Helicopter landing vs fixed wing departure - vortex??
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Helicopter landing vs fixed wing departure - vortex??
Everyone knows theres no vortex between departing and arriving aircraft, as the arrival will be on the deck long before they reach the point at which the departure rotated....however, what are the procedures for a helicopter with skids, which approaches the runway before "landing", and then remaining a few feet above the ground as they hover taxi down the full length to vacate. Surely they are susceptable to the vortex from a fixed wing departure?? Any thoughts/comments?
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Ooh blimey guys, someones in here asking difficult questions. Maybe if we ignore him he'll go away!
Seriously though BB, I cant think of any specific regulations regarding the situation you describe ( local instructions may cover it ) although I do stand to be corrected. Possibly Aberdeen controllers would be the guys with the most experience with this.
I would suggest that this is a situation where a controller would earn their money by using experience and judgement. Helicopters often have a higher wake vortex category than their weight would suggest ( due to the downwash ) but this is more to do with other traffic following the helicopter.
Another factor that would have to be taken into account would be Jet efflux or prop wash from the previous departure. Taking this and the vortex into account I would suggest that the controller would use a time based seperation between the two aircraft to ensure the effects of both have disipated. If the spacing was tight then perhaps the helicopter could be instucted to let down on the threshold and await taxi instructions. Also intermediate holding points ( if available ) could be used so that the helicopter clears the runway before the point at which the previous departure was airborne.
Hope this helps a little.
Seriously though BB, I cant think of any specific regulations regarding the situation you describe ( local instructions may cover it ) although I do stand to be corrected. Possibly Aberdeen controllers would be the guys with the most experience with this.
I would suggest that this is a situation where a controller would earn their money by using experience and judgement. Helicopters often have a higher wake vortex category than their weight would suggest ( due to the downwash ) but this is more to do with other traffic following the helicopter.
Another factor that would have to be taken into account would be Jet efflux or prop wash from the previous departure. Taking this and the vortex into account I would suggest that the controller would use a time based seperation between the two aircraft to ensure the effects of both have disipated. If the spacing was tight then perhaps the helicopter could be instucted to let down on the threshold and await taxi instructions. Also intermediate holding points ( if available ) could be used so that the helicopter clears the runway before the point at which the previous departure was airborne.
Hope this helps a little.
The Veloceraptor of Lounge Lizards
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BigBoeing;
There can be significant vortex wake behind helicopters. A few years ago during the British Grand Prix shuttle a PA28 got caught up in the vortex of a Sikorsky S61. Sad result one dead instructor and one dead student. The S61 and AS332 Super Puma are wake category medium, however their effects are closer to heavy. I fly a mid weight helo (vortex cat light) and the effects are closer to medium. Where I'm based there are lots of baby aeroplanes and some quite nice vintage bits of kit ATC regularly warn other aircraft, especially some of the light vintage ones about the vortex, trouble is none of us really know what the effect levels are, we just know they are there from the moment we move off the ground cushion until we come to a steady hover. There has never been an accurate measurement of helicopter wake turbulence.
Having witnessed the S61 and PA28 accident I'm not shy about letting others know about the possible effects. Landing at Sumburgh one day in an S61 a Viscount hit our turbulence, in the pub that night he said it was like flying into a very violent CB.
VH
There can be significant vortex wake behind helicopters. A few years ago during the British Grand Prix shuttle a PA28 got caught up in the vortex of a Sikorsky S61. Sad result one dead instructor and one dead student. The S61 and AS332 Super Puma are wake category medium, however their effects are closer to heavy. I fly a mid weight helo (vortex cat light) and the effects are closer to medium. Where I'm based there are lots of baby aeroplanes and some quite nice vintage bits of kit ATC regularly warn other aircraft, especially some of the light vintage ones about the vortex, trouble is none of us really know what the effect levels are, we just know they are there from the moment we move off the ground cushion until we come to a steady hover. There has never been an accurate measurement of helicopter wake turbulence.
Having witnessed the S61 and PA28 accident I'm not shy about letting others know about the possible effects. Landing at Sumburgh one day in an S61 a Viscount hit our turbulence, in the pub that night he said it was like flying into a very violent CB.
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Unless things have changed, the MATS Pt 1 requires the application of vortex separation where "projected flight paths will cross". In the scenario quoted that would be the case and wake vortex would be applicable.
.4
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In the UK S61,and the 332 family are small category.At Aberdeen where there are one or two based,then we give light fixed wings the correct vortex spacing behind.This includes a light fixed wing dep after a heli arrival where the flight paths are expected to cross.
If the heli is a light category,then a bit of common sense and a caution vortex may be in order.The Mats part 1 does not cover a small heli intersection departure followed by a full length fixed wing light departure.
As for helis being affected by fixed wings,then I have never seen it.Plenty of cases the other way round though.
If the heli is a light category,then a bit of common sense and a caution vortex may be in order.The Mats part 1 does not cover a small heli intersection departure followed by a full length fixed wing light departure.
As for helis being affected by fixed wings,then I have never seen it.Plenty of cases the other way round though.
niknak
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Even though we have heli strips north of the holding points of the fixed wing runway, because they are not sufficiantly spaced, we are required to treat all helicopter ops to the same vortex wake requirements as we would if they were making an approach to the runway.
I believe that this is the CAA requirement at any licensed aerodrome.
A bit of a pain in the arse, but cheaper than having to paying damages in the High Court.
I believe that this is the CAA requirement at any licensed aerodrome.
A bit of a pain in the arse, but cheaper than having to paying damages in the High Court.
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No vortex between arrivals and departures?
BigB,
Just a slight correction here to be pedantic. Light B767 in strong headwind rotates close to touchdown markers... Arriving B737 or any other medium/light/whatever type needs to be warned...
"caution vortex wake, departed B767 rotated abeam....". I've had to use this several times, but I grant you, it is rare!
I think the chopper issue has been addressed.
Cheers,
CR
Just a slight correction here to be pedantic. Light B767 in strong headwind rotates close to touchdown markers... Arriving B737 or any other medium/light/whatever type needs to be warned...
"caution vortex wake, departed B767 rotated abeam....". I've had to use this several times, but I grant you, it is rare!
I think the chopper issue has been addressed.
Cheers,
CR
