Reply #122: Tricky [View All]

[k-robjoe]

Do you get a ground speed of the exhaust of "about 1100 mph" ( Russell / Stanley ), or do you get one of "at the most, MINUS 125 mph " ( RH )?

I´m kind of leaning towards Russell and Stanleys number I must say. But from there to saying what effect those 1100 mph would have on Frank Probst, that is indeed more tricky.

( Would the plane be going at almost max thrust? Since it was going at almost max speed, and still it was reportedly speeding up. Would thrust from the engines be far stronger than that of the 747 blowing a car off the runway (Gif ) ?

"American Airlines flight 77 was 757-223 with Rolls-Royce RB211 535E4-B engines. They have a max thrust of 43,100 lbs (192 kN) each or a total max thrust of 86,200 lbs (384 kN). Since the "757" was flying at high speed at its approach at almost zero altitude (at the edge of its performance evelope) the engines would be at max thrust, or close to max thrust.
86,200 lbs of thrust is a phenomenal amount of energy. (...) A 747 taxiing would generate a much smaller amount of thrust. As can be seen in the video mentioned previously in this thread, a vehicle is blown off the runway by a 747's thrust."
http://letsroll911.org/ipw-web/bulletin/bb/viewtopic.php?t=14&postdays=0&postorder=asc&start=600 )