Take off safety speed single engine aircraft

[newtothegame200]

Hi all, I am fairly new to flying, on my way to a GFPT currently.

I just would like to find the quantified value of take off safety speed for aircraft. I know where the definition is in CAO 20.7.4, but what is it exactly? Is it based off stall speed of the aircraft, or rotate etc??

thanks all

[Tinstaafl]

Vtoss is specified in the take-off performance chart for the aircraft and is the speed to be achieved at 50'. The performance charts are based, in part, on achieving this speed at that 50' height. Note that Vtoss isn't the speed at which you rotate. Vtoss must not be less than 1.2 Vs1 (the stall speed in that configuration) but certification also has to account for handling qualities & protective buffers eg for turbulence, so it can be greater than 1.2 Vs1.

Multi-engine aircraft have an additional requirement that it must not be less than 1.1 Vmc, and handling/controllability requirements have to allow for complete failure of an engine.

Vr is something less than Vtoss and may not be less than Vs1 (single engine types), or 1.05 Vmc & 1.1 Vs1 (multis). You rotate at Vr and the aircraft lifts off, all the while accelerating to achieve Vtoss at 50'.

The requirements for the performance numbers are specified (in the US) in Title 14 of the Code of Federal Regulations (Aeronautics and Space), PART 23—AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES.

Other countries generally follow those criteria.


Oh, and here's a link to CFR14, Pt23: eCFR; Code of Federal Regulations (http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&rgn=div5&view=text&node=14:1.0.1.3.10&idno=14#14:1.0.1.3.10.2.60.8)