After a few hours sleep, the Waddington crews who had been on the Marignane raid last night left their diversion airfields in Cornwall and began trickling back to their own station, where the fog had cleared. After a two-hour flight the first aircraft arrived back at about 11.45.
463 Squadron left three aircraft unserviceable at Predannack. Almost joining them on the list of the broken was 467’s LM450 at St Eval. This was the aircraft which had apparently suffered an overheating port outer engine on the homeward flight last night. The Coastal Command engineers at St Eval had a look and couldn’t fault the engine, though they were not Merlin experts, and suggested that the trouble may have been a defective gauge in the cockpit. With that in mind, and not wanting to spend another day in Cornwall or risk the chance of a long train trip back to Waddington the aircraft’s captain, Dan Conway, discussed with his crew and decided on an unorthodox and highly unofficial plan of action: 
I said to Engineer Ray, ‘It’s a long runway and possible to get off on three motors. What say we start it up and let it run at low revs? Probably the gauge anyhow. Once about ready to get airborne you can shut it down and we can always unfeather it again to look good on landing. I can’t see the Flying Control letting us take off with one engine feathered.’
And so they did, taking off with all four props turning to keep up appearances for the controllers, feathering the offending engine shortly afterwards and proceeding to Waddington on three. But by this time the Waddington weather had closed in again and they found themselves diverting to nearby Bardney, where they unfeathered the propeller so it windmilled on arrival, again looking good for the tower. And finally, when word was received that Waddington was again clear, they went through the same process for the short flight back to base, where a ground inspection revealed – surprise, surprise – that the oil temperature and pressure gauges were both unserviceable. The Lancaster had performed beautifully on three engines. “As a matter of fact”, Conway later wrote, “the tricky bit was the taxying on the port inner and starboard outer, rather than using the two outer motors as usual. This was because the two outer throttles were longer than the others and bent in over them for ease of taxying normally.”
Waddington crews would be given the night off, but 5 Group were still active elsewhere on Friday night. Small forces of Lancasters were despatched to four factories throughout France. One aircraft failed to return but all targets were hit hard. Particularly noteworthy was an attack by 16 aircraft from 617 Squadron on a needle bearing works at La Ricamerie, near St Etienne. Both the leader (Wing Commander Leonard Cheshire) and the deputy leader encountered trouble while trying to mark the target as cloud meant they could not see it from an angle, only from directly above it. Essentially on the fly, Cheshire came up with a new marking technique. Diving low under the clouds, he dropped 30lb incendiaries on both the eastern and the western edge of the target area, and told the crews to aim at the middle of the glow coming through the clouds. Later photo reconnaissance showed the improvised technique had been most effective and the factory was completely destroyed.
Bomber Command also sent Mosquitos to Duisburg and almost a hundred aircraft on various special operations over the Continent. One Stirling was lost.
This post is part of a series called 467 Postblog, posted in real time to mark the 70th anniversary of the crew of B for Baker while they were on operational service with 467 Squadron at RAF Waddington, Lincolnshire. See this link for an in-depth explanation of the series, and this one for full citations of sources used throughout it. © 2014 Adam Purcell
 This quote, and the story, is from Conway (1995), The Trenches in the Sky, p.128-9. The ORB makes no mention of shutting down the engine on return from Marignane.
 Conway (1995), p.129
 Lawrence, W.J. (1951), No. 5 Bomber Group, R.A.F. 1939-1945, p.161
 Night Raid Report No. 548