I can't be the Berlin Air Safety Centre.

I think it most probably refers to the Army Service Corps, whose proper title was the Royal Army Service Corps. This passage is in a book on Rudolf Hess in "Camp Z", which was at Mytchett Place in Surrey. Hess was held there from 1941, after his capture.

"The Royal Army Service Corps (RASC) was a corps of the British Army. It was responsible for land, coastal and lake transport; air despatch; supply of food, water, fuel, and general domestic stores such as clothing, furniture and stationery (but not ammunition and military and technical equipment, which were the responsibility of the Royal Army Ordnance Corps); administration of barracks; the Army Fire Service; and provision of staff clerks to headquarters units.
It is now part of the Royal Logistic Corps."
http://en.wikipedia.org/wiki/Royal_Army_Service_Corps

A small point worth bearing in mind is that the RASC was based at Aldershot, which is quite close to Mytchett.

So either writer of the memo being quoted here mistakenly referred to BASC when he/she meant RASC (thinking of it as the British Army Service Corps), or (quite likely) it is a typo, resulting from a misreading of R. R and B are quite similar letters; if there was a smudge or dot at the bottom of the R it could easily be read as a B.

There is no other likely meaning that occurs to me.

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Note added at 44 mins (2012-05-15 09:10:50 GMT)
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By the way, another small point in relation to Jack's suggestion: the Catering Corps was actually called the ACC (Army Catering Corps), not the BACC.

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Note added at 47 mins (2012-05-15 09:13:29 GMT)
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The ACC was formed in March 1941 as part of the RASC.
http://en.wikipedia.org/wiki/Army_Catering_Corps