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From: chad@anasazi.UUCP (Chad R. Larson)
Newsgroups: net.aviation
Subject: Re: Commercial aircraft power-to-weight
Message-ID: <457@anasazi.UUCP>
Date: Mon, 30-Dec-85 23:25:09 EST
Article-I.D.: anasazi.457
Posted: Mon Dec 30 23:25:09 1985
Date-Received: Wed, 1-Jan-86 04:57:27 EST
References: <59200011@trsvax>
Reply-To: chad@anasazi.UUCP (Chad R. Larson)
Organization: Anasazi, Phoenix Az.
Lines: 37

In article <59200011@trsvax> gm@trsvax writes:
>
>...Of the currently flying (subsonic) airliners, which one has
>the highest power-to-weight ratio?...
>
There are standards in the FAA's certification procedures that specify
minimum performance characteristics for aircraft in degraded
configurations.  One of those configurations is with an
inoperative engine.  This means, for example, that a four-engined
plane needs to have much less power reserve than a two-engined
plane (since the engine-out configuration for a two-engined plane
is single-engined).  From this you can see the twin engine type
planes will be built with good power-to-weight ratios (as you
noted about the 737's).  This doesn't always translate into
take-off acceleration, however.  Most airlines now use take-off
power computations to determine the minimum power setting for any
given field/temperature/wind combination, under the assumption
that lower power settings save fuel, wear and noise.  Percevied
acceleration by the passenger is more often a function of the
above parameters than the power-to-weight.

For what it's worth, I've known captains with enough seniority to
fly any route they wanted who flew 737's instead of 747's/DC-8's.
They said the 737 is more like a sports car when compared to the
bigger planes.  More power reserve, better roll rate, etc.  Also,
they get used on short hauls which means more take-offs &
landings (the fun part).

The Concorde is, of course, a different deal.  It has massive
power to be able to overcome the drag associated with super-sonic
flight.  It also uses that power (afterburners, even!) to get to
the high lift-off speeds its delta wing requires within normal
runway lengths.  It *does* have strong acceleration.

	-crl

Generic disclaimer goes here...