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

  • Tiger


  • 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.

  • 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?

  • 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.

  • 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.

  • 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.

  • 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.