Just wondering if anyone may be able to point me to a suitable website or other tech forums that can provide some realistic data on single engine service ceilings for light piston twins, e.g. Seminole, Partenavia, Baron. Or maybe some of you out there have info you can provide me yourself.
If a jaundiced mind can put a few caveats into the discussion ..
(a) be very wary of published light aircraft performance data
(b) if it comes from the manufacturer, it will be based on just about the best conditions you can find
(c) an older aircraft, turbulence in particular, ISA plus deviations, non-optimum handling by the pilot .. etc ... etc.... and the quoted level goes down ... down ... down ...
All performance data is achieved under the most favourable conditions the manufacturer can find, not just light aircraft, Boeing, Airbus same same.
If the aircraft has an Airplane Flight Manual or equivalent in the Type Certification Data Sheet ( or equivalent), that is certified data, compiled to the requirements of the time/era of certification.
Remember that most FAA FAR 23 twins, unless they are certified to the "Commuter amendment", don't have a certified engine out performance at all.
Hence the old saying " A single engine aeroplane, with twice the chance of engine failure".
Interestingly enough, in the rare case of a forced landing in a "conventional" light twin, the incidence of loss of control is a statistically significant issue, and something that obviously doesn't apply to a single, including C208/PC-12 and so on.
Many pilots, depending on experience, would be well advised to treat an engine failure in a light twin as a single, unless the god's and the conditions are really on your side.
Not quite that simple. The requirement for 6000lb plus aircraft has for many years involved a modest OEI climb capability .. for the present regs (23.67) this is a respectable requirement. The problem is with the below 6000lb twins where it is all downhill ....
Most Ozzies will be aware that the Shrike Commander, eg, runs at a higher weight here than in the US as the Australian OEI climb requirement under ANO101.22 was less restrictive than the FAA requirement .....
While the manufacturer will always go for the best conditions to test (so that, near invariably, climb testing is done in a very stable weather pattern somewhere near dawn) the FAR 25 data is provided for a useful range of operating conditions .. the FAR 23 pilot gets not very much at all by comparison .. although the situation has been getting better in recent years ...
Last edited by john_tullamarine; 23rd Jun 2002 at 09:07.
Piston Twins - Single Engine Ceiling
