1
$\begingroup$

What is the highest speed at which a Cessna 172 can taxi without lifting off the ground? If you removed the wings, how fast could it taxi? (Answers only answering the first part are fine; I doubt the published specifications include "maximum wingless taxi speed")

$\endgroup$
2
  • 8
    $\begingroup$ please don't change the headline ("How fast can a Cessna 172 taco?") $\endgroup$ Oct 10, 2022 at 6:44
  • 5
    $\begingroup$ I'm just happy this isn't about the speed at which at 172's wings turn into a taco $\endgroup$
    – zymhan
    Oct 10, 2022 at 16:05

1 Answer 1

5
$\begingroup$

The Cessna 172 has an NACA 2412 airfoil with 1 1/2 degree of wing incidence at the root with 3 degrees of negative washout at the wing tips.

According to the Airfoil Tools data charts, this will generate a lift coefficient of around 0.4, compared with 1.6 at stall.

If the "stall speed" is around 50 knots at maximum coefficient of lift, then the Lift Equation can be used to determine the speed required to fly with 1/4 the coefficient of lift:

50$^2$ × 1.6 = X$^2$ × 0.4

X = around 100 knots

So, theoretically, it could be done, but it would be very tough on the nose wheel and is not recommended. Key here would be the trim setting, which controls the elevator. If it were set for "take off", then that is what will happen (even without yanking the stick back) at around 65 knots.

On a brighter note, it does encourage one not to slam on the brakes after nosewheel touchdown when landing for fear of being lifted back into the air from a slight headwind gust. Have a nice taxi back to your parking spot.

$\endgroup$
1
  • $\begingroup$ Generally, trim setting is reduced significantly during transition to cruise airspeeds. $\endgroup$ Oct 10, 2022 at 12:37

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .