Robert Haston
Dec6-04, 07:17 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>If you want to help out our Special Operations troops, here\'s your chance:\n\nI am an HH-60 Helicopter pilot in the USAF here at Patrick AFB, FL. I\'m\ndodging the bureaucratic nightmare of our test and evaluation system and\ngoing solo developing a simple system to recover survivors from a helicopter\nwithout going below the speed where a helicopter\'s downwash (and dust cloud)\ncatches up with it. This "Haston Recovery System" will be based on the\nFulton Recovery System which used cargo planes to snatch people with.\n\nThis moderate speed gives the helicopter 20% more lift, also, making\nrecovery possible in air too thin to hover. I am doing this because of\nmishaps in rescue attempts in high altitude and dusty regions. We lost a\nhelicopter and Flight Engineer just last month. Being able to snatch\ncritically wounded out of high threat situations (such as we couldn\'t do in\nSomalia and Afghanistan) may save lives. Also, recovery loops are becoming\nstandard equipment in survival harnesses. Being able to snag someone\nwithout stopping would be a good tool for hot landing zones.\n\nI have consulted an expert in the stunt equipment business (Lane Leavitt).\nHe said either a bungee (with the elastic portion on pulleys inside the\nhelicopter to avoid snapping into the rotors) system or pneumatic ratchet\nwould work. His videos of stuntmen flying all over the place make my task\nlook small in comparison. He said it is easy once you need to spec out the\ndesign.\n\nAny method would require a pre-tension equal to or greater than the\nsurvivor\'s weight, so any line paid out to reduce shock would be recovered,\nleaving the survivor no closer to the ground once recovered. The retrieval\nend will be a latch enclosed in a plastic tube on the end of a rope. A tail\nwill be at the end to show where the hook is, and allow for the Flight\nEngineer to judge height.\n\nMy strategy for an end around run on the bureaucracy is to design the\nsystem, describe it as off the shelf, attach an attractive sales package,\nand acquire it through a vendor like it was just waiting there at Wal-Mart\nall along, just waiting for its bar code to be swiped.\n\nNow the answer lies in designing it to the numbers. I have long since\nforgotten all my physics math.\n\nThe basic numbers are the H-60 "translational (as in hover to forward\nflight) lift" region is 16-30 knots. If I had to pick a number, I would say\n25 knots true air speed (13 M/s?) which would equal a safe ground speed in\na zero wind condition.\n\nI also understand that the height of the helicopter would have great\ninfluence, as the force in the rope would be at near zero with the\nhelicopter almost overhead at pickup, but rapidly increasing as it moved\npast. This was evidenced by footage of the Fulton system (as seen in the\nGreen Berets and Thunderball) which showed the survivor gently lifting\nvertically, then shooting off on a tangent (literally, or would that be a\nsine?).\n\nWhile height adds length of line used to accelerate, it also requires the\nsurvivor to be lifted as well as accelerated. I am guessing that this\ncancels out, so there is no inherent need for more height. The one thing\nthat is needed though, is to ensure the survivor rises slightly to clear\nnearby obstacles. I am assuming that a decent height used by the helicopter\nto clear its blades, say 20 feet would accomplish this.\n\nI am guessing that the added g load would be something like speed divided by\nthe amount of rope payout. 6.5 meters would give you 2g.\n\nWhat I would like to have is a formula I could plug into a spreadsheet,\nwhere I could input ground speed, helicopter height, survivor weight, pre\nload, and elasticity of the bungee or ratchet system.\n\nThe main desired results would be maximum g load on the survivor; and line\nextension, and minimum survivor altitude caused by line\nextension.\n\nThe cooler looking (acceleration load charts, survivor height charts, etc.)\nthe better\n\nTesting will be the easy part, a maximum weight recording scale, a couple\ndrop tests, then a boom of a truck driving by at 28 MPH, then helo tests.\n\nThanks for any assistance,\n\n\n--\nRobert Haston\nSatellite Beach, FL\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>If you want to help out our Special Operations troops, here's your chance:
I am an HH-60 Helicopter pilot in the USAF here at Patrick AFB, FL. I'm
dodging the bureaucratic nightmare of our test and evaluation system and
going solo developing a simple system to recover survivors from a helicopter
without going below the speed where a helicopter's downwash (and dust cloud)
catches up with it. This "Haston Recovery System" will be based on the
Fulton Recovery System which used cargo planes to snatch people with.
This moderate speed gives the helicopter 20% more lift, also, making
recovery possible in air too thin to hover. I am doing this because of
mishaps in rescue attempts in high altitude and dusty regions. We lost a
helicopter and Flight Engineer just last month. Being able to snatch
critically wounded out of high threat situations (such as we couldn't do in
Somalia and Afghanistan) may save lives. Also, recovery loops are becoming
standard equipment in survival harnesses. Being able to snag someone
without stopping would be a good tool for hot landing zones.
I have consulted an expert in the stunt equipment business (Lane Leavitt).
He said either a bungee (with the elastic portion on pulleys inside the
helicopter to avoid snapping into the rotors) system or pneumatic ratchet
would work. His videos of stuntmen flying all over the place make my task
look small in comparison. He said it is easy once you need to spec out the
design.
Any method would require a pre-tension equal to or greater than the
survivor's weight, so any line paid out to reduce shock would be recovered,
leaving the survivor no closer to the ground once recovered. The retrieval
end will be a latch enclosed in a plastic tube on the end of a rope. A tail
will be at the end to show where the hook is, and allow for the Flight
Engineer to judge height.
My strategy for an end around run on the bureaucracy is to design the
system, describe it as off the shelf, attach an attractive sales package,
and acquire it through a vendor like it was just waiting there at Wal-Mart
all along, just waiting for its bar code to be swiped.
Now the answer lies in designing it to the numbers. I have long since
forgotten all my physics math.
The basic numbers are the H-60 "translational (as in hover to forward
flight) lift" region is 16-30 knots. If I had to pick a number, I would say
25 knots true air speed (13 M/s?) which would equal a safe ground speed in
a zero wind condition.
I also understand that the height of the helicopter would have great
influence, as the force in the rope would be at near zero with the
helicopter almost overhead at pickup, but rapidly increasing as it moved
past. This was evidenced by footage of the Fulton system (as seen in the
Green Berets and Thunderball) which showed the survivor gently lifting
vertically, then shooting off on a tangent (literally, or would that be a
sine?).
While height adds length of line used to accelerate, it also requires the
survivor to be lifted as well as accelerated. I am guessing that this
cancels out, so there is no inherent need for more height. The one thing
that is needed though, is to ensure the survivor rises slightly to clear
nearby obstacles. I am assuming that a decent height used by the helicopter
to clear its blades, say 20 feet would accomplish this.
I am guessing that the added g load would be something like speed divided by
the amount of rope payout. 6.5 meters would give you 2g.
What I would like to have is a formula I could plug into a spreadsheet,
where I could input ground speed, helicopter height, survivor weight, pre
load, and elasticity of the bungee or ratchet system.
The main desired results would be maximum g load on the survivor; and line
extension, and minimum survivor altitude caused by line
extension.
The cooler looking (acceleration load charts, survivor height charts, etc.)
the better
Testing will be the easy part, a maximum weight recording scale, a couple
drop tests, then a boom of a truck driving by at 28 MPH, then helo tests.
Thanks for any assistance,
--
Robert Haston
Satellite Beach, FL
I am an HH-60 Helicopter pilot in the USAF here at Patrick AFB, FL. I'm
dodging the bureaucratic nightmare of our test and evaluation system and
going solo developing a simple system to recover survivors from a helicopter
without going below the speed where a helicopter's downwash (and dust cloud)
catches up with it. This "Haston Recovery System" will be based on the
Fulton Recovery System which used cargo planes to snatch people with.
This moderate speed gives the helicopter 20% more lift, also, making
recovery possible in air too thin to hover. I am doing this because of
mishaps in rescue attempts in high altitude and dusty regions. We lost a
helicopter and Flight Engineer just last month. Being able to snatch
critically wounded out of high threat situations (such as we couldn't do in
Somalia and Afghanistan) may save lives. Also, recovery loops are becoming
standard equipment in survival harnesses. Being able to snag someone
without stopping would be a good tool for hot landing zones.
I have consulted an expert in the stunt equipment business (Lane Leavitt).
He said either a bungee (with the elastic portion on pulleys inside the
helicopter to avoid snapping into the rotors) system or pneumatic ratchet
would work. His videos of stuntmen flying all over the place make my task
look small in comparison. He said it is easy once you need to spec out the
design.
Any method would require a pre-tension equal to or greater than the
survivor's weight, so any line paid out to reduce shock would be recovered,
leaving the survivor no closer to the ground once recovered. The retrieval
end will be a latch enclosed in a plastic tube on the end of a rope. A tail
will be at the end to show where the hook is, and allow for the Flight
Engineer to judge height.
My strategy for an end around run on the bureaucracy is to design the
system, describe it as off the shelf, attach an attractive sales package,
and acquire it through a vendor like it was just waiting there at Wal-Mart
all along, just waiting for its bar code to be swiped.
Now the answer lies in designing it to the numbers. I have long since
forgotten all my physics math.
The basic numbers are the H-60 "translational (as in hover to forward
flight) lift" region is 16-30 knots. If I had to pick a number, I would say
25 knots true air speed (13 M/s?) which would equal a safe ground speed in
a zero wind condition.
I also understand that the height of the helicopter would have great
influence, as the force in the rope would be at near zero with the
helicopter almost overhead at pickup, but rapidly increasing as it moved
past. This was evidenced by footage of the Fulton system (as seen in the
Green Berets and Thunderball) which showed the survivor gently lifting
vertically, then shooting off on a tangent (literally, or would that be a
sine?).
While height adds length of line used to accelerate, it also requires the
survivor to be lifted as well as accelerated. I am guessing that this
cancels out, so there is no inherent need for more height. The one thing
that is needed though, is to ensure the survivor rises slightly to clear
nearby obstacles. I am assuming that a decent height used by the helicopter
to clear its blades, say 20 feet would accomplish this.
I am guessing that the added g load would be something like speed divided by
the amount of rope payout. 6.5 meters would give you 2g.
What I would like to have is a formula I could plug into a spreadsheet,
where I could input ground speed, helicopter height, survivor weight, pre
load, and elasticity of the bungee or ratchet system.
The main desired results would be maximum g load on the survivor; and line
extension, and minimum survivor altitude caused by line
extension.
The cooler looking (acceleration load charts, survivor height charts, etc.)
the better
Testing will be the easy part, a maximum weight recording scale, a couple
drop tests, then a boom of a truck driving by at 28 MPH, then helo tests.
Thanks for any assistance,
--
Robert Haston
Satellite Beach, FL