Can Helicopters fly inverted? (Merged threads)
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Flying inverted
My little brain tells me flying inverted for longer than a brief period in a Helicopter is not possible due to the rotors hitting the tailboom and the problem of the rotors producing lift the wrong way to keep said helicopter flying for long, but since the Lynx has got such rigid rotor's I am not 100% sure, could someone help me out and confirm my simple suspicion?
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Long shot:
a) I have NO idea about brain sizes!
b) IF we consider RC-helicopters as bonafide helicopters (they fly wit the same pricipals!), then you can see the Acrobatic versions fly upside down as long as the RC-pilot wishes!!
c) DON'T try it in a full-size!
3top
a) I have NO idea about brain sizes!
b) IF we consider RC-helicopters as bonafide helicopters (they fly wit the same pricipals!), then you can see the Acrobatic versions fly upside down as long as the RC-pilot wishes!!
c) DON'T try it in a full-size!
3top
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Hold on to your hat.
Brilliant Stuff,
In the near future, flying inverted in a helicopter will be just as easy as flying inverted in a fixed-wing aircraft.
'Absolutely' Rigid Rotors, plus the negative blade pitch that is required for Reverse Velocity Utilization will make this possible.
___________
Now back to building the machine, that will build the blade, that will fly inverted.
In the near future, flying inverted in a helicopter will be just as easy as flying inverted in a fixed-wing aircraft.
'Absolutely' Rigid Rotors, plus the negative blade pitch that is required for Reverse Velocity Utilization will make this possible.
___________
Now back to building the machine, that will build the blade, that will fly inverted.
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what us the max negative that the lynx is normally set up for ? , the only time you would need negative in normal ops I would think is when you are landing on a moving deck .
Dave Jackson, after you have solved the problems of the blades, rotor head (there will be some serious forces hanging around the blade attachments!!) and negative collective, don't forget to redesign the engine.
It will need an inverted flight sump, to keep oil going to the oil pump, different scavenge system because the oil will no longer drain to the bottom, and an inverted fuel system to again keep the pump supplied with fuel as it sloshes from side to side and to the top.
Ensure the aircraft gets vacuumed after every flight - get zero or negative g and all the dust and grit comes up off the floor.
Design map pockets that are very tight, to stop them coming loose. Buy a pile of new maps, because now the pilots will tear them pulling them out, and ruin them when stuffing them back in. Forget designing inverted flight coffee cup holders, I think Lockheed made one some years ago for a Hercules, and each one cost $20k.
Add to that the coffee percolator that will keep going after a thermonuclear magnetic pulse, and I think we are complete.
It will need an inverted flight sump, to keep oil going to the oil pump, different scavenge system because the oil will no longer drain to the bottom, and an inverted fuel system to again keep the pump supplied with fuel as it sloshes from side to side and to the top.
Ensure the aircraft gets vacuumed after every flight - get zero or negative g and all the dust and grit comes up off the floor.
Design map pockets that are very tight, to stop them coming loose. Buy a pile of new maps, because now the pilots will tear them pulling them out, and ruin them when stuffing them back in. Forget designing inverted flight coffee cup holders, I think Lockheed made one some years ago for a Hercules, and each one cost $20k.
Add to that the coffee percolator that will keep going after a thermonuclear magnetic pulse, and I think we are complete.
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Inverted flying
Re the 'Inverted Flying' thread.
As a display pilot, can I put in a few pennorth, but only dealing with the smaller machines I fly. (PS Wish someone would offer me a go in a Lynx/Chinook)
Even the humble Schweizer 300 model will invert for a few seconds. (Just pop into my Shoreham office for a peek at the photos if your'e a non believer) and ditto the the Enstrom 280/480, MD 500/Gazelle et al.
What use is any of it.?
I've asked myself that question too many times, and have been somewhat accusingly asked it by some highly experienced guys. I only see it as a problem, if you feel it brings a swashbuckling attitude to our industry, something I constantly endeavour to avoid. But on the positive side, it DOES BRING HELI SALES, as I recall, oh so well in the early 1970's when the world was knocking the newcomer Enstrom.
I copied the great American display pilot, Mike Meger and managed to produce a display routine good enough for Farnborough, and all I can say is it put the marque on the map and subsequently I sold 138 Enstrom 28/280 Sharks in a ten year period.
At my end of the industry we need to constantly bring in the punters if we are to thrive, even survive ! And display flying does that. I've lost count of how many times, I've been approached at air shows with a worthwhile enquiry.
Of course, the articulated M/R head can't accept a smell of negative G, and to make sure of that, I leave my pace notes on the co pilots seat, and the second headset on its hook. If they move, I wake up!.
The carrier ops machines need the negative pitch to keep the skids/wheels in deck contact on a heaving ship of course, and as has been said here, the models don't seem to care which way up they are. Just a week ago, at a Draycott Farm venue, I watched Paul Heckles display his aerobatic skills at night !!!! Illuminated M/R blades and horizontal bar through the airframe. An awesome show when he spent as much time inverted as with the M/R disc the right way up.
In the 1986 World Championships at Cranfield, the German factory pilot, Charlie Zimmerman, (where are you now Charlie?) flew the B105. During his display routine, Charlie inverted the ship, entered a descending flat spin, before cycling out to level flight! Not surprising he was awarded the first place. Another German, Herman Fuchs, repeated the manoeuvre and got second.
I'm not sure I should invite any of you to 'try this at home,' but all that is needed to be inverted in the loop, is the right 'gate speed' for type, then assist the normal high speed flap back in the climb with aft cyclic, look over the shoulder for a horizontal horizon and with a quick glance at the instruments for a minimum height and manoeuvre speed on the dials, and if satis, progressively lower collective to its lowest position as the cyclic is pulled through aft. On non-correlated pistons, the Rrpm needs to be monitored as the extra G comes on in the descent and pull out.
In the USA, I've seen. the MD pilots use the manoeuvre many times for air show and publicity purposes, but again would widen my ears to any of you who had views in the oppposite camp on such flying.
As I retire from display work after 1200 practice routines and public shows, I'd dearly like to see some youngsters come along and progress things. I know for sure, there are so many more show manoeuvres to be discovered than I have produced over the years. Subject always to the maker's Flight Manual limitations. But guys, a CAA approved DA, (display authority) is mandatory.
I have always maintained an 'open' view on all this and perhaps a few comments from out there would be more than interesting.
Dennis Kenyon.
.
As a display pilot, can I put in a few pennorth, but only dealing with the smaller machines I fly. (PS Wish someone would offer me a go in a Lynx/Chinook)
Even the humble Schweizer 300 model will invert for a few seconds. (Just pop into my Shoreham office for a peek at the photos if your'e a non believer) and ditto the the Enstrom 280/480, MD 500/Gazelle et al.
What use is any of it.?
I've asked myself that question too many times, and have been somewhat accusingly asked it by some highly experienced guys. I only see it as a problem, if you feel it brings a swashbuckling attitude to our industry, something I constantly endeavour to avoid. But on the positive side, it DOES BRING HELI SALES, as I recall, oh so well in the early 1970's when the world was knocking the newcomer Enstrom.
I copied the great American display pilot, Mike Meger and managed to produce a display routine good enough for Farnborough, and all I can say is it put the marque on the map and subsequently I sold 138 Enstrom 28/280 Sharks in a ten year period.
At my end of the industry we need to constantly bring in the punters if we are to thrive, even survive ! And display flying does that. I've lost count of how many times, I've been approached at air shows with a worthwhile enquiry.
Of course, the articulated M/R head can't accept a smell of negative G, and to make sure of that, I leave my pace notes on the co pilots seat, and the second headset on its hook. If they move, I wake up!.
The carrier ops machines need the negative pitch to keep the skids/wheels in deck contact on a heaving ship of course, and as has been said here, the models don't seem to care which way up they are. Just a week ago, at a Draycott Farm venue, I watched Paul Heckles display his aerobatic skills at night !!!! Illuminated M/R blades and horizontal bar through the airframe. An awesome show when he spent as much time inverted as with the M/R disc the right way up.
In the 1986 World Championships at Cranfield, the German factory pilot, Charlie Zimmerman, (where are you now Charlie?) flew the B105. During his display routine, Charlie inverted the ship, entered a descending flat spin, before cycling out to level flight! Not surprising he was awarded the first place. Another German, Herman Fuchs, repeated the manoeuvre and got second.
I'm not sure I should invite any of you to 'try this at home,' but all that is needed to be inverted in the loop, is the right 'gate speed' for type, then assist the normal high speed flap back in the climb with aft cyclic, look over the shoulder for a horizontal horizon and with a quick glance at the instruments for a minimum height and manoeuvre speed on the dials, and if satis, progressively lower collective to its lowest position as the cyclic is pulled through aft. On non-correlated pistons, the Rrpm needs to be monitored as the extra G comes on in the descent and pull out.
In the USA, I've seen. the MD pilots use the manoeuvre many times for air show and publicity purposes, but again would widen my ears to any of you who had views in the oppposite camp on such flying.
As I retire from display work after 1200 practice routines and public shows, I'd dearly like to see some youngsters come along and progress things. I know for sure, there are so many more show manoeuvres to be discovered than I have produced over the years. Subject always to the maker's Flight Manual limitations. But guys, a CAA approved DA, (display authority) is mandatory.
I have always maintained an 'open' view on all this and perhaps a few comments from out there would be more than interesting.
Dennis Kenyon.
.
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Dennis Kenyon,
Thank you very much indeed for your detailed explanation.
I bow my head in awe!!
Sadly I have never seen you live but I was given a video of one of your displays and it was a thing of beauty.
Everone who has added they 2 penny's thank you !
Thank you very much indeed for your detailed explanation.
I bow my head in awe!!
Sadly I have never seen you live but I was given a video of one of your displays and it was a thing of beauty.
Everone who has added they 2 penny's thank you !
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Having flown a display or two, I also welcome Dennis to the forum!!
The concept of inverted flight has two components, one while holding positive G, and one where the negative G is a trimmed condition.
Any helicopter can be made to show the first positive G condition, if for a brief period. The second requires a very stiff rotor head, stiff blades and a skilled pilot. Even so, no helicopter has the fuel and oil systems to support other than a brief period of negative G. Engine flameout and engine/transmission damage are quite likely if more than about 5 to 10 seconds of negative G are held.
Other than for display purposes, inverted flight is relatively useless, of course. Even airplanes find it better to roll inverted and then pull positive G when a push-down is needed.
The concept of inverted flight has two components, one while holding positive G, and one where the negative G is a trimmed condition.
Any helicopter can be made to show the first positive G condition, if for a brief period. The second requires a very stiff rotor head, stiff blades and a skilled pilot. Even so, no helicopter has the fuel and oil systems to support other than a brief period of negative G. Engine flameout and engine/transmission damage are quite likely if more than about 5 to 10 seconds of negative G are held.
Other than for display purposes, inverted flight is relatively useless, of course. Even airplanes find it better to roll inverted and then pull positive G when a push-down is needed.
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I haven't flown any attack helicopter, but I seem to recall an Apache pilot telling me that negative g pushover of as much as -2g was used to terrain follow when the terrain was too steep for collective climbs/descents.
A far cry from flying the trimmed negative g that Nick mentioned, but aerodynamically, if you can reach -2g upright you should be able to maintain -1g inverted. Of course, the -2g period would be a constantly changing pitch attitude, so the inverted case would be of a limited duration.
Matthew.
A far cry from flying the trimmed negative g that Nick mentioned, but aerodynamically, if you can reach -2g upright you should be able to maintain -1g inverted. Of course, the -2g period would be a constantly changing pitch attitude, so the inverted case would be of a limited duration.
Matthew.
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Aesir,
The Navy says that flying inverted will result in significant cost savings. They believe that this action this will scare the enemy off without have to use expensive missiles. It's called the 'Top Gun' effect and it was developed by the renowned scientologist Mr. Tom Cruise.
Ascend Charlie,
Lower Rear Admiral Ican B. Bought (nickname 'Rectum') did not realize the extra cost of aerobatics engines. Wanting to continue the tradition of saving the taxpayer's money, he has stipulated that inverted flight will only be done during autorotations.
The Navy says that flying inverted will result in significant cost savings. They believe that this action this will scare the enemy off without have to use expensive missiles. It's called the 'Top Gun' effect and it was developed by the renowned scientologist Mr. Tom Cruise.
Ascend Charlie,
Lower Rear Admiral Ican B. Bought (nickname 'Rectum') did not realize the extra cost of aerobatics engines. Wanting to continue the tradition of saving the taxpayer's money, he has stipulated that inverted flight will only be done during autorotations.
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Flight inverted
Hallo Widgeon.... did you really fly one of those ??
As for inverted 'autorotation' and gaining height. The answer is a definite YES.
After one particular practice, I recall only too well, my old boss, Roy Spooner, (spoonair and all that) expressing concern at how I would cope if the engine let go when I was inverted. With a half tongue in cheek, I replied, "Not a lot extra to do Roy, as often I've split the needles anyway." I don't think he passed out.
But seriously, if a tad too much aft cyclic is used at the top, and with the lever down, the needles will certainly split in an Enstrom or the Schweizer. And when I've had a moment to check the VSI, one IS gaining height, though I've never confirmed this with a positive increase on the altimeter.
Thank you Nick and others for your welcome to pprune. Yes, now I've slowed down and am planning to write in my retirement, I'd love to join you chaps with a contribution or two.
And Mr kissmysquirrel, I AM looking to locate suitable interested younger pilots with a view to producing a 'duo' display, but it will have to be sponsored, or my plan can't go anywhere.
This winter, I plan to attack likely firms. If/when I get a positive response, I'll be looking more actively for three pilots with a view to forming a display team duo for 2007. I have one good guy now and we would want two more, and perhaps a year to get things in order.
The team would be 100% professional, ie full time pilots, dedicated aircraft in house colours, engineer, and ops. Preferred pilots would need a fair level of fixed wing aerobatic experience and perhaps 1000 hours or so on rotary, but nothing needs to be set in rock. But tons of the right mental approach is necessary.
'Twill all be in pprune if/when it can happen.
Dennis Kenyon
As for inverted 'autorotation' and gaining height. The answer is a definite YES.
After one particular practice, I recall only too well, my old boss, Roy Spooner, (spoonair and all that) expressing concern at how I would cope if the engine let go when I was inverted. With a half tongue in cheek, I replied, "Not a lot extra to do Roy, as often I've split the needles anyway." I don't think he passed out.
But seriously, if a tad too much aft cyclic is used at the top, and with the lever down, the needles will certainly split in an Enstrom or the Schweizer. And when I've had a moment to check the VSI, one IS gaining height, though I've never confirmed this with a positive increase on the altimeter.
Thank you Nick and others for your welcome to pprune. Yes, now I've slowed down and am planning to write in my retirement, I'd love to join you chaps with a contribution or two.
And Mr kissmysquirrel, I AM looking to locate suitable interested younger pilots with a view to producing a 'duo' display, but it will have to be sponsored, or my plan can't go anywhere.
This winter, I plan to attack likely firms. If/when I get a positive response, I'll be looking more actively for three pilots with a view to forming a display team duo for 2007. I have one good guy now and we would want two more, and perhaps a year to get things in order.
The team would be 100% professional, ie full time pilots, dedicated aircraft in house colours, engineer, and ops. Preferred pilots would need a fair level of fixed wing aerobatic experience and perhaps 1000 hours or so on rotary, but nothing needs to be set in rock. But tons of the right mental approach is necessary.
'Twill all be in pprune if/when it can happen.
Dennis Kenyon
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Matthew,
Dont for a second beleive -2G in an Apache. It has a 4% hinge offset rotor, which will lose roll control at about -1 G and its blades are certainly not capable of producing 40,000 lbs of negative thrust. Chalk that tale up to too much Budwiser and too few ethics!
I certainly can believe zero or even -1/2G, though.
Remember, at zero G the aircraft is making the same radius downward that a 2G pullup produces upward. Each case has 1G of maneuver being performed from the trimmed 1G level.
Dont for a second beleive -2G in an Apache. It has a 4% hinge offset rotor, which will lose roll control at about -1 G and its blades are certainly not capable of producing 40,000 lbs of negative thrust. Chalk that tale up to too much Budwiser and too few ethics!
I certainly can believe zero or even -1/2G, though.
Remember, at zero G the aircraft is making the same radius downward that a 2G pullup produces upward. Each case has 1G of maneuver being performed from the trimmed 1G level.
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Hi all!
Nick, Dennis,
you are the specialists on this thread:
How does one get a display permit??
I remember the discussion about the chap in South Africa who looped and rolled the 407, though it seems without Bell's and the CAA's "agreement".
It would seem to me that NO one will accept any responsibility IF the sought after maneuvers are not in the POH.
What manufacturer would - today - still agree to authorize such routine done in their product?
Dennis how did you manage that with Schweizer ( ....love the video with the backflip!)?
When I first time heard about the 407 routine in SA, I thought WOW, now Bell has something to shut up everyone who badmouthes the 407 for its "turbulent" infancy ( ...me included)!
However they didn't really appreciate the effort, did they!!!
On the other hand the Aussy Army did routines regulary at airshows rolling/looping A-Stars on regular inspections/maitenance and supposedly they are still flying today!
Can't imagine Frank to give anyone a "go ahead" for some fun in a R-22/44 either!
So, how did you ever manage to get the OKAY from CAA/manufacturer?
3top 
Nick, Dennis,
you are the specialists on this thread:
How does one get a display permit??
I remember the discussion about the chap in South Africa who looped and rolled the 407, though it seems without Bell's and the CAA's "agreement".
It would seem to me that NO one will accept any responsibility IF the sought after maneuvers are not in the POH.
What manufacturer would - today - still agree to authorize such routine done in their product?
Dennis how did you manage that with Schweizer ( ....love the video with the backflip!)?
When I first time heard about the 407 routine in SA, I thought WOW, now Bell has something to shut up everyone who badmouthes the 407 for its "turbulent" infancy ( ...me included)!
However they didn't really appreciate the effort, did they!!!
On the other hand the Aussy Army did routines regulary at airshows rolling/looping A-Stars on regular inspections/maitenance and supposedly they are still flying today!
Can't imagine Frank to give anyone a "go ahead" for some fun in a R-22/44 either!
So, how did you ever manage to get the OKAY from CAA/manufacturer?
3top
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Flying inverted
For 3top,
The DA, (display authority) is straightforward. You make contact with the GAD at CAA, either Rob Metcalfe, Dave Evans or Keith Thompson.
Advise you want the DA. Providing they consider your experience adequate, you will be given a DA application and assessment form. You bring that to me or a rotary DAE (display evaluator)
We chat through your proposed display routine and your associated display attitude and knowledge of 403, (display manual.) Next you demonstrate the routine as discussed. No heroics, no special wheezes, just a simple and straightforward display routine that sticks exactly to the planned brief.
If all satisfactory, the DAE forwards his recommendation to the CAA for issue of a DA or otherewise. Just bear in mind, that even when received, your DA will say "Flypasts Only !!!!!!!!!!! "
That's the approval aspect.
To move on to the manoeuvres. All FM's state "no aerobatic manoeuvres" So what are aerobatics? The CAA will advise.... any manoeuvre that exceeds 90 degrees in roll or 60 degrees in pitch.
I have flown my standard display routine before the Enstrom factory officials and have their outline blessing for the manoeuvres flown.
Insurance needs to be tackled next. My insurers, have added to my policy. Occasional display flying by the insured only.
God bless with your efforts.
Dennis Kenyon
The DA, (display authority) is straightforward. You make contact with the GAD at CAA, either Rob Metcalfe, Dave Evans or Keith Thompson.
Advise you want the DA. Providing they consider your experience adequate, you will be given a DA application and assessment form. You bring that to me or a rotary DAE (display evaluator)
We chat through your proposed display routine and your associated display attitude and knowledge of 403, (display manual.) Next you demonstrate the routine as discussed. No heroics, no special wheezes, just a simple and straightforward display routine that sticks exactly to the planned brief.
If all satisfactory, the DAE forwards his recommendation to the CAA for issue of a DA or otherewise. Just bear in mind, that even when received, your DA will say "Flypasts Only !!!!!!!!!!! "
That's the approval aspect.
To move on to the manoeuvres. All FM's state "no aerobatic manoeuvres" So what are aerobatics? The CAA will advise.... any manoeuvre that exceeds 90 degrees in roll or 60 degrees in pitch.
I have flown my standard display routine before the Enstrom factory officials and have their outline blessing for the manoeuvres flown.
Insurance needs to be tackled next. My insurers, have added to my policy. Occasional display flying by the insured only.
God bless with your efforts.
Dennis Kenyon