Re: MD-80: Lawn Dart or Efficient Design?

From:         "David G. Davidson" <>
Date:         08 Aug 96 12:11:54 
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>apparently good serviceability (any airline mechanics here who
>can comment on that?)

I can and I think you'll find that most mechanics that have had an
oppurtunity to work on any MD product versus Boeing (we'll just talk
narrow-body here) will think that the MD product is a big pain in the
butt, in general, to work on. Like anything they each have there good
and bad points.

*AC Packs - Boeing's system is better. Placing the components in the
belly is much better than hanging them from the top of the tail cone as
MD has done. It is very difficult to work on a MD pack. The tail cone is
always dark, hot and hard to move around in. Also the MD AC system
doesn't cool as well as the Boeings.

*Pneumatic System - Again Boeing has the edge, with components located
on the engine or in the airstair area on a 727. The MD system is more
complicated and the augmentation valve is located at the bottom of that
damn tail cone.

*Hydraulic System - servicing is more difficult on the MD product.
Working on the MD components is difficult since they are located in the
wheel well and you have to stand on the curved and always slippery

Not to be outdone though, the 727 'B' pumps are located in a miserable
location and are not easy to deal with.

*APU - Terrible on a MD, with the apu exhaust duct going through the
right half of the tail cone. That makes it that much harder to do
anything in the tail cone.

The 737 APU installation is far from perfect though. Oil servicing is
unreal and working on the thing requires the removal of the large,
stainles-steel "bath tub" that surrounds it.

727 APU installation is the best of the three, but also far from ideal.
The 757/767 are the one's to copy here.

*Flight Controls - much simpler on an MD, but just doesn't seem right to
fly an airplane that big with control tabs.

*Electrical System - goofy use of Cross-tie relay on the MD. Power
center located behind FC FA seat is bad. Changing power relays is a big
chore. Simpler and easier to understand system on the Boeings.
MD also has a habit of hiding relays and circuit breakers in odd and
inaccessable places

*Standby Compass - requires use of glareshield mounted mirrors to use on
the MD (extra cheesy!) Lot's better on the Boeings.

*Main Gear Downlock Spotlights - horrible on the MD. No excuse for this.

*Crew Seats - Much better on an MD than that over-engineered stuff found
on the 727 and 737. Seems newer 737s have the same seats that the later
MDs have.