Re: Maintenance questions

Date:         01 Dec 96 04:08:53 
From:         Reid Fairburn <cr_king@cr_king.seanet.com>
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At 06:18 AM 11/25/96, you wrote:
>Some more questions from someone who doesn't know too much about
>aircraft but who is interested in them.

I will throw out some general answers but I am not an expert on this side
of the airplane.

>A friend is coming back from Paris later this week and I heard he
>discovered his friend is going _to_ Paris on the same plane on
>the turnaround.  I think it might be an Airbus (Air France) on
>the Toronto - Paris run.
>
>What all will be happening to this plane between flights?  I know
>there's the passengers and luggage and cargo off and on.  Must be
>a galley going off and a new one going on and the same for
>sanitary waste.  Then there's fuel to be pumped aboard.
>
>But what else happens?

Cargo unloaded and loaded, Passengers unloaded and loaded, Airplane
is cleaned and any quick interior maintenance could be accomplished on
things like the movie system, interphones, lights, etc., Old food and
supplies are unloaded and new food uploaded, all the sanitation facilities
are serviced, water tanks are filled, fuel is uploaded, engines are given a
quick inspection for things like oil levels, blade condition, leaks of
hydraulic, oil, or fuel, minor repairs to engine and systems as required by
pilot or maintenance inspection reports, a thorough airplane preflight
inspection for systems integrity and tire/brake conditions, structural
integrity is given a quick visual inspection, and sometimes I would think
the airplane might get washed and deiced if appropriate.  Also, when there
are maintenance items of serious nature, these must be fixed before the
airplane departs.  Last, but not least, the flight crew changes, the flight
plans are filed, crew briefings take place, and passengers are bedded down
for the flight.  Not bad for a couple of hours, huh!

>After being in the air for 6 hours (or whatever it is) do they
>have to check/change oil and do a big number of maintenance tasks
>after a flight of that length?  Just curious.

Generally, oil levels are just checked.  After XX number of operating
hours, the oil will be changed and other maintenance will be accomplished
on a scheduled basis which will take the airplane out of the flow for a
day or so.

>Also (as long as I'm in an asking mood) how much of the time are
>planes like this on the ground (maintenance, etc.) compared to
>being in the air.  I'm sure the owners don't keep them on the
>ground any longer than they actually have to (they can't make
>money sitting on the tarmac) but how much of a typical 24 hour
>cycle are they actually in the air?  What percentage of a week?

This varies with each airline with a good guess at the average being about
12 to 14 hours for small airplanes (737 size) and up to 18 or more for
the large overseas carriers.  Airplanes sitting on the ground accrue
interest costs without earning any income...and the fleet interest is
something you don't even want to hear even when discussed in terms of
hours!  (might make you very nervous about Christmas time when the bills
roll in!) Luckily, the airliners of today are very reliable and have a
good record of not needing continual maintenance...you can run the pants
off of them without too much worry...land most airlines do.


Reid Fairburn
Creative Kingdom, Inc.
cr_king@cr_king.seanet.com
206-946-4815