Posted: 9/17/2006 1:07:00 PM EDT
| So I'm looking at my 1/48 model of the F-22 and the 20mmc annon has a diamond-shaped panel above the wing that is supposed to open to allow the gun to fire without compromising Stealth. Head-on however, there does not seem to be much clearnce for the shells to clear the wing by much, especially if fired while pulling G's. Could be an effect of the model and the scale, but there just doesn't seem to be much room there, given the thickness of the skin. So, is the gun retractable when not in use? Can't find any info on this...apparently, on the F-22 the cannon is an after-thought. |
I'm sure the engineers have it all figured out. And no, it was not an afterthought. I personally love the "I noticed something on a model and I think it might be a problem" attitude. 
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| I think you can chalk it up to the model not being able to fully replicate the contours of the jet. In the photos I've seen that clearly show the cannon port (and there really aren't that many), it looks like there's juuuuuuust enough room for the projectile to exit. |
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1) The gun was designed in from day 1. 2) The gun is fixed. 3) The door opens inward. (doesn't look thast way to me though). 4) Stealth is compromised when the gun is fired. Stealth is not compromised when gun is not in use. Answers from a friend who worked on the program. |
I'll see your toy 20mm pop gun and raise you a Mauser BK27 or GSh-30-1 ANdy 
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You'll need exactly 20mm of clearance. at 1/48 scale that's about half a milimeter. The gun is also probably pointed up a couple of degrees. It's going to look a little weird on a model. I assure you, it works. Matt |
| I really don't think the OP thought, even for a minute, that he had stumbled across some deep hidden truth about a massive flaw in the F-22 program. I think he was looking for more information about this particular feature that is not really well-rendered on the model. |
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Gun footage starting at 1:15. video.google.com/videoplay?docid=-6412839466457907763&q=f-22&hl=en |
Not near the ego it takes to be an ass to someone trying to understand how something works. Remember, there are no stupid questions. |
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Gee, thanks mr. Garrison |
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So, I'm an asshole; no surprise to those who know me. Here is an interesting reprint of an article that was first printed in 1991: http://www.sci.fi/~fta/atf-2.htm The gun was a requirement from the start. While absent from the prototype, I'm sure the designers had a good idea how they were going to implement the gun system. They would have had to reserve space and weight for it. http://www.fas.org/man/dod-101/sys/ac/docs/n20000112_000043.htm |
No, anything over 19mm is condidered to be a cannon, and if explosive their projectiles are called shells. |
No, no I did think they had not though this through, and would saw through the wing with the first burst 
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You see, I have have not been able to find that kind of info. That is very interesting! How many degrees is it tilted up, you think? |
Trust Andy to chime in with them negative waves since it is American. "Always with the negative waves Why don't you knock it off with them negative waves? Why don't you dig how beautiful it is out here? Why don't you say something righteous and hopeful for a change?" |
"Crap" |
It's not negative. It's truthful. The 20mm seeks destruction by putting as many rounds in the target in as little time as possible. It's the 5.7mm of aircraft guns. The Mauser is the .45 of aircraft guns. A hit or two is all you need. Of course, that comes with a slower rate of fire. Remember the M61 was developed in the 1950s. We didn't have laser range finders and high speed firecontrol computers, so they had to make up for the inexactness of the firecontrol solution with quantities of fire. |
And I'll up you to a GAU-8.
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GSh-30-1 (30mm): Rate of fire: 1,500rpm. Weight of projectile: 14.1 oz. BK-27 (27mm) Rate of fire: 1,700rpm. Weight of projectile: 9.2 oz. M61 (20mm): Rate of fire: 6,000rpm. Weight of projectile: 3.5 oz. It takes an M61 @ a second to spin up to it's full 6,000 rpm. The BK-27's rate of fire is 'instantaneous'. After 0.5 secs, the BK-27 has put twice the weight of shell down range than the M61 which catches up after 1 second. A couple of hits from projectiles @ 30mm will knock the wing off most fighters at a significantly longer range and single barrelled cannon are intrinsically more accurate than a gatling type gun. ANdy |
  
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That's some pretty cool vid! |