Helicopter Awareness

[designrs]

I understand the danger of being under a helicopter in the pattern (major rotor downwash).
Is there and danger in being above a helicopter?

How fast does helicopter "wake turbulence" fade?
For example, say you are on downwind or base planning to land on a runway that a helicopter just passed over... any issues?

[Wm.Ince]

I understand the danger of being under a helicopter in the pattern (major rotor downwash).
Is there and danger in being above a helicopter?

Not really.
If you are close enough to be affected from above, you are definitely too close to the aircraft period.

How fast does helicopter "wake turbulence" fade?

Pretty fast, but for a short duration it is severe. Understand, the turbulence being produced is vertical, which is a shear.

For example, say you are on downwind or base planning to land on a runway that a helicopter just passed over... any issues?

Here is the bottom line, in my humble opinion (4,700 hours of helicopter time), unless you cross wake turbulence momentarily, if you are close enough to encounter continuous helicopter turbulence, you are definitely flying too close to begin with.
In flight, the rotor downwash of a helicopter dissipates fairly rapidly, especially if there is any appreciable wind blowing.
That withstanding, when a helicopter is hovering near the ground (in ground effect, a distance at or less than rotor diameter) the downwash and turbulence is high velocity and very hazardous, especially to light aircraft. Light aircraft should avoid taxiing close to helicopters, period. Helicopter pilots are well aware of the rotor downwash hazard and are trained to keep it to a minimum around airplanes, buildings and anything not secured.
A major consideration is the category of the helicopter. Heavy helicopters, such as the Sikorsky Flying Crane and Boeing Chinook will produce much more severe rotor turbulence than lighter helicopters, such as a Robinson or Bell Jet Ranger.
As a light sport pilot now, I want nothing to do with any rotorwash, nomatter what produces it. . . .

[designrs]

Thanks Bill. While primary training at a very busy airport I was cautioned by my instructor about close proximity to a larger helicopter. The other day I just happened to have a smaller helicopter at my home airport, at a distance but in the pattern at the same time. Thus the question. Thank you for your thorough answer from your lengthily experience!

[Jack Tyler]

FYI at our previous home base (KSPG), frequented by USCG Jayhawks and USA-R Blackhawks, tower would observe a 3 min wake turbulence caution for GA a/c when these H-60's were landing & taking off and with typically light Tampa Bay winds. I don't recall that same caution warning being issued for the Bells and Bayflite's EC-135 evac helos. So as Bill reports, size does seem to make a significant difference.

[drseti]

Don't underestimate the dangers of overflying a helicopter. About 23 years ago, an Aerostar carrying Senator John Heinz flew out of Williamsport PA (then my home base) to Philadelphia. Approaching KPHL to land, the Aerostar pilot (who I knew) had a gear unsafe warning. Heinz was at the time a leading contender for the Democratic presidential nomination. A Sunoco Jet Ranger flying in the vicinity kindly offered to under-fly the Aerostar and determine whether the gear was down. The resulting midair collision killed all onboard both aircraft, and the lawsuits that ensued nearly put the Williamsport FBO (then run by a friend of mine) out of business.

PS - My friend Lola Taylor, who ran the FBO, ended up having to sell the business. It exchanged hands three more times, before Lola's son Jim (who had grown up at that FBO as a line-boy) ended up taking it over just this year. (welcome home, Jimmy!)

[MrMorden]

Helicopters, otherwise known as "spinning whirlygigs of death", are a menace to all humans and possibly western civilization. I stay as far away from them as possible.

[drseti]

Helicopters, otherwise known as "spinning whirlygigs of death"

Or as collections of spare parts, flying in loose formation...

[MrMorden]

Helicopters, otherwise known as "spinning whirlygigs of death"

Or as collections of spare parts, flying in loose formation...

Another good description. I try never to fly in or around any flying vehicle whose principles of operation are based on black magic and voodoo rather than than aerodynamics.

[drseti]

A prudent stance to take, Andy. Consider how a helicopter takes off. You apply inordinate amounts of power, the wing rotates, and somehow it rises off the surface. By rights, it should just screw itself into the ground.

[MrMorden]

A prudent stance to take, Andy. Consider how a helicopter takes off. You apply inordinate amounts of power, the wing rotates, and somehow it rises off the surface. By rights, it should just screw itself into the ground.

They don't lift themselves up. Like Chuck Norris doing pushups, they push the world down.

[designrs]

By rights, it should just screw itself into the ground.

LOL!!

[CTLSi]

......

[Merlinspop]

A prudent stance to take, Andy. Consider how a helicopter takes off. You apply inordinate amounts of power, the wing rotates, and somehow it rises off the surface. By rights, it should just screw itself into the ground.

They don't lift themselves up. Like Chuck Norris doing pushups, they push the world down.

They don't fly; they beat the air into submission.

[sandpiper]

Yep, helicopters are different but I love 'em. Although I did well in Army flight school, it still took about 50 hours before I started thinking "maybe it won't kill me".

You know that the rotor is held on with one nut, right. It's called the Jesus nut because if it ever comes off..............

[MrMorden]

You know that the rotor is held on with one nut, right. It's called the Jesus nut because if it ever comes off..............

You are not convincing me to love them...