Service record Canadian navigator in England - help with attachments

[Roger3095]

I am having trouble with a couple of parts of a service record relating to where a relative, an RCAF navigator, was stationed in England.  I have worked out that 3(O)AFU is No.3 (Observers) Advanced Flying Unit, Halfpenny Green, Wolverhampton. 23 OTU is 23 Operational Training Unit, Pershore. 3 PRC is No. 3 Personnel Reception Centre, Bournemouth.  But I am stuck on (1) Att. (attached?) to ACOS and (2) something that looks a bit like Army (Henley), but the way it is written looks very much more like Benley or Senley.  Presumably this was a holding depot.  I understood that 3PRC had satellite holding stations at Innsworth and Hastings.  There is no "t" so it is not Bentley.
He ended up being killed on his 36th mission flying in Halifax III bombers from RAF Tholthorpe.  Suggestions appreciated. Roger Cousens

[daretodiscover]

Roger,

ACOS was Aircrew Officers School located at Sidmouth in Devon. Opened in March 1943

https://discovery.nationalarchives.gov.uk/details/r/C7161173

https://www.sidmouthherald.co.uk/news/20452359.service-honour-significant-role-played-raf-sidmouth-wwii/

https://www.rafmuseum.org.uk/documents/research/RAF-Historical-Society-Journals/Journal-42.pdf

The very similar Air Crew Officers School (ACOS) was set up at Sidmouth in
April 1943. It provided four weeks of general duties instruction for up to 1,500
students at a time. As with the NCOs, the course was primarily intended for newly
commissioned EATS graduates who were supposed to attend between PRC and AFU
– although this was neither essential nor exclusive; some EATS graduates by-passed
the course while some officers promoted from the ranks in the UK were able to attend.
In April 1944 the ACOS moved to Hereford where it remained until the end of the war

DTD

[tonepad]

Possibly RAF Kenley where there was a Canadian Wing:

https://www.kenleyrevival.org/content/history/faces-of-kenley/the-canadians-at-kenley


Tony