Hi Peter
I'm at work so don't have access to all my files, but I do have this on my 41 Squadron wesbite (
http://brew.clients.ch/RAF41Sqdn.htm):
Date 19 August 1941
Up/Down 1005/1200 (Timings only for 41 Squadron, but not for other Squadrons involved)
Sortie Circus 81, 11-Aircraft bomber escort targeting the Gosnay Power Station in France
Bombers 6 Blenheims of No. 2 Group, Bomber Command
Escort Wing 41, 610 and 616 Squadrons (Tangmere)
Escort Cover Wing 452, 485 and 616 Squadrons (Kenley)
Target Support Wings 306, 308 and 315 Squadrons (Northolt) and 403, 603 and 611 Squadrons (Hornchurch)
Rear Support Wing 72, 92 and 609 Squadrons (Biggin Hill)
Whilst the aim of the sortie was to nock out Gosnay Power Station, the operation in fact had a secondary objective. In the end, the attack on Gosnay was abandoned and no bombs were dropped due to the amount of storm cloud cover over the target area. However, the secondary objective was successfully accomplished. The 11 Group ORB states,
"The 6 Blenheims made rendezvous over Manston at 10.30 hours with the Escort Wing and proceeded via Dunkirk to St. Omer aerodrome where W/Cdr. Bader's 'Leg' was dropped by parachute which was seen to open." [TNA AIR 25/200]
The cloud cover was 10/10ths at between 8,000 and 10,000 feet and large cumulus clouds reached up to 20,000 feet. Ironically perhaps, the very cloud cover, which hid their approach to Gosnay, was the same that made conditions over the target area unsuitable for the attack on the power station, and thus the objective was abandoned. The bombers turned for England, but their path back over occupied France was not as quiet as their way in. The Escort Wing, of which 41 Squadron was a part, only saw a few German aircraft on their return home, but noted they "showed no inclination to fight" [TNA AIR 25/200].
However, the weather continued to deteriorate to such a state that the Blenheims were forced to drop to just 1,000 feet to get under the cloud. This resulted in them being attacked with flak from German ground forces, which were probably shocked to see six RAF bombers roar over their heads at little more than 300 metres. The result, according to the 11 Group ORB, was that "all the aircraft were hit and one observer was wounded" [TNA AIR 25/200].
Hope this helps
Regards
Steve