Torque and P-factor

[Marten Kemp]

I'm a 200-hour private pilot and was wondering about
torque and P-factor effects in high-powered aircraft,
especially warbirds.

From what I've read they could be significant,
especially during takeoff and landing, and were a major
reason for operational write-offs. Narrow-track gear
were especially vulnerable.

With my most robust flying being in a 182 about the
only experience with P-factor was with a little
pull to the left on takeoff.

--
-- Marten Kemp (Fix ISP to reply)

[Orval Fairbairn]

In article >,
Marten Kemp > wrote:

> I'm a 200-hour private pilot and was wondering about
> torque and P-factor effects in high-powered aircraft,
> especially warbirds.
>
> From what I've read they could be significant,
> especially during takeoff and landing, and were a major
> reason for operational write-offs. Narrow-track gear
> were especially vulnerable.
>
> With my most robust flying being in a 182 about the
> only experience with P-factor was with a little
> pull to the left on takeoff.

In addition to P-factor, you can encounter inertial coupling between the
prop and airframe when making pitch changes (such as landing flare or
lifting the tail on takeoff) with the large warbirds.

[Marten Kemp]

On 8/11/2013 3:45 PM, Orval Fairbairn wrote:
> In article >,
> Marten Kemp > wrote:
>
>> I'm a 200-hour private pilot and was wondering about
>> torque and P-factor effects in high-powered aircraft,
>> especially warbirds.
>>
>> From what I've read they could be significant,
>> especially during takeoff and landing, and were a major
>> reason for operational write-offs. Narrow-track gear
>> were especially vulnerable.
>>
>> With my most robust flying being in a 182 about the
>> only experience with P-factor was with a little
>> pull to the left on takeoff.
>
> In addition to P-factor, you can encounter inertial coupling between the
> prop and airframe when making pitch changes (such as landing flare or
> lifting the tail on takeoff) with the large warbirds.

Thanks. This is kinda-sorta related to an alternate-history
timeline where a bunch of starships from about 1000 years
in the future wind up near Earth in 1920. One of the new
tech things they're doing is pushing aircraft technology
up a bit - mainly with higher-powered radial engines, all-
metal construction, wide-track tricycle gear, flaps, disc
brakes, fuel injection and dual mags.

http://www.alternatehistory.com/discussion/showthread.php?t=181588
(free registration required)


--
-- Marten Kemp (Fix ISP to rply)

[Dudley Henriques[_3_]]

On Sunday, August 11, 2013 10:54:08 AM UTC-4, Marten Kemp wrote:
> I'm a 200-hour private pilot and was wondering about
>
> torque and P-factor effects in high-powered aircraft,
>
> especially warbirds.
>
>
>
> From what I've read they could be significant,
>
> especially during takeoff and landing, and were a major
>
> reason for operational write-offs. Narrow-track gear
>
> were especially vulnerable.
>
>
>
> With my most robust flying being in a 182 about the
>
> only experience with P-factor was with a little
>
> pull to the left on takeoff.
>
>
>
> --
>
> -- Marten Kemp (Fix ISP to reply)

You are correct. The forces can be considerable, especially at low airspeed, high angle of attack and during changes in pitch.
One thing to remember concerning this is that although spiral slipstream forces, gyroscopic precession, and P Factor are yaw associated, torque is a correction in ROLL not yaw.
These forces are easily controlled by proper control use, allowing dynamic pressure to develop on control surfaces via airspeed, and carefully controlled changes in pitch.
Dudley Henriques