Scantlings

Another fatal incident off the coast of OZ. Nine hull-loss incidents in 26 years doesn't sound atrocious, but on the other hand, it seems like a lot. So, questions for all you pilots (and non-piiots too):

- is this aircraft more crash prone than any other military aircraft?
- are the crashes operator error, or a design defect?
- are VTOL and STOL aircraft inherently more dangerous than rotary wing and fixed wing aircraft? (I suspect the answer is DEFINITELY)

I could research this but I'm too lazy and besides, would rather hear what you guys say.

Tim Ford wrote:Another fatal incident off the coast of OZ. Nine hull-loss incidents in 26 years doesn't sound atrocious, but on the other hand, it seems like a lot. So, questions for all you pilots (and non-piiots too):

- is this aircraft more crash prone than any other military aircraft?
- are the crashes operator error, or a design defect?
- are VTOL and STOL aircraft inherently more dangerous than rotary wing and fixed wing aircraft? (I suspect the answer is DEFINITELY)

I could research this but I'm too lazy and besides, would rather hear what you guys say.

Tim

Unfortunately, I know far too much about the Osprey and it's frailties.

More Crash prone than any other military aircraft? No but not on the "safe as a church" end of the spectrum

Generally causes are operator driven but the airplane can really suck you in.

Are vtol/stol inherently more dangerous? No but they have flight characteristics that put them into single point of failure mode on every flight.

Biggest problem with the osprey is it's neither fish or fowl. It is a tilt rotor, the first operational one and it has the aerodynamic properties of a tilt rotor. Lots of discussion on how to train a pilot for an Osprey as there are learned behaviors in helicopters and in fixed wing aircraft that can kill you in the Osprey. Biggest danger area, and one involved in several accidents, is what is referred to as "vortex ring state". Basically a descending, lifting rotor can enter into a ring of sinking air (help pilots call this settling with power). More power just means a faster descent. You actually have to fly forward out of your own downwash to escape. In a two rotor helicopter, the fore and aft balance is such that the forward rotor gets into it first, dropping the nose and encouraging forward flight out of the condition.

In the Osprey, entering VRS can happen to either rotor first and results in a dramatic roll off. Solution is pretty simple. There is a hard restriction against descending more than 500 fet per minute at less than 80 knots airspeed. Obey that and you stay out of VRS. Unfortunately some helo tactical maneuvers can take you very close. Try those in an Osprey and you might die. Do you train an Osprey pilot in fixed wing aircraft with a helo transition or a helo pilot with a fixed wing transition? We had a lot of trouble deciding that. Biggest issue is ingrained behaviors. In a helo, when bad things start to happen, you put it on the ground in the nearest clearing. In fixed wing, altitude is life and you climb to give yourself options. What do you do in the Tilt Rotor?

On the other hand, I've not seen a better integrated cockpit. My kids stepped into the full fidelity simulator and flew it with just rudimentary instruction - at 9 and 11 years old. The two rotors have a torque connection (failure of that was cause of one crash) so a single engine failure keeps both proprotors powered. The capabilities are a game changer for the marines for vertical landing in unprepared lz's and transit (including refueling) at 275-300 mph, 3 times the speed of a helo. Getting somewhere with a load of troops, evacuating a casualty or just plain maneuvering in the battlefield is changed by the presence of Ospreys.

As a first of its kind, we will learn, unfortunately by killing folks on occasion. Haven't heard any rumors on this one yet (good friend is the Deputy PM but you don't ask at this point). Marines have decided they want the goods and will risk the not so goods to get them.

I'll point out that most at sea landing accidents are caused by aircrew error.

Larry & Tim,

My kid, the Marine, says the Osprey is the best! The grunts like getting places fast, but also getting AWAY fast. As he puts it: "There are so many things that are 100 times more dangerous than flying in an Osprey, why worry? The only reason you're asking, Dad, is because you don't know about the really scary shit. We love Osprey."

I just moan and close my eyes.

B

BeauV wrote:Larry & Tim,

My kid, the Marine, says the Osprey is the best! The grunts like getting places fast, but also getting AWAY fast. As he puts it: "There are so many things that are 100 times more dangerous than flying in an Osprey, why worry? The only reason you're asking, Dad, is because you don't know about the really scary shit. We love Osprey."

I just moan and close my eyes.

B

Beau,

For marine leadership, it comes down to the battfeild flexibility. And the Osprey is a winner hands down. Add in the Frog (CH-46) was on its last legs and the Osprey looks great to a company Commander.

I'm caught in the middle. I've been a part of reviewing several Osprey accidents and a close friend lost her husband (and our neighbor) in one so every accident is a renewed trauma for her. Of the 3 accidents where I have "insider knowledge", 2 were material failure leading to an unflyable aircraft and one was a combination of pilot error and command/leadership error. For an aviator, reviewing each data set of a strip chart and then running a slow speed and real simulation of the crash while listening to cockpit tapes is not a lot of fun, particularly when you know the result is that the people die.

Larry, thanks for those insights. I can completely understand the pain of sorting through that sort of data. Yuck! Thank you for doing that sort of job, it must be seriously painful.

I'm always amazed at the attitude of the Marines when it comes to the loss of life. Everything I have is just second hand: my son and his friends talking. There is also a serious amount of "Don't get my Marines killed!" mixed in coming from the commanders. I suppose that some of what I hear is the bravado of young people.

Your description of the problems one can have flying into one's own downwash is really interesting! I can certainly see an aggressive pilot making that error trying to get his passengers on to the ground quickly under fire. A friend was a chopper pilot in Vietnam and talked about hitting the ground so hard coming in under fire that he compressed a disk in his back. It's easy to say: "Don't fly like that." to someone, but I can easily see the pressure of battlefield action pushing that missive out of one's mind.

BeauV wrote:Larry, thanks for those insights. I can completely understand the pain of sorting through that sort of data. Yuck! Thank you for doing that sort of job, it must be seriously painful.

I'm always amazed at the attitude of the Marines when it comes to the loss of life. Everything I have is just second hand: my son and his friends talking. There is also a serious amount of "Don't get my Marines killed!" mixed in coming from the commanders. I suppose that some of what I hear is the bravado of young people.

Your description of the problems one can have flying into one's own downwash is really interesting! I can certainly see an aggressive pilot making that error trying to get his passengers on to the ground quickly under fire. A friend was a chopper pilot in Vietnam and talked about hitting the ground so hard coming in under fire that he compressed a disk in his back. It's easy to say: "Don't fly like that." to someone, but I can easily see the pressure of battlefield action pushing that missive out of one's mind.

http://www.globalsecurity.org/military/ ... 22-vrs.htm

Beau,

Technically factual (but written by a non advocate of V-22 who drove us crazy in 2000-2001) explanation of VRS in the V-22. My friend's husband was the pilot or the Marana aircraft that resulted in 19 dead. Part of the problem is budget pressure in a flight test program. Prior to Marana, the program team knew you could fall off the edge of the earth and set a very conservative flight limit to allow testing to continue while more funds were sought and flights planned to dig closer to the edge. The Marine operational testers knew the limits were conservative and started violating them, putting themselves closer to the edge. On the mishap flight, the flight lead started a late descent and the winds over the LZ ended up a slight tailwind rather than the forecast slight headwind. That created a steep descent angle. The mishap aircraft was the wingman and having trouble maintaining position, not recognizing the extremist situation his flight lead put him in.

All very understandable from a tactical, mission focused perspective but essentially the entire descent was outside approved flight conditions. Would you be happy if your United pilot flew an approach in a "we'll either land safely or all die" mode?

That's the challenge. John got put in a fatal box by his flight lead but the command climate that "those limits are BS and we know better than the development community" meant his copilot (nor the crew in the lead aircraft) did not recognize the imminent crash and let the inevitable happen. Lots of work since then to characterize the flight condition and provide warnings but there is still a "don't go there" place in the envelope.

It's why I stress that tilt rotors are different from both fixed wing and helicopters. We did Ourselves a disservice with the sales pitch that it takes off and lands like a helo and transits like a fixed wing. What it does is fly like a tilt rotor.

I'm an Osprey believer but we have to understand it's limitations as well as embrace it's strengths.

Thanks, I'll read this later today when I get a break. Nice to learn this stuff.

Thanks fellows, excellent info. Thanks for taking the time.

I just saw on the morning news that five F-15s have crashed in the past few years, so maybe the Osprey gets a bad rap.

But thanks for a great read and one helluva lot of info!

Larry,

Do you think a jet version of the Osprey would be superior? Is it feasible?

Ajax wrote:Larry,

Do you think a jet version of the Osprey would be superior? Is it feasible?

Could it be done? Sure, but vertical flight is all about mass flow and turboshaft driven rotors are very hard to beat.

Wait, let me rephrase the question-

The marine F-35 variant has VTOL capability. Some sort of large fan with a lid that opens. That's not a "jet," I understand.
What if a similar system of these fans were incorporated into a fixed-wing craft? Would it eliminate the VRS?

Always interesting reading your insights on these things Larry.

A mutual friend of a few on here is working on this program. Was quiet about it for quite awhile until it finally hit the news. https://www.darpa.mil/news-events/2016-03-03

Ajax,

The lift fan in the F-35B is what shut Boeing out of the competition. The mass flow from that gearbox and shaft driven axial fan provides substantially more vertical "thrust" than the reaction jets on the Harrier and proposed by Boeing for their F-37 variant.

It also provides more than a dozen single point of failure components that must work. Failure of just one means the pilot has a couple of seconds to eject before the airplane will crash. Makes the safety nazis crazy but so far, LM has delivered on reliability.

Slick. Aurora has some smart folks. Notice that they still rely on turbothrust with multiple axial fans. V-22 could easily be described as a "you don't have to be best. Being first has a strength all of its own.

Can you tell I'm between appointments at the hospital today and not in the office?

This place has an amazing array of smart, talented, knowledgeable people.
I come here for the educational benefits.

kimbottles wrote:This place has an amazing array of smart, talented, knowledgeable people.
I come here for the educational benefits.

Me too ..

LarryHoward wrote:

BeauV wrote:Larry & Tim,

My kid, the Marine, says the Osprey is the best! The grunts like getting places fast, but also getting AWAY fast. As he puts it: "There are so many things that are 100 times more dangerous than flying in an Osprey, why worry? The only reason you're asking, Dad, is because you don't know about the really scary shit. We love Osprey."

I just moan and close my eyes.

B

Beau,

For marine leadership, it comes down to the battfeild flexibility. And the Osprey is a winner hands down. Add in the Frog (CH-46) was on its last legs and the Osprey looks great to a company Commander.

I'm caught in the middle. I've been a part of reviewing several Osprey accidents and a close friend lost her husband (and our neighbor) in one so every accident is a renewed trauma for her. Of the 3 accidents where I have "insider knowledge", 2 were material failure leading to an unflyable aircraft and one was a combination of pilot error and command/leadership error. For an aviator, reviewing each data set of a strip chart and then running a slow speed and real simulation of the crash while listening to cockpit tapes is not a lot of fun, particularly when you know the result is that the people die.

Larry,

Thanks for the article, I forwarded it to my son. He let me know that even he had heard about this problem. At least the word is getting out. He then responded with something like: "If we could get in and out of places faster on choppers, we'd choose those. If we could land/take-off C-130s wherever we're going, we'd choose those. The Osprey is loved because of what it lets us do. It is NOT loved because it's a great aircraft. A C-130 is a GREAT aircraft."

Slick470 wrote:Always interesting reading your insights on these things Larry.

A mutual friend of a few on here is working on this program. Was quiet about it for quite awhile until it finally hit the news. https://www.darpa.mil/news-events/2016-03-03

Hah, yes I was thinking about him too, Andy, especially when Rich chimed in about the fans. I remember one of his first UAV projects, it was like a flying air conditioner compressor.

BeauV wrote:

LarryHoward wrote:

BeauV wrote:Larry & Tim,

My kid, the Marine, says the Osprey is the best! The grunts like getting places fast, but also getting AWAY fast. As he puts it: "There are so many things that are 100 times more dangerous than flying in an Osprey, why worry? The only reason you're asking, Dad, is because you don't know about the really scary shit. We love Osprey."

I just moan and close my eyes.

B

Beau,

For marine leadership, it comes down to the battfeild flexibility. And the Osprey is a winner hands down. Add in the Frog (CH-46) was on its last legs and the Osprey looks great to a company Commander.

I'm caught in the middle. I've been a part of reviewing several Osprey accidents and a close friend lost her husband (and our neighbor) in one so every accident is a renewed trauma for her. Of the 3 accidents where I have "insider knowledge", 2 were material failure leading to an unflyable aircraft and one was a combination of pilot error and command/leadership error. For an aviator, reviewing each data set of a strip chart and then running a slow speed and real simulation of the crash while listening to cockpit tapes is not a lot of fun, particularly when you know the result is that the people die.

Larry,

Thanks for the article, I forwarded it to my son. He let me know that even he had heard about this problem. At least the word is getting out. He then responded with something like: "If we could get in and out of places faster on choppers, we'd choose those. If we could land/take-off C-130s wherever we're going, we'd choose those. The Osprey is loved because of what it lets us do. It is NOT loved because it's a great aircraft. A C-130 is a GREAT aircraft."

Beau,

That's the point. Despite its limitations, the Osprey provides Marines with a capability they don't have without it. It's incumbent on the aviators to stick within its limits. Unlike those detractors who believe asymmetric VRS should be a show stopper to operational use, it's representative of tilt rotor aerodynamics in a similar manner to fixed wing aircraft experiencing an approach turn stall. Every aircraft has aerodynamic "don't go there" portions defining the edge of the envelope. The Osprey can bite. Unfortunately, that happens during a portion of flight where helicopters perform better. Ok. If the mission required a hot entry and steep descent, don't use an Osprey in the same way that you don't climb into a Huey to go 300 miles quickly.

Sometime in the wee small hours, Sunday morning, coming back from St Marys City, we were off PAX and a C-130 circled in just over us and went on in for a night landing. Man, it was awesome, and not what we were expecting off Cedar Point at 1 am.

It seems that the Marines have called a 24-hour pause in aviation operations so folks can think about safety. The recent Osprey accident followed by a C-130 crash seems to have precipitated this.

http://www.npr.org/sections/thetwo-way/2017/08/11/542894245/following-recent-crashes-marine-corps-orders-pause-in-flight-operations?utm_source=twitter.com&utm_campaign=npr&utm_medium=social&utm_term=nprnews

One of our ex-junior race team kids now fly's them for the Marines. Good kid and very smart, the marines are picking right by picking him.

Ajax wrote:Wait, let me rephrase the question-

The marine F-35 variant has VTOL capability. Some sort of large fan with a lid that opens. That's not a "jet," I understand.
What if a similar system of these fans were incorporated into a fixed-wing craft? Would it eliminate the VRS?

IIRC, when the F35 was in the prototype stage, there was an incident that was like VRS in that it happened at very low altitude and involved the ground interfering with the air stream.