a new Captain would get one or two trips to gain some experience,
How would that work, I wonder? Does it mean riding as supernumary in another crew?
A pilot either flew an operational sortie with his crew, or he didn't fly at all,
AFAIK.
My father converted to Lancs from Wellingtons from 9th August 1943 (before he did any flying over Germany apart from a bombing trip on 4th Sept 1939).
On 21 Sept he did a "Bombing & Air Firing Exercise Wainfleet" with his crew.
On 22nd September, he did a 1 hour flight "NFT and Liaison with AMPV", followed by a 5:30 bombing trip to Hanover, all with the same crew.
On 23rd September they flew to Mannheim, on 24th they flew "Base - Ford - Base" and on 26th a sortie "NFT - API Test" for 40 minutes, followed by Hanover again but aborted (2:30 flight time) due "Rear Gunner u/s"; it's not clear if he meant the guns or the gunner.
On 29th Sept. it was a trip to Bochum with the same crew, and on October 2nd it was Munich. On the return from that they were shot down in a fighter attack, and the aircraft exploded on the way down at 6,000 ft, thus proving the adage about 5 trips.
Perhaps if he had flown the "experience" trips, things might have turned out better. (He survived, just, to spend the rest of the war in SLIII, thus taking part in the "long march" in the final stages.)