Saturday, February 6, 2016

MV-22 Crash Findings

An anonymous reader pointed me to this link of an article reporting on the MV-22 crash in Hawaii in May 2015 (1).  I thank him for the heads up and suggestion to write a post.

To refresh your memory, an MV-22, one of a flight of two, attempted an initial landing which resulted in a complete brownout due to dust, hovered for a period of time at an altitude of perhaps 30 ft, rose, hovered again, and then dropped straight down to the ground.  Two Marines were killed and 20 injured. 

The incident report lays the blame on pilot error despite the pilots violating no rules or guidelines, command error for not selecting a better landing site, and command error for the poor emergency response to the crash.  Punishments have been recommended for many personnel associated with the exercise.  The report and the findings are straightforward as those things go but utterly fail to address the more important warfighting lessons to be learned.  In other words, the incident was investigated as a peacetime, commercial flight incident rather than a combat training incident.


Crash Film - Note the Brownout Conditions and Engine Flameout

As a combat training incident, the main lesson should be that the MV-22 is ill-suited to combat landings.  The MV-22 made a very slow descent and approach before any dust was generated.  This offers enemy gunners an excellent opportunity to target and shoot the aircraft.  Comparing this approach to flims of Viet Nam era helo landings reveals the difference in speed and aggressiveness of approach and landing.  Viet Nam helo landings were high speed, compact, and aggressive with a last moment flair to settle.  The landing process took a fraction of the time that the MV-22 landing does.  The longer the landing time, the greater the vulnerability of the aircraft. 

I’m not an MV-22 pilot but it appears that the initial approach got the aircraft to within 10 ft or so of the ground with less than total brownout conditions.  Had the pilot simply continued the landing, even blind, for 10 more feet the result would have been a safe landing.  The decision to stop and pull back up is what doomed the flight.  Once you’ve reached 10 ft, just continue straight down and the worse that can happen is a slightly bumpy landing.  Taking off again may be a problem but the landing could have been accomplished.  Again, I’m speculating as a non-pilot so take this for what it’s worth.

Some might say that this was a peacetime landing and that in war the MV-22 landings will be considerably faster and more aggressive.  If true, then why are we practicing techniques we won’t use in combat?  Train like you fight, fight like you train, right?  That said, everything I’ve read about MV-22 combat landings suggests that this type of slow, spread out landing is our tactical plan for combat and it’s due to the inherent limitations of the aircraft.  The MV-22 appears ill-suited to effective combat landings.

The next lesson is that, contrary to faulting the command elements for not pre-surveying the landing site and selecting a safer one, acknowledgement must be made that, in combat, landing sites can’t generally be pre-surveyed.  You pick a site and go with it, good or bad.  A total abort is always an option but few sites are going to offer perfect landing characteristics.  If the assault aircraft can’t handle the variety of landing conditions that combat might reasonably dictate, then the aircraft is ill-suited to the role.  Is the MV-22 limited to only “perfect” landing spots?  If so, that severely limits the aircraft's usefulness.

I urge you to read the article but read it from a combat perspective rather than a civilian mishap perspective.

______________________

As an aside, the recommended disciplinary measures against a wide variety of personnel including a fair amount of the chain of command is interesting.  I'll watch to see whether the same punishment zealousness accompanies the Iranian seizure of our boats which I view as a much more serious offense.

(1)Military.com, “Billows of Dust, a Sudden 'Pop' and an Osprey Falls from the Sky”, Hope Hodge Seck, Jan 29, 2016,


18 comments:

  1. I've read different sources about this accident, but one thing is crystal clear: leadership is protecting their decision to procure this aircraft by blaming the aircrew who did nothing outside normal procedures and training (note that NATOPS procedures are being amended.) The MV-22 is not suitable for landings in areas with debris and sands that can be kicked up by high velocity (prop)rotor downwash. The MV-22 is particularly vulnerable to FOD ingestion when the nacelles are rotated vertically - i.e. landing mode. It is a known issue for this aircraft, and has not been fully corrected despite over 20 years in development and service.

    As far as continuing the landing, that's bit of Monday morning quarterbacking. Aviators are trained to wave off when they are outside of parameters, or of their own comfort zone. It is a basic tenet of aviation safety.

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    1. This wasn't an unknown LZ, it has been used thousands of times by Marine helos training in Hawaii. As that test pilot noted, since the V-22s rotors are much smaller, they must spin much faster and produce three times more downwash than a similar size helo. This why our Navy chose the MH-60S for Vetrep 20 years ago and pulled out of the HV-22 idea. Moreover, since the engines tilt, the engine exhaust blows downward like a torch sandblasting the ground, sometimes igniting brush too!

      It can't land on asphalt either, or it becomes goo. As a result, the big CH-53E has been pressed to do basic helo stuff like ship ops and fast roping, which is why two collided recently.

      The Marines have hidden this problem by rarely landing V-22s on non-hard surfaces, and when they do the LZs are especially selected. V-22 safety regs require an hour long engine water spray wash after EACH landing on a dirt LZ! On Okinawa, they spent millions of dollars building concrete landing pads for the V-22s in the remote training areas just for this reason!

      Finally, they never did a "drop test" for the V-22 in development because they knew it would fail. After the Vietnam experience, a big focus was a stronger fuselage that wouldn't break apart in a hard landing, hence the tough Blackhawk. But as you see in this landing (and the lesser known crash at Creech airfield in Nevada in 2013) a hard landing caused it to break open, and the fuel leaked and set the composite skin on fire, and it burned up. The V-22 was built as light as possible because performance was so bad, yet it failed to meet the required KPP anyway, and can only lift ~8000lbs, although the stats list an absurd 10-15,000 lbs.

      The other thing this proves once and for all, the V-22 cannot fly with its rotors up if it loses an engine, and its small rotors provide little automatic braking power. The program always points out that a single engine can power both rotors, but not enough to keep it airborne. It can't fly safely long distances over water either, because if loses an engine it can feather it and the drag is so great range is cut in half. Something our Navy will soon discover once it tries it in the COD role.

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    2. Sorry, I meant it can't feather. If it loses an engine flying and the complex gearbox cross rotor system fails, it must shut down the other and glide to a landing, somewhere. The cross shaft is not a single metal shaft, but a strange series of 14 lightweight plastic parts, that don't last long. This is why I was shocked our Navy even considered it for COD! We'll lose a couple a year ditched at sea.

      Here is a positive V-22 article from a pilot that is explains this:

      http://www.verticalmag.com/features/features_article/20112-flying-the-v-22.html#.UexWNW14nH0

      And this what he wrote:

      At this point, the Osprey is cruising along essentially as a twin-engine turboprop airplane, flying at the same speeds, altitudes and flight rules as traditional turboprops. The primary difference is the lack of ability to fly with one proprotor feathered, (which is one of the major training obstacles of multi-engine airplane transitions). Should a proprotor gearbox fail in airplane mode, causing the related proprotor to stop, the only recourse is to shutdown both engines and conduct a power-off glide and emergency landing; the adverse yaw is just too great for the rudders to overcome, leaving few options.

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    3. "As far as continuing the landing, that's bit of Monday morning quarterbacking."

      It is. Had the pilot aborted and left the area, nothing would have happened. The decision to stay, hover in the cloud, and reattempt the landing apparently led to the fatal amounts of sand ingestion. The pilots had no way of knowing this. This would constitute a lesson learned: land or abort - don't hesitate and retry.

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    4. " V-22 safety regs require an hour long engine water spray wash after EACH landing on a dirt LZ!

      That doesnt make sense! Some needs to do some basic research as previously it was found gas turbines can be cleaned by a a few ounces of readily available light but hard material such as ground up walnut shells!
      Its like cleaning your car only with a hose , you have to still do something that touches surface to remove grime.
      The Osprey predecessor CH46 and its cousin the Ch47 Chinook both use connecting shafts- which were often chopped by the flexible rotor blades if the pilots werent very careful. Ordinary helicopters can chop off rear fuselage too in some circumstances.

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  2. The civilian tiltrotor, AW609, which has been in development forever, had an aircraft crash for unknown reasons last October.

    http://theaviationist.com/2015/10/30/agustawestland-aw609-tilt-rotor-prototype-aircraft-crashes-in-italy-killing-two-test-pilots/

    Bell dropped out as a partner in that program a few years ago. They knew the FAA wouldn't cert it for passenger aircraft.

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  3. I really wish the XC-142 and CL-84 tilt-wing projects had been continued. I'm not at all convinced that tilt-rotors are a good idea.

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  4. For an excellent of the history of the V-22 development, along with the reasons for decisions that have been made, read the book The Dream Machine.

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  5. The V-22 is based on a fundamentally flawed idea - tilt rotors, which carry quite a few drawbacks.

    This has become like the LCS, a very expensive project, but one that does not offer much given the costs.

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    1. The very idea of the V22 *seems* to me rooted in an idea that we'd be in a 90's type environment for a very long time:

      Delivering marines quickly, but without much in the way of real opposition.

      Again, its fine for the V-22 to be built as a test. Like 1-2 LCS that they tested would be fine. But again, we've taken an 'interesting' design and doubled down on it to the point that its now going to do COD too.

      We seem very adept at creating expensive systems that do multiple jobs poorly.

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  6. The Marine Corps should have gone with a mixture of AH60L BattleHawk and Super Stallions instead of V22. Lets count the problems with the V22.
    1. Cost, for the price you could get about 3 AH60s or even the SPECOPS versions
    2. Size, for the size of a large lift helo, you get a medium lift helo that can fly like a plane for a small part of the flight regime.
    3. Any country that has SSM that forces your amphib group out to 100nm also likely has an IADs that will shoot down every one of your V22s.
    4. Cant fast rope (watch the numerous videos... it is not safe)
    5. Cant provide suppressive fire well because of the placement of the engines. They had to look at a remote turret (taking up carrying capability) as a possible add on.
    6. Time to unload.. cant really hang around in a combat LZ but it will take awhile to unload 22 out the back. Often better to go with a small load quicker to unload.
    7. Cited problems with LZs and the heat that come off the engines. I have supervised 60's and 53's landing on sports fields for HA/DR. Cant do that with V22.
    8. Poor ability to either glide or auto rotate with engine problems (and they have them in spades)
    9. Reliability. Onboard a LHA they have a piss poor FMC rate. The thing is extremely complex and sucks up maintenance hours and deck space when they have to unfold her to work on her.
    10. Cost per flight hour, several times higher than other helos.
    11. Vertrep ability.... extremely poor due to the heat and the downdraft

    So what should we do... Keep 3-4 per MEU, replace the rest with a 6 pack of 53s and 12+ AH60s (you could even get ride of the UH-1s) and go with 18 AH60 you could fit that many with the opened up deckspace. Also it would give you the ability to do Armed attack work to augment you AH1s.

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    1. Very nice comment. Gotta agree.

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    2. And note that your AH60 is already in production for the Navy as the MH-60S. The training, parts and sustainment pipeline already exists, with maintenance support available from every Navy warship and every Army Division.

      And the Knighthawk is far superior in tight or hot LZs. Check out this video of things a V-22 wouldn't even attempt.

      https://www.youtube.com/watch?v=yVgXPHE63wM

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    3. I don't have a problem with trying out new Tech. If we didn't do that we wouldn't have helos at all.

      The problem is we committed before wringing out the issues (like the ones above).

      We also lost a lot of Marines before folks listened to the engineers and redesigned the nacelles and understanding the Vortex Ring State or at least avoiding it.

      I would like to see some V-22 kept for technology wring out, but as you say there are other alternatives for combat now.

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    4. Don't forget how much lift the V-22 loses in hot and high conditions compared to a CH-46 or 53

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  7. The central problem with the V22 is that the Marines decided with very little push back from the Navy a concept of warfare for assault from the Sea. The only reason to go V22 for operations over other helos is for speed and range and you only get that by flying like a prop aircraft. The idea that you can successfully move from a seabase to the assault at over 100-200 miles in range is the core of this issue. Based on new Marine Philosophy, you don't need to secure a beach and move materials ashore to assault the objective, you can move almost right to the objective and hike over for the assault. Now their are numerous flaws in this thinking that a good wargame could have exposed like.... you land your company of Marines via V22 (out of range of supporting arms) and a SA-11/SA-10 moves into the region? How does the rest of the MEU get there? Cant lift LAVs or even unarmored Hummers via V22 at aircraft speeds. So now your stuck with a foot unit that relies upon air support for everything. Did the Marines not read BLACKHAWK DOWN? Those helos got shot down with RPGS? How about the Apache's independent assault (aerial envelopment) during OIF (ie the one where they lost 2 birds and got the rest of the unit so shot up that they were combat ineffective for about a week undergoing repairs) or the hundreds of helos we lost in Vietnam? High cruising speed does not change the low speed approach to landing that the V22 has and thus it is at its most vulnerable. The V22 is solely a product of a failed Marine Concept of war that no one looked at close enough to point out the flaws.

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    1. There is a post forthcoming on this. Stay tuned!

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    2. Yes the V-22 facilitated the Marine concept for long range landings, and maybe avoiding amphibious landings altogether.

      However look at SecNav Lehman and Senator Goldwater's excitement at the technology. They saw that flying prototype XV-15 at the 81 Airshow and were determined to buy it (both are aviators BTW).

      And because SecNav loved it, he was not about to negate a concept that facilitated getting this new tech.

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