Of course CDI is against the program...although they portray themselves as a "non-partisan" group, they are a who's who of liberal democrat fundraisers. They originated from the 1970's Fund for Peace. CDI's next target is the F-22 program. Keep an eye open; they have it in for ALL defense spending.

Posted by: MrsDigger at October 4, 2007 10:13 AM

vortex ring state can be avoided in the osprey! just by rolling the nacelles down. what other helo can do that? i will admit i was scared to death to fly on the osprey at first. but after taking my time to learn the aircraft by working on it, not reading about it. i have come to love this airframe. the possibilities are endless and alot of lives are going to be saved because of this aircraft. just ask anyone who has worked on them. flying in the Marine Corps is 100% volentary so no one would fly on it if they did not feel safe!!!

Posted by: osprey crew chief at September 5, 2007 08:50 AM

"The surviving engine doesn't "take over instantly". The rotor drive trains are mechanically linked. Unless the drive train breaks, both rotors always stay at the same rpm."

Really? What's all this about then: "Under normal operating conditions, each proprotor gearbox is powered by the nearest engine via the engine output shaft. In the event of engine power loss, the proprotor gearbox associated with the failed engine receives power from the opposite engine through the interconnect drive system." (http://www.globalsecurity.org/military/systems/aircraft/v-22-survive.htm) ?

I agree that the surviving engine won't take over instantly--but that seems to be the hope.

You cheerleaders should see if you can't qualify as aircrew on them. Then it'd be *your* lives on the line too. There's nothing like risking your very own one-and-only personal butt to motivate a re-think about what's 'acceptable'.

Posted by: Mairead at January 30, 2007 05:04 AM

"In an Osprey, Vortex Ring State causes it to roll and crash, as only one prop loses thrust."

How is that different than a Phrog, which also has two rotors? The only difference is front/back versus left/right.

"Moreover, the Osprey's surviving the loss of a single engine during STOL operation depends on the fragile technology of the surviving engine being able to take over *instantly* and drive both propellors strongly enough to prevent a fatal roll."

The surviving engine doesn't "take over instantly". The rotor drive trains are mechanically linked. Unless the drive train breaks, both rotors always stay at the same rpm. This is similar to the system on a Phrog, which as noted above also has two rotors, with all the same issues surrounding maintaining power to both rotors. The fact that the Phrog's rotors are front/back versus left/right provides absolutely no safety advantage (at least not in regards to powering the rotors). If the Phrog lost lift in one rotor, it would flip and crash. If the Osprey lost lift in one rotor, it would roll and crash.

"blackhawk's climb/descent rate, I believe, is 2000 feet/minute"

That sounds at least 50% too high.

Posted by: chuck at January 29, 2007 10:22 PM

Will more soldiers die in Ospreys because the pilot descended too quickly despite additional equipment, software, and training? Yes but not in numbers significantly different than combat helicopter losses.

The osprey is a revolutionary aircraft. It offers the ability to self deploy, use aerial refueling, with longer range and reduced susceptibility en route to the fight at the price of additional vulnerability to ground fire when deploying troops compared to a dual engine heavy copter (IMO). As long as it's used intelligently, it is well worth the trade off and should ultimately save lives.

Posted by: Nathan at January 29, 2007 12:19 PM

Glide? You must be joking. My field isn't aeronautics, but one look at that wingspan tells me it will glide like a rock.

The gliders used as assault transports in WW2 had only a 1:10 glide angle because of their limited wingspan, compared to 1:22 for standard gliders. But even their wingspan was on the order of 2X the Osprey's, and their airframe was much closer to a traditional glider's airframe: fabric-covered wood and light metal tubing stringer construction, no engines.

Moreover, the Osprey's surviving the loss of a single engine during STOL operation depends on the fragile technology of the surviving engine being able to take over *instantly* and drive both propellors strongly enough to prevent a fatal roll.

Don't kid yourself. That thing is nothing but a disaster with engines. If it goes into production, all the contractors and the uniformed program staff will be living off the blood of the Marines it kills.

Posted by: Mairead at January 29, 2007 10:20 AM

The Osprey does both (windmill and glide) however. In a catastrophic failure of both engines (which there is a very slim possibility of happening) it can do either/both. Remember in a autorotation, it is not just a straight down descent!! In fact, that would destroy a helicopter quickly when it hit the ground. There is a forward component to it as well, something the Osprey is better suited to take advantage of because it has wings. The wings dont fall off that easily. Plus as previously mentioned, the Osprey can totally lose one engine and still keep on flying. Again, this is an advantage that most US helicopters do not share. Helicopters also have a very vulnerable tail rotor, unlike the Osprey. If that thing quits, you are in a world of trouble as well. It "guarantees a catastrophic failure". Plus many US Helicopters are vulnerable to a phenomena known as mast-bumping, where literally the rotors do fall off the helicopter. The Osprey does not exhibit this phenomena due to the structure of its rotor hub. So, I do not see what is so catastrophic about failure in the Osprey. Please provide specifics next time, particularily as compared to similar helicopter/plane malfunctions.

Any way you put it, aviation is a dangerous game. Particularily in helicopters where the margin for error is small and the things that can go wrong are multitudinous. Our current generation of helicopters as well are ancient things that are reaching the end of their lives for the most part, and the Osprey represents a much safer alternative. I pay attention to the Class A mishap reports... do you?

Posted by: tz at January 28, 2007 02:26 PM

Any engineer worth the name knows that failures are guaranteed. It's the nature of the physical universe. So a big engineering task is always to change catastrophic failure into survivable failure.

The Osprey guarantees catastrophic failure by design. If it cannot windmill down, and it cannot glide down, then any time something happens to one of the propulsion subsystems, that aircraft and its occupants are dead.

The effect is the same as if, in a conventional aircraft/helicopter, engine failure were to result in a wing/rotors falling off. How many such aircraft would ever be accepted for duty?

This is not rocket science.

Posted by: Mairead at January 28, 2007 09:34 AM

>There is already a ramp-mounted M-240 and they are (I think) reviving a 20mm chin gun similar to
>the Cobra's. This was put on hold during development. I have talked to many of the current
>pilots and a large number of phrog guys who all are big fans, and have a ton of confidence in it.

I've heard that the plan to add weapons was uphold, but I never heard any news afterward. Thanks for the comment that it sound like it's being reconsidered. There are also other considered alternatives and plans. These include V-22 tilt rotor escort, UAV, and directed energy weapon. The rotor on the side is just in a bad place to add weapons on the wings. I would love to see an AV-22 with some missiles (including stinger missile) and rocket pods added, something similar to the Russian Hind where you could provide close air support for the troops it dropped.

Posted by: pedestrian at January 26, 2007 09:39 AM

The deal about vortex ring state and the Osprey is not a big deal. The Osprey is just as, if not less susceptible to it as any other helicopter is. In fact, the only reason they really were having a problem with it in the first place, and one of the contributing factors to that Class A mishap where all those Marines were killed was that the Marine Corps was transitioning both fixed and rotorary winged pilots to the Osprey. Some of the fixed wing pilots were not as familiar with VRS as the helo guys were and therefore unsafe in the aircraft. This has since been remedied by extra training and safety aids. As they say, NATOPS is written in blood. Also, as for rotor down landing, this is possible in an ELP scenario to do safely. The rotors break away away from the body of the aircraft. Furthermore, it is handleable in single engine scenarios, unlike the Phrog (CH-46). Finally, the room inside it is larger than the CH-46 and they are working on getting it defensive weaponry. There is already a ramp-mounted M-240 and they are (I think) reviving a 20mm chin gun similar to the Cobra's. This was put on hold during development. I have talked to many of the current pilots and a large number of phrog guys who all are big fans, and have a ton of confidence in it. Its range additionally gives us more training opportunities as you can get more Xs out per hop. I also have been on one several times, and have been impressed each time. That large crash and the time it has taken to develop have just given it a bad rap. Plus CDI is known to be a luddite almost anti-military think tank. The technology involved in it is so new, it is a wonder that it has gone so well!! Any new technology has growing pains. Look at the F-14, Blackhawk, M-2, F-18, etc. and you will see a difficult birth. Most of these are now tried and true members of the military, but went through developmental phases that involved sometimes several crashes. However, the F-18 and F-14 are single or dual seat aircraft, which were being flown by test pilots, so people hardly noticed. However, when you have a dual piloted aircraft with 1 or 2 crewchiefs/aircrew and 30 guys in the back, this creates much more of a stir! Hence the subsequent bashing of the Osprey.

PS- the speed isnt the capability the Marines are most excited about. While nice, and you are hard to hit, the big thing is the range and payload it gives. When you are flying almost always from a boat to your destination, it gives the Marine Corps much more of a reach to things like Embassys and other targets. The oft cited example used by my Osprey peers was the Iran hostage crisis. The entire mission could have been flown with room to spare and no dicey refueling in under one night with 6 hours of planning for the air side. Now tell me that isnt a useful capability!

Posted by: tz at January 25, 2007 11:09 PM

Check out this response to the article here from www.airwarriors.com a forum for naval aviation.

http://www.airwarriors.com/forum/showthread.php?t=134138&highlight=v-22
http://www.airwarriors.com/forum/showpost.php?p=292855&postcount=48

This guy seems to be obsessed with VRS, as if it was a new phenomena that the V-22 discovered a couple of years ago. He briefly touches on other topics, but he keeps pounding the VRS drum. He does the tricky "converting fpm to mph" math to try to make it sound as if this aircraft is creeping into an LZ. I suppose that if we were to park a V-22 at 1000' directly over a zone and descend vertically down, 800 fpm would seem slow. The V-22 is actually harder to get into VRS than conventional helos--the 800fpm gives A LOT of margin. It also has a rate of descent warning system to let you know when you're hitting the limit.

The author goes on to state that the rate of descent limits prevent aggressive manuevering to avoid threats in the zone. One, he's obviously not a pilot. Not a whole lot of radical jinking goes on during short final. The die is cast at that point--either you're landing or you're waving off. Regardless, he forgets that one can have his own opinion, but not his own facts. Considering that manuevering limits for the V-22 in nearly all regimes at a minumum exceed the CH-46's (I make this comparison because I was a phrog guy), I fail to see how he can reach this conclusion. Moreover, in the true test of manueverability--changing energy state--the V-22 blows any other rotorcraft away. This is where the picture of V-22s inching into the zone is destroyed by facts. We can be coming in at well over 200 knots to within a couple miles of the LZ, land (with a turn on final too, even, if you want), and transition back to APLN going over 200 again within a mile of the other side.

He dilutes his points by criticizing the APR-39 (V2), as if this is proprietary V-22 technology. Guess what--that's the standard the fleet is going to. Drop that complaint elsewhere. He further exposes his lack of flight experience by confusing IR and RF signatures in regard to the "stealth paint" and the disc reflectivity (guess those 51' rotors on the 46 were invisible to radar). He also misunderstands the use of a threat warning system, implying that a pilot would use it coming into a zone trying to correlate threats to a map. Crap. You need type and direction for avoidance, which is what the system gives.

As far as engine failures are concerned--the Osprey has an advantage a helo doesn't--it can transition and get wingborne lift. It can fly in APLN single-engine in most weights and conditions. Time means options--dump fuel, go to a runway, etc. Yeah, when you land you'll have about half the power you did before--well no sh!t, Sherlock, it's a 2-engine aircraft. This business about a regular helo storing energy for a SE landing is crap--he's confusing single-engine with autos.

Just some rants. These critics are like whack-a-moles. You keep pounding, they keep popping up. If it were up to these critics, we'd still ride to battle in massed formations on horseback--simple, reliable, not subject to vortex ring state.

Posted by: raptor10 at January 25, 2007 05:21 PM

I like the promise of the Osprey, but I see a huge flaw...the Osprey with its current tilt-rotor design is forced to land like a helicopter. Correct me if I'm wrong, but it seems that no matter what the situation, as it comes in for a landing, the Osprey's wings must tilt upward.

Can no one imagine that in combat situations, such an orderly landing might not be possible? The Osprey really needs to be able to land like a regular plane, belly down OR as a helicopter.

My fear is that the survivability in a crash or forced landing will be very, very bad because rotor design.

Posted by: Paul at January 25, 2007 03:09 PM

Years back I was driving into Washington DC when an Osprey and what I thought was a Chinook (realize now it was probably a Frog) came buzzing low and fast overhead down 395.

They crossed around the 14th street bridge and chased each other all over the city. I remember think in "I hope that thing (osprey) doesn't fall out of the sky!"

I'm pretty skeptical about the Osprey, but here's hoping it pans out.

Posted by: Philip Shade at January 25, 2007 02:47 PM

Good post, I'm looking forward to the rest of the series.

Posted by: TrustButVerify at January 25, 2007 12:29 PM

There are a couple worries I have (again, as total unprofessional observer).

The cure for vortex ring state is a (I believe software) limited descend rate of 800 feet/minute (9 mph). Which is more important in the helecopter's mission: vertical or horizontal speed? A blackhawk's climb/descent rate, I believe, is 2000 feet/minute (22 mph). [1]

Also, the downwash of the propellers is by definition much worse than a standard helecoptor, nothing can be done about that.

OTOH, the greater range and horizontal speed do seem to be a big benefit.

My biggest concern however, is what could have been bought by the marines instead? Would giving up only 100 MPH in straight line flight (and therefore using a conventional helecoptor) have allowed a vehicle which would have cost 1/5th as much?

[1] The bigger concern is that you really can't push this. On a conventional helecopter, at high altitude you can easily recover, and low altitude you smack the ground vertically. Owch but not necessarily catastrophic. In an Osprey, Vortex Ring State causes it to roll and crash, as only one prop loses thrust.

Posted by: Nicholas Weaver at January 25, 2007 12:12 PM