What's New With The Civil Tiltrotor?
Originally Posted by Stinger10
Surprise! You're AW negative again....
The only thing I have been negative about with respect to AW is the essentially pointless flash-in-the-pan Project Zero.
https://www.flightglobal.com/news/ar...n-push-416790/
Emphasis mine.
Now wheres FH1100....?
16 SEPTEMBER, 2015 BY: DOMINIC PERRY LONDON
AgustaWestland will fly the third prototype of its AW609 tiltrotor late this year as the manufacturer accelerates testing activity ahead of planned certification in 2017.
Two flight-test articles dating from the early days of the programme, then a joint development with Bell, have been used for the validation campaign so far and have amassed 1,300h, alongside 300h of ground runs.
But with the initial aircraft "now reaching the end of its useful life", according to Paul Edwards, experimental test pilot at AgustaWestland, the arrival of two subsequent prototypes is required to attain US Federal Aviation Administration (FAA) approval.
Prototype three is "in final build" at the manufacturer's plant in Vergiate, Italy, he told a conference on future rotorcraft on 14 September. It will be transported to its Philadelphia, Pennsylvania facility – the location of the tiltrotor’s eventual final assembly line – late this year, to be used for icing trials and then cold weather testing.
The fourth flight-test article, which will have the production standard cockpit installed, is also being produced in Philadelphia.
Service entry is scheduled for 2018, says Edwards, and he anticipates rapid take-up of the Pratt & Whitney Canada PT6-powered type.
"This aircraft is going to be part of the aviation fabric far more quickly than a lot of people realise," he says.
With no certification standard existing for the tiltrotor, AgustaWestland has worked with the FAA to develop hybrid rules – the Powered Lift Certification Requirement – that draw on regulations from both the fixed- and rotary-wing worlds.
These involve proving that the aircraft can perform both gliding and autorotation landings in the event of engine failure, as well as rapid reconversion from forward flight, and flare before touchdown.
So far, 28 power-off reconversions have been performed, says Edwards, although he cautions that it has yet to pass certification trials for the engine-out state.
Edwards says the evaluations have also dispelled the view that tiltrotors are particularly vulnerable to vortex ring settling.
"Tiltrotors are not susceptible to vortex ring," says Edwards. "We had to try really hard to get there."
"It was about to fly itself out when we applied the recovery technique. Both rotors are not going to enter vortex ring simultaneously – it slides sideways to get itself out."
Describing the AW609’s capability, Edwards highlights toa recent flight he performed from Yeovil in the UK to Cascina Costa in Italy. The 627nm (1,160km) sector was completed in just 2h 18min, albeit with a “strong tail wind”.
AgustaWestland will fly the third prototype of its AW609 tiltrotor late this year as the manufacturer accelerates testing activity ahead of planned certification in 2017.
Two flight-test articles dating from the early days of the programme, then a joint development with Bell, have been used for the validation campaign so far and have amassed 1,300h, alongside 300h of ground runs.
But with the initial aircraft "now reaching the end of its useful life", according to Paul Edwards, experimental test pilot at AgustaWestland, the arrival of two subsequent prototypes is required to attain US Federal Aviation Administration (FAA) approval.
Prototype three is "in final build" at the manufacturer's plant in Vergiate, Italy, he told a conference on future rotorcraft on 14 September. It will be transported to its Philadelphia, Pennsylvania facility – the location of the tiltrotor’s eventual final assembly line – late this year, to be used for icing trials and then cold weather testing.
The fourth flight-test article, which will have the production standard cockpit installed, is also being produced in Philadelphia.
Service entry is scheduled for 2018, says Edwards, and he anticipates rapid take-up of the Pratt & Whitney Canada PT6-powered type.
"This aircraft is going to be part of the aviation fabric far more quickly than a lot of people realise," he says.
With no certification standard existing for the tiltrotor, AgustaWestland has worked with the FAA to develop hybrid rules – the Powered Lift Certification Requirement – that draw on regulations from both the fixed- and rotary-wing worlds.
These involve proving that the aircraft can perform both gliding and autorotation landings in the event of engine failure, as well as rapid reconversion from forward flight, and flare before touchdown.
So far, 28 power-off reconversions have been performed, says Edwards, although he cautions that it has yet to pass certification trials for the engine-out state.
Edwards says the evaluations have also dispelled the view that tiltrotors are particularly vulnerable to vortex ring settling.
"Tiltrotors are not susceptible to vortex ring," says Edwards. "We had to try really hard to get there."
"It was about to fly itself out when we applied the recovery technique. Both rotors are not going to enter vortex ring simultaneously – it slides sideways to get itself out."
Describing the AW609’s capability, Edwards highlights toa recent flight he performed from Yeovil in the UK to Cascina Costa in Italy. The 627nm (1,160km) sector was completed in just 2h 18min, albeit with a “strong tail wind”.
Now wheres FH1100....?
Didn't we have a link in one of the Osprey threads to a discussion of what the test pilots did at altitude after the Marana crash?
The abrupt roll they discovered when trying to induce VRS suggests that the following
may not be entirely accurate, and is at face value self-contradictory.
EDIT: Summary of some Ospray VRS testing here.
Here is what I think that statement means: It is very difficult to induce vortex ring state in a tilt rotor (609) but it can be done (as part of a test profile?).
Mr Edwards has been flying these things and I have not. He knows how those machines fly. It's the summary of what he's learned, and is trying to express to the general public, that has me puzzled.
The abrupt roll they discovered when trying to induce VRS suggests that the following
"Tiltrotors are not susceptible to vortex ring," says Edwards. "We had to try really hard to get there."
EDIT: Summary of some Ospray VRS testing here.
Here is what I think that statement means: It is very difficult to induce vortex ring state in a tilt rotor (609) but it can be done (as part of a test profile?).
Mr Edwards has been flying these things and I have not. He knows how those machines fly. It's the summary of what he's learned, and is trying to express to the general public, that has me puzzled.
Last edited by Lonewolf_50; 16th Sep 2015 at 21:51.
SansAnhedral:
Oh, I'm still here...although...since I'm nearly retired now I pay less and less attention to silliness like these irrelevant forums.
But look, it's not about whether a tilt-rotor can or cannot get into VRS (we know it can), and neither is it about how difficult or not it is to get into. That's all just a smokescreen produced by the manufacturer and the starry-eyed, fanboys who think the tilt-rotor is something "new" or ground-breaking when it is neither.
The PROBLEM with the tilt-rotor configuration...the thing they cannot predict, eliminate or even reduce is A-VRS - in other words ASYMMETRICAL-VRS: One proprotor goes into VRS and the other does not.
It's fine when you're ready for it. Why, just tilt those nacelles forward and fly away. Simple!
But what if you're not expecting it? What if you're already really busy at the bottom of a screwed-up approach (oh, that never happens)...or maybe you're not the super-duperest pilot you think you are...and *one* proprotor goes into incipient VRS? The wing on that side drops and the pilot instinctively makes an opposite control input. Adding opposite control to a dropping wing in a tilt-rotor increases the collective pitch on that side, the side that is starting to go into VRS.
Even the lowest time, self-appointed-expert Robbie Ranger knows what happens when you increase the collective on a rotor going into VRS.
But that'll never happen in a tilt-rotor, right? Right.
Glad we're all on the same page.
Yes, yes, fixed-wings stall, and sometimes well-trained, supposedly experienced airline pilots do just that (e.g. Asiana in San Francisco and the infamous numbnuts in that Air France 447 Airbus). But you know what? A stall in a fixed-wing is announced by the stall-warning horn (not presently invented for tilt-rotors because VRS is UNPREDICTABLE) and a fixed-wing stall is recoverable! Just lower the nose. When a tilt-rotor on short-final gets into A-VRS and rolls over on its back you can cancel Christmas: Everyone onboard is going to die. With basically no warning.
THAT is the problem with the tilt-rotor: A-VRS. Do away with that little peculiarity and I'm on board!
I hope all of you prospective BA-609 pilots are as good as you think yous are! I am confident that I will be long gone before the first civil tilt-rotor ever hits the market.
Thank you, I shall now go back into hibernation.
Now wheres FH1100....?
But look, it's not about whether a tilt-rotor can or cannot get into VRS (we know it can), and neither is it about how difficult or not it is to get into. That's all just a smokescreen produced by the manufacturer and the starry-eyed, fanboys who think the tilt-rotor is something "new" or ground-breaking when it is neither.
The PROBLEM with the tilt-rotor configuration...the thing they cannot predict, eliminate or even reduce is A-VRS - in other words ASYMMETRICAL-VRS: One proprotor goes into VRS and the other does not.
It's fine when you're ready for it. Why, just tilt those nacelles forward and fly away. Simple!
But what if you're not expecting it? What if you're already really busy at the bottom of a screwed-up approach (oh, that never happens)...or maybe you're not the super-duperest pilot you think you are...and *one* proprotor goes into incipient VRS? The wing on that side drops and the pilot instinctively makes an opposite control input. Adding opposite control to a dropping wing in a tilt-rotor increases the collective pitch on that side, the side that is starting to go into VRS.
Even the lowest time, self-appointed-expert Robbie Ranger knows what happens when you increase the collective on a rotor going into VRS.
But that'll never happen in a tilt-rotor, right? Right.
Glad we're all on the same page.
Yes, yes, fixed-wings stall, and sometimes well-trained, supposedly experienced airline pilots do just that (e.g. Asiana in San Francisco and the infamous numbnuts in that Air France 447 Airbus). But you know what? A stall in a fixed-wing is announced by the stall-warning horn (not presently invented for tilt-rotors because VRS is UNPREDICTABLE) and a fixed-wing stall is recoverable! Just lower the nose. When a tilt-rotor on short-final gets into A-VRS and rolls over on its back you can cancel Christmas: Everyone onboard is going to die. With basically no warning.
THAT is the problem with the tilt-rotor: A-VRS. Do away with that little peculiarity and I'm on board!
I hope all of you prospective BA-609 pilots are as good as you think yous are! I am confident that I will be long gone before the first civil tilt-rotor ever hits the market.
Thank you, I shall now go back into hibernation.
Last edited by FH1100 Pilot; 26th Sep 2015 at 14:43.
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I hope it's a long winter
FH your argument is devoid of facts.
Your assumption that a stall in a fixed wing aircraft is announced as opposed to VRS being unannounced in a Tiltrotor is false. The V-22 and the AW609 both have visual and aural VRS warning indications.
Your assertion that VRS is ‘UNPREDICTABLE’ is also false. If you take the time to read the many good papers available through AHS and other societies you’ll find that VRS is very predictable. From those papers you’ll find the data of both Tiltrotor aligns very nicely allowing for accurate predictions to be made and limits set. This isn’t theoretical data, its data from actual flight test with roll off events. What is also known is that to get into VRS you have to exceed the flight manual limit by a minimum of 100%.
You also over simplify a fixed wing stall recovery. NASA, NTSB and the FAA all tell us that in the fixed wing world LOC is the largest cause of fatal mishaps. Depending on operation stalls make up 25-40% of LOC mishaps. If the recovery technique is so simple why is it the leading cause of fatalities in the fixed wing world? In your straw man you have the poor Tiltrotor pilot “really busy at the bottom of a screwed-up approach” but in your fixed wing argument the pilots are ‘numbnuts’ if they get into a stall. Reality is that many landing mishaps no matter what type of aircraft are a result of pilots getting “really busy at the bottom of a screwed-up approach”. The facts are that recovery from a stall isn’t always so simple. The wrong control input, i.e. instinctively adding aileron in an asymmetrical stall can result in the aircraft entering an unrecoverable spin when close to the ground, just as you assert that adding the wrong input will cause the Tiltrotor to roll over. The Tiltrotor requires one simple movement, thumb forward. As long as the nacelles are moved it doesn’t matter what the pilot does with the other controls. You would argue that the Tiltrotor pilot will get confused and make the wrong input. Maybe, but that holds true for every airframe does it not?
What is the biggest recommendation for avoiding a stall? Training and recognition. When I went through my Citation initial type rating every session we focused on stall recovery and recognition, clean stalls, dirty stalls, and approach turn stalls, etc. When I go for recurrent what do we focus on? Stall recovery and recognition. Why? So that the recovery is instinctual and immediate because stalls have been identified as a risk. The same is true of Tiltrotor training and VRS. VRS will be trained to just as stalls are and the pilot’s ability to react correctly will be no different than for a stall. The truth is that fixed wing aircraft fly much closer to the stall boundary (<10-20% margin depending on type) than a Tiltrotor does to the VRS boundary (>100% margin for all Tiltrotors).
“When a tilt-rotor on short-final gets into A-VRS and rolls over on its back you can cancel Christmas: Everyone onboard is going to die. With basically no warning“.
Same is true of a fixed wing stall close to the ground. So what’s the point? The same agencies mentioned above also found that most fixed wing stalls happen below pattern altitude with the majority happening below 250 ft AGL, not much chance of a recovery from that is there?
Your assumption that a stall in a fixed wing aircraft is announced as opposed to VRS being unannounced in a Tiltrotor is false. The V-22 and the AW609 both have visual and aural VRS warning indications.
Your assertion that VRS is ‘UNPREDICTABLE’ is also false. If you take the time to read the many good papers available through AHS and other societies you’ll find that VRS is very predictable. From those papers you’ll find the data of both Tiltrotor aligns very nicely allowing for accurate predictions to be made and limits set. This isn’t theoretical data, its data from actual flight test with roll off events. What is also known is that to get into VRS you have to exceed the flight manual limit by a minimum of 100%.
You also over simplify a fixed wing stall recovery. NASA, NTSB and the FAA all tell us that in the fixed wing world LOC is the largest cause of fatal mishaps. Depending on operation stalls make up 25-40% of LOC mishaps. If the recovery technique is so simple why is it the leading cause of fatalities in the fixed wing world? In your straw man you have the poor Tiltrotor pilot “really busy at the bottom of a screwed-up approach” but in your fixed wing argument the pilots are ‘numbnuts’ if they get into a stall. Reality is that many landing mishaps no matter what type of aircraft are a result of pilots getting “really busy at the bottom of a screwed-up approach”. The facts are that recovery from a stall isn’t always so simple. The wrong control input, i.e. instinctively adding aileron in an asymmetrical stall can result in the aircraft entering an unrecoverable spin when close to the ground, just as you assert that adding the wrong input will cause the Tiltrotor to roll over. The Tiltrotor requires one simple movement, thumb forward. As long as the nacelles are moved it doesn’t matter what the pilot does with the other controls. You would argue that the Tiltrotor pilot will get confused and make the wrong input. Maybe, but that holds true for every airframe does it not?
What is the biggest recommendation for avoiding a stall? Training and recognition. When I went through my Citation initial type rating every session we focused on stall recovery and recognition, clean stalls, dirty stalls, and approach turn stalls, etc. When I go for recurrent what do we focus on? Stall recovery and recognition. Why? So that the recovery is instinctual and immediate because stalls have been identified as a risk. The same is true of Tiltrotor training and VRS. VRS will be trained to just as stalls are and the pilot’s ability to react correctly will be no different than for a stall. The truth is that fixed wing aircraft fly much closer to the stall boundary (<10-20% margin depending on type) than a Tiltrotor does to the VRS boundary (>100% margin for all Tiltrotors).
“When a tilt-rotor on short-final gets into A-VRS and rolls over on its back you can cancel Christmas: Everyone onboard is going to die. With basically no warning“.
Same is true of a fixed wing stall close to the ground. So what’s the point? The same agencies mentioned above also found that most fixed wing stalls happen below pattern altitude with the majority happening below 250 ft AGL, not much chance of a recovery from that is there?
