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Old Apr 10, 2006, 9:52 PM   #31
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David French wrote:
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170mph is 979.2m/sec
No it's not, its 76 m/sec.
All I can say is oops.

Tis worth doing those kind of calculations, and putting them out where they can be shown to be wrong if they are.
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Old Apr 10, 2006, 9:53 PM   #32
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squirl033 wrote:
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i've also seen a pretty impressive maneuver performed by the MiG-29, in which the aircraft comes in horizontally at about 250 kts, then pulls into a vertical climb with afterburners. after a climb of about 1000 feet, the pilot cuts the throttles to idle, and the airplane slides back toward the ground backweards, vertically, for several hundred feet, before the pilot drops the nose to horizontal and advances the throttles to full military power again. i don't know what the Russians call this maneuver, buti sawit performed in 1989 at the Abbotsford Airshow, and heard a whispered, "aw, sh*t!" from behind me. when i turned around, there were two USAF F-16 pilots - neither of whom were apparently aware of the MiG's capability in this regard. obviously, this maneuver, unlike the Cobra ( which is primarily just a show trick), has some serious ramifications for aerial combat, and i suspect those F-16 jocks were hoping they'd never face a MiG-29 in wartime!
Hi,

The maneuver is called a "vertical reverse". It can be performed by the F-16 and the newer American F-22 as well. It is really more a demonstration of how well the engines can work when they have the airflow through them disrupted.

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Old Apr 10, 2006, 10:01 PM   #33
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squirl033 wrote:
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actually, i don't believe any US jets can do anything like that climb-and-fall-back thing. the only way the MiG gets away with it, as iunderstand it,is because the '29 has auxiliary intakes on top of the wing shoulders, and main intake doors that shut automatically at idle. this was designed to permit operation from dirt runways without FODding the engines, but some enterprising soul discovered it also gave the MiG a new trick to employ in ACM. apparently the top-mounted intakes prevent reverse airflow through the engine during the "fall-back" portion of the maneuver, andkeep the engines from stalling...


Hello,

I have seen video of the F-16 doing the vertical reverse and within the last 1 month I have seen video of the F-22 doing it. Really no practical value either except in a guns fight with a poorly trained attacker.

I did not realize there would be so much aviation interest here. For those who are interested, this debate first started over on a military flight sim web page: www.fighterops.com
There are actually a number of real pilots who make postings on that web page:

The direct link to the discussion that let me to post here is this one:
http://www.fighterops.com/forum/showthread.php?t=4716

Thanks for all of the feedback!
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Old Apr 10, 2006, 11:40 PM   #34
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(170 mi / 1 hr)* (1 hr / 3,600 s) = (170 mi / 3600 s)
(170 mi / 3600 s) * (1,609 m / 1 mi) = (76 m / 1 s)

BTW, this method of unit conversion via cancelling units is called Stoichiometry. You can't go wrong when you use it.

BillDrew wrote:
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David French wrote:
Quote:
Quote:
170mph is 979.2m/sec
No it's not, its 76 m/sec.
All I can say is oops.

Tis worth doing those kind of calculations, and putting them out where they can be shown to be wrong if they are.
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Old Apr 11, 2006, 4:08 AM   #35
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I get sick at Alton Towers, so I don't think I'll be trying these anytime soon. :lol:
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Old Apr 11, 2006, 8:13 AM   #36
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First "Cobra"-- Viktor Pugachev, if memory serves me...

slipe wrote:
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But then it still doesn't have much any engine exhaust signs, horizontal line of some fence in background is sharp.
And here's how well engine exhaust shows if there's anything else than completely flat color surface behind.
I see no problem with exhaust. Once up to speed it doesn't take anywhere near military power to maintain say 350 knots in that aircraft. And he could have reduced power because he was going a little faster than he wanted. At the angles taken it wouldn't necessarily show. The second shot does show exhaust.

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i've also seen a pretty impressive maneuver performed by the MiG-29, in which the aircraft comes in horizontally at about 250 kts, then pulls into a vertical climb with afterburners. after a climb of about 1000 feet, the pilot cuts the throttles to idle, and the airplane slides back toward the ground backweards, vertically, for several hundred feet, before the pilot drops the nose to horizontal and advances the throttles to full military power again. i don't know what the Russians call this maneuver, but i saw it performed in 1989 at the Abbotsford Airshow, and heard a whispered, "aw, sh*t!" from behind me. when i turned around, there were two USAF F-16 pilots - neither of whom were apparently aware of the MiG's capability in this regard. obviously, this maneuver, unlike the Cobra ( which is primarily just a show trick), has some serious ramifications for aerial combat, and i suspect those F-16 jocks were hoping they'd never face a MiG-29 in wartime!
I happened to be at the Paris Airshow the first time they demonstrated the cobra in the West. I have no idea who the pilot was. I still had friends flying F-16s and their reaction was pretty strong even though that sort of thing has no combat value. Their problem was with the philosophy of the fly-by-wire setup on the F-16. The engineers had determined there was no practical reason for the pilot to push beyond certain limits and the plane just wouldn't let them do it. Not only were the F-16 airshows pretty dull but FA-18 drivers were pulling their planes out of the envelope in jousts and the Falcon drivers couldn't do that. The pilots got a couple of concessions. They greatly expanded the allowable parameters and made the stick move – it had been solid and just worked on pressure.

Falling back on your exhaust probably has less combat value than the cobra. In air combat speed is life. I'm guessing the F-16 drivers were grumping about the limits the engineers had put on their controls. The MIG-29 would be the last plane in the world to have to resort to such suicidal tactics. The Russians developed a dogfighting missile for the MIG-29 that will go wherever the pilot's head is turned. They don't have to become sitting ducks to get behind another aircraft.

Many fighters do that same maneuver falling back on their exhaust anymore. I don't know whether they increased the parameters enough on the F-16 flight system to do that, but I've seen several other fighters do it.

I was referring to a distraction for the audience. Another plane on a photo op would probably detract from the effect of a low altitude pass.

You don't notice ground effect at those speeds. I'm sure it is there but you have so much control authority you don't notice it. I've been at just a few feet at 600 knots indicated in firepower demonstrations and ground effect doesn't seem to want to keep you from hitting the ground.
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Old Apr 11, 2006, 9:26 AM   #37
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slipe wrote:
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Their problem was with the philosophy of the fly-by-wire setup on the F-16.* The engineers had determined there was no practical reason for the pilot to push beyond certain limits and the plane just wouldn't let them do it.* Not only were the F-16 airshows pretty dull but FA-18 drivers were pulling their planes out of the envelope in jousts and the Falcon drivers couldn't do that.
Few years ago in airshow I saw F/A-18F and it seems to have quite nice low speed aerodynamics.
Yeah, F-16 "aerodynamics" is apparently quite heavily caused by what FBW allows, high alfa maneuvers always cause challenge for engines and last thing needed in one engine plane would be compressor stall... which was actually considerable problem with engines of early F-14 models.


For how serious engine failure can be check airshow crash in Ukraine.
http://www.spacedaily.com/news/plane-crash-02a.html
http://www.smh.com.au/articles/2002/...497446606.html



squirl033 wrote:
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the only way the MiG gets away with it, as i*understand it,*is because the '29 has auxiliary intakes on top of the wing shoulders, and main intake doors that shut automatically at idle. this was designed to permit operation from dirt runways without FODding the engines, but some enterprising soul discovered it also gave the MiG a new trick to employ in ACM. apparently the top-mounted intakes prevent reverse airflow through the engine during the "fall-back" portion of the maneuver, and*keep the engines from stalling...
Problem in those fall backs is such that it severely limits airflow available to compressors and routing intake to elsewhere from direct line definitely won't help in that... Unless that secondary intake happens to face backwards.




Juggernaut wrote:
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I have seen video of the F-16 doing the vertical reverse and within the last 1 month I have seen video of the F-22 doing it.

I did not realize there would be so much aviation interest here.
There aren't many videos from Raptor so did you find those from net?


BTW, would have been really intersting to see what capabilities of YF-23 really were, while lack of (complex and heavy weight mechanical) thrust vectoring surely limits lowest speed maneuverability its design gives very low drag and is otherwise highly unstable with large aerodynamic control surfaces.
Well... maybe that airfoil design could work as starting point when fluidic thrust vectoring becomes available.
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Old Apr 11, 2006, 8:46 PM   #38
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Quote:

Juggernaut wrote:
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I have seen video of the F-16 doing the vertical reverse and within the last 1 month I have seen video of the F-22 doing it.

I did not realize there would be so much aviation interest here.
There aren't many videos from Raptor so did you find those from net?


Hi,

I believe I saw it in some promotional video from the USAF itself.

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Old Apr 11, 2006, 11:34 PM   #39
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[quote] style="BACKGROUND-COLOR: #ffffff"Sorry - bad formatting
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Old Apr 11, 2006, 11:38 PM   #40
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Few years ago in airshow I saw F/A-18F and it seems to have quite nice low speed aerodynamics.
Yeah, F-16 "aerodynamics" is apparently quite heavily caused by what FBW allows, high alfa maneuvers always cause challenge for engines and last thing needed in one engine plane would be compressor stall... which was actually considerable problem with engines of early F-14 models.
I had a flight engineer who had flown FA-18s, Kaffirs and F-16s for the Navy. He spent 2 years as a fleet F-18 pilot and then the rest of his career as a Miramar aggressor pilot. He flew against everything in the US inventory on a regular basis and many others at Red Flag. He felt the F-16 was the best fighter in the world in a dogfight. His is an opinion I respect, so the updated controls weren't that restrictive. And a Navy pilot isn't likely to heap undeserved praise on an Air Force fighter.

I also had a flight engineer who had retired from the Air Force and his last assignment had been as the commander of the F-15 squadron at the Fighter Weapons School at Nellis. He surprised me by saying probably the most dangerous fighter in the world in a real fight is the F-14 because of the Phoenix missile. I had thought it wasn't maneuverable enough to be effective against another fighter and was just for bombers. He said you could always outmaneuver it but you couldn't ignore one. They come in from above unpowered and you can't see them, so you have to start pulling Gs when you anticipate it arriving based on the launch warning. The F-14 crews are competent at seeing that the Phoenix arrives just before the planes come into AMRAAM and Sparrow range. So while the enemy is avoiding the Phoenix the F-14 executes a medium range missile attack – one that can't be outmaneuvered. The Top Gun aggressor pilot confirmed that.

The early F-14s had engine problems because the engine they had designed it for wasn't available.

I thought the most dramatic engine failure ever was the Mig-29 at the Paris airshow when one flamed out when the pilot was holding it vertical with power. I'm amazed at how good Russian ejection seats are. They evidently sold a lot of ejection seats after that mishap. I wish I had been there to see that since nobody was killed.

Quote:
BTW, would have been really intersting to see what capabilities of YF-23 really were, while lack of (complex and heavy weight mechanical) thrust vectoring surely limits lowest speed maneuverability its design gives very low drag and is otherwise highly unstable with large aerodynamic control surfaces.
Well... maybe that airfoil design could work as starting point when fluidic thrust vectoring becomes available.
I thought it was a mistake to go for the F-22 over the F-23. The F-23 was a better aircraft for a high threat environment.

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