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Old 18th Dec 2005, 00:06
  #244 (permalink)  
Airbubba
 
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>>The aircraft involved is a 737NG. The reversers on 737NG can be deployed if either radar altimeter senses less than 10 feet altitude.

Seems like there was a mishap years ago where a B-737-300 crew (Piedmont or USAir?) used an unauthorized short field technique from the -200. They closed the throttles and pulled up on the T/R levers in the flare. Unfortunately, as you mentioned the glass 73's use RA instead of weight on the wheels and a very hard landing ensued after the buckets popped while still airborne. ValuJet had similar incident where they pulled breakers on a DC-9 to try to fix a ground-air sensing problem with pressurization. Unfortunately autospoilers were fooled too, another hard landing. Ground-air sensing has subtle and significant effects to many systems on current airliners.

Here's the report on the ValuJet incident:

http://www.ntsb.gov/publictn/1996/AAR9607.pdf

With the NG's I think the reversers will still come out with weight on the wheels if the 10ft RA signal is not present due to a fault, does this sound right?
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