Re: irrational fear of flying
Originally Posted by
echappist
Yikes indeed. Squeaky bum just reading about the event and listening to the transcript.
According to this
article, ~300 m separation between the two planes at the minimum point of separation. At what speeds do planes take off? ~200 mph iirc? Which would mean maybe 3 seconds worth?
I believe that the 300m referenced is the distance between the two planes when the Delta flight stopped on the runway. The Delta crew appear to have executed the takeoff abort very well.
To generalize, a narrow body airliner takes off at ~150-180 MPH. Takeoff speeds vary greatly based primarily on aircraft weight, temperature, altitude, flap configuration, and obstacles (both natural and manmade) near the airport. Transport category aircraft rely on three "takeoff speed" numbers: V1, VR, and V2. V1 is maximum speed to abort a takeoff. At speeds up to and including V1, the aircraft can stop on the available runway. Beyond V1, the aircraft can safely takeoff within the remaining runway after an engine failure. VR is the rotation speed at which the pilot flying pulls the nose up to the specified takeoff pitch attitude. The aircraft becomes airborne shortly after VR. Once airborne, the pilots use the V2 takeoff safety speed to meet obstacle clearance and controllability requirements with a failed engine. With all engines working, you can blast through V2 very quickly. There are many more subtle variables that play into these "V speeds" including runway contamination (water, ice, slush, snow) and reduced power takeoffs. Yup, most takeoffs are made at less than full power to reduce stress on the engines. Saab2000 can chime in with much more accurate numbers since he currently flies one of the most widely used airline aircraft.
Greg
Old age and treachery beat youth and enthusiasm every time…
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