Re: Fuel Dump Question

Date:         30 Nov 98 03:07:39 
From:         "Phil" <dredbyte@concentric.net (remove)>
Organization: Concentric Internet Services
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JF Mezei wrote in message ...
>Question:
>    Since dumping of fuel is used for an emergency which requires the
>    plane to land ASAP, (are there other uses?), why would the FAA want

Or, fuel dumping may be necessary to lighten the plane enough to fly at
a safe altitude. For example a 727 will fly okay on two engines, but if a
second engine failure occurs during  a missed approach, the a/c
may sink unless fuel is dumped. Having gear and lift devices out cause
enough drag to make flight quite unsafe on one engine. A single engine
landing in the 727 uses only flaps 5 degrees, so a heavy airplane will
use a lot of runway in addition to being unable to climb on one engine.

>    the fuel dumping system to retain enough fuel to climb and fly for
>    45 minutes? Is this to allow for a missed approach? Do missed
>    approaches really take that long, do planes really climb back to 10k
>    feet?

If the situation is really bad (nearest alternate field far away), a miss and
reroute can eat up a lot of time and fuel, especially at low altitudes.

So, the fuel is dumped to reduce weight, but not to an unsafe level. One
must keep reasonable options available in case circumstances take a
turn for the worse. Therefore some safeguarding is built in.

Also, the ability to dump fuel depends on the sutuation - if there are
buses being de-energized to deal with an electrical fire, some or all
of the dump system may not function.

Hope this helps shed some light on fuel dumping.

Phil Collier