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2006-07-22 Science & Technology
Navy Probes Multiple V-22 Surges, Stalls
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Posted by Steve 2006-07-22 11:52|| || Front Page|| [1 views since 2007-05-07]  Top

#1 I'd rather go to Iraq then get on one of these things.
Posted by tu3031 2006-07-22 12:47||   2006-07-22 12:47|| Front Page Top

#2 Acquisition costs of a CH-47 is $35-40 million. A V-22 is $100+ million. Is a V-22 really worth 3 CH-47s just to get a 50% speed increase?
Posted by ed 2006-07-22 13:06||   2006-07-22 13:06|| Front Page Top

#3 gold plated dead bird but no new anti-IED HUMVV replacement
Posted by Clerert Uneamp2772 2006-07-22 13:43||   2006-07-22 13:43|| Front Page Top

#4 #2
Is a V-22 really worth 3 CH-47s just to get a 50% speed increase?


“Unlike conventional rotary wing aircraft, which must be transported into overseas theaters of operation aboard amphibious shipping or heavy lift transport planes, the V-22 can self-deploy thousands of miles over water to get itself to the fight,” Taylor said in the statement.
Posted by Idiom Police 2006-07-22 13:53||   2006-07-22 13:53|| Front Page Top

#5 Great. But it isn't going to assault over thousands of miles. The land assault range is listed at 200nm, amphib assault range 50nm, remarkably similar to the CH-47F.
Posted by ed 2006-07-22 14:07||   2006-07-22 14:07|| Front Page Top

#6 It takes 12 CH-47s to move 180 marines 70 miles and the time required is 2 Hours and 15 Minutes.

It will take 8 V-22s to move the same 180 marines and will only take 17 minutes to cover the 70 miles...

Less time in the air means less death for our boys on the ground...
Posted by Blackvenom-2001 2006-07-22 14:13||   2006-07-22 14:13|| Front Page Top

#7 V-22 will be like the CH-47. Deployed by ship and self deploy only in an emergency, both V-22 and MH-47 can self depoly. After all those hours for self deployment the scheduled maintenance will ground both aircraft and take nearly as much time to repair as it would to ship it. Only in a crisis event where a few could be sent ahead and others to follow will work for this self deployment myth.

As for the compressor stall/surges these are really not as big a deal as it sounds. It is common and they will figure out the inlet or bleed air issues with it. The engines seem to have some issues with compressor blade erosion requiring frequent engine replacement. This is something that can get fixed.

The aircraft still has fundemental flight control issues. These will not get fixed as easy as the engine issues. My vote goes with Ed. We could by a number of 47's for the cost of one V-22. Once the V-22 gets into theater it is limited in mission profile, HUMVV wont fit in it but they will fit into a 47. I believe a 47 will haul more troops as well. This thing is going to turn into an herring.
Posted by 49 Pan 2006-07-22 14:15||   2006-07-22 14:15|| Front Page Top

#8 BV, probably need to redo your math. 70 miles is a hop in both airframes. More like the difference between 20 and 30 minutes here. The real safety issue is when they get to the objective site. The 47 you can fast rope from. CV-22 is still a must land event, this takes time and under fire is critical. The 22 can not get into the confined spaces that a 47 can, I know were talking confined spaces for giant aircraft here. But it can not land on a two lane road and can not let the Marines fast rope from it either.
Posted by 49 Pan 2006-07-22 14:22||   2006-07-22 14:22|| Front Page Top

#9 Huh?
CH-47s: 70 miles and the time required is 2 Hours and 15 Minutes = 31mph. Cruise speed is listed as 143knots. Did you mean 28 minutes?
V-22s will only take 17 minutes = 247mph. Cruise speed is listed as 240knots

Also, the CH-47F lists a higher gross vertical takeoff weight (54,000 lbs, http://www.boeing.com/rotorcraft/military/ch47d/docs/CH-47F_overview.pdf) than a V-22 (47,500 lb, http://www.fas.org/man/dod-101/sys/ac/v-22.htm)


For the cost of 8 V-22s, 24 CH-47s can be bought. That means twice as many troops landed in the same time, or money left over to buy equipment to suppress enemy defenses. Maybe I am naive, but we seem to be getting to point where we have so few assets can no longer afford losses, whether combat, accidents or maintenance down time.
Posted by ed 2006-07-22 14:32||   2006-07-22 14:32|| Front Page Top

#10 49Pan, do you fly CH-47s? I'm not sure the compressor blade erosion problems can be fixed. The engines looks like they have such large air requirements that they cannot use filters, unlike helicopters. During low hover or landing the engines have to be sucking in mass quantities of bad things.
Posted by ed 2006-07-22 14:44||   2006-07-22 14:44|| Front Page Top

#11 Nope, I flew MH-6's. But I've been blown aroud by them on many occasions! The inlet on the V-22 looks to me like an airplane design with that bottom inlet, and your right a giant dirt sucking device. Your right on the second point also, a barrier filter would be a monster. Time for the engineers to get back to work. I would expect until they can fix it they will limit the bird to hard stand take offs and landings. I heard they are going through compressor sections at a surprising rate. I really don't think they will ever kill this aircraft program. I think it will take a few generations of engeneering to get it combat ready and I think the combat roll will slide away from Direct Action to Logistical Support.
Posted by 49 Pan 2006-07-22 15:00||   2006-07-22 15:00|| Front Page Top

#12 I think the combat roll will slide away from Direct Action to Logistical Support

Interesting. Thanks for sharing your experience.
Posted by ed 2006-07-22 15:20||   2006-07-22 15:20|| Front Page Top

#13 http://www.navair.navy.mil/v22/index.cfm?fuseaction=news.detail&news_id=148

Well this is where I got my info from... maybe I shouldn't believe everything I read... hmmmmm... what a novel idea
Posted by Blackvenom-2001 2006-07-22 16:46||   2006-07-22 16:46|| Front Page Top

#14 Ooopss I also see that the article I was referring too...was talking about the CH-46s and not the CH-47's which are a lot larger... man I got to quit drinking so much coffee.
Posted by Blackvenom-2001 2006-07-22 16:49||   2006-07-22 16:49|| Front Page Top

#15 No worries. The real issue is that the Marines, who from my Army perspective deserve nothing but the very best. I'm afraid they will get the V-22 instead. We can all do better than this.
Posted by 49 Pan 2006-07-22 21:00||   2006-07-22 21:00|| Front Page Top

#16 Sounds like a variable stator vane or variable bleed valve problem disrupting airflow through the compressor.
Posted by tzsenator 2006-07-22 22:48||   2006-07-22 22:48|| Front Page Top

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