Hello,
Can anyone link me to a calculator or help me find the information necessary to calculate Vx and Vy speeds in a Cessna 172? I am understanding that these speeds will change based on the weight of your aircraft.
I’ve already done a google search but I can’t find a good POH listing or information specific to the calculation and I was hoping you guys could shed some light on it for me. Thanks!
I had the impression for the 172 (and many other light GA aircraft) they just quote the one speed which is based on max gross weight. There are no performance tables like you get with larger planes.
However I do not fly the 172 so do not quote me on that.
In practice, in a low powered aircraft like 172 the difference between climbing out at Vx or Vy or some other speed in between is not huge, here is an article:
Section 5 covers computing airspeeds for weight and pressure altitude at various temperatures. Hope it helps.
Regards
Vx is the INDICATED airspeed (shown on Airspeed indicator) that results in the best climb ANGLE relative to the ground. Vy is the best rate of climb. Vx is generally used when climbing over an obstacle on take-off. For example, trees at the end of the runway, we want to climb to the greatest height before we get to the trees. Now, as much altitude as possible needs to be more than the height of the trees. Enter climb gradient. See page 134 of the POH linked on this page. After that, we are trying to climb to our cruising altitude as quickly as possible, but we are less concerned with how much ground slides by below us. In this case we use Vy. See page137 (5-17). The speeds are listed at Max gross unless otherwise noted, but in practice, they are slower, but only by a few knots.