How fast is jet blast?

Question

I know jet blast is deadly, but just how fast is it on average?

Answer 1

Thrust=Mass x Velicity =friction in a stable speed situation.

>600mph dischage for a Hawker Harrier hover blast

Answer 2

At idle thrust, e.g. the slowest it can go, it's around

100 mph right behind the engine

50 mph by the end of the tail

35 mph up to 150 feet behind tail

Takeoff power (usually full power, but not always)

300 mph behind engine

200 mph next to tail

150 mph 50 feet behind tail

100 mph 200 feet behind tail

NOTE: 300 mph is similar to a category 5 hurricane.

Generally, commerical airliners have slower jet blasts while military jets have faster jet blasts.

Reason:

Slower=less fuel used compared to faster

Faster=more speed

Answer 3

At the core it can approach Mach 1.  It is VERY dangerous.

There are not many rampers who do not respect jetblast.  Those who do not quickly learn how painful is can be to get tossed out of a moving cart by a 500mph jet of hot air.