Re: Seat mile costs

Date:         13 Jan 99 02:13:40 
From:         "Antoin Daltun" <>
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I believe it is actually necessary to filter the published "actual" data,
much of which does not make sense (for instance negative maintenance costs
if a lot of warranty claims are paid or credited in the quarter) and some of
which is driven by very carrier specific circumstances (different seating
configurations, prices of the aircraft, sector lengths, fuel prices, cost
allocations, block hours reported as flying hours or v.v.).

The manufacturers' data is probably reasonable to compare their own aircraft
(and may be on the web-site or in brochures that the PR departments can give
you).  When manufacturers show their aircraft as having seat-mile costs 8%
less than the opposition, it may be true under the specific rules used for
the comparison but not in the real world.  Since maintenance costs vary by
age, the answer may never be known!  One guide is that if, for instance,
B737-700/800 and A320 are both selling well, the airlines must believe that
the units costs are fairly close.  If they were not, the aircraft would go
out of production.

The importance of cargo is great for many non-US airlines.  If you credit
cargo revenue as a cost off-set, it transforms the relative seat-mile costs
of a wide-body compared to a narrow-body.  This is one reason why the B767
sold better internationally than the B757.  [Range is obviously also

Sorry if this sounds negative!  The question is a good one, but like many
good questions, the answer is quite difficult!

Antoin Daltun