Originally Posted by
SWAcapt
Most of us thought the same thing. On the day of the mishap, I was of the belief that all turbojet/turbofan airliners were certified with stopping data that did not include the use of t/r's and that they were added 'gravy'. I have since heard that that data in our onboard performance computers (OPC) for our -300s does not account for the use of reverse thrust (SWA software product). I heard that the -700s did use the effects of reverse thrust and that this is a Boeing software product. I do not know to this date if the -700 certified stopping distances use t/r effect or if they just added it to the OPC software to increase the performance perception. Perhaps a Boeing engineer or some
one with an actual Boeing 737NG flight manual could enlighten us.
Had recurrent this week and asked this very question. At the time of the accident, the 300/500 did not use T/R in it's landing distance calculations. The 700 at the time did however, which the crew did not know. This tidbit was not in the FOM and the crew assumed that they had reverse thrust to add into the landing distance like the 300/500. They tried multiple scenarios in the OPC and all of them gave a positive stopping margin the lowest being 40-60 feet with MAX autobrake.
All OPC now includes the T/R's for stopping distance's for all aircraft. These guys spent all 2 hours of the CVR talking about options and using good CRM to make a decision. The data they had was "mixed". A citation landed just prior to the accident airplane and advised that the end of 31C braking action was poor to NIL. Tower never passed this on to these guys. If they had and they heard NIL, then I assume they would have diverted.