21 A.A.C.U.

[Ross Debenham]

Have recently purchased a AMLC post marked Field Post Office 45, circa 10 July, 1944, and censored using Type R11 censor marker number 278, which were both used in Accra, Gold Coast. The AMLC is from a member of 21 A.A.C.U. which I surmise could denote an Airfield Construction Unit. If I am wrong in this summation, could members please enlighten me to what this denotes.

[Michael Dobbs]

Ross

The following has been taken from The National Archives catalogue - and so I presume that AACU stands for Anti-Aircraft Co-operation Unit, although there are also a number of files which refer to it as Anti Air Cooperation Unit, whether this is a completely different type of unit I don't know.  No reference to 21 AACU unfortunately.

File reference: AIR 29/49/2
1 Anti-Aircraft Co-operation Unit, Indian Air Force, Drigh Road; became 22 AACU, IAF December 1942; disbanded 17 March 1943; reformed 17 March 1943 to include AACU's at Dum Dum as B Flight, Juhu as C Flight, Mehgaon as D Flight; C Flight moved to St Thomas Mount 2 July 1943; D Flight moved to Katni 30 December 1943; includes unit magazine 'Target' July 1944; B Flight moved to Alipore by 1 August 1944; B Flight moved to Digri 11 September 1944; HQ moved to Ambala 15 June 1945; A Flight includes detachment at Poona; B Flight disbanded 22 December 1945; HQ moved to Santa Cruz 28 February 1946; C Flight moved to Sulur 10 April 1946; D Flight disbanded 11 May 1946; A Flight detachment became B Flight; C Flight disbanded 31 January 1947.

Mike

[Ross Debenham]

Thanks Mike, I didn't think of anti-aircraft. I wonder if there was an Indian unit in Accra.

[Michael Dobbs]

Ross

Wikipedia lists the units but gives no further information:
https://en.wikipedia.org/wiki/List_of_Royal_Air_Force_units_%26_establishments

Aaah - at last - I have now found a file in The National Archives which relates to 21 AACU!
File: AIR 29/49/1
21 Anti-Aircraft Co-operation Unit; formed June 1943 Takoradi, moved to Oshogbo, West Africa 6 August 1943.

Mike

[Ross Debenham]

Thanks again Mike.

[Michael Dobbs]

Ross

[b]No 22 Anti-Aircraft Co-operation Unit RAF[/b]

The National Archives shows the reference number to be AIR 29/49/1; however reference number AIR 29/49/1 to AIR 29/49/5 are all bound in the same binder - you order one you get them all.  They are Operations Record Books (RAF Form 540) for what became 21 to 25 Anti-Aircraft Co-operation Units (AACU).  Those for 22 to 25 AACU were typed and/or handwritten on to the large RAF Form 540 pages and were behind a card title page produced by the Air Historical Branch, Air Ministry upon which was listed 22 to 26 AACU, which were originally formed, in the main, under other unit titles.  That for 21 AACU was typewritten on foolscap plain paper and had been placed in front of the Air Historical Branch card cover, albeit within the bound volume.

The typewritten 21 AACU document was headed "SUB-FORM 540"and in manuscript "21 AACU Oshogbo West Africa".  This consisted of 5 pages with very short abbreviated notes for each entry date.  It does not state a date of formation or previous unit name nor date of disbandment.  It covers the period June 1943 to March 1944.

What is an AACU?  There was no clear definition given in any or the ORB entries; however, there is a reference in No 22 AACU to it being a flying unit used for drogue towing.  A drogue is a conical or funnel-shaped device with open ends, towed behind an aircraft and used as an aerial target for gunnery practice or as a windsock.

The typewritten entries for No 21 AACU show that in June 1943 it was at Takoradi, Gold Coast.  It referred to aircraft flying targets ([i]not[/i] drogues); but all the targets flown appear to break away from their towing aircraft.  As a result all targets were examined and reinforced with fabric.  In July 1943 targets were examined again for serviceability of all chords and a large percentage had to be changed. 

There is an entry for 5 August 1943 which stated that three Defiant aircraft were chosen for co-operation at RAF Oshogbo, Nigeria.  The Flight was to relieve No 1432 Flight.  It was stated that the work would be mainly towing for the 1st A.T. Light Ack Ack Regiment [i](this was the wording used; there was no clear indication as to what this unit was)[/i], but that attacks on troops and M.T. vehicles would also be done.  It would appear that the whole unit did not move to Oshogbo (or did it??) as there are references to aircraft returning to Takoradi.  It was stated that the aircraft were largely involved in "towing" - presumably targets as there were almost daily listings of Defiant aircraft towing or on reconnaissance.

On 24 September 1943 a Flight (or the Flight?) moved to Ikeja (Lagos) for co-operation with 4th Heavy Regiment.  It was then stated that during the month of October no co-operation with the 4th Heavy Regiment was possible because the Regiment had no guns!  On 8 December 1943 one aircraft returned to Oshogbo after completion of co-operation with 4th Heavy Regiment.

On 15 December 1943 one aircraft flew to Ibadan and 12 ground crews travelled to Ibadan by road. 

There appears to be no further useful entries and no entries before June 1943 or after December 1943.  I can find no other entries in The National Archives on files for No 21 AACU.

Regards, Mike

[Ross Debenham]

Thanks Mike, very interesting indeed. Ros

[Nick Colley]

Chaps, from: Flying Units of the RAF, by Alan Lake, Airlife Publishing, 1999:

21 AACU was formed December 1942 at Takoradi, equipped with (apparently) one Defiant aircraft, serial DS152.

It was disbanded 31st March 1944 at Ikeja, Nigeria. ---> Your combination of the return address and the date seems to be difficult to reconcile?  :-\

It was reformed at Robertsfield, Liberia in February 1945, equipped with a Defiant, serial DS157.

The unit disbanded 10th May 1945 at Robertsfield.

chrs
N

[Ross Debenham]

Thanks Nick, another mystery. For your information I have attached a scan of the return address on the inside of the letter. Ross

[Nick Colley]

Ah-ha!. No ambiguity there, then! Well, that just goes to show we postal historians sometimes know better than the 'official' histories and reference texts.

chrs
N

[Ross Debenham]

Isn't the first time, won't be the last I suppose.