GA take off performance
Thread Starter
Joined: Oct 2005
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From: Derbyshire
GA take off performance
More of a request here than a question, but could anyone direct me towards a sample of a takeoff performance chart / graph for a general aviation aircraft? Something that will determine the gross TODA / TORA? Just a sample will do for refrence purposes.
Furthermore, does anyone know why the TODA is taken to 50ft for GA and 30ft for comercial ops? My understanding was that 30ft was inteded for large aircraft to clear runway lights etc, though i cant see why GA should have an extra 20 ft, or is that perhaps a safety margine for the PPL holder? Incase anyone was interested where I obtained this informantion, it came from the OA PPL course on the cd's.
Regards,
Antony
Furthermore, does anyone know why the TODA is taken to 50ft for GA and 30ft for comercial ops? My understanding was that 30ft was inteded for large aircraft to clear runway lights etc, though i cant see why GA should have an extra 20 ft, or is that perhaps a safety margine for the PPL holder? Incase anyone was interested where I obtained this informantion, it came from the OA PPL course on the cd's.
Regards,
Antony
Fixed+Rotary (aircraft, not washing lines)
Joined: Jan 2005
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From: Peak District, Yorkshire, UK
Antony
This may help in what you are looking for, but not a performance chart for any specific GA aircraft.
http://www.gasco.org.uk/upload/docs/...afety16-18.pdf
GASCo's Performance Calculator a.k.a. "Avoiding the Far Hedge"
On the subject of the 50' clearance limit - could be something to do with trees which are quite common near some airfields.
This may help in what you are looking for, but not a performance chart for any specific GA aircraft.
http://www.gasco.org.uk/upload/docs/...afety16-18.pdf
GASCo's Performance Calculator a.k.a. "Avoiding the Far Hedge"
On the subject of the 50' clearance limit - could be something to do with trees which are quite common near some airfields.
Joined: Apr 2001
Posts: 231
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From: London UK
Screen height (30 or 15 feet depending upon dry or wet conditions) and obstacle clearance are very different things. Light and heavy types are certificated to different schedules hence the difference.
Larger types are certificated with guaranteed performance in that, having reached the V1 they are going to complete the take-off to the end of the Net Take Off Flight Path (at least 1500 feet with all the obstacle clearance data).
Light types do not necessarily enjoy such good performance.
The 50 foot obstacle is simply a way of standardising performance data and producing conditions that are likely to be encountered.
Larger types are certificated with guaranteed performance in that, having reached the V1 they are going to complete the take-off to the end of the Net Take Off Flight Path (at least 1500 feet with all the obstacle clearance data).
Light types do not necessarily enjoy such good performance.
The 50 foot obstacle is simply a way of standardising performance data and producing conditions that are likely to be encountered.
Thread Starter
Joined: Oct 2005
Posts: 43
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From: Derbyshire
To the best of my knowledge, T/O performance graphs for GA aircraft are based upon ideal conditions achieved by a single test pilot. Maybe they could consider displaying a poor performance example so the GA pilot could gain a better idea of what would really happen? What do you think?
Antony
(PS many thanks for the advice and links)
Antony
(PS many thanks for the advice and links)
Joined: Apr 2001
Posts: 231
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From: London UK
Depending upon the type you are looking at the graphs may be gross (unfactored) or net (factored).
The gross performance data must be representative - no heroics required. In order to achieve very close to those numbers you must fly the aircraft as close to the criterea stated on each graph. Net performance should be attainable by the worst pilot on the worst day in the worst aircraft but there is a limit.
If the approach speed at gross mass is 67kt and you choose to use 75kt (like most clubs that operate the Warrior, for example) then all the net factorisation in the world will be fairly worthless as you burn up excess 1/2rho V squareds (sic) in the rather prolonged flare.
m
The gross performance data must be representative - no heroics required. In order to achieve very close to those numbers you must fly the aircraft as close to the criterea stated on each graph. Net performance should be attainable by the worst pilot on the worst day in the worst aircraft but there is a limit.
If the approach speed at gross mass is 67kt and you choose to use 75kt (like most clubs that operate the Warrior, for example) then all the net factorisation in the world will be fairly worthless as you burn up excess 1/2rho V squareds (sic) in the rather prolonged flare.
m
