Reasonable argument Muff, but in the specific case of a 172SP (down and welded gear) with a normal cruise TAS of 115 knots (older 172's 110 knots), how reasonable is it to expect that it would be able to maintain a minimum (perf Cat B speed) of 120 knots indicated during a level segment of an Initial Approach, as per AIP ENR 1.5 sub 1.15.1.
P!ssing in the wind, is the phrase that comes to mind.
Edit
The intent of the ability to change performance category is surely not to be decided each and every flight. I operate an aircraft that is flown to a different perf category to that which its Vat would otherwise say. But each and every pilot must operate it on every flight to that category. Besides in the case of a C172, which handling speed would require it to be operated in Cat B. Apart from Vne and Vno, Va @ MTOW is the only limit speed that cracks 100 knots.
Last edited by Trent 972; 13th Nov 2010 at 13:10.