Quote:
Originally Posted by P2
You are correct. It' s not a major issue. Thousands of jets land every day and don't depart the prepared surface. You are however always landing above the speed where you could hydroplane.
I'll disagree with your statement regarding reverse thrust. They are more effective at making noise then stopping.  No doubt they do help, especially if the RW is less than good braking action. The meat of the deceleration are brakes especially after the the spoilers are up killing the lift and you have your full weight on your wheels. |
In ultimate stopping on a short dry runway, the brakes will be much more effective than reverse thrust, but in normal operation of a 737-800 on a wet runway with steel brakes, reverse thrust is initially more effective. From 130 knots (67m/s) to 100 knots (51m/s) at an average landing weight around 55t it will need to shed 50MJ of energy, a CFM56-7B at 50% reverse thrust (about 20% of maximum thrust) will provide about 20kN of retardation, so a 5 second burst at an average speed of 60m/s will shed 6MJ of energy per engine, so most likely the most significant retardation force during that 5 second burst if you are not in an emergency stop situation.
SOP for 737ng operation at the airline I used to work for was to use reverse thrust for initial retardation on wet runways, the 737-800 needs all the help it can get when the runway is short and wet due to relatively poor speed brake effectiveness and potential aquaplaning.
I’m not a pilot, but was in aeronautical R&D from a degree and career perspective, spending far too much time with aeronautical mathematics but later ended up in IT in the airline industry
