V-22 a questionable design at best

It is not really complicated. The chart you are looking at is an Official Navair Flight Test Performance Chart for the V-22 Flight Envelope. It shows the data collection points during V-22 Flight Testing by Bell/Boeing/Pax River. The chart plots-on the VERTICAL scale- the limit load performance of the V-22 rotors, (labeled Nz in terms of the Number of "G"s pulled) at the airspeed in Knots indicated on the Horisontal scale. If you isolate your inspection to the lower left corner between 0 and 40 Knots, you will find only 3 data points above 1.0 G and 3 below 1.0. The AVERAGE is about 1.15G. While you are sitting looking at the chart, you are in a state of equalibrium at 1.0G and 0 Knots. Note that out of several thousand data points collected, the tests for low airspeeds 0-60 Knots is important because this indicates how much reserve 'G's are available for Manuevering/Agility performance-or will be available before the V-22 will be expected to stall. In the normal situation where there are cross winds/gust/pilot control inputs, etc. we find that there is little likelihood - except on a clear, smooth, no wind day, that the rotors will see identical forces - and we will always have an assymetrical situation. If a pilot is under fire or stress, trying to escape from mortars or guns, or making any effort to exit a combat situation, he will try to do so instinctively and rapidly. The assymetric configuration plays very powerfully under combat stress conditions. If he is hovering or moving below 40-60 knots at realtively low altitute above the ground, and he tries to make any maneuver requiring more than 1.20 "G"s, the rotor will either stall and settle(crash ) to the ground or he may find himself in an uncommanded rollover (crash)!! No one - no matter how good or experienced they are can ask a 1.2G limited aircraft to pull 2.0G's without a significant surprise - and perhaps the death of his crew!Note that ALL military helicopters have been tested and certified for 2.00 'G"s or more. There is a significant difference here - and it is a fatal one. Typically we find that helicopter pilots under fire will immediately act to bank,roll, turn and pull away from the mortar blast, gunfire, rocket , etc. With 2.0 G capability he can pull away with as much as a 60 degree angle of bank (auto nuts will understand this immediatly-and as our USNA physics teachers showed us-if you are driving on a 60 Degree turn of a race track you will pull exactly 2.0G.) If on the other hand, if you are driving down a road with only a 10 degree or so bank, at the same speed as for a 60 Degree bank, centrifugal force will cause you to roll over (maybe several times! -and break up you aut big time!!)Next - if we look in the Navy V-22 NATOPS (Pilots Flight Manual) which is the Navy/USMC BIBLE for pilots-and which was available to the pilots of the V-22 Marana Mishap, you will find that the Rotor Flight Load Limits when in Helo/Vtol Mode, are clearly stated as being 2.0 G and 60 Degree Angle of bank as flight limits!! (again -note that this is SIGNIFICANTLY - maybe small numbers-but a BIG DIFFERENCE between life/death)Almost every pilot will tell you that he can remember the G loads available in any type aircraft he flew. Some of the gofast guys had limits of 5-6-7 G's or so. The Piper Club, the Huey, H-46 and all other Rotorcraft used by the USMC, Navy, USAF and Army have a minumum limit of 2.0G. Some-like Apache and gunners can do better. The question then - is if an experienced pilot is told that his Limits are 2.0G and 60 deg bank angle, it is THAT limit which he will feel he can comfortly and safely use.Since line Pilots don't often see flight test charts (which in this case were supposed to be used for the Contractor and Navair to determine exactly WHAT would be printed in the Pilots BIBLE (i.e.Natops)-- he would not be aware that if he tried to pull a 60 Degree (2.0G) maneuver at lower speeds in a combat area ---he WOULD find out rapidly that he DID NOT have this capability and he would either settle into ground, slide sideways into the ground (crash) or could do a quick roll or even a snap roll --- all of them without control (an uncommanded rollover).We are talking about something happening in less than 1-4 seconds!! Did any of you read closely what happened to both aircraft in the Marana AZ accident?? Lead pilot lucked out and bounced on the ground till he hit a ditch. His wingman was doing several things: descending rapidly (at some 40-50kts?), banking in formation, and trying to slow down all at once. (p.s. NATOPS manual states clearly that abrupt mult-axis control movements are prohibited!!)Any rapid attempt to bank back into formation position-particularly when he had less than 2.0 "G" capability could initiate a quick stall in the outbord rotor (other pilots would think high wing) == at which time the low rotor would then-like a 50-60 ft lever with several hundred thousands +++++ foot pounds of leverage (lots of moment arm -AND inertia between the two widely displaced rotors!) and voila!! ROLLOVER.Given the FACT that flight testing showed that there was no way the pilot could get anywhere near the published limits, he was a sitting duck, just waitng for an accident. Question to ponder : Who was responsible for the aircrew NOT knowing the true/correct V-22 "G" and Angle of Bank limits??? (it sure as hell wasn't 2.0 G and 60 Deg!)Footnote: Their is NO way to FIX this problem. It is and has been inherent in "side by side" laterally displaced rotor machines since the first crash of the German Fa-61 on 13 Feb 1928!! (followed by many similar occurrences)THE MAJOR Safety of Flight issue of the V-22 IS the rotor design, which was maximized for speed and range. Consideration of safe/low airspeed envelope (thats the little dashed line near the top of each envelope segment on the chart)-- was given short shrift.THUS-The only way to correct this problem is to increase the rotor performance which could make it safer-near the ground and at slow combat terminal mission areas-and would also allow the pilots to "autorotate" safely after engine failure. (This is REQUIRED to be demonstrated by all helicopters-but because of Navair waivers-was set aside.) The V-22 pilots/report that it cannot be done safely (except occsionally in the Simulator).BUT CATCH 22!! (v-22 that is) You can only fix this problem by increasing blade numbers (4 or 5 blades on each rotor). BUT, You will find out that the empty weight will be increased (nacelles already weigh some 7000LBS-hanging at end of wing). AND-you can't just change the rotors and feel happy!! One major consideration in most aircraft-and particularly in rotorcraft - is the design problems with vibrations and harmonics-which WILL also require fuselage/wing/tail design changes. IF you want to spend another $5-10 Billion you would unfortunately find that the V-22 designers were really squeezed into a near impossible design corner. The end product would be far safer -BUT - would weigh even more when empty, and THUS would have a worse payload than it already has!! (note: the payload/empty weight ratio of the V-22 is worse than virtually every aircraft flying in the world today!!)Note: The USMC MH-53E can "lift" roughly 100% of its empty weight. The V-22 can "lift" only 1/3rd to 1/4th of its empty weight. (At/above 10,000ft where other helicopters can at least do some work, the V-22 is Placarded and Prohibited)This tutelage is gladly provided to you by the V-22 Red Ribbon Panel-a loosely organized group of over 130 Combat Helo pilots, Flight Test Pilots (including 3 FORMER V-22 FLIGHT TEST Pilots!!!), guys with BS/MS rotor/aero, and three of the best rotorcraft engineering and scientific experts in our Universities. Our work has taken over 14-15 months, literally several thousand e-mails, hundreds of papers, reports and briefings (which perhaps the Offical Blue Ribbon Panel couldn't understand * or were ill prepared or experienced for their task-led by chance - by a ret USMC Gen and a USMC L/C helper-NONE with any indepth experience or hands on knowledge of the subject at hand!!). We do NOT have any financial interests in the V-22 or any other Program!! We ARE hell bent to dig up the facts and the truths and to set aside the eighteen years of well practised "MANTRAS" which many of you have read and heard for years!Before Willy cuts me off, we stand ready to respond to any simple straight forward questions, but not public relation concerns. If you can find yourself a copy of the NATOPS you probably won't need us. There is enough there to scare most of us old pilots. (later we will tell you about our ongoing effort looking at German efforts/failures and why Russia TRASHED their tiltrotor projects some 10-15 years ago! If you understood the above and its import, you will be able to address supporters of a lost and VERY DANGEROUS cause.Goodnight Gentlemen. (Our Motto is similar to the Jolly Greens "That Others May Live" and add-"that goes for pilots also")

It is not really complicated.

The chart you are looking at is an Official Navair Flight Test Performance Chart for the V-22 Flight Envelope. It shows the data collection points during V-22 Flight Testing by Bell/Boeing/Pax River.

The chart plots-on the VERTICAL scale- the limit load performance of the V-22 rotors, (labeled Nz in terms of the Number of "G"s pulled) at the airspeed in Knots indicated on the Horisontal scale.

If you isolate your inspection to the lower left corner between 0 and 40 Knots, you will find only 3 data points above 1.0 G and 3 below 1.0. The AVERAGE is about 1.15G.

While you are sitting looking at the chart, you are in a state of equalibrium at 1.0G and 0 Knots.

Note that out of several thousand data points collected, the tests for low airspeeds 0-60 Knots is important because this indicates how much reserve 'G's are available for Manuevering/Agility performance-or will be available before the V-22 will be expected to stall.

In the normal situation where there are cross winds/gust/pilot control inputs, etc. we find that there is little likelihood - except on a clear, smooth, no wind day, that the rotors will see identical forces - and we will always have an assymetrical situation.

If a pilot is under fire or stress, trying to escape from mortars or guns, or making any effort to exit a combat situation, he will try to do so instinctively and rapidly. The assymetric configuration plays very powerfully under combat stress conditions.

If he is hovering or moving below 40-60 knots at realtively low altitute above the ground, and he tries to make any maneuver requiring more than 1.20 "G"s, the rotor will either stall and settle(crash ) to the ground or he may find himself in an uncommanded rollover (crash)!!

No one - no matter how good or experienced they are can ask a 1.2G limited aircraft to pull 2.0G's without a significant surprise - and perhaps the death of his crew!Note that ALL military helicopters have been tested and certified for 2.00 'G"s or more. There is a significant difference here - and it is a fatal one.

Typically we find that helicopter pilots under fire will immediately act to bank,roll, turn and pull away from the mortar blast, gunfire, rocket , etc. With 2.0 G capability he can pull away with as much as a 60 degree angle of bank (auto nuts will understand this immediatly-and as our USNA physics teachers showed us-if you are driving on a 60 Degree turn of a race track you will pull exactly 2.0G.)

If on the other hand, if you are driving down a road with only a 10 degree or so bank, at the same speed as for a 60 Degree bank, centrifugal force will cause you to roll over (maybe several times! -and break up you aut big time!!)Next - if we look in the Navy V-22 NATOPS (Pilots Flight Manual) which is the Navy/USMC BIBLE for pilots-and which was available to the pilots of the V-22 Marana Mishap, you will find that the Rotor Flight Load Limits when in Helo/Vtol Mode, are clearly stated as being 2.0 G and 60 Degree Angle of bank as flight limits!! (again -note that this is SIGNIFICANTLY - maybe small numbers-but a BIG DIFFERENCE between life/death)Almost every pilot will tell you that he can remember the G loads available in any type aircraft he flew.

Some of the gofast guys had limits of 5-6-7 G's or so. The Piper Club, the Huey, H-46 and all other Rotorcraft used by the USMC, Navy, USAF and Army have a minumum limit of 2.0G. Some-like Apache and gunners can do better. The question then - is if an experienced pilot is told that his Limits are 2.0G and 60 deg bank angle, it is THAT limit which he will feel he can comfortly and safely use.Since line Pilots don't often see flight test charts (which in this case were supposed to be used for the Contractor and Navair to determine exactly WHAT would be printed in the Pilots BIBLE (i.e.Natops)-- he would not be aware that if he tried to pull a 60 Degree (2.0G) maneuver at lower speeds in a combat area ---he WOULD find out rapidly that he DID NOT have this capability and he would either settle into ground, slide sideways into the ground (crash) or could do a quick roll or even a snap roll --- all of them without control (an uncommanded rollover).

We are talking about something happening in less than 1-4 seconds!! Did any of you read closely what happened to both aircraft in the Marana AZ accident?? Lead pilot lucked out and bounced on the ground till he hit a ditch. His wingman was doing several things: descending rapidly (at some 40-50kts?), banking in formation, and trying to slow down all at once. (p.s. NATOPS manual states clearly that abrupt mult-axis control movements are prohibited!!)Any rapid attempt to bank back into formation position-particularly when he had less than 2.0 "G" capability could initiate a quick stall in the outbord rotor (other pilots would think high wing) == at which time the low rotor would then-like a 50-60 ft lever with several hundred thousands +++++ foot pounds of leverage (lots of moment arm -AND inertia between the two widely displaced rotors!) and voila!! ROLLOVER.

Given the FACT that flight testing showed that there was no way the pilot could get anywhere near the published limits, he was a sitting duck, just waitng for an accident.

Question to ponder : Who was responsible for the aircrew NOT knowing the true/correct V-22 "G" and Angle of Bank limits??? (it sure as hell wasn't 2.0 G and 60 Deg!)Footnote: Their is NO way to FIX this problem. It is and has been inherent in "side by side" laterally displaced rotor machines since the first crash of the German Fa-61 on 13 Feb 1928!! (followed by many similar occurrences)THE MAJOR Safety of Flight issue of the V-22 IS the rotor design, which was maximized for speed and range. Consideration of safe/low airspeed envelope (thats the little dashed line near the top of each envelope segment on the chart)-- was given short shrift.THUS-The only way to correct this problem is to increase the rotor performance which could make it safer-near the ground and at slow combat terminal mission areas-and would also allow the pilots to "autorotate" safely after engine failure.

(This is REQUIRED to be demonstrated by all helicopters-but because of Navair waivers-was set aside.) The V-22 pilots/report that it cannot be done safely (except occsionally in the Simulator).BUT CATCH 22!! (v-22 that is) You can only fix this problem by increasing blade numbers (4 or 5 blades on each rotor). BUT, You will find out that the empty weight will be increased (nacelles already weigh some 7000LBS-hanging at end of wing).

AND-you can't just change the rotors and feel happy!! One major consideration in most aircraft-and particularly in rotorcraft - is the design problems with vibrations and harmonics-which WILL also require fuselage/wing/tail design changes.

IF you want to spend another $5-10 Billion you would unfortunately find that the V-22 designers were really squeezed into a near impossible design corner.

The end product would be far safer -BUT - would weigh even more when empty, and THUS would have a worse payload than it already has!! (note: the payload/empty weight ratio of the V-22 is worse than virtually every aircraft flying in the world today!!)Note: The USMC MH-53E can "lift" roughly 100% of its empty weight. The V-22 can "lift" only 1/3rd to 1/4th of its empty weight. (At/above 10,000ft where other helicopters can at least do some work, the V-22 is Placarded and Prohibited)This tutelage is gladly provided to you by the V-22 Red Ribbon Panel-a loosely organized group of over 130 Combat Helo pilots, Flight Test Pilots (including 3 FORMER V-22 FLIGHT TEST Pilots!!!), guys with BS/MS rotor/aero, and three of the best rotorcraft engineering and scientific experts in our Universities. Our work has taken over 14-15 months, literally several thousand e-mails, hundreds of papers, reports and briefings (which perhaps the Offical Blue Ribbon Panel couldn't understand * or were ill prepared or experienced for their task-led by chance - by a ret USMC Gen and a USMC L/C helper-NONE with any indepth experience or hands on knowledge of the subject at hand!!).

We do NOT have any financial interests in the V-22 or any other Program!!

We ARE hell bent to dig up the facts and the truths and to set aside the eighteen years of well practised "MANTRAS" which many of you have read and heard for years!Before Willy cuts me off, we stand ready to respond to any simple straight forward questions, but not public relation concerns. If you can find yourself a copy of the NATOPS you probably won't need us.

There is enough there to scare most of us old pilots. (later we will tell you about our ongoing effort looking at German efforts/failures and why Russia TRASHED their tiltrotor projects some 10-15 years ago!

If you understood the above and its import, you will be able to address supporters of a lost and VERY DANGEROUS cause.Goodnight Gentlemen. (Our Motto is similar to the Jolly Greens "That Others May Live" and add-"that goes for pilots also")

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