What's the latest on tilt rotors?

[Cyclic Hotline]

End of the road for the 609?

Can't say I'm very surprised to be honest. New technology is fine, but this technological leap would be like the Wright Brothers building a jet in 1910. The service and technology evolution are not there and this would represent an unprecedented move for commercial aviation, especially in light of the experience of the V-22.. .. .Still sad news.... .. .From Rotorhub.com. .. .Textron has ordered work to stop on the Bell/Agusta 609 civil tiltrotor, an almost certain prelude to cancellation of the project, sources tell Helicopter World. . .. .The word ‘frozen’ is being applied to the project at the present time because ‘termination’ has contractual implications that still have to be worked through. Textron’s Russ Meyer, brought in to run both Cessna and Bell in a recent management shuffle, is understood to have pulled the plug on the project. Meyer is said to have become convinced the project was too ‘costly’ and ‘complicated’ to survive in today’s marketplace. . .. .In Ft Worth, Tx., Bell spokesman Carl Harris declined to confirm or deny the report, stating he needed to get further information on the status of the project. Loss of the 609 would be a major blow to Bell’s hopes to become a tiltrotor company, and will complicate relations with Italy’s Agusta Aerospace which invested heavily in the project.- David S. Harvey. . . . <small>[ 15 March 2002, 05:28: Message edited by: Cyclic Hotline ]</small>

[Lu Zuckerman]

Knowing Agusta, they might just ask the Italian Government for supplemental funding and continue the program themselves.

[UNCTUOUS]

<a href="http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000658.html" target="_blank">http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000658.html</a>. .. .<a href="http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html" target="_blank">http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000289.html</a>. .. .<a href="http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000557-2.html" target="_blank">http://www.pprune.org/ubb/NonCGI/Forum11/HTML/000557-2.html</a>. .. .<a href="http://www.pprune.org/cgibin/ultimatebb.cgi?ubb=get_topic&f=11&t=001388" target="_blank">http://www.pprune.org/cgibin/ultimatebb.cgi?ubb=get_topic&f=11&t=001388</a>

[widgeon]

Sad to say the pioneers in any technology are not always the ones who reap the rewards , remember the DH Comet , TSR2 , Avro Arrow . What ever happened to the prop fan , the rotordyne ?. I am sure that there will eventually be a commercial tilt rotor but I dont think the 609 will be it. Probably something a bit bigger that you could actually run a commercial service with. What next Agusta Bell in Fort Worth ?

[Nick Lappos]

A saving grace will be the fact that the 609 will not have to try to meet its promises. It has more power than the S-92 and Black Hawk, at 60% of the gross weight, it has 3 times the flight critical components of a helicopter, its disk loading makes it more prone to VRS (in spite of the inaccurate statements made by its Marketeers) and it carries 8 people for all that.. .. .Note the bait-and-switch tactics of the TR guys. The TR was always compared with a helicopter with half the power. The TR Marketeers compare 609 (4000 horses) with S-76 (1800 horses) and V-22 (12000 horses) with Black Hawk (4000 horses). Its easy to win with a stacked deck. There is an old Aeronautical Engineering saying, "With enough power, the Brooklyn Bridge can be made to fly.". .. .Given the same installed power and lower cost, a conventional helicopter has more range, carries twice the payload, costs less per seat mile, has half the critical failure modes, but does take 35% more time to do the journey.. .. .It is these facts that the new Bell management faced when they decided to wait and see.

[The Sultan]

Lu, Sorry I mean Nick. I can not tell you guys apart anymore.. .. .No one compares the V-22 to the UH-60. They compare it to the 53.. .. .The Air Force has stated that using current mission profiles in Afganistan the V-22 can do the same mission as the CH-53 in 4 hours instead of 7 hours and with no a-t-a refuelings where the 53 requires 3. Where's your range and "I can do anything you can do" here, Nick? Buy the way this is 75% faster not 35%.. .. .So Nick: Why can the 53 not meet all of your claims? It has basically the same power and weight as an Osprey. Is it only because it lacks the speed and range with the same mission load?. .. .As to VRS. You know better. Helicopters with lower flow enter VRS at much lower sink rates than a V-22. Therefore, the V-22 is less likely to encounter this if flown within a more generous envelope than current fielded rotorcraft. Remember, VRS was discovered on helicopters so it is not a tiltrotor only phenomenon. You get into it close to the ground and you are going to get hurt. . .. .One last point: Would you care to demonstrate the S-92 at gross weight, under 30 knots, 2500+ fpm sink rate, at night on goggles with no corrective action until your 200 feet above the ground?. .. .The Sultan

[rotorque]

This should be good !!

[slgrossman]

Seems to me we're getting into an apples and oranges comparison here. Unless I'm mistaken the 609 was intended primarily for commercial use (with the hope of some side business from the Coast Guard). This entails a whole different set of considerations compared to a military ship performing military missions. Apparently, the economics of the 609 were insufficient to justify its continuation. I don't believe the V-22 is as sensitive to the cost/benefit equation.. .. .Commercial operators generally can't afford to take the risk of implementing revolutionary technology. If they can't make it pay from day one they go out of business. So they tend to stick with incremental advances and an evolutionary process.. .. .The military is not constrained by the need to make a profit. I think many commercial products would not exist had they not been developed first for military use. The MV-22 is the first tilt rotor to be fully developed and as such is a mish-mash of compromises. It's rather unfair to condemn it based on comparisons to helicopters which are much further down their evolutionary path. Follow-on versions of this aircraft will undoubtedly optimize the technology as it finds its niche, and tilt rotor technology will become indispensible.

[Lu Zuckerman]

To: The Sultan. .. .I see that you are still working at Bell Helicopter, which explains your support for the V-22 just like Nick who works for Sikorsky and who supports their products. The persons that should be supportive of any product are the guys that fly it and the guys and girls that maintain them.. .. .Here is the evolution of a design and it does not begin with a group of engineers. A group of generals and admirals get together and try to prognosticate into the future relative to what the battle conditions are and where this battle is to take place. Because of my involvement I will use the Apache as an example. These generals determined that the next war was to take place in Germany when the Russians broke through the Fulda Gap using massed armor. The Russians would push the Allies back as far a Spain before they could mass a retaliatory force strong enough to not only push the Warsaw Pact forces back but to totally defeat them.. .. .In order to do this they would require a means of defeating the armored forces. They assumed that the Warsaw Pact forces would be constituted of divisions and battalions of a certain size with an assumed number of armored vehicles. They also assumed that the main ground to air weapon to be used against attack helicopters was the ZSU-23-4 weapons system. They decided that they would need so many attack helicopter companies with so many attack helicopters assigned to them. They then decided that to maintain an effective force they would have to have 80% availability. In order to defeat the ZSU-23-4 the helicopter would have to be resistant to a single hit by a 23mm High Explosive round in any one of several areas of the helicopter. To maximize turn around the Army specified that an engine or a transmission or a rotorblade or a main transmission must be removed and replaced in thirty minutes and the MTBF would be low enough to ensure the required availability.. .. .Now lets look at the Apache now. They have never achieved the required availability. It takes 16 MMH to remove and replace a main rotorblade. The MTBF on the components has never been achieved. The helicopter that is designed to withstand a direct hit from a 23mm HEI round was engaged with some small arms fire in Afghanistan and high tailed it out of the area. The helicopter is so complicated that Army technicians can not support it with most of the major maintenance being accomplished by civilian contractors. In short, the Apache has not performed to the expectations of those generals and admirals in the meeting described above.. .. .Now we get back to what the Air Force general said about the value of the V-22 in a battle scenario like that taking place in Afghanistan. Every thing he said was based on the performance figures quoted by Bell and Boeing and did not relate to the recent performance of the V-22 in the test phase. The V-22 is incapable of sustaining major battle damage without being rotated back to the States to an overhaul facility or back to Bell or Boeing depending on what was damaged. The same may be true for the Comanche. This will have a major effect on availability.. .. .The military does not want to take possession of those V-22s that have already been built and which have been placed in long term storage until Bell/Boeing have worked out all of the bugs.. .. .Both Bell and Boeing will have to work long and hard to make the V-22 work in a military environment and then they have to wonder if marines and sailors can maintain it in a battle or shipboard environment.. .. .Here is another point you should give strong consideration and that is the vibratory environment on the hangar deck. Most of the ground support equipment used in support of the V-22 is mounted on vibration isolators. This constant vibratory environment generated by the ships' screws is strong enough to destroy a hydraulic test stand on a trip from San Diego to Honolulu if it were not isolated. Just think what it will do to the gearboxes and the folded blades on the V-2 as well as other elements susceptible to vibration.. .. .One final point, if a V-22 lands on its’ assigned spot on the LHA and it can't fold its’ blades it will be pushed over the side in order to free that space for the next V-22. That’s a bit severe and it all depends on the reliability of the folding mechanism.. . . . <small>[ 18 March 2002, 19:49: Message edited by: Lu Zuckerman ]</small>

[ShyTorque]

I have always had a keen interest in the tilt-rotor concept.. .. .IMHO, it is a highly specialised aircraft bringing its own set of problems, not least those of low speed manouevrability and VRS of the inner rotor during low speed descending turns. I can think of many instances where this type of aircraft could not operate, including central London, because of it's requirement for a relatively uncomplicated approach path. My main interest centered around the pilot experience required. From an aircrew point of view, is it best regarded as a helicopter that flies fast or a fixed wing that can hover? . .. .I cannot help comparing this type of aircraft to the world's largest helicopter project, the MIL MI-12, first flown in the early 1970s. This was a side-by-side twin rotor helicopter with a wingspan greater than a Boeing 747 (just under 210 feet, as opposed to the latter's 196 feet) and a proposed max weight of 231,485 lbs. It was realised that it actually needed a large airport to operate from and it's payload could be more economically flown in a fixed wing aircraft - and it was cancelled.

[Lu Zuckerman]

To: Shy Torque. .. .Among the many reasons the program was cancelled was that the original design had the advancing blade on the right side flying counter clockwise as viewed from above and the left rotor rotating in a clockwise direction as viewed from above. This placed an extremely high loading on the outriggers and they folded up. In order to correct the problem they had to completely redesign the transmission system as well as the outriggers.

[3 D]

For what it's worth I think it is a shame that the program has been stopped.. .. .It may be far from perfect in its current form but surely most concepts are in there early development. . .. .We only learn if we try.

[Dave Jackson]

ShyTorque,. .. .You may be interested in this web page on the . .<a href="http://avia.russian.ee/vertigo/ka-22-r.html" target="_blank">Kamov Ka-22 "Vintokryl"</a>. It is very similar to the V-22, except for the separate rotors and propellers, which are optimized for the two flight realms.. .__________________. .. .Lu.. .. .You mention the direction of rotation. A sketch on the Ka-22 web side above shows that it had (forward on the outside) rotation.. .. .I believe that Flettner started with the (forward on the outside) rotation on his first intermeshing helicopter. He then changed to the 'breast stroke' (forward on the inside). Since then, all intermeshing helicopters have used the 'breast stroke'. . .. .The renowned helicopter aerodynamicist W.Z. Stepniewski submitted a report a couple of years ago in which he proposed an intermeshing transport helicopter incorporating the Advancing Blade Concept. Strangely, his proposal had the rotors turning (forward on the outside). . .. .Maybe he felt that 'breast stroking' should be left to the pilots? <img border="0" title="" alt="[Smile]" src="smile.gif" />. . . . <small>[ 18 March 2002, 23:36: Message edited by: Dave Jackson ]</small>

[John Eacott]

LZ said: "The (Apache) helicopter that is designed to withstand a direct hit from a 23mm HEI round was engaged with some small arms fire in Afghanistan and high tailed it out of the area.". .. .On what do you base that assertion? If it was the well publicised article in The New York Daily News, by that toe rag Leo Standora, then you should be aware of the other side of the coin, as posted on numerous NG's:. .. ."1. Six Apaches defended the downed MH 47. .. .2. What the reporter failed to mention is that one Apache had its Tgt Acq Designation Sensor blown off by an RPG that did not explode and stayed in the fight shooting the 2.75 nails and 30mm. .. .3. A second Apache took an RPG in the engine area, had an oil line severed and hits to the xmsn causing the xmsn to go dry. The AH 64 stayed on station firing up all ammo, and returned to base THIRTY EIGHT MINUTES after all oil was out of the xmsn.. .. .4. One Apache had its tail wheel blown off, all AH 64s from 3/101 were shot to Sh*t AND NOT ONE CREWMEMBER WAS LOST! The Apache is a flying tank.. .. .5. The lying a$$ low rent piece of $hit Leo Standora states the 64s were taken down by rifle and pistol fire. The effective fire was rocket propelled grenades, B 40 RPGs and the acft stayed on station after being hit.. .. .6. This is just another one of those, "so what is your point?" pieces of $hit coming from the media that is ill researched, and perpetuated by a newspaper so low rent I won't put in my dog's cage for them to $hit on. A$$hole maggot media puke.. .. .THESE Apaches are in Dick Cody's Division, the 101st Airborne. Cody MAKES sure the Apache crews are highly trained, spirited, highly motivated warriors. Cody is the one that led the Apaches into Iraq, behind the MH-53Js and blew away the radar site, 0100, 19 Jan 1991.. .. .These USMC Cobras have NO WHERE near the night fighting capability of the Apaches, so blow that $hit up someone else's skirt. Additionally, AFTER THE FIGHT is over is no time to be bragging about the AH 1W. Where were they when the paper was blank? They would NOT have survived in that fight. Marines aren't in the real fight, so get over it.. .. .I got this piece of $hit off a USMC selected reading file of news stories I get every day from USMC. IT IS TIME FOR THE FKING USMC TO UNDERSTAND WE ARE ALL IN THIS TOGETHER, and quit pouting because they got put back on their boats so the larger United States Army with longer staying power could be deployed.. .. .The Marines must have forgotten about how they did not support the SF at Lang Vei in Jan 68 when it was being overrun by tanks. The United States Army Special Operators HAVE NOT FORGOTTEN that sterling USMC effort.. .----------- Mike Sloniker, US Army retired.". .. .Apologies for the language, this is as posted to refute the ill founded knocking of the Apache. Whilst I have no personal views/experience either way, it behoves some posters to be less dogmatic in their criticisms, especially when they have little or no background on which to make their assertions.

[ShyTorque]

Dave J,. .. .Thanks for the link, interesting page.. .. .Next, the Fairey Rotordyne, now THAT was a project that could have worked.

[Lu Zuckerman]

To: John Eacott. .. .Quote:. .. .“LZ said: "The (Apache) helicopter that is designed to withstand a direct hit from a 23mm HEI round was engaged with some small arms fire in Afghanistan and high tailed it out of the area.". .. .“On what do you base that assertion? If it was the well publicised article in The New York Daily News, by that toe rag Leo Standora, then you should be aware of the other side of the coin, as posted on numerous NG's:”. .. .Response:. .. .The action in which the Apaches “high tailed it” was photographed and described by a news broadcaster on CNN who accompanied the ground troops on Operation Anaconda.. .. .When deployed in the Gulf War the Apaches never engaged the enemy in the manner in which the helicopter was designed. Most of their operations were as a standoff weapon firing their chain guns from several thousand meters from the target. The helicopter was designed to engage the enemy at close quarters. That is why the US Army specified the 23mm survivability requirement. They also operated in a standoff mode while firing their missiles. If you ever saw the news footage of Apaches in Desert Storm you will have seen them aligned ten or twelve abreast firing their weapons and not directly engaging the enemy. In watching the CNN footage regarding Operation Anaconda I was surprised that the Apaches got so close to the enemy and if they took the damage that you described then it attests to the design and construction of the airframe. Regarding your comment about the Apache staying on station after loosing all of his gearbox lubricant the helicopter is designed to do just that. Inside each gear in the transmission there is a felt wick which holds a large amount of oil. If the transmission oil is lost the trapped oil will be discharged through small holes in the gear by CENTRIFUGAL FORCE and this reserve oil supply will last for a minimum of thirty minutes. The pilot that stayed on station was not being heroic he was flying the helicopter the way it was designed.. .. .Quote:. .. .“Whilst I have no personal views/experience either way, it behoves some posters to be less dogmatic in their criticisms, especially when they have little or no background on which to make their assertions”. . .. .Response: . .. .I worked as a contract consultant on the Apache during the initial response to the Army proposal where I set up the Maintainability program for the helicopter defining what was necessary to incorporate in the design to meet the Army’s’ design for maintainability goals. I was called back a second time to respond to the Army’s queries relative to the program plans. Upon completion of that assignment I went to work for Bell Helicopter as a manager of technical assistance (Product Support). That lasted three years and upon my return to the States I went to work at Hughes Helicopters as supervisor of Maintainability design overseeing the design for Maintainability for the whole aircraft. I believe that gives me the authority to make certain statements about the Apache.. .. .Now if you want to discuss the low availability and poor maintainability of the Apache we can start another thread.

[Cyclic Hotline]

Anyway, back tothe original topic.. .. .It appears a Sikorsky/Bell tiltrotor compromise may have been reached.. . <img src="http://us.f1.yahoofs.com/users/f5c8b277/bc/My+Photos/S+61+T.jpg?bc4ow58A3xdBAbsb" alt="" /> . .. .Courtesy of Rotorhead over at <a href="http://www.canadianaviation.com/" target="_blank">Canadian aviation</a>

[tgrendl]

Lu,. .. .Like your comments most times, always make me think a bit.. .. .The Apache stuff is off though.. .. .Attack helos are not designed to "fight the enemy up close" they are designed to kill the enemy using the last third of the appropriate weapons useable range.. .. .Every baby attack pilot knows what BRASSCRAFF stands for. It's fundamental to fighting the aircraft.. .. .As a contractor we could swap out a blade and have it flying within limits in about an hour at the most. That's real time not flight time. It usually took two .2 or .3 flights to do that. The changeout time for the blade was around 10 minutes with two people.. .. .Don't blame the airframe for the inefficient use and training of personel in the service.. .. .The strap pack issue you mentioned earlier is valid but not for the stated reason.. .. .The 500 series aircraft use the same type strap pack but don't suffer from the same breakage problems.. .. .But put those aircraft on a tricycle system and have people taxi them around everywhere and they would.. .. .We may be short training, experience, spares and flight time but those guys fighting the aircraft weren't short of guts.. .. .keep up the good posts ! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />

[Flying Lawyer]

Just in case anyone is wondering why Nick Lappos, who usually devotes an enormous amount of his time answering and explaining points on Rotorheads has not responded, he is on vacation in the UK at present.. .I had dinner with him last night - his conversation is as impressive and fascinating as his contributions to the Forum.. .. .Lu says ".......... just like Nick who works for Sikorsky and who supports their products." . .It's true Nick is proud of Sikorsky Lu, but equally he never once 'knocked' other manufacturers. He has such enthusiasm for helicopters that he seems to want everyone to succeed, not just Sikorsky.. .The forum has an enormous asset in having someone of his distinction both as an engineer and as a test pilot contributing to Rotorheads.

[Lu Zuckerman]

To: tgrendl and All. .. .First of all I would like to state that I was not disparaging the pilots of the Apaches in either Desert Storm or in Afghanistan. I have a great deal of respect for not only combat pilots but all pilots. I had the opportunity to become an Army Aviator and I turned it down.. .. .Evidently the Army (my opinion) had something to prove. The first time the Apache was in combat was in Panama and they performed very poorly due to the high humidity which worked into the electronics suite and had to be removed using a hair dryer. In Desert Storm the Apache was not allowed to engage the enemy directly because of many problems including low reliability. The next time the Apache was involved in a combat situation was in the Balkans and in that theater the Apaches were not allowed to fly patrols because of heavy ground fire as well as poor performance. To counter your point of the Apache being used in a standoff situation the Apache was the Army’s A-10 which engages the enemy well within the effective range of small arms and machine gun fire. That was the concept promoted by the Army especially since the Cheyenne program was cancelled. The Cheyenne had only a Mini Tat and Tow missiles, which required fairly, close in flying. When the Cheyenne was cancelled the AAH program was born. The Apache was originally designed to carry TOWs and air to ground rockets along with the chain gun. It wasn’t until the design had been finalized that the Hellfire Missile was made available for installation on the Apache and this gave it true stand off capability.. .. .My reason for addressing the poor reliability and maintainability is twofold:. .. .1) Hughes Helicopters intentionally held back a report to the US Army, which addressed twenty-seven different design faults that would directly effect the reliability and maintainability of the Apache. The report was released only after the Army accepted the Apache as designed. Since the report was time sensitive it was overtaken by events. In operation all twenty-seven deficiencies manifested them selves. The engineering department would not cooperate with the product assurance department so when a design defect was noted it was ignored. Another trick used by engineering was to intentionally withhold the drawings for sign off by R&M until they had accumulated several hundred and they would tell us to sign them off within one hour or, they would sign them off for us. They had no regard for R&M because it was totally alien to the Hughes Helicopter engineering management.. .. .2) My comments about the poor reliability and maintainability of the Apache after it was fielded were based on a report made by the Government Accounting Office (GAO). The title of the report is APACHE HELICOPTER Serious Logistical Support Problems Must Be Solved to Realize Combat Potential. Many of the 27 items described above were identified in this report. The findings of the report were in accordance with a request from the US Congress.. .. .Regarding the similarity between the strap packs on the model 500 and the Apache they are similar in only one way. They are constructed of laminations of stainless steel that withstand CENTRIFUGAL FORCES and, they allow pitch changes and flapping. Because of their construction they also allow leading and lagging. The basic designs are different but the concept is the same. The major differences are in the blade design. The 500 I believe has symmetrical airfoils and the Apache has unsymmetrical airfoils. The unsymmetrical airfoil makes the Apache blade unstable due to movement of the center of pressure. Another thing is the Apache blade and those of the 500 have a negative twist. With the twist the angle of attack is different for each blade station and this makes the center of pressure move differently for each station thus making the blade unstable. This instability causes the rear strap pack hit the rotorhead causing the strap pack elements to fatigue.. .. .Here are figures quoted in the GAO report dealing with MMH to perform a specific job.. .. .Because the PPRuNe forum doesn’t print tables I’ll try to accommodate the forum.. .. .Component. .1) Main Rotor Blade. .2) Main Rotor Strap Pack. .3) Tail Rotor Swashplate. .. .Maintenance Man Hours. .1) 14-26. .2) 32-44. .3) 8. .. .Aircraft downtime. .1) 8 hours. .2) 3-4 Days. .3) 8 Hours. .. .The design spec required that each of these elements among others be removed and replaced within 30 minutes using no more than two men.. .. .If you can do it faster, more power to you. The Army reflecting US Army mechanics quoted these figures.. . . . <small>[ 20 March 2002, 15:47: Message edited by: Lu Zuckerman ]</small>