Osprey Aeromechanics and Pilot Error

Bryant Jordan at our sister blog DoD Buzz wrote about the Headquarters Marine Corps’ explanantion behind what happened last April when an MV-22 crashed during an exercise in Morocco that killed two crewmembers.  Here’s an excerpt from Bryant’s post:

The accident occurred as the Osprey was taking off, turning to avoid a busy landing field even as it was rotating its proprotors to transition from helicopter mode to fixed wing.

As it did that, the center of gravity moved forward – pointing the Osprey’s nose down – and a strong tailwind pushed the plane forward and downward. The co-pilot, he said, failed to adjust the nacelles during the turn to overcome the effects of the nose-down altitude.

“The aircraft is now committed and it flies into the ground,” said Marine Corps Lt. Gen. Robert E. Schmidle Jr., deputy commandant for Marine Corps Aviation. The Osprey only reached an altitude of about 50 feet above the ground before it crashed, killing two Marine aircrew members, Cpls. Robby A. Reyes and Derek A. Kerns.

Had the pilots kept the aircraft in helicopter mode until they had gained speed and altitude, the accident probably would not have happened, Schmidle said.

Longtime DT readers may remember a post back in 2006 where I predicted there would be six Class A V-22 mishaps within the first three years of fleet introduction.  Among my itemized flight scenario predictions was this:

The test pilots (both active duty and civilian) did amazing work during the High Rate of Descent (HROD) phase of developmental test at NAS Patuxent River back in 2002 and 2003. They validated the V-22’s vortex ring state (VRS) envelope. (DT readers will remember that VRS was what caused an Osprey to crash near Marana, Arizona back in 2000, killing 19 Marines.) Improvements have been made in the vertical speed displays and aural warning systems. But the fact remains that — while there are no “unknown unknowns” about VRS and that there is a buffer between the operational rate of descent limit of 800 feet per minute and where VRS occurs — the rate at which the V-22 develops a high rate of descent is unique to the V-22. Basically, the crew has to hawk the VSI gauge constantly during a descent. A moment’s inattention can result in the vertical speed getting out of hand. (The test pilots actually had an inadvertant VRS entry during HROD testing because they got distracted for a second.) So imagine junior pilots during high op-tempo periods (deployed) at night, on goggles, and operating with not enough sleep (never happens if you follow NATOPS, right?) Yes, this is a training issue in that crews can be taught to watch the VSI readout on the display, but in spite of the comprehensive understanding Osprey crews have of the phenomenon (thanks to the Developmental Test Team at Pax River), somebody’s going to be tired and distracted (and maybe under fire) and will enter VRS close to the ground. The outcome won’t be good.

And in the case of this Morocco crash the outcome wasn’t good.  Doubtful VRS was the issue, but vertical speed obviously was.

The comments with Bryant’s post vividly show the two camps most interested parties fall into:  Those who believe that pilot error will always be part of the equation as long as humans are in the loop, and those who believe the V-22 is inherently flawed because of its design, etc.

No airplane is crash-proof.  If a pilot wants to fly a JSF into the ground he can.  Even drones crash on occasion.  But sometimes airplanes have aeromechanic tendencies that make them crash-prone.  (Along with having worked in the V-22 Joint Program Office for three years as the spokesman, I have 2,800 hours as a Tomcat RIO; talk to me about inducing yaw rates at high angles of attack with that airplane.)

The V-22’s operational mishap rate would suggest the airplane is NOT crash-prone.  However, certainly relative to conventional rotary wing aircraft, the Osprey has — literally — more moving parts, and that can bite a pilot when operating near the ground.  As Gen. Schmidle said, had this co-pilot done everything but program the nacelles forward at that time he probably wouldn’t have hit the ground.

A couple of flight adages come to mind:

  • There are no new mishaps; just new pilots causing the same old mishaps.
  • You can only tie the record for low flight.

Ward Carroll is the editor of Military.com. During his 20-year Navy career Ward served in four different F-14 squadrons. After his retirement from the Navy, he served as the the public affairs officer for the V-22 Osprey program at the Naval Air Systems Command.

  • Nick

    Oh, are the dead people at fault? SOP

    • Curt

      No, both the pilot and copilot survived, you might want to actually read the post.

  • Tiger


    • tiger

      Cat pilot error post. Bobbi likes to type too……

      • Dfens

        Apparently the cat deserves to die. And when he does, all the other cats can tell us how he had it coming — because they’d never do anything like that!

  • Mitch S.

    Another scenario for the simulators.

  • Dfens

    What does it take to put a warning system in the V-22 that tells the pilot he doesn’t have the airspeed nor the altitude to push the rotors forward as far as he is commanding them? The aircraft would need a pitot probe and a radar altimeter, both of which are already in place. This aircraft has been under development at taxpayers’ expense for decades and doesn’t have something so basic as a simple warning on the nacelle angle? It is a wonder it flies at all.

    Hopefully the Safety Investigation Board will recommend that at least a warning is put in place. The Accident Investigation Board remains the usual white wash at the taxpayers’ and pilots’ expense as usual. I hope Ward got his 30 pieces of silver for selling out.

  • Guest

    I wonder if the pilots frquently violate the NATOPS in this manner while performing expedited takeoff accelerations, or whether this was truly a one time incident.

  • elmondohummus

    I confess to ignorance, since I’m neither a pilot nor military, but I do have a question about something: Are pilots supposed to avoid rotating the nacelles from vertical to horizontal until they’ve gained a certain altitude? If not, wouldn’t that be the common sense reaction to this crash: Implementing a minimum “nacelle rotation” altitude?

    Or, is the issue that such a restriction exists, but the pilots did not heed it?

    • LoSul

      Its not strictly based on altitude but also airspeed. NATOPS refers to 40 ktas in helicopter mode before transition at low altitudes.

    • RunningBeard

      Yes, it is in place,
      No, he did not heed it.

      Thus, co-pilot error. Sadly, he will live with the knowledge that two marines died because of his mistake. Three casualties from the simple adage, not enough lift under the wings and you can’t fly. The pilot probably had his eyces out the windows looking for obstacles, until he heard the engine pitch change (coming off of load) at the wrong time. Shucks! :(

      • Dfens

        There was plenty of lift. What was lacking was control authority. In this case, the opposite of lift.

  • Harry

    The computer automatically dips the nose 5% as the nacelles rotate forward to offset PUWSS, which occurs when the rotor wash impacts the tail area. However, a strong tailwind can offset that too, so it was the software that dipped the nose as it moved forward, causing it to crash. Google PUWSS V-22 to learn move.

    • LoSul

      Yes, but pitch up with side slip is mitigated by flying the profile specified in NATOPS, which is to get some airspeed before the transition. To claim the software “caused” the crash is a bit disingenuous.

      • Dfens

        Because if the pilot pitches the nose down it is his fault for crashing the vehicle, but if the software does it, then it is God’s gift to the world of aviation. It doesn’t matter that the software has more data available to than the pilot has, nor can software ever be at fault because it was insufficiently designed. After all, the pilot exists to serve the vehicle. Blessed be the vehicle and the program from wince it came. And f the pilot. If one crashes or dies, then get another one.

        • Pilgrimman

          You have severe mental problems.

      • Rob

        This crash had absolutely nothing to do with pitch up with side slip. That occurs when the wind is 30-60 degrees off the nose. The empennage is ineffective because it is in the rotor wash. The nacelles are automatically driven down at a rate faster than the pilot is able to command them in order to give the pilot more stick margin. Most commonly occurs when landing on the boat, not taking off with a tailwind. Completely separate things here.

  • jamesb

    May I remind people that V-22’s are SUPPOSED to become part on HMX-1….

  • jamesb

    part of the HMX-! fleet…..

    but WILL NOT carry the POTUS

  • Harry

    They are support aircraft for HMX-1 because our Generals decided they needed the CH-53Es from HMX-1 in Afghanistan rather than new V-22s, so the V-22s replaced them, but not for VIP use, only for Marines.

  • Winston

    Unless the Osprey program employs a design modification to include some anti-gravity device….

    This aircraft was and is NOT worth the lives lost.

  • Winston

    Really! If the Osprey is so great, why not give it to POTUS?

    • Vaporhead

      Probably not as easy to transport a CV22. Can the wings and nacelles fold back so it can be shoved into a C-17?

    • Curt

      Requirement for Marine 1 is that it not damage the rose garden lawn. The V-22 is too heavy.

      • Czar

        Its not that it’s too heavy, or that its too big for the pad, or the rotor wash. The exhaust coming from the nacelles will scorch the grass and it will not look nice. That’s why POTUS won’t use it. That and other defensive reasons.

    • Tiger

      It’s a bit big for the White house pad.

      • 6113

        It’s not that it’s too big, it’s the rotor wash that is the problem.

        • tiger

          So is that program dead or in limbo? Last I heard, we sold the unused choppers to Canada.

          • 6113

            As far as I know it’s still in limbo. The airframes were sold to Canada.

    • Czar

      If you can name a current operational (gray) Marine Corps helicopter that transports the president, your argument can be valid but you cant. The president only flies in H-3 or the H-60. The Marine Corps doesn’t use either of those operationally. So we should get rid of all Marine Corps helos. How about all the Army and Navy ones too since they don’t transport the president.

  • Apache SP

    The problem with this accident was that the copilot (the pilot on the controls during the accident) turned from facing into the wind during takeoff to turning away to avoid blowing over tents. The resulting tailwind at low speed coupled with the rotating nacelles is what caused this accident. No pilot should willingly take off with a tailwind due to the negative aerodynamic factors. They could have fixed the tents.

  • Czar

    The software did not dip the nose. It is not programmed to do that. You can takeoff with a perfectly level deck. And there is a system in place that lets the pilots know how fast they can transition safely. It is depicted graphically on the MFD. Pilots flying outside of NATOPS is absolutely not a common practice. Doing that will get your wings pulled in a heartbeat. These pilots will not fly in the military again, but neither will the crew chiefs.

  • Czar

    The software did not dip the nose. It is not programmed to do that. You can takeoff with a perfectly level deck. And there is a system in place that lets the pilots know how fast they can transition safely. It is depicted graphically on the MFD. Pilots flying outside of NATOPS is absolutely not a common practice. Doing so will get your wings pulled in a heartbeat. These pilots will not fly in the military again, but neither will the crew chiefs.

  • Helfyr

    More lives and another $110 million gone. This extremely complex aircraft sounded great thirty years ago. Unfortunately, no matter how many times requirements were lowered it continues to struggle. The reasons Marine Corps leaders and politicians who forced this machine on us are apparent and they have little to do with national defense. The Army declared the Osprey “unsuitable for combat operations”. The single small machine pointing backwards tells a lot.

    • ghostwhowalks

      Just as well you have the final word and not all the experts , who do this for a living.

      Bit of course sitting in your armchair is just like flying the real thing and putting yourself in danger

      • helfyr

        Just to set the record straight, I am one of the experts. I am a retired military pilot who has done my share of combat tours. Currently have over 18,000 hours as P.I.C.
        In my current job I am regularly flying and landing in the mountains at night on NVG, often at MGW.

        This Osprey has not delivered on its promises. It has seriously reduced hover payload above 3000 P.A. It has a small inadequate cabin. It is very expensive to buy and maintain. Availability rates are well below acceptable levels. Based on the evidence, it is difficult to fly. It has has far too many limitations and restrictions for a frontline military aircraft. Finally, it is incapable of defending itself from even minimal threats.

        • Thomas L. Nielsen

          Question: Have you flown the Osprey?

          Also, please clarify for me:

          “It has seriously reduced hover payload above 3000 P.A.”: Seriously reduced, compared to what?

          “It has a small inadequate cabin”: Based on what criteria is the Osprey cabin “small and inadequate”?

          Regards & all,

          Thomas L. Nielsen

        • Tiger

          If you want to talk undelivered promises, try the AH-64 Apache & atack choppers in general.

    • Tiger

      Folks said the same stuff about the M-16 50 years ago. Still here, still working.

  • James

    Bottom-line…if you put ANY aircraft in an aero situation is shouldn’t be in, bad things are going to happen.

    As for whether or not automation is needed to prevent this from happening…NO. We have almost 150,000 hours flying this aircraft & for 99.9% of them the training that is given early on & reinforced through out works.

  • jamesb

    You DO have some V-22 driver here, eh?

    Follow the flight rules seems to be the call….

    But the a/c does have a rep….
    Like it or not….

    • ghostwhowalks

      Boeing 727s had a bad rep too , when first indroduced the new style T tail meant pilots were slow to change their flying practices to avoid the type of stall.
      Eventually it went on to be a workhorse of passenger fleets

  • jamesb

    drivers…..sorry about that

  • tipover

    The F-15 had a bad rep, so did the CH-53, F-104, the B26(?) Marauder and the Boeing Stratofortress. Some were in service long enough to finish long term development, others you flew by the numbers in the flight manual or died. Too many here have opinions developed 15 years ago and can’t let go no matter the facts w/r to the current V-22.

  • Dfens

    Poor little V-22. Everyone’s being mean to it. Breaks my heart. Who cares that it’s killed over 40 people? People aren’t important. Weapons programs are important.

    • tiger

      The 747 has killed many times more. Want to bash it?

  • James

    Conversion protection IS good. It is designed to prevent damage to aircraft components. TRANSITION protection would be bad IMO…it would hamstring pilots and prevent them from being able to fly the aircraft (with in limits) when they need to.

    • LoSul

      We have a winner here!

      This is it in a nutshell. Without conversion protection, you WILL damage rotor components and COULD get into an unrecoverable position. Without transition protection, you COULD get into an unrecoverable position but the rotor can handle it.

      The protection systems are in place to prevent the pilot from exceeding the limits of the machine, not getting out of evnelope in all situations.

      At altitude or without a tailwind, there is nothing that would nor should have limited this pilot from performing the same maneuver.

      • Dfens

        No, we have 2 winners here.

  • Call me crazy, but we have the technology to make it so the pilots cannot get cocky and crash the plane.
    While I understand that the pilots would not want a “box” limiting their flying, it seems these accidents keep happening in much the same way.
    It reminds me of the attempts to test “stall” on the early flying wing aircraft. It just made them crash. The pilots seem to be treating the craft like its boundaries must be pushed.
    With this aircraft, flying precision is staying well within the flying boundaries. Not on the edge of them.
    The situation also reminds me of the Harrier Jump Jet. When they first introduced them they only allowed veteran pilots to fly them.
    Then they started bringing in brand new “Nuggets” into the program. The crash rate skyrocketed.
    I do not know how you become an Osprey pilot, but if it is not already this way maybe it is time to make it so you have to have a certain amount of hours with another platform before you can switch over…..

  • Army Helo Pilot

    To complex for the combat environment- Slope limits/ Limited LZ-PZ availabitity/ Brown out- rotorwash signiture/ maneuverability/ lacking forward/ side door gunners/ limited anti/de-icing capabilities. Keep 3 to do airshows with the A/F. Besides, if the Chinese and Russians aren’t copying it, that should tell you something.

    • Riceball

      Funny how AFSOC seems to have no problems with their Ospreys and, from what I understand, like them every bit as much as the Corps. Just because the Army doesn’t want Ospreys doesn’t automatically make it bad, I imagine the Army doesn’t want them because A) they need the money elsewhere like for replacing everything printed in that god-awful UCP, B) I don’t think it fits any real Army need since the Army doesn’t have a medium lift helo like the CH-46 that needs replacing.

    • Czar

      Too complex for combat? Lets talk about these issues you bring up. Slope limits: 9 deg all the way around, 3 more than the phrog on cross slope. Limited LZ: Not sure what you mean by that. It can land anywhere a helo of comprable size can land as long as you don’t want the grass scorched i.e the White House. Brown out: can land in a complete brown out with the pilots completely on an instrument scan on the glass inside the cockpit. Rotor wash is large because of high disk loading. Not much you can do about that if you want to land on a boat. Maneuverability: max AOB is 60, max nose up 35 degrees, max 4g’s, negative g’s limited to 10 seconds per flight. Belly Gun can face in any direction. Anti-ice/de-ice equipment on the windshield, engine inlet, spinner, proprotor, wing, pitot tube, AOA sensor. I wish people had their facts straight.

      • Czar

        Haha they censored c0ckpit.

        • Czar

          caulk pit?

  • Mitchell Fuller

    Army Helo Pilot. Succinct synopsis of liabilities. I like the concept of V 22: takes off like a helicopter, flies like a plane, lands like a helicopter (always have). But the reality is this is a dangerous a/c to operate. It’s more dangerous to its crew and passengers then the enemy

    Marines would be better served by a modernized CH 46 (four bladed, larger fuel tanks, more powerful engines) and the CH 53 K

    • LoSul

      “But the reality is this is a dangerous a/c to operate. It’s more dangerous to its crew and passengers then the enemy ”

      Where do you get this idea? Be specific. Because the facts are its is objectively less dangerous than almost every other flying machine in Marine inventory. Do you believe the CH53 series is dangerous? Because it has a much worse record in its service…to the tune of 330+ killed in USMC accidents. I wonder if it has literally been more dangerous to its crew than the enemy.

      Also, a CH53K is a totally different class of aircraft. Replacing a V22 with a 53K makes absolutely no sense. I do not understand the constant comparison of the two with respect to mission replacement.