in both cases the aircraft achieves its maximum speed at 16,000ft but then both climb and speed decrease until the aircraft reaches its service ceiling of 23,000ft. An The Lancaster III can simply carry 10,000libs more weight. An aircraft at its service ceiling is at a climb rate of 100ft/minute (0.5m/sec) and is on the edge of a stall with little margin for manoeuvring. With reduced load we can get the Lancaster III operating at 23,000ft but the aircraft will be much slower in speed and climb than a B17G.
So, let's argue the point, as Glider rightly points out, why is that a problem? It's a bomber, not a fighter, far less likely to be achieving this over the target area, at which point of the flight regime the aircraft is at cruising speed and best altitude that the operation dictates. When fully laden you don't blat up at your maximum climb speed after take-off, you'd short change yourself of fuel. You climb at the most economic rate of climb to the best altitude for the operation required and the time it takes and speed of the climb is of secondary importance to preserving fuel economy at its maximum weight, which is at take-off.
n aircraft at its service ceiling is at a climb rate of 100ft/minute (0.5m/sec) and is on the edge of a stall with little margin for manoeuvring.
Taken from the document "A review of the performance and handling trials of ten production Lancaster Mk.III aircraft"
All up weights from 63,000 lbs to 54,000 lbs
4.13. Climb in FS Gear at max. climbing power, i.e. 2850 rpm + 9lb/sq in boost. Mean of ten aircraft.
Rate of climb: Constant from 12,000 ft to the full throttle height. 590 ft/min
Full throttle height, 15,800 ft
Time from 12,000 ft to 20,000 ft, 16.7 min
Service ceiling 23,200 ft
Here:
Lancaster III Performance (wwiiaircraftperformance.org)
Taken from the document " Memorandum Report on B-17G Airplane AAF No. 43-37746"
One climb... was run at a take-off gross weight of 57,650 lbs, cowl flaps wide open, calibrated airspeed 138 mph and 2,300 rpm and 38 inches of mercury. The results are as follows:
Altitude Bhp per engine Rate of climb Ft/min Time to climb min Gross weight lbs
SL 985 720 0 57,600
10,000 990 640 14.5 56,950
15,000 995 550 22.5 56,570
25,000 1015 270 47.5 55,550
Here:
Memorandum Report on B-17G Airplane, AAF No. 43-37746 (wwiiaircraftperformance.org)