It was a Perfect Day in Hawaii’s Eternal Summer

Mishap from the air. We believe that the mishap aircraft is down, and the aircraft visible is waving off.

Mishap from the air. We believe that the mishap aircraft is down, and the aircraft visible is waving off.

A perfect day, until the crash. Aviation Week has an evocative article about the crash of a Marine MV-22 Osprey in Hawaii on 17 May 2015. (A registration may be required, but no pay).

Despite the destruction of the airframe, only two of the Marine passengers on this combat-training mission, and none of the crew, were lost. But AW got hold of either a released Article 15-6 investigation report, or one hell of a leak from the actual accident board report (which is a closely held document, not releasable to the public).

It took about an hour for the Osprey to reach the Oahu coast from the Essex, arriving at about 11:30 a.m. Hawaii time. Outside, an 11-kt. wind topped off a 75F morning under slightly overcast skies as the pilots dealt with a slight glare. From the cockpit all was clear within 20 mi. of the beach. The pilots started their descent to 6,500 ft. and then to 1,500 ft. About three miles out, the pilots reduced power. The Osprey then began the riskiest stage of its flight—conversion to helicopter mode and preparation for landing, raising the nacelles and lowering the landing gear when it reached about 110 kt. a half mile before the beachline.

The Osprey crossed the beach at 80 kt. about 620 ft. above the sand, part of a formation of five MV-22s taking part in the exercise. In the cabin, some Marines would note the change in view from the vast blue Pacific to green fields and fences—a lot of fences. This would be a tight landing area.

The MV-22 began a right turn toward LZ Gull. That’s when the confusion started—the tiltrotor was following a flight path about 50 yards southeast of the intended landing point. One of the other formation Ospreys, Mayhem 12, radioed a warning: Mayhem 11 was in the wrong zone, it was too far to the right and off the range complex.

Fifty yards made all the difference, as did the failure to recon the DZ properly, and these errors would be compounded momentarily.

Inside the cabin, as they heard the change in the engine pitch announcing the switch from flight to imminent landing, the Marines strapped on their gear and unstrapped themselves from their safety harnesses. This had become common practice to allow them to exit the aircraft as quickly as possible. It was also a flagrant safety violation. They smacked themselves and each other on their plated chests. Officers held up two fingers—two minutes to landing and assault. Some again checked their magazines.

Using the nearby fence line as a reference point, the pilots started to creep their Osprey toward the LZ, with the large tree to their left. It did not look good, and they radioed the rest of the crews: “We’re going to wave this off …” The noise abatement area to the north severely constricted their ability to maneuver.

But a ragged flight formation was the least of their problems. As the aircraft descended to 25 ft., Mayhem 11 encountered brownout conditions that engulfed the Osprey—rotor downwash was kicking up a thick fog of sand and dust, obliterating points of visual reference.

“‘Brown out’ landings are one of the most difficult operations a helicopter or tiltrotor aircraft can conduct and require detailed planning for success,” investigators would later note. Those aboard Mayhem 11 were ill-prepared to perform one.

They waved off the first landing attempt, then came right back to the same place to try again.

Their next approach profile was exactly the same, producing another severe brownout. The aircraft became engulfed in dust about 25 ft. off the ground as the pilots struggled to get their bearings. It proved impossible to maintain a stable hover due to the unavailability of a clear, unobstructed view of the landing zone. The aircraft moved vertically and laterally off its mark, and the pilots realized they were climbing without meaning to. To reset and attempt another landing, the Osprey climbed to about 110 ft. to get out of the dust cloud as the pilots shifted controls, cued up a new hover page and hit the trim release button, so the aircraft wouldn’t drift from its spot in the sky.

Typical V22 dust devil on arid LZ. (Not a photo from this mishap).

Typical V22 dust devil on arid LZ. (Not a photo from this mishap).

The downwash of a V-22 has to be experienced to be believed. It is much stronger than the downwash of any other hovering rotorcraft — worse than the H-47, the H-53, the long-retired CH-54, and even the mighty Russian Mi-26. It’s very unpleasant to be under, and frightening to fast-rope from.

In addition, brownout not only ruins pilot (and crew chief) visibility, it also sluices a dry river of particulates into the engine intakes. The USMC and other Osprey operators were about to learn an expensive lesson about the plane’s ability to filter these particles.

Mayhem 11 had surpassed its limits for brownout exposure. Neither landing pass by itself had exceeded the 60-sec. brownout limit, and procedures said nothing about a combined limit within any certain period of time. The pilots were operating within accepted procedures. After this day, though, those procedures would be changed.

In the traditional story of Faust, the Devil requires the knowledge-seeking doctor to sign in blood. Flight manuals and operating limitations, also, are sometimes written in blood.

As the pilots tried to set the aircraft down for a third time, those watching the attempt from a nearby hill lost sight of the Osprey in the dust, but they heard a loud pop and saw three red flashes from the bottom exhaust of the port side engine nacelle, followed by black smoke. The pop also was heard within the V-22 itself, penetrating the hearing protection worn by the Marines. The left-hand engine had begun to clog with sand and dirt filled with reactive minerals—calcium, magnesium, aluminum and silicon—that had melted in the combustor and resolidified on the fixed first-state turbine vane. The engine surged, dipping the Osprey immediately left and rolling some of the passengers inside.

Mishap aircraft burns out. The Marines pulled all out, survivors and dead alike, and none were claimed by the fire. But it was close.

Mishap aircraft burns out. The Marines pulled all out, survivors and dead alike, and none were claimed by the fire. But it was close.

The aircraft was, perhaps, at 10 or 15 feet above the fence when the engine began to fail and the crew tried to power their way out of the imminent crash.

Inside the cockpit, time seemed to slow as the adrenaline flowed. The pilots felt the aircraft settling in its own downwash and they knew something was wrong. The Osprey started to fall. The crew chief yelled, “Power!” And then it seemed like the entire aircrew was yelling at once in unison: “Power! Power! Power!”

Both pilots slammed full forward the thrust control lever, which moves fore and aft like an airplane throttle, in an attempt to gain power and altitude. But there was nothing stopping the Osprey now—it plunged to the ground at a speed of about 36 ft. per second.

For comparison’s sake, the old MC1-1B/C parachute descended at about 18-22 feet per second with a normal load (150-300 lb.).

The crash destroyed the aircraft, killed two Marines, and injured 18 more. The casualty list would have been much worse if the Marines hadn’t self- and buddy-rescued before the noxious fumes from burning Osprey pieces could finish them.

Osprey mishaps get a lot of ink, but the aircraft is surprisingly safe, and surprisingly robust. The ship’s accident and fatal-accident rate is lower than some other combat types. One very expensive accident resulted when an Osprey tumbled off a flight deck and hit the water, getting partly submerged. The pilots never stopped fighting and they saved the aircraft, although one crewman bailed out after impact — and was not recovered by USS Boat. (Salt water corrosion meant that this would have been a Class A mishap even without the fatality, but that Osprey was repaired and flies on). The Marines are operating a couple hundred of the unique birds.

A similar “hard landing” in a Chinook or 53 would likely have caused more serious injuries and more fatalities. Unlike those aircraft, the airframe does burn (and release toxic fumes as it goes) which puts a premium on self-help after the parts are done bouncing.

Do Read The Whole Thing™. The comment section is a mixed bag of informed and uninformed personnel, if you read the comments it should be clear who is who.

18 thoughts on “It was a Perfect Day in Hawaii’s Eternal Summer

  1. W. Fleetwood

    A tangential question. Why is the crash report not releasable to the public, which is to say the actual owners of the vehicle? Granted, there aren’t a lot of civilian Ospreys out there, and I can see a review/redaction process for actual military secret stuff. But still, isn’t one of the reasons for the crash investigation to prevent a recurrence of the event? On its face it seems counter productive.

    Wafa Wafa, Wasara Wasara.

  2. James

    Damn,the engine melted dust and it re solidified before it could exit,that is some very quick material changes.I am surprised with all the tech ect. out that there isn’t so far a way to filter better but most engines still need oxygen to complete their combustion cycles.

    1. KenWats

      The smaller the gaps in the filter, the greater the pressure drop across the filter. In other words – the harder it is to pull through the filter.

      Kinda cool how quickly the dust melted and resolidified. I guess it makes sense when you think about the volume of air that must be flowing through the engine and how quickly that would cool off very fine particles with lots of surface area. Still pretty amazing.

    2. Hognose Post author

      Turbines need incredible quantities of air. Indianapolis banned turbines by restricting intake size circa 2970.

  3. Boat Guy

    Sorry if I can’t share your apparent enthusiasm for the MV-22 over the 53, specifically the MH-53. I see it as an example of ” ‘Better’ is the enemy of ‘good enough’ “. Deck/hangar space considerations and “space in the box in the back” are just two of the MV-22 shortcomings I find crucial.

    1. Loren

      50 years from now, everything will be VTL and you have to start somewhere. What really gripes me is the F-35 reliving McNamara’s F-111 all things for everybody stupidity.

    2. Aesop

      It still beats the hell out of what it replaced, a helicopter designed and first flown in 1962, and whose last new model rolled off the production floor in 1971, before most current squadron commanders were born.
      In the Marines, the alternative to “new” is “nothing; use the same tired old crap from three wars ago”.
      Ask the guys driving the current AAVs. Or currently carrying canteen cups from 1943 (I sh*t you not).

      You wanna talk new airframes, let’s cancel the F-35 Thunderjug, and get the entire four-service defense budget back from the Black Hole Of Lockheed. Then there’ll be something to work with.

      1. Boat Guy

        What’s your bitch with the canteen cups? They still work for me – as they have since I was a Private; longer ago than I care to think on. Got something better?
        And NO it doesn’t ” beat the hell out of” the -53 in many important respects. I really don’t give a damn when the -53 was designed any more than I care about how old the design of the Ma Deuce is.

        1. Aesop

          The MV-22 was never intended as a replacement for the CH-53, but rather for the farking ancient CH-46 Bucket O’ Bolts.

          And when the airframes in question had been rattling themselves to pieces for better than 45 years, still had patches on the skins in the ’90s from hot LZs in Vietnam in the ’60s, were best referred to by their own squadron senior maintenance weenies as “a loose association of parts flying in formation”, and you have to fly on the goddam things with several tons of howitzer slung underneath, fluid leaking all over the internal cargo bay from multiple worn out fittings, and with pilots nearing retirement who are younger than the birds, it ain’t the same thing at all as something as brick solid as a serviceable Ma Deuce.

          You aren’t comparing apples and oranges, you’re comparing apples and pineapples.

          I also had a 1941 105mm howitzer assigned to me in the late 1980s with the breech stamped with the dates it was rebarrelled: 1942 (after Guadalcanal), 1952 (after Chosin), and 1969 (after Tet and Khe Sanh). Which means jack and squat to the discussion, because a 40 year old hunk of iron with a fresh gun tube – which works otherwise exactly as designed 40 years earlier – is not the same thing as 40,000 aircraft parts all made by the lowest bidder when Nixon was president, none of which perform as originally installed after thousands of hours in the air. And I didn’t try to get the howitzer to fly.

          Notably, both the ancient CH-46s and the even older howitzers were tending to have the same flight dynamics towards the end of my service (both dropping like bricks), which was years before the Osprey replaced them.

          Unlike individual and crew-served weapons, airframes get old, and helos age about 10 times faster than any fixed wing craft. Continuing to fly legacy helos for decades and decades is tantamount to training kamikazes, and in the case of transport helos, some of the kamikazes you’re making are stored in the back half, with no say in the ceremony. That may have worked for the IJN, but not so much for the current USMC. That’s why I give a damn.

          And if we weren’t trying to shoehorn the A-6, A-7, AV-8, A-10, F-16, F/A-18, three French hens, two turtledoves, and a farking partridge in a pear tree into the F-35 airframe, there would have been budget money to design a replacement for the -53. But that money got eaten by the Thunderjug, which still doesn’t work right, and hasn’t reached IOC anywhere, with anyone, buckets of ink and happy gas notwithstanding.

          1. Bart Noir

            The replacement for the CH-53 was not only funded, it has been designed and is in flight test right now.
            It is called the CH-53K and is a huge improvement over the older ones. The “Kilo” will serve alongside the V-22 for a long time, likely for the next 5 or 6 generations of Marines if historical precedent is followed!

        2. Roguetechie

          Haha, you just had to say it!

          Don’t get me wrong, I love the ma deuce and am truly in awe of the fact that it still serves on with the distinction and usefulness it still has. That being said though, maybe if we spend just a little less on future scorch marks in the landscape of the next big war we could afford to buy better lighter 50’s which we already designed long ago yet somehow decided not to build.

          Note: I’m not referring to the xm806 or the other abortions with low fire rates and etc but the very good AAI lwgphmg which had dual feeds, could convert to 12.7×108 14.5kpv and 20mm Vulcan rounds pretty quickly and simply. As an added bonus they’d be really amenable to swapping in armored casings that contain gun and optics etc for RWS use.

          Love or hate the v22 and the F35 one thing that’s indisputable is the seriously deleterious effects they’ve had on the procurement of newer and better equipment in way too many other areas. Thank God we have that old equipment that was so good and that we stored so much of to fall back on. Unfortunately though between DRMO and decades of robbing peter to pay Paul has us finally reaching the end of the line with some of these deep stocks.

    3. Hognose Post author

      The replacement of the HH-53 with the -60 was a bigger size cut. PJs told me they hated it. There really wasn’t much room in the back of a Pave Low. Real problem was they never replaced the airframes. They were flying Son Tay vets in Afghanistan.

  4. BAP45

    Any idea on what the difference in crash rates between osprey and traditional helicopter would be? These do get a lot of press so I can see how it could skew perception.

  5. Ti

    Stationed in HI w 25th ID as an H-1(dual mos 67N/Y, so A&UH-1’s) crewchief in ’80. Never had one of those loss of ref to ground incidents as I remember in the unit. I do recall that Rucker published an internal army aviation incident sheet for ALL Aviation personnel “Flight Facts”. I’m sure Marine Aviation has the same today. I read those when they came out monthly, then I was involved in an “incident”, that made the rag. After that I called it FRIGHT FACTS.

    The “air filter” on the T53 was really interesting. The particle air separator had an outside screen that roughly had 4 – 5mm openings. Next area at the engine intake was a very circuitous path of ducting that created low flow zones allowing the particles to lose momentum and drop to the bottom of the separator where there was an opening for the dust to drop out. Imagine how much air flow had to be conditioned to run through that engine at full mil power. The smaller material behaves like the air and it is not filtered at all.

  6. robroysimmons

    SNAFU is not sold on these, something about the time it takes to land one makes it a slow flying duck and while it is going to the target zone its faster than an attack helo and slower than a jet escort.

    And since I am playing expert after a great night’s sleep, if it is too ungainly to roll off a Gator carrier’s flight deck or come down on a short field it is a colossal waste of cash outside of some sneaky pete uses. Harriers could roll off the decks loaded down (kind of neat to watch them lumber up to the end of the deck and easily take off).

    Anyway if the Ukrainian unwar is any sign of the future forget slow and low flying helos they’re future scorch spots on the ground, the military would be better off investing in Danners for their troops.

    1. robroysimmons

      I got to agree with SNAFU the Corps’ air wing is screwing up the MC big time, they will be lucky to be left with guarding the white house after the misrule of the future Lockheed board of directors guild.

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