Beware of the rotor wash

Extremely lucky pilot. But, looking at the video, I’m not sure the reason is the prop wash. This looks more like a ordinary stall cased by pulling the stick violently. The pilot may have been surprised by the sudden irregular air from the prop wash, and did the wrong thing – pulling the stick.

I have downloaded the video in 720P using this and using Sony Vegas tweaked up the brightness and contrast, re-rendered it and uploaded it to Vimeo:

I too am not convinced the helicopter had anything to do with it. The left roll and later up-pitch happen far too gradually. Also 30 seconds is a long time.

30 seconds is nothing. Helicopters are always treated by ATC as “medium” for wake turbulence purposes. Propwash is by large worse than fixed wing wake turbulence. Besides, we don’t know the meteo conditions at that place.

I entirely believe that could have been the affect of the rotor vorticies. If the air is calm, or a gentle breeze right down the runway, the vorticies can remain a hazard over the runway for minutes. The other hazard, related to helicopter vorticies and not fixed wing, is the helicopter probably accelerated out of a hover. The downwash changes to “wing like” vorticies as the helicopter accelerated through “translation speed” (I’d guess 30 knots or so). Thus, the vortices might suddenly start at a point in space, so the Cirrus just hit them, rather than eased into them, as intensity increased from fixed wing type. Excellent training video, thanks for the tweaking Peter.

I entirely believe that could have been the affect of the rotor vorticies.

Maybe. But from the video the Cirrus starts with a slow initial roll, then a much more rapid increase in pitch. This causes the Cirrus to stall. This looks more or less exactly like a snap roll. Will be interesting to see what the NTSB experts eventually say, or maybe they already have?

An experienced RAF QFI was killed in a similar incident# at Oxford about 20 years ago when he flew into the wake of a helicopter that had hover taxied across the runway on a flight from the Silverstone Grand Prix.

This triggered a number of doccuments including a Pink AIC warning of the dangers of helicopter vortices

Controllers and pilots should consider wake vortices generated when helicopters hover taxi across active runways and apply the
appropriate wake turbulence separation minima. Caution should be exercised when a helicopter or fixed-wing aircraft of lower
weight category is cleared to land on a runway immediately after a helicopter of higher weight category has taken off from that
runway’s threshold. Additionally it should be borne in mind that the downwash and associated turbulence generated by a
hovering helicopter can drift a substantial distance downwind and may therefore affect an adjacent runway.

There was an accident in Germany, where a DR400 was turned through the wake turbulence of an AN2, 39 seconds behind. They were not that lucky.

here

The vortex systems cannot be compared directly, but I can not imagine that the impact is significantly less.

[ I replaced the horrible URL which had a temporary (expiring) session key and no .pdf filetype with a locally stored one… some web developers should be sent on a course – Peter ]

I landet seconds after a eurocopter hovert away from the runway!I will never do this again. Go around and wait, the turbulence are horrbile.

The wing touches the ground very soon after the roll to port. So any movement off the centre line is NOT as a result of the roll.

Yet when he his wing touches the ground he is more than a full wing span off the edge of the runway (so quite a bit off the centre-line).

It would be interesting to see a view along the centre-line. It would seem that either the pilot was very late in doing something about a developing situation, or there was a lot of lateral change in the flight path which didn’t affect the stability of the aircraft.

I would have felt safe after 30 second, so I’ve learnt something from that video. So thanks for posting!

If I was concerned about the heli, then I’d have been on the ground much earlier than that, but being honest, I probably wouldn’t have been concerned about a heli 30 second later.