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#11
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Air Force Aerial Refueling Methods: Flying Boom versusHose-and-Drogue
Ed Rasimus wrote:
On Sat, 01 Jul 2006 08:38:55 GMT, Guy Alcala wrote: Ed Rasimus wrote: snip Ed, you only did that on a KC-135, right? If so, I submit that your sole drogue experience is with the drogue universally acknowledged (by those with experience of 'real' hose and drogues) to be the worst piece of **** ever to be stuck on a tanker. Grabbing the first account to hand, John Trotti's ("Phantom over Vietnam"): I didn't say it was good, just that it was the hardest thing I ever tried to do. I really don't relate it to the installation on the tanker. It should have been fairly straightforward since the boom extended the drogue well below any turbulence off the tanker. I attributed it to the short probe (retractable) on the F-105. When flying with F-100F Weasels, I never noted them having anywhere near the difficulty that we did in getting gas using their wing mounted probe. It would be interesting to see if any F-105 drivers had tanked from regular drogues and what their experience was. AIUI, the problem with the KC-135 add-ons were two: 1. Lack of hose length (low inertia due to the lack of hose weight causing it to bounce around a lot), and 2. The heavy metal fitting just forward of the drogue, which (because of the wild flailing of the drogue due to item 1) was perfectly capable of smashing the canopy and/or the pilot's head if it made contact. At least the first was apparently a not-unknown occurrence, which is why many navy pilots seem to have been actually afraid of the system. snip Then you have to add in the effects of multi-point refueling into the mix. BTW, did you ever have a tanker unable to pass you gas? Guy I've never been behind a multiple receiver capable tanker. I don't think I'd be very comfortable knowing that someone else was just a few feet off my wingtip, not looking at me and trying to chase a drogue. Throw in night or weather and the inevitable "Murphy" factor of someone forgetting which side to come off the hookup after topping off and the picture gets pretty scary. At least one account I've read, IIRR the flight lead puts his less-experienced wingman on the left hose, because it's safer and more comfortable (because the pilot can see both the hose, the tanker and the other fighter without turning his head a lot), while the more experienced lead is on the right where the view is more limited. Offhand I don't recall reading any problems as to who comes off which side (back up to unkink the hose, then clear away from the tanker seems pretty instinctive), but we've got several people here who can inform us otherwise if that's the case. Never had a tanker unable, but have heard of the situation. I relate a personal screw-up story in Palace Cobra in which I got saved by an emergency tanker and in that instance the controllers ran a second tanker in two mile trail with the primary just to cover that eventuality. I've always assumed they would have a spare tanker per anchor. It was somewhat common in the F-4 to have receptacle door problems which could usually be cured by the boomer hammering to pop it open or tap it closed. Nothing like using an expensive, relatively high tech piece of equipment as a hammer;-) I wonder if the KC-10s do that with what are presumably far more expensive FBW booms? Guy |
#12
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Air Force Aerial Refueling Methods: Flying Boom versusHose-and-Drogue
Dave Kearton wrote:
Guy Alcala wrote: I've been wondering -- although it would undoubtedly eliminate much of the cost and simplicity advantage of probe and drogue over boom and receptacle, does anyone here think it would it be technically possible, given modern miniaturization, to develop a drogue with active stabilization? After all, KC-10 booms have been FBW for 25 years or so, so given miniaturized controls and inertial elements, could a drogue be space-stabilized so it didn't bounce around as much in turbulence? Could you even use fiber-optics and guide the drogue manually (in multi-place tankers)? Would such a capability be useful, or is it just easier to let it move around and have the a/c chase it? Alternatively, would it be better to have the drogue seek the probe, in somewhat similar fashion to the way a radar or IR seeker attempts to null out error messages? Just thinking out loud in the wee hours. Guy surround the basket with hair ? But seriously folks .....an IR LED on the probe with a receiver on the basket - should do the trick - with appropriate software & control surfaces, of course. So, do any of our local experts who've BTDT think any of this would be worthwhile, or are they satisfied with the current capability? Guy |
#13
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Air Force Aerial Refueling Methods: Flying Boom versusHose-and-Drogue
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#14
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Air Force Aerial Refueling Methods: Flying Boom versus Hose-and-Drogue
On Sat, 01 Jul 2006 23:27:32 GMT, Guy Alcala
wrote: Ed Rasimus wrote: On Sat, 01 Jul 2006 08:38:55 GMT, Guy Alcala wrote: Ed, you only did that on a KC-135, right? If so, I submit that your sole drogue experience is with the drogue universally acknowledged (by those with experience of 'real' hose and drogues) to be the worst piece of **** ever to be stuck on a tanker. Grabbing the first account to hand, John Trotti's ("Phantom over Vietnam"): I didn't say it was good, just that it was the hardest thing I ever tried to do. I really don't relate it to the installation on the tanker. It should have been fairly straightforward since the boom extended the drogue well below any turbulence off the tanker. I attributed it to the short probe (retractable) on the F-105. When flying with F-100F Weasels, I never noted them having anywhere near the difficulty that we did in getting gas using their wing mounted probe. It would be interesting to see if any F-105 drivers had tanked from regular drogues and what their experience was. AIUI, the problem with the KC-135 add-ons were two: 1. Lack of hose length (low inertia due to the lack of hose weight causing it to bounce around a lot), and 2. The heavy metal fitting just forward of the drogue, which (because of the wild flailing of the drogue due to item 1) was perfectly capable of smashing the canopy and/or the pilot's head if it made contact. At least the first was apparently a not-unknown occurrence, which is why many navy pilots seem to have been actually afraid of the system. The hose on the KC-135 drogue was 12 feet, which sounds like a lot of range for formation flying, but turns out not to be all that much in practice. I never really noticed any turbulence for the drogue in my limited experience. The issue was pilot technique. The first thing we learned was that it was virtually impossible to fly the probe into the drogue. Any attempt to control the end game usually resulted in some form of PIO gyrations and no hookup. Best method was to stabilize several feet behind the drogue with the probe lined up. If you could, line up the probe for about the ten o'clock position on the basket. Then look straight forward and push the throttle up to move ahead. Don't look at the drogue. Ideally you would fly into the basket. More commonly as you closed the airflow over the nose would push the basket smoothly up and away from the aircraft. In the worst case scenario the probe would hook the corner of the basket nearest the airplane. Two possibilities then--either the probe would slide into the funnel and connect or the probe would tip the basket off and it would then flail leading to the aircraft impact you describe. Even worse situation would be catching the basket, bending the probe and ripping off the hose leaving unretractable probe tenously holding heavy metal lined basket and x number of feet of hose thrashing the side of the airplane in front of your left intake. We had a souvenier basket in the squadron briefing room in the 4526th CCTS at Nellis when I checked out. A student in a prior class had brought it home on a flight. Ed Rasimus Fighter Pilot (USAF-Ret) "When Thunder Rolled" www.thunderchief.org www.thundertales.blogspot.com |
#15
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Air Force Aerial Refueling Methods: Flying Boom versus Hose-and-Drogue
"Guy Alcala" wrote in message . .. Dave Kearton wrote: Guy Alcala wrote: I've been wondering -- although it would undoubtedly eliminate much of the cost and simplicity advantage of probe and drogue over boom and receptacle, does anyone here think it would it be technically possible, given modern miniaturization, to develop a drogue with active stabilization? After all, KC-10 booms have been FBW for 25 years or so, so given miniaturized controls and inertial elements, could a drogue be space-stabilized so it didn't bounce around as much in turbulence? Could you even use fiber-optics and guide the drogue manually (in multi-place tankers)? Would such a capability be useful, or is it just easier to let it move around and have the a/c chase it? Alternatively, would it be better to have the drogue seek the probe, in somewhat similar fashion to the way a radar or IR seeker attempts to null out error messages? Just thinking out loud in the wee hours. Guy surround the basket with hair ? But seriously folks .....an IR LED on the probe with a receiver on the basket - should do the trick - with appropriate software & control surfaces, of course. So, do any of our local experts who've BTDT think any of this would be worthwhile, or are they satisfied with the current capability? Guy |
#16
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Air Force Aerial Refueling Methods: Flying Boom versus Hose-and-Drogue
"Guy Alcala" wrote in message
. .. But seriously folks .....an IR LED on the probe with a receiver on the basket - should do the trick - with appropriate software & control surfaces, of course. So, do any of our local experts who've BTDT think any of this would be worthwhile, or are they satisfied with the current capability? I am sure that there is a defense contractor out there who thinks this idea is worthwhile.... JD |
#17
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Air Force Aerial Refueling Methods: Flying Boom versus Hose-and-Drogue
Ed,
More commonly as you closed the airflow over the nose would push the basket smoothly up and away from the aircraft. This was especially true of the A-6, with its huge, blunt nose. More generally, this was perhaps the trickiest part of learning how to plug - especially at night. -- Mike Kanze "You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer." - Frank Zappa "Ed Rasimus" wrote in message ... On Sat, 01 Jul 2006 23:27:32 GMT, Guy Alcala wrote: Ed Rasimus wrote: On Sat, 01 Jul 2006 08:38:55 GMT, Guy Alcala wrote: Ed, you only did that on a KC-135, right? If so, I submit that your sole drogue experience is with the drogue universally acknowledged (by those with experience of 'real' hose and drogues) to be the worst piece of **** ever to be stuck on a tanker. Grabbing the first account to hand, John Trotti's ("Phantom over Vietnam"): I didn't say it was good, just that it was the hardest thing I ever tried to do. I really don't relate it to the installation on the tanker. It should have been fairly straightforward since the boom extended the drogue well below any turbulence off the tanker. I attributed it to the short probe (retractable) on the F-105. When flying with F-100F Weasels, I never noted them having anywhere near the difficulty that we did in getting gas using their wing mounted probe. It would be interesting to see if any F-105 drivers had tanked from regular drogues and what their experience was. AIUI, the problem with the KC-135 add-ons were two: 1. Lack of hose length (low inertia due to the lack of hose weight causing it to bounce around a lot), and 2. The heavy metal fitting just forward of the drogue, which (because of the wild flailing of the drogue due to item 1) was perfectly capable of smashing the canopy and/or the pilot's head if it made contact. At least the first was apparently a not-unknown occurrence, which is why many navy pilots seem to have been actually afraid of the system. The hose on the KC-135 drogue was 12 feet, which sounds like a lot of range for formation flying, but turns out not to be all that much in practice. I never really noticed any turbulence for the drogue in my limited experience. The issue was pilot technique. The first thing we learned was that it was virtually impossible to fly the probe into the drogue. Any attempt to control the end game usually resulted in some form of PIO gyrations and no hookup. Best method was to stabilize several feet behind the drogue with the probe lined up. If you could, line up the probe for about the ten o'clock position on the basket. Then look straight forward and push the throttle up to move ahead. Don't look at the drogue. Ideally you would fly into the basket. More commonly as you closed the airflow over the nose would push the basket smoothly up and away from the aircraft. In the worst case scenario the probe would hook the corner of the basket nearest the airplane. Two possibilities then--either the probe would slide into the funnel and connect or the probe would tip the basket off and it would then flail leading to the aircraft impact you describe. Even worse situation would be catching the basket, bending the probe and ripping off the hose leaving unretractable probe tenously holding heavy metal lined basket and x number of feet of hose thrashing the side of the airplane in front of your left intake. We had a souvenier basket in the squadron briefing room in the 4526th CCTS at Nellis when I checked out. A student in a prior class had brought it home on a flight. Ed Rasimus Fighter Pilot (USAF-Ret) "When Thunder Rolled" www.thunderchief.org www.thundertales.blogspot.com |
#18
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Air Force Aerial Refueling Methods: Flying Boom versusHose-and-Drogue
Doug \"Woody\" and Erin Beal wrote:
On 7/1/06 8:48 AM, in article , "Ed Rasimus" wrote: On Sat, 01 Jul 2006 08:38:55 GMT, Guy Alcala wrote: Ed, you only did that on a KC-135, right? If so, I submit that your sole drogue experience is with the drogue universally acknowledged (by those with experience of 'real' hose and drogues) to be the worst piece of **** ever to be stuck on a tanker. Grabbing the first account to hand, John Trotti's ("Phantom over Vietnam"): Guy, I'm personally of the opinion that it is MUCH harder to tank in turbulence on a WARPS or WOPR (wing mounted KC-135 or KC-10) than on the "iron maiden." The hoses are so long that the effects of turbulence become huge. Thanks. That's 180 deg. from every other opinion I've read (and the explanations for the difficulty), so it just goes to show that when it's a matter of opinion there's rarely 100% agreement on anything. I wonder if this might be a/c specific - which a/c were you flying in which you experienced both locations so you could compare? I've never been behind a multiple receiver capable tanker. I don't think I'd be very comfortable knowing that someone else was just a few feet off my wingtip, not looking at me and trying to chase a drogue. Throw in night or weather and the inevitable "Murphy" factor of someone forgetting which side to come off the hookup after topping off and the picture gets pretty scary. Multiple receiver stuff isn't that hard. Truly, the guy on the other side is merely an afterthought--except I seem to remember that on the Brits' Victor, there was a significant aileron trim required to keep the jet from turning inboard. The wingtip vortices always were trying to pull you in. As another example of a/c specific refueling behavior, an acquaintance, ex A-7E, mentioned that he found it easier to tank off an A-4 carrying a buddy store on the C/L, than off an A-7 carrying one underwing. IIRC, he said that with the A-7 his vertical tail was in the tanker's wing vortice, and a fair amount of cross-control was needed. Not a big deal either way, but something he was aware of. So that brings up another question. In the opinion of pilots here, preferably with direct personal experience, what was the easiest/hardest combination of tanker and receiver? Do you know of any combinations that weren't cleared for refueling? If you want to offer opinions based on what you've heard from other people that's fine, but secondhand information is, well, secondhand;-) Guy |
#19
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Air Force Aerial Refueling Methods: Flying Boom versusHose-and-Drogue
Ed Rasimus wrote:
snip In the worst case scenario the probe would hook the corner of the basket nearest the airplane. Two possibilities then--either the probe would slide into the funnel and connect or the probe would tip the basket off and it would then flail leading to the aircraft impact you describe. Even worse situation would be catching the basket, bending the probe and ripping off the hose leaving unretractable probe tenously holding heavy metal lined basket and x number of feet of hose thrashing the side of the airplane in front of your left intake. We had a souvenier basket in the squadron briefing room in the 4526th CCTS at Nellis when I checked out. A student in a prior class had brought it home on a flight. So, was part of the hose still attached when he landed, or had it broken off? Making a landing in the former case would be, uh, interesting;-) Guy |
#20
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Air Force Aerial Refueling Methods: Flying Boom versus Hose-and-Drogue
On Sun, 02 Jul 2006 19:54:29 GMT, Guy Alcala
wrote: Ed Rasimus wrote: In the worst case scenario the probe would hook the corner of the basket nearest the airplane. Two possibilities then--either the probe would slide into the funnel and connect or the probe would tip the basket off and it would then flail leading to the aircraft impact you describe. Even worse situation would be catching the basket, bending the probe and ripping off the hose leaving unretractable probe tenously holding heavy metal lined basket and x number of feet of hose thrashing the side of the airplane in front of your left intake. We had a souvenier basket in the squadron briefing room in the 4526th CCTS at Nellis when I checked out. A student in a prior class had brought it home on a flight. So, was part of the hose still attached when he landed, or had it broken off? Making a landing in the former case would be, uh, interesting;-) Guy Hah! You recall I mentioned that the hose was twelve feet from connection knuckle to basket fitting. If you've ever stood next to a Thunderchief you would appreciated that even if all 12 feet had been grabbed, the hose would not quite reach the ground. He only had about three feet of hose and most of it shredded away. The real concern was that either the basket was going to come off the probe or the probe was going to break off and go down the intake to FOD the engine. Ed Rasimus Fighter Pilot (USAF-Ret) "When Thunder Rolled" www.thunderchief.org www.thundertales.blogspot.com |
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