V1 in smaller aircraft
Thread Starter
V1 in smaller aircraft
Hi, non aviator so please bear with me.
As I understand it V1 is called when there is insufficient runway to stop the aircraft so it is committed to flight.
When a smaller aircraft is operating from a long runway, so there is still room to stop from Vr, is V1 still called?
Just curious, thank you.
As I understand it V1 is called when there is insufficient runway to stop the aircraft so it is committed to flight.
When a smaller aircraft is operating from a long runway, so there is still room to stop from Vr, is V1 still called?
Just curious, thank you.
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When V1 increases as the runway gets longer, the maximum value is the associated Vr (or 'rotate'). So instead of calling 'V1,Vr' very quickly, the standard convention is just to call Vr meaning 'don't stop now, and rotate please!'.
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Upper limit of V1 is Vmbe (max brake energy) and lower limit is Vmcg. It can be moved between the two and it is generally constrained by runway length or Vr.
I think a pilot reaction time of a couple of seconds is built into V1 and most would not react well to a call of "Veeeonerotate!". Anything greater than a 3 or 4 knot split seems worth calling though.
I think a pilot reaction time of a couple of seconds is built into V1 and most would not react well to a call of "Veeeonerotate!". Anything greater than a 3 or 4 knot split seems worth calling though.
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AeroSpark,
If I zero in on your reference to "smaller" aircraft, I assume that you refer to light, non Transport category aircraft. Smaller transport category aircraft like the Jetstream 31 still obey essentially the same rules as a B747, and V1 is called.
If my assumption is correct that you do refer to light, non Transport category aircraft, such as the Beechcraft Baron, Partenavia PN68, single engined aircraft etc., then there is no certification requirement that the aircraft be able to reject a takeoff by no later than V1 and stop within the available runway length, and thus no V1 is calculated, or available.
If no V1 is available, then it cannot be called (but even if it was the pilot would be talking to him/herself).
Regards,
Old Smokey
If I zero in on your reference to "smaller" aircraft, I assume that you refer to light, non Transport category aircraft. Smaller transport category aircraft like the Jetstream 31 still obey essentially the same rules as a B747, and V1 is called.
If my assumption is correct that you do refer to light, non Transport category aircraft, such as the Beechcraft Baron, Partenavia PN68, single engined aircraft etc., then there is no certification requirement that the aircraft be able to reject a takeoff by no later than V1 and stop within the available runway length, and thus no V1 is calculated, or available.
If no V1 is available, then it cannot be called (but even if it was the pilot would be talking to him/herself).
Regards,
Old Smokey
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In addition to Old Smokey's excellent reply (as usual), care should be exercised with regards to light twins, either piston or turbopropellor powered), as climb performance in the climb on one engine can be marginal, at best (except on certain types...the CE441 for example).
It is generally recognised that one needs to attain Vyse to get any sort of positive climb performance. and further, the closer you can get to that speed, while still on the runway, so much the better.
With some types this can be rather difficult, as the aeroplane will start to 'wheelbarrow' on the nose wheel, so a slower liftoff speed needs to be used...with very much reduced climb performance should an engine fail at the most inopportune time.
It is generally recognised that one needs to attain Vyse to get any sort of positive climb performance. and further, the closer you can get to that speed, while still on the runway, so much the better.
With some types this can be rather difficult, as the aeroplane will start to 'wheelbarrow' on the nose wheel, so a slower liftoff speed needs to be used...with very much reduced climb performance should an engine fail at the most inopportune time.
