Flaps

[Mark Anderson]

I have been collecting old Comanche magazine advertisements from the sixties. Piper advertised for the 1962 Comanche that the flaps were improved, higher lift and better for short field landings. Is there really any aerodynamic difference in the flaps between 1961-1962 models, besides being electric? Would these flaps be interchangeable?

Thanks,

Mark

[Zach Grant L1011jock]

Yes the flaps are different. The manual flaps use an asymetric hinge type fowler flaps setup resulting in a Cherokee-esque flap movement, simply hinging below the wing, so moving slightly aft as they are extended down. The electric flap models actually use a tracked fowler type flap (think Cessna singles), where the flap translates aft as well as down, while using 3 flap tracks and rollers to do so. No they are not interchangeable, nor are the speed mods that interface with the flaps and wing (gap seals, spats etc). I would add that there really is not much difference operationally between the two types of Comanche flaps besides the power source, and more maint. required for flap tracks and rollers. The planes still go in and out of the same runways, and the flaps add lift, and drag, to an otherwise clean wing. The infinite adjustment capability of the electric flaps do make a difficult endeavour of repeatable partial flaps landings, which is why I advocate an all or nothing flap approach to electric flap birds. One more thing, the manual flaps survived until 1964, as they were the only flap system ever installed on the 180.

[N3322G]

Mark, Please excuse the slight thread hijack.

Zach, like the new photo - what a very spacious 'Comanche' cockpit

[Hank Spellman]

Zach did not mention another important difference between the two flap designs: the effect on the weight and balance loading envelope.

If you compare the two envelopes (available in the type data sheets), you will see that the electric flap models allow for an increased forward loading over the manual flap model at higher weights. This is important because the 250's tend to be a little heavy in the nose.

The aft limits are the same.

Hank

[Mark Anderson]

Zach and Hank, thanks for the explanation and background. I never noticed the difference. I like the manual flaps on my 61 model. Next time I see an electric flap model I will look for the differences. I just about always use 2 notches for take off and full for landing. I figure this way when I am heavy or using a short runway I won't forget to use flaps.

[9089P]

Not to disagree with Zach but I have electric flaps and use partial flaps on a regular basis with no problems. My flap indicator gauge is consistent in its readings (I checked by putting indicator lines on the flaps using black electrical tape) and fairly accurate with regard to the 1/2 flap indication(bottom of the white arc on the flap gauge). I generally put the gear down on the 45 and go to 1/2 flaps on the turn to downwind for better vis and to further slow down. Go to full flaps on final unless there is a hefty cross wind.

Good luck, Don