"Snowbird" wrote in message
m...
I'll be interested in what others say, but my take on this is:

As far as I know, all the V-speeds you're talking about are a direct
function of stall speed.

For landing, true. For takeoff, not true. Vx and Vy, being the result of
excess thrust and excess power (respectively), depend not just on the fixed
characteristics of the airframe, but also the declining characteristics of
the engine (and are not directly related to stall speed in any case).

Now, that said, I agree with the others who point out that if the airplane's
performance has changed enough that the published V speeds are not correct,
then the airplane needs fixing. A slight reduction in engine power might be
expected, but one large enough that Vx and Vy have changed enough for the
pilot to notice warrants repair.

And as you say, even the airframe can suffer during its lifetime in ways
that might affect stall speed. But again, I'd say that if the stall speed
has increased above the published speeds, the correct course of action is to
fix the airplane.

And generally speaking, I wouldn't expect the stall speed to change in a way
noticeable to any but the most detail-oriented test pilot; changes in gross
weight are going to be much more significant, and those mostly occur due to
differences in loading (how many passengers, what weights, amount of fuel
carried, etc.). 30 pounds of accumulated junk, while not unheard of, is
still unusual, and even that much extra weight isn't going to produce a
noticeable change on the airspeed indicator when stalling the airplane.

I'm in complete agreement that it's foolish to add airspeed on landing. The
extra speed might put you farther away from some problems (premature stall)
but it's guaranteed to put to closer to other problems (long landing,
porpoising, nose strike, etc.). Adding airspeed to compensate for gusts is
reasonable, but adding airspeed just because you think the airplane is old
is not, and is unsafe.

Pete