[41Sqn_Banks]

Originally Posted by camber

Well this is pretty clear and supported by the reference. the Spittie pilots doing that test climbed at constant IAS mostly and recorded climb rate.

Obviously the pilot can choose to climb at constant IAS if aircraft capability permits. I take it, this statement should be:

Vx (IAS for best climb angle) and Vy (IAS for best rate of climb) will never be constant with altitude."

This is true enough but I know a flight instructor that had it a bit confused . So climb tests at constant IAS (such as that Spittie one) may not be capturing optimum rate of climb at each altitude? Interesting.

Spitfire I Pilot's Notes state:

CLIMBING

9. For maximum rate of climb the following speeds are recommended: -

Ground level to 12,000 feet 185 m.p.h. A.S.I.R.

12,000 feet to 15,000 feet 180 " "

15,000 " 20,000 " 170 " "

20,000 " 15,000 " 160 " "

Hurricane I Pilot's Notes state:

Optimum climbing speeds (A.S.I. reading)

For aeroplanes fitted with 2-bladed wood airscrews to Drg. No. Z. 3895 and with kidney type exhaust manifolds, the optimum full throttle indicated climbing speed at sea level and up to 10,000 ft. is constant at 157 m.p.h., A.S.I. reading with a reduction of 1 m.p.h. for each additional 1,000 ft. of altitude.

Note. - The all-up weidght of the aeroplane during the tests upon which the above climbing speeds are based was 6,000 lb.