Recently I was thinking about how important is to hide the first stage of an engine compressor for stealthiness purposes. Remember the famous grid on F117 and the "S" lead of F23 and F22 to prevent the enormous echo doppler caused by moving parts?..
Now, take a look to F117's, B2's and YF23 nozzles and compare them whit the relatively conventional ones of F22: Last stage of turbine is still visible..
Well, the question is: then when the raptor is observed from behind (when it's backing home) how stealth is?...
Sponsor
Posted: Jul 24, 2008 - 3:52 PM
F-16.net Sponsor
This message from our sponsor will disappear if you log on as a member.
Raptor_One
Posted: Jan 20, 2007 - 08:21 AM
Elite
Joined: Aug 19, 2004
Posts: 1086
Location: New York, NY
The 2D thrust vectoring nozzles have a stealthy design which reflect some of the radar energy. The nozzles also conceal a good portion of the aft turbine section when in cruise/supercruise. Less so in AB. It's a design compromise. The F-22 will not be as stealthy from the rear as from the front.
loflyn
Posted: Jan 20, 2007 - 05:30 PM
Regular User
Joined: Oct 12, 2005
Posts: 21
Status: Offline
Take a look at Jay Miller's Aerofax: Lockheed Martin F/A-22 Raptor, pages 107 and 127. There's a 'feature' in the afterburner that takes care of this. I'll just say that the turbine is NOT directly visible from behind.
apags27
Posted: Jan 20, 2007 - 05:43 PM
Active member
Joined: May 02, 2005
Posts: 152
Location: AZ
Status: Offline
Luckily not to many things would be able to catch up to the Raptor.
Luckily not to many things would be able to catch up to the Raptor.
Exactly. Anything not already destroyed when the Raptor is ingressing would be at a serious disadvantage trying to chase down a supercruising raptor on it's way home. The constant high speed shrinks the engagement envelope.
sferrin
Posted: Jan 22, 2007 - 07:47 PM
Elite
Joined: Jul 22, 2005
Posts: 914
Status: Offline
Radar blocker in the tail pipe. Check the radar blockers in the Super Hornets intakes. Same concept.
Isn't it the point to not leave anyone alive to be able to view it from behind? LoL
_________________ Crew Chief
Mountain Home AFB 2000-2005 ~ Acft 91-0370
Sheppard AFB 2005- NOW
www.myspace.com/mechfromhell
idesof
Posted: Jan 25, 2007 - 08:59 PM
Elite
Joined: May 29, 2006
Posts: 640
Status: Offline
checksixx wrote:
You won't get a pic Neno... it doesn't exist...
Not true. Jay Miller's F-22 book is loaded with pictures of the Raptor's a$$ in its last pages with a clear view inside its engines. It certainly does not look like any engine I've ever seen from that perspective...
sferrin
Posted: Jan 26, 2007 - 02:58 AM
Elite
Joined: Jul 22, 2005
Posts: 914
Status: Offline
idesof wrote:
checksixx wrote:
You won't get a pic Neno... it doesn't exist...
Not true. Jay Miller's F-22 book is loaded with pictures of the Raptor's a$$ in its last pages with a clear view inside its engines. It certainly does not look like any engine I've ever seen from that perspective...
It's in there. I remember reading about it in AvWeek a couple years back. I've got the Jay Miller book too. It's definitely got the blockers in there. Unless "checksixx" actually works on them and they've decided to remove them all (which makes no sense). On the other hand it could be a "fit in time of war" item or something I suppose.
"Lockheed has been working diligently with Pratt & Whitney to reduce the infrared, acoustic, and radar signatures of the JSF engine. In addition, knowledge acquired in the F-22 program undoubtedly will be integrated into the JSF. Specifically, experts speculate that the F-22 engine exhaust radar blocker will be applied to the JSF as well. Engineers have toiled to develop a device to block the radar return of the exhaust cavity and simultaneously survive the extreme temperatures (Fulghum “Stealth is Still…” 46)"
Not true. Jay Miller's F-22 book is loaded with pictures of the Raptor's a$$ in its last pages with a clear view inside its engines. It certainly does not look like any engine I've ever seen from that perspective...
It's in there. I remember reading about it in AvWeek a couple years back. I've got the Jay Miller book too. It's definitely got the blockers in there. Unless "checksixx" actually works on them and they've decided to remove them all (which makes no sense). On the other hand it could be a "fit in time of war" item or something I suppose.
I worked with the Raptor's and I can't believe your comments. In your own pic you decided to link to its very clear what those are. I can confirm that your super secret RADAR blockers are in fact 'tail-pipe plugs' with remove before flight streamers. They put those in...kind of like intake covers...to keep out FOD. You may not want to believe everything you read...
sferrin
Posted: Jan 26, 2007 - 07:45 PM
Elite
Joined: Jul 22, 2005
Posts: 914
Status: Offline
checksixx wrote:
I worked with the Raptor's and I can't believe your comments. In your own pic you decided to link to its very clear what those are. I can confirm that your super secret RADAR blockers are in fact 'tail-pipe plugs' with remove before flight streamers. They put those in...kind of like intake covers...to keep out FOD. You may not want to believe everything you read...
LOL. Well those definitely aren't what I'M talking about. Go take a look at a picture of the radar blocker in the inlet of the Super Hornet. They look somewhat like that. And I definitely know what the rear end of an afterburning turbofan looks like WITHOUT them.
checksixx
Posted: Jan 26, 2007 - 08:23 PM
Elite
Joined: Jul 20, 2005
Posts: 1021
Status: Offline
Well I've looked into the tailpipe's of Raptor many times and I can tell you that I've never seen anything other than the augmenter section rear end...The fact that you posted the pic which clearly shows an ordinary everyday item and then changed your tune..."LOL. Well those definitely aren't what I'M talking about."....makes me wonder just what you are talking about. For those of us that actually know what the tailpipe in a Raptor looks like, post a pic of what your describing for us...