Ikeda and MSgt Manji Miyawaki.

Wartime History
On February 1, 1943 embarked aboard Taiyo bound for Truk. On February 7, 1943 arrives Moen 1 Airfield (Harushima) and conducted test flights and gunnery training. In the middle of February 1943 moved to Vunakanau Airfield (West Airfield) near Rabaul under the supervision of 12th Hikodan (12th Flight Brigade). While moving, a Ki-45 piloted by Kadota and Ki-46 Dinah piloted by Motoyama went missing.

On March 2, 1943 pilot 2nd Lt. Wakayama died in an accident.

On March 16, 1943 Ki-46 Dinah piloted by MSgt Manji Miyawaki took off on a mission. Over Talasea, intercepted B-17F "Lulu Belle" 41-24358 and made two ineffective frontal attacks from 11 o'clock. During a third pass, hit by gunfire from the nose guns and top turret and crashed into the sea and exploded and sank on impact. Afterwards, the B-17 flew low over the crash to strafe the bodies of the crew in retribution for Japanese planes observed strafing U.S. crews after they bailed during the Battle of the Bismarck Sea.

In early April 1942, Headquarters, 12th Hikodan moves to Wewak.

During May 1943, disbanded and the remaining personnel and planes were transfered to the 13th Semtai.

Commanding Officer (C.O.)
Captain Sentaro Chiba

References
Ken's Men Against The Empire Volume I (2020) pages 161-162 (March 16, 1943)
Thanks to Minoru Kamada for additional information

Contribute Information
Do you have photos or additional information to add?