Michelle P wrote:
An interesting dilemma.
The manual for the 172 N tells you that 0-10 degrees is acceptable for
takeoff. However it does not tell you what affect it has at low altitude
300 feet MSL Density altitude around 2500 MSL. It only states that it
will have a detrimental affect at high altitude on a hot day. It also
does not give an airspeed for Vy flaps 10 degrees.

In talking to another pilot who has an 172 L has states that his manual
says if 10 degrees flaps are used it will decrease ground roll and
decrease climb rate. Having an overall detrimental affect.

The only definitive number the 172N manual states for flaps 10 degrees
is Vx.

First hand experience seems to confirm what the 172 L manual says.

What do you all think?
Michelle

I used to rent a 172L a lot many years ago, and used 10 degrees to
reduce the takeoff roll but for me it *increased* the rate of climb
slightly at airspeeds between Vx and Vy. Any more than 10 degrees and
it certainly hindered climb rate, but on really soft or muddy turf
strips, I'd use a little more than 10 degrees by carefully bumping the
flap switch down in short spurts during the takeoff roll until it felt
better and got the mains off the ground, then once a positive rate of
climb was established I'd carefully retract the flaps a small amount at
a time until the airplane was happier. A lot of the other renters hated
the spring-loaded up/down flap switch in the 172L because you had to
keep it pushed up or down to run the flap motor, but I liked being able
to 'fine-tune' the flaps to what felt best in a given takeoff situation.