V22 Osprey discussion thread Mk II
McPave
I see your point.
With regard to rearward or nose down slope landing conditions, can the pilot use full aft nacelle?
Nothing inherently wrong ( at least by comparison with pure helicopter procedures currently in place ) with doing that for slopes, by the way.
Thanks,
John Dixson
With regard to rearward or nose down slope landing conditions, can the pilot use full aft nacelle?
Nothing inherently wrong ( at least by comparison with pure helicopter procedures currently in place ) with doing that for slopes, by the way.
Thanks,
John Dixson
Were there different Wing Incidence Angles flight tested in either the XV-15 or V-22 programs?
I wonder what the performance differences would be for the machine if it was maximized for performance and not for Blade/Wing fold?
I wonder what the performance differences would be for the machine if it was maximized for performance and not for Blade/Wing fold?
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Regarding putting a software limit on the ability of the pilot to move past the 75 degree nacelle position before reaching 40kts during forward transition:
Mcpave said:
That is very true in the Osprey as pilots in combat need to have every available option and 'trick up their sleeve' to deal with unanticipated situations not encountered in normal operations, but they need to work within defined limits as a matter of survival as he said.
On the commercial side software limits will be mandated for those pilots operating in a much more benign environment. The 609 civil tiltrotor does in fact have a nacelle inhibiting capability with software limits for the nacelle takeoff position that will not allow it to move past 75 degrees until 40kts has been reached not allowing pilots to fly out of the conversion corridor during take off (W-D proof which is needed on the civil side).
It is incredible what computers can do, but we have to find the correct man vs. machine balance for given external environments. Combat environments do not equate to civil commercial ops, and there will be differences.
Mcpave said:
...you have to put some faith in the crews to do the right thing...
On the commercial side software limits will be mandated for those pilots operating in a much more benign environment. The 609 civil tiltrotor does in fact have a nacelle inhibiting capability with software limits for the nacelle takeoff position that will not allow it to move past 75 degrees until 40kts has been reached not allowing pilots to fly out of the conversion corridor during take off (W-D proof which is needed on the civil side).
It is incredible what computers can do, but we have to find the correct man vs. machine balance for given external environments. Combat environments do not equate to civil commercial ops, and there will be differences.
Last edited by 21stCen; 15th Jul 2012 at 18:05.
It is incredible what computers can do, but we have to find the correct man vs. machine balance for given external environments.
John: given the requirements as stated for UTTAS, I can say with firm conviction that if I was asked to do a 15 deg lateral slope landing, I'd look REAL HARD for an alternate LZ or change my angle into the landing site.
That's uncomfortably close to dynamic tipover angle ...
Slopes
Lonewolf, part of the UTTAS eval was to train 10 Army pilots from the 101st in the aircraft ( Boeing did as well with theirs ). Part of that syllabus was to do the entire slope envelope. The Army pilots in the group had been selected to cover the range of individual piloting skills, and they could all do these landings, so don't sell yourself short. As to dynamic rollover, I always cringe when reading the scare stories, because the whole key to making steeper slope landings do-able is to do it slow and in perfect control all the way to touchdown of the downhill wheel, whichever one that is.
Relating this discussion to the V-22, I had been hopeful to learn what the V-22 configuration can manage as to slope landing capability. One would expect it to have very decent capability laterally, for instance. Should be OK nose up as well, leaving the nose down direction as the primary question and whether they can use all -7.5 degrees of aft tilt and whatever aft cyclic pitch is in the control system to provide a reasonable capability for a tactically used machine.
Thanks,
John Dixson
Relating this discussion to the V-22, I had been hopeful to learn what the V-22 configuration can manage as to slope landing capability. One would expect it to have very decent capability laterally, for instance. Should be OK nose up as well, leaving the nose down direction as the primary question and whether they can use all -7.5 degrees of aft tilt and whatever aft cyclic pitch is in the control system to provide a reasonable capability for a tactically used machine.
Thanks,
John Dixson
Last edited by JohnDixson; 16th Jul 2012 at 14:42. Reason: grammar
Maybe the Osprey would try to land on most slopes with nose facing up hill.
I'll leave that to the operators to sort out. Each sloped landing has to consider the wind, terrain, and the usual pile of factors.
I'll leave that to the operators to sort out. Each sloped landing has to consider the wind, terrain, and the usual pile of factors.
Relating this discussion to the V-22, I had been hopeful to learn what the V-22 configuration can manage as to slope landing capability. One would expect it to have very decent capability laterally, for instance. Should be OK nose up as well, leaving the nose down direction as the primary question and whether they can use all -7.5 degrees of aft tilt and whatever aft cyclic pitch is in the control system to provide a reasonable capability for a tactically used machine.
MP.....now you have me intrigued.
What I perceived you to say in that last post is you can raise/lower the nose with cyclic while maintaining a constant nacelle angle relative to the ground and thus achieve the same angle with the fuselage as the slope?
Is it my fourth morning beer that has me confused?
What I perceived you to say in that last post is you can raise/lower the nose with cyclic while maintaining a constant nacelle angle relative to the ground and thus achieve the same angle with the fuselage as the slope?
Is it my fourth morning beer that has me confused?
What I perceived you to say in that last post is you can raise/lower the nose with cyclic while maintaining a constant nacelle angle relative to the ground and thus achieve the same angle with the fuselage as the slope?
Dear me.....the Osprey is a very unusual thing to fly....the Army will never be able to operate them things! Hang on a mo'......if a bunch of Jarheads can get it figured out....any fuzzy cheeked young Warrant Officer or Officeress should find it a piece of cake.
So then.....if one was to beep the Nacelles well forward....say right to the limit of aft cyclic control.....giving the aircraft a very nose high attitude but nacelles still pointing straight up.....you could make a helicopter type takeoff merely by leaving the nacelles where they are and applying forward cyclic to accelerate until you hit max forward speed for that particular Nacelle position then have to go on into airplane mode by rotating the nacelles fully forward?
So then.....if one was to beep the Nacelles well forward....say right to the limit of aft cyclic control.....giving the aircraft a very nose high attitude but nacelles still pointing straight up.....you could make a helicopter type takeoff merely by leaving the nacelles where they are and applying forward cyclic to accelerate until you hit max forward speed for that particular Nacelle position then have to go on into airplane mode by rotating the nacelles fully forward?
Last edited by SASless; 17th Jul 2012 at 18:30.
CH-47 Lingo
SAS,
McP beeping nacelles forward in a hover isn't awfully different than manually beeping the CH-47 speed trim actuators forward in hover, am I correct?
Thanks,
John
McP beeping nacelles forward in a hover isn't awfully different than manually beeping the CH-47 speed trim actuators forward in hover, am I correct?
Thanks,
John
Last edited by JohnDixson; 17th Jul 2012 at 19:39. Reason: Typo
I love it when people actually talk about helicopter (and tilt rotor) flying in one of these threads. 
More of that won't go unappreciated.
More of that won't go unappreciated.
Last edited by Lonewolf_50; 17th Jul 2012 at 21:41.
John,
Seems I recall having the Speed Trims extended at least than 60 knots or so put severe stress on the Aft Vertical Shaft. In theory it would have made for a much higher nose high attitude while hovering for sure.
For those "not knowing of Chinooks"....each rotor head has an electrically operated....airspeed controlled system called Speed Trims that operate to level the airframe at high airspeeds and reduce drag. Each head has an electrically powered actuator that provides some forward tilt to the head based upon an airspeed input. The system operates automatically and has switches in the cockpit to allow for manual operation if required or as a means to retract the Speed Trims if they fail in the extended position. If the aft actuator remains extended at low speed or a hover....a lot of stress is applied to the Aft Vertical Shaft that extends from the Aft Transmission to the Aft Rotor Head.
Seems I recall having the Speed Trims extended at least than 60 knots or so put severe stress on the Aft Vertical Shaft. In theory it would have made for a much higher nose high attitude while hovering for sure.
For those "not knowing of Chinooks"....each rotor head has an electrically operated....airspeed controlled system called Speed Trims that operate to level the airframe at high airspeeds and reduce drag. Each head has an electrically powered actuator that provides some forward tilt to the head based upon an airspeed input. The system operates automatically and has switches in the cockpit to allow for manual operation if required or as a means to retract the Speed Trims if they fail in the extended position. If the aft actuator remains extended at low speed or a hover....a lot of stress is applied to the Aft Vertical Shaft that extends from the Aft Transmission to the Aft Rotor Head.
Last edited by SASless; 17th Jul 2012 at 22:39.
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Slope Landings
A gentleman who is considered one of the most experienced tiltrotor pilots in the world having spent decades flying the XV-15, V22, and 609 had this to say about slope landings in tiltrotors:
Slope landings were done on the XV numerous times with the preferred direction being upslope using nacelle angle to match the slope. We did these up to 15 degrees upslope in mild wind conditions and kept some thrust on the rotor as the brakes weren't the best. Downslope we used 95 degree aft nacelle limit plus some aft cyclic which translates to a bit extra flapping and landed on 10 degree slopes.
The max we demonstrated sideslope was a bit over 5 degrees due to potential nacelle strike issues with crosswinds.The preferred method is upslope with a tiltrotor as you have much more capability with forward nacelles (dial in nacelle angle to match the slope)but should the situation require other directions , these can be accommodated within the potential limits mentioned. If you recall, we even hovered at 60 degrees nacelle (30 degrees nose up) just to demonstrate capability but no qualified aviator would attempt a slope landing at that absurd angle. Great air show maneuver however, and has potential for target tracking in an attack configuration.
This all should apply for the V-22 AND 609, but can't speak for the current flight manual limits, and the 609 has not demonstrated capability as of present time."
The max we demonstrated sideslope was a bit over 5 degrees due to potential nacelle strike issues with crosswinds.The preferred method is upslope with a tiltrotor as you have much more capability with forward nacelles (dial in nacelle angle to match the slope)but should the situation require other directions , these can be accommodated within the potential limits mentioned. If you recall, we even hovered at 60 degrees nacelle (30 degrees nose up) just to demonstrate capability but no qualified aviator would attempt a slope landing at that absurd angle. Great air show maneuver however, and has potential for target tracking in an attack configuration.
This all should apply for the V-22 AND 609, but can't speak for the current flight manual limits, and the 609 has not demonstrated capability as of present time."
Last edited by 21stCen; 18th Jul 2012 at 07:45.
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V22 as Grumman C-2 greyhound Replacement
A change of direction here.
The UK is, in my opinion, going to require some sort of aircraft that can be utilised in the same manner as the USA make use of the Greyhound for its QE II carriers. It will have to be VSTOL & could possibly may use of a ramp for assisted take off (I suspect the V22 may not like this, but could be wrong).
The V22 and Greyound are able to carry similar weight loads and person numbers. Ranges are different (Greyhound has a significantly better range).
Do people see the V22 as being a suitable Greyhound replacement? If so why? If not a suitable replacement, why not? Is there an aircraft better suited to this role?
Cheers,
Hval.
The UK is, in my opinion, going to require some sort of aircraft that can be utilised in the same manner as the USA make use of the Greyhound for its QE II carriers. It will have to be VSTOL & could possibly may use of a ramp for assisted take off (I suspect the V22 may not like this, but could be wrong).
The V22 and Greyound are able to carry similar weight loads and person numbers. Ranges are different (Greyhound has a significantly better range).
Do people see the V22 as being a suitable Greyhound replacement? If so why? If not a suitable replacement, why not? Is there an aircraft better suited to this role?
Cheers,
Hval.
Last edited by hval; 18th Jul 2012 at 12:24. Reason: Carriers
capability wise....probably. Range would matter but could be worked around in most cases.
Cost-wise....draw your own conclusion....one Osprey or a fleet (several) ofGreyhounds.
Cost-wise....draw your own conclusion....one Osprey or a fleet (several) ofGreyhounds.
Cost-wise....draw your own conclusion....one Osprey or a fleet (several) ofGreyhounds.
MV22 - $65 million (CH53K price is projected to be the same or higher currently)
C-2 - $39 million
Sans,
As usual....you miss the mark by miles. In case you have not had your cataract surgery or skipped your morning coffee....or just have a hang up on the Sikorsky CH-53K......read the posts and see where you went off the rails will you. There should be 18 airframes in mothballs at Davis-Monthan AFB that could be SLEP'd to the new standard and if Grumman still has the tooling for re-starting the production line again....unit costs would be less than in the past. Add in the fact the Navy has reduced the number of Carriers....that leaves more aircraft to go around for the remaining carriers. Maintenance costs alone would prove an advantage over Osprey's.
The sad note is if one builds a carrier without Cats.....one limits the capability of the vessel tremendously. There is a long lived thread in the Military Forum about just that issue....the UK's new Carrier and its design. If their carrier continues not to have the ability to cat launch or trap fixed wing aircraft....and thus being totally reliant upon 22's and F-35's....they might just be making a very expensive and sad mistake. The cost of the 22 and the risk of the F-35 program being cancelled....could doom the new carriers before they are built and commissioned.
As usual....you miss the mark by miles. In case you have not had your cataract surgery or skipped your morning coffee....or just have a hang up on the Sikorsky CH-53K......read the posts and see where you went off the rails will you. There should be 18 airframes in mothballs at Davis-Monthan AFB that could be SLEP'd to the new standard and if Grumman still has the tooling for re-starting the production line again....unit costs would be less than in the past. Add in the fact the Navy has reduced the number of Carriers....that leaves more aircraft to go around for the remaining carriers. Maintenance costs alone would prove an advantage over Osprey's.
The sad note is if one builds a carrier without Cats.....one limits the capability of the vessel tremendously. There is a long lived thread in the Military Forum about just that issue....the UK's new Carrier and its design. If their carrier continues not to have the ability to cat launch or trap fixed wing aircraft....and thus being totally reliant upon 22's and F-35's....they might just be making a very expensive and sad mistake. The cost of the 22 and the risk of the F-35 program being cancelled....could doom the new carriers before they are built and commissioned.
Last edited by SASless; 18th Jul 2012 at 15:08.