Mh, have a defined speed for getting airborne by all means, but can we call it something other than rotation speed pleasebq.?
Why not and what schould we call it then?
In our C172N Superhawk (180HP) I trim it a lot more than the original November, hold the yoke back to relieve the nose strut and at approximately 60 it lifts off by itself. Then, to avoid overheating the cylinders (EDM700 shows warnings) I accelerate to cool things until reaching 95.
We consider 65, 70 and 75 as Vx, best glide and Vy.
One major error pilots will make is assuming that Vx and Vy are independent of configuration, weight, and density altitude. On my Bonanza, Vy in the POH is listed at 96 Kts. What is not stated in the POH, is that this figure is for the clean configuration at a density altitude of 5000 feet and maximum gross weight. If you attempt a go around and accelerate to Vy while the gear and the flaps are down, the aircraft will barely climb, if at all. On the other hand, Vy for this configuration is actually 70 Kts and the airplane will climb quite nicely. That is a 25 Kt difference from the POH value! My point is you need to understand under what conditions these speeds apply. My experience teaching Bonanza pilots is they are oblivious to this fact.
One major error pilots will make is assuming that Vx and Vy are independent of configuration, weight, and density altitude.
And propeller pitch too when a fixed pitch prop has been changed, or converted to/from a variable pitch prop.
Mh, have a defined speed for getting airborne by all means, but can we call it something other than rotation speed please?
Why not and what schould we call it then?
The reason not is because it is not applicable to a single engined aircraft.
You could call it takeoff speed, I suppose. My students seem to manage fine with that, but I try to get them judging when the aircraft is ready to fly by the way the controls feel. Sometimes I have to give them a hint…
Strictly speaking V1 and V2 are for multi engine jet aircraft, no reason why Vr is so constrained.
NYCY good point, made me check out Eckalbar’s flying the beech bonanza, where he carries out tests to establish Vx and Vy in different configurations. While never flown a Bonanza, the book is a great primer for exploring performance in other types.
I am with PiperC on Vr.
Vr is a swept wing concept, I am not even sure the Slowtation needs Vr, in an aerodynamic sense of the word. Using it in GA speak is a bit like wearing epaulettes for basic civil aviation training.
I use lift off speed. Sure some GA types need some positive back pressure, but this is not rotation in the swept wing sense of 15 degrees plus pitch up.
I don’t agree that Vr only applies to swept wing aircraft. Neither does the FAA. Part 23 specifies “AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES”. Section 23.51 specifies takeoff speeds:
Sec. 23.51 Takeoff speeds.
(a) For normal, utility, and acrobatic category airplanes, rotation speed, VR, is the speed at which the pilot makes a control input, with the intention of lifting the airplane out of contact with the runway or water surface.
(1) For multiengine landplanes, VR, must not be less than the greater of 1.05 VMC; or 1.10 Vs1;
(2) For single-engine landplanes, VR, must not be less than Vs1; and
(3) For seaplanes and amphibians taking off from water, VR, may be any speed that is shown to be safe under all reasonably expected conditions, including turbulence and complete failure of the critical engine.
I don’t call it Vr particularly but I think rotate as the airspeed hits 85 unless I am very heavy then I add a bit. But I don’t think it matters. Flying is flying. While we shouldn’t get obsessed with using Multi Engine jet terminology, let’s no go too far the other way either.
NYCY note my modifier, in the aerodynamic sense of the word.
In a soft field take off the control input is actually before Vs as you are holding the control column back – are we then in violation of the airworthiness certificate?
