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Well the FAA has regulations on length between planes taking off becasue of jet blast.
Originally posted by ULTIMA1
Well you are talking about seperation at landing due to wake turbulence.
I was talking about seperation at TAKEOFF due to jet blast.
In other words, during the Takeoff phase of flight a fast, large jetliner should never take off behind a much smaller and slower two-seater aircraft until it is out of the way. A local controller can allow an aircraft in line for takeoff to "taxi in position and hold" in the run-up area while another aircraft is on its takeoff roll.
While there have been instances where wake turbulence caused structural damage, the greatest hazard is induced roll and yaw. This is especially dangerous during takeoff and landing, when there is little height for recovery. Wake turbulence-induced roll rates can be extreme. Countering roll rates may be difficult or impossible, even in high performance aircraft with excellent roll control authority. In fixed-wing aircraft, wake vortices begin as the nose is rotated for takeoff and continue throughout flight until the nosewheel touches down on the runway once again.
During ground operations and during takeoff, jet engine blast (thrust stream turbulence) can cause damage and upsets if encountered at close range. Exhaust velocity versus distance studies at various thrust levels have shown a need for light aircraft to maintain an adequate separation behind large turbojet aircraft.
Originally posted by Pilgrum
I think there's at least one who says he had to drop to the ground for fear of being hit but that action would have minimised the effect on him and it was grossly exceeded by the explosion a moment later.
Originally posted by weemadmental
does this video stop all the arguements in this thread, low fly by, over light aircraft and people, and they arent rocking !!l
Originally posted by Zaphod58
I don't know if it's deliberate or not, but you are confusing jet blast and wingtip vortices.
[edit on 4/6/2008 by Zaphod58]
1.1.1 Wake turbulence is the term used to describe the effect of the
rotating air masses (wake vortices) generated behind the wing tips of
aircraft in flight. These vortices are two counter-rotating cylindrical air
masses trailing aft from the aircraft and are particularly severe when
generated by large and wide-bodied aircraft. The vortices are most
dangerous to following aircraft during the take-off, initial climb, final
approach and landing phases of flight. They tend to drift down, and when
close to the ground move sideways (outwards) from the track of the
generating aircraft.
2.1.1 Pilots are cautioned of the hazards caused by jet blast and propeller
slipstream to taxiing aircraft, to aircraft taking off or landing, and to
vehicles and personnel operating on the aerodrome.
2.1.2 Jet blast and propeller slipstream can produce localised wind
velocities of sufficient strength to cause damage to other aircraft, vehicles
and personnel.
Originally posted by SlightlyAbovePar
Just curious Ultima, how many different angles are you going to take in your very own thread before you concede.
Originally posted by SlightlyAbovePar
(1) Either he's purposefully lying in the pursuit of his agenda or (2) he doesn't fully understand what he's talking about.
during takeoff, jet engine blast (thrust stream turbulence) can cause damage and upsets if encountered at close range. Exhaust velocity versus distance studies at various thrust levels have shown a need for light aircraft to maintain an adequate separation behind large turbojet aircraft.
Originally posted by weedwhacker
Sometimes it's just important to sit back, and listen....and disagree, of course!! BUT, don't automatically disagree until you've listened thouroughly....
Peak vortex tangential speeds exceeding 300 feet per second have been recorded.
The greatest vortex strength occurs when the generating aircraft is HEAVY, CLEAN, and SLOW.
a. Because of the possible effects of wake turbulence, controllers are required to apply no less than specified minimum separation for aircraft operating behind a heavy jet and, in certain instances, behind large nonheavy aircraft (i.e., B757 aircraft).
1. Separation is applied to aircraft operating directly behind a heavy/B757 jet at the same altitude or less than 1,000 feet below:
(a) Heavy jet behind heavy jet-4 miles.
(b) Large/heavy behind B757 - 4 miles.
(c) Small behind B757 - 5 miles.
(d) Small/large aircraft behind heavy jet - 5 miles.
2. Also, separation, measured at the time the preceding aircraft is over the landing threshold, is provided to small aircraft:
(a) Small aircraft landing behind heavy jet - 6 miles.
(b) Small aircraft landing behind B757 - 5 miles.
(c) Small aircraft landing behind large aircraft- 4 miles.
Further, turbulence generated within the vortices can damage aircraft components and equipment if encountered at close range.
during takeoff, jet engine blast (thrust stream turbulence) can cause damage and upsets if encountered at close range. Exhaust velocity versus distance studies at various thrust levels have shown a need for light aircraft to maintain an adequate separation behind large turbojet aircraft.
c. A 3-minute interval will be provided for all aircraft taking off when the operations are as described in subparagraph b1 and 2 above, the preceding aircraft is a heavy/B757 jet, and the operations are on either the same runway or parallel runways separated by less than 2,500 feet. Controllers may not reduce or waive this interval.
d. Pilots may request additional separation i.e., 2 minutes instead of 4 or 5 miles for wake turbulence avoidance. This request should be made as soon as practical on ground control and at least before taxiing onto the runway.
Originally posted by ULTIMA1
Originally posted by Pilgrum
I think there's at least one who says he had to drop to the ground for fear of being hit but that action would have minimised the effect on him and it was grossly exceeded by the explosion a moment later.
Yes the same person who claimed he was 6 feet away, who would have been blown away by jet blast.
Originally posted by ULTIMA1
2. Even the FAA warns about jet blast being a concern to aircraft in the air at takeoff.
during takeoff, jet engine blast (thrust stream turbulence) can cause damage and upsets if encountered at close range. Exhaust velocity versus distance studies at various thrust levels have shown a need for light aircraft to maintain an adequate separation behind large turbojet aircraft.