Rotary Air to Air Refuelling - now with pic!
Helicopter Pilots Get It Up Quicker
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Rotary Air to Air Refuelling
Having seen air to air fast jet and fixed wing on numerous occasions, (only on TV unfortunately), I have alwayts been impressed by the flying accuracy of those involved.
Whilst half watching a program the other evening about the ?USCG I think they were flying a Blackhawk???, but ended up ditching due to not being able to RV with the tanker. The following footage certainly showed the boom on the front of the helicopter.
I was wondering how much harder or easier is it to refuel rotary inflight? Are the same tankers used? Is it possible to match the speeds as easily? I am assuming the risks are probably higher due to the potential rotor strikes and harder due to the downwash?
Whilst half watching a program the other evening about the ?USCG I think they were flying a Blackhawk???, but ended up ditching due to not being able to RV with the tanker. The following footage certainly showed the boom on the front of the helicopter.
I was wondering how much harder or easier is it to refuel rotary inflight? Are the same tankers used? Is it possible to match the speeds as easily? I am assuming the risks are probably higher due to the potential rotor strikes and harder due to the downwash?
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'A Perfect Storm' has a lot to answer for...
However, in answer to your question:
Some helicopters can inflight refuel in the same way as FW aircraft, though in UK I think it's just Mk3 Chinook (not sure about Mk2) and possibly Merlin too (anyone from Freak Sqn care to help?).
Main trouble is finding a tanker that can fly slow enough to allow the helicopter to keep up. UK no longer has C130 ac capable of tanking as far as I know, and our jet tankers fly too fast.
Close formation in helicopter is slightly trickier than FW, but just requires practice. Downwash shouldn't be a player in AAR as it should be well behind the helicopter.
Tip strikes are possible. I've seen video footage of MH53 cutting off its own refuelling probe when pilot was a bit too eager to push forward cyclic to correct his position. Doh!!
I'm willing to stand corrected on all of this, as I haven't done it myself. The only AAR I've done has been hovering next to a ship, plugged into a hose! A Sea King can't keep up with much else...
However, in answer to your question:
Some helicopters can inflight refuel in the same way as FW aircraft, though in UK I think it's just Mk3 Chinook (not sure about Mk2) and possibly Merlin too (anyone from Freak Sqn care to help?).
Main trouble is finding a tanker that can fly slow enough to allow the helicopter to keep up. UK no longer has C130 ac capable of tanking as far as I know, and our jet tankers fly too fast.
Close formation in helicopter is slightly trickier than FW, but just requires practice. Downwash shouldn't be a player in AAR as it should be well behind the helicopter.
Tip strikes are possible. I've seen video footage of MH53 cutting off its own refuelling probe when pilot was a bit too eager to push forward cyclic to correct his position. Doh!!
I'm willing to stand corrected on all of this, as I haven't done it myself. The only AAR I've done has been hovering next to a ship, plugged into a hose! A Sea King can't keep up with much else...
Helicopter Pilots Get It Up Quicker
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It wasn't actually the film but a documentary on the series of storms that the Perfect Storm film was based on...
I was referring to the downwash from the rotor disk onto the refuelling boom rather than from the tanker. Would have thought it would continually push the noozle down and away from the helicopter until the hose angle was too acute to make the connection.
Guess no one else has tried it or is it currently classified?
I was referring to the downwash from the rotor disk onto the refuelling boom rather than from the tanker. Would have thought it would continually push the noozle down and away from the helicopter until the hose angle was too acute to make the connection.
Guess no one else has tried it or is it currently classified?
Pilotwulf, there is a general misconception that a helicopter rotor in forward flight produces downwash throughout its entire disk. This is incorrect. As with any wing, the "downwash" occurs toward the rear.
That is correct. The downwash 'footprint' is a function of the helicopter's forward speed: The faster it moves, the further back the downwash is spread.
Downwash doesn't affect the AAR capability of the Chinook HC3 or the Merlin. Although the lastest Chinook model is not quite ready for service.
Yes the Merlin does have a probe.
Downwash doesn't affect the AAR capability of the Chinook HC3 or the Merlin. Although the lastest Chinook model is not quite ready for service.
Yes the Merlin does have a probe.
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Yep, the rotor wake spins downward and aft, with an angle that approximates the geometric sum of the downwash speed (about 20 to 45 knots for most helicopters) and the forward speed.
I happened to fly a series of wake impact flights in the S-76 back when and noted this:
At hover, the wake is near vertical, with some contraction. At 40 knots, the wake struck the nose of the aircraft, at the radome. At 60 knots, it struck the cabin, in line with the pilot's door, at 80 knots it struck above the race-car fairing about mid point and by 125 knots, it struck the rotor pylon/swashplate fairing, almost parallel with the rotor.
refuel probes are stuck far out (they extend by fuel pressure on Sikorsky's) to get the refuel basket on the hose end away from the rotor tips. Rotor downwash plays no part in the refuel handling, but airplane wake is a big factor, and staying away from the wing wake is a nice idea. The US military uses C-130's for refuel, and has no rotory assets as tankers, that I am aware of.
I believe the event depicted in the film Perfect Storm is true enough as shown with regard to the refuel problems, which were severe due to cloud and turbulence (all refuel operations are VFR-ish).
I happened to fly a series of wake impact flights in the S-76 back when and noted this:
At hover, the wake is near vertical, with some contraction. At 40 knots, the wake struck the nose of the aircraft, at the radome. At 60 knots, it struck the cabin, in line with the pilot's door, at 80 knots it struck above the race-car fairing about mid point and by 125 knots, it struck the rotor pylon/swashplate fairing, almost parallel with the rotor.
refuel probes are stuck far out (they extend by fuel pressure on Sikorsky's) to get the refuel basket on the hose end away from the rotor tips. Rotor downwash plays no part in the refuel handling, but airplane wake is a big factor, and staying away from the wing wake is a nice idea. The US military uses C-130's for refuel, and has no rotory assets as tankers, that I am aware of.
I believe the event depicted in the film Perfect Storm is true enough as shown with regard to the refuel problems, which were severe due to cloud and turbulence (all refuel operations are VFR-ish).
Helo AAR
Pilotwolf
Go to" www.raf.mod.uk/documents/atp56a,and read all about the mysteries of sticking a long thing into a small round thing,day or night
I don`t believe "we" have any Chinooks or Merlins yet capable of AAR and we certainly dont have any suitable tankers either.Unless ,at some time in the future the C-130J will be fitted with pods on the wings, as it`s`not possible(geometrically) to use a centre-line hose. As you will see, the r/w technique is different from the f/w one,and there is not a lot of speed -range capability available either. Read well,and come back later, questions will be asked!!
Go to" www.raf.mod.uk/documents/atp56a,and read all about the mysteries of sticking a long thing into a small round thing,day or night
I don`t believe "we" have any Chinooks or Merlins yet capable of AAR and we certainly dont have any suitable tankers either.Unless ,at some time in the future the C-130J will be fitted with pods on the wings, as it`s`not possible(geometrically) to use a centre-line hose. As you will see, the r/w technique is different from the f/w one,and there is not a lot of speed -range capability available either. Read well,and come back later, questions will be asked!!
I've done quite a bit of helo air refueling, it's a unique capability pretty much monopolized by the US right now, although there are other nations that have the capability they just don't exploit it like the US military does.
It's actually fairly easy to refuel, the biggest problems stem from turbulence and poor pilot technique. The basket used for helo a/r has a slightly larger "skirt" around the spokes which gives it more stability at the slower speeds. The C-130 is flying very slow, around 115 KIAS, just above stall. Pilots tend to have the most difficulty if they stare at the basket while trying to make contact, because the basket will bounce around but the hose remains fairly stable. Basically you line the probe up on the hose, use the hose and wing as a reference, then drive on in from about 5 feet. As you get closer, your reference begins to shift more towards the basket, but always keeping your eyes moving.
After contact you slide up and out a bit, lining up with the wingtip of the 130. There are markings on the hose and you simply keep within those to maintain fuel flow. It's much easier to refuel on the left side than the right because of the airflow from the props. The hose on the right actually slants away from the aircraft.
To Nick: Actually the probe is extended and retracted using bleed air from the engines and not fuel pressure. H-47s use a fixed probe which is VERY long. The reason for this is due to the forward rotor, the probe must be quite a bit longer and a retracted probe concept just doesn't work. The 47 is a bit more stable for a/r due to no tail rotor, but the probe does bounce a bit more, lever arm thing happening there.
While I've never FW air refueled, I've heard that it's actually easier to helo a/r but don't quote me on that. There's actually a reduction in power required while tucked in behind the C-130 wing, kind of like drafting in auto racing. Lastly, while yes it's fairly simple to stick a probe on a helo, it's a different story for finding the tankers, that's always the limitation.
It's actually fairly easy to refuel, the biggest problems stem from turbulence and poor pilot technique. The basket used for helo a/r has a slightly larger "skirt" around the spokes which gives it more stability at the slower speeds. The C-130 is flying very slow, around 115 KIAS, just above stall. Pilots tend to have the most difficulty if they stare at the basket while trying to make contact, because the basket will bounce around but the hose remains fairly stable. Basically you line the probe up on the hose, use the hose and wing as a reference, then drive on in from about 5 feet. As you get closer, your reference begins to shift more towards the basket, but always keeping your eyes moving.
After contact you slide up and out a bit, lining up with the wingtip of the 130. There are markings on the hose and you simply keep within those to maintain fuel flow. It's much easier to refuel on the left side than the right because of the airflow from the props. The hose on the right actually slants away from the aircraft.
To Nick: Actually the probe is extended and retracted using bleed air from the engines and not fuel pressure. H-47s use a fixed probe which is VERY long. The reason for this is due to the forward rotor, the probe must be quite a bit longer and a retracted probe concept just doesn't work. The 47 is a bit more stable for a/r due to no tail rotor, but the probe does bounce a bit more, lever arm thing happening there.
While I've never FW air refueled, I've heard that it's actually easier to helo a/r but don't quote me on that. There's actually a reduction in power required while tucked in behind the C-130 wing, kind of like drafting in auto racing. Lastly, while yes it's fairly simple to stick a probe on a helo, it's a different story for finding the tankers, that's always the limitation.
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Mcpave,
Thanks for the info, I have flown lots of the systems, but never plugged in.
I must insist - The fuel probes on the H-53, H-60 and S/H-92's use fuel pressure to extend.
Thanks for the info, I have flown lots of the systems, but never plugged in.
I must insist - The fuel probes on the H-53, H-60 and S/H-92's use fuel pressure to extend.
Avoid imitations
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It can't be that difficult.
AAR
P-W, If you try the first bit ,www.raf.mod uk, and then scroll through,you will come to the "documents" at the bottom of the page. syc
We use the front mounted camera to con ourselves in. As it is helmet pointing, all the observer has to do is stare at the probe and I fly the nozzle smack down its throat.
Downwash from the frocklifter is reasonable, especially if you come at it from well above.
Downwash from the frocklifter is reasonable, especially if you come at it from well above.
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handyandyuk,
If you go to www.funvids.net and then go to the military category you will find the CH53 clip and some other good ones as well. If you get bored, the animals category has some good clips as well!
If you go to www.funvids.net and then go to the military category you will find the CH53 clip and some other good ones as well. If you get bored, the animals category has some good clips as well!
To Nick,
Well, sounds like we have a mexican standoff. While I'll admit that I can't attest to the 60 or 92, I'm positive that the Sikorsky helo I fly uses bleed air, unless my flight manual is wrong. I defer to your expertise and more extensive research contacts.
Care to place a friendly wager?
Well, sounds like we have a mexican standoff. While I'll admit that I can't attest to the 60 or 92, I'm positive that the Sikorsky helo I fly uses bleed air, unless my flight manual is wrong. I defer to your expertise and more extensive research contacts.
Care to place a friendly wager?
TC,
I thought you would have that bloke out on the skid for that one? Then he could just grab the thing and open up the cap and fill to the top. Pretty handy lad for cleaning the windscreen too.....
Great piccie
Two thumbs up.
I thought you would have that bloke out on the skid for that one? Then he could just grab the thing and open up the cap and fill to the top. Pretty handy lad for cleaning the windscreen too.....
Great piccie
Two thumbs up.
Gatvol
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Thomas Coupling,
Thats one fast Helicopter as I see no flaps on the Military KC-135. A bit High Altitude also.......
Fish On........................................
Thats one fast Helicopter as I see no flaps on the Military KC-135. A bit High Altitude also.......
Fish On........................................