Top Gun movie - Jet wash/Flat spin

Bwadwey · by **Bwadwey** » 15 Jun 2005, 02:43

In the scene when Maverick and Goose eject, what kind of problem were they in? Somethign called a jet wash I think. What does it mean and how is it created?

DeepSpace · by **DeepSpace** » 15 Jun 2005, 03:14

Firstly, it's a fact that when the air enters the engine from the air intake it must be at a sub-sonic speed. Inside the air intake if the F-14 there are a few hydraulic-propelled "plates" that compress the air while the plane flies at super-sonic speed (it's deployed automatically), and therefore the air slows down before it reaches the engine. This system is equivalent to the moving intake of the F-15.

So, in that scene they fly in a sub-sonic speed, and suddenly they cross another jet's trails. That fast-moving air reaches the engines too fast (that system wasn't deployed since they flew in a subsonic speed), and the engine stalled. As a result they entered a falt spin, which is hard to recover from.

VPRGUY · by **VPRGUY** » 15 Jun 2005, 17:33

I know it was a movie but... how does an F-14 (or any twin fighter jet) get into a flat spin from losing one engine? Even if the other is in full AB, I would think the engines are close enough to the centerline that it would generate a good yaw, probably a roll as well, but a flat spin?

It is a tough maneuver to get out of; it is also a tough maneuver to get into, and even purpose-designed high end aerobatic aircraft need specific control inputs to enter a flat spin (usually, anyway). I can see a regular spin even, since twin prop aircraft are easy to spin if you lose an engine.

Pretty cool diagrams and description of the F-14 intake system, Deepspace

trailmix · by **trailmix** » 16 Jun 2005, 14:18

lol... I love this stuff

In the conventional RAM jet the air must be a subsonic speed. NASA proved that supersonic combustion IS possible with their Mach 10+ SCRAM jet last year.

~mix

shiz302 · by **shiz302** » 19 Jun 2005, 09:40

That spin makes about as much sense as goose hitting his head on the canopy too.

Bwadwey · by **Bwadwey** » 21 Jun 2005, 23:51

So since the Tomcat and the eagle have the things in their air intakes to change the speed of airflow going into the engine. Then how about the F-16 and F-18 , do they have these things in there intakes when they go supersonic speeds?

MikeMan · by **MikeMan** » 22 Jun 2005, 06:11

First let me say that Top Gun used to be one of my favorite movies of all time.

However that spin was one of the things that always bothered me about the movie.

The others were:

1. Final fight, how does maverick cover 180 miles to the dogfight in 60 seconds?
2. Why no radar guided missiles?
3. Why launch a single aircraft as backup?
4. Speed = life, so why slow down?

DeepSpace · by **DeepSpace** » 22 Jun 2005, 11:09

Bwadwey wrote:So since the Tomcat and the eagle have the things in their air intakes to change the speed of airflow going into the engine. Then how about the F-16 and F-18 , do they have these things in there intakes when they go supersonic speeds?

No, the F-16's intake doesn't have any moving parts. It slows down the air by its far installation from the aircrafts nose (about 4 meters), and separation from the body (note that there is a space between the intake and the aircraft itself).

About the intake of the F-18, I guess they used the same principle, because the F-18 came from the YF-17, which competed against the F-16 in the LWF program.

AIr-Strike31 · by **AIr-Strike31** » 01 Jul 2005, 04:58

Wow, first of all Just Wow'
The 80’s!
WOW! :shock:

Anyways, I have a question about Hollywood and real life Air combat,
Ill keep it simple though. I know that it’s not likely but what’s with that ejection in this movie, is it possible for the canopy to poses that kind of a problem?

THNX

shiz302 · by **shiz302** » 01 Jul 2005, 10:28

Dunno how the tomcat works but if it's anything like the F-16 there is a lanyard connecting the canopy to the seat rockets. Directly or indirectly, and once the canopy has pulled far enough away, then the seat will eject. Kceject can prolly give you a better explanation.
Watch behind enemy lines, that shows it pretty well.

Kosmos · by **Kosmos** » 01 Jul 2005, 12:30

Shiz302: You have to remember that Maverick say "Watch the canopy" just before they punch out... I guess Goose didn't watch the canopy

shiz302 · by **shiz302** » 01 Jul 2005, 18:01

Kosmos wrote:Shiz302: You have to remember that Maverick say "Watch the canopy" just before they punch out... I guess Goose didn't watch the canopy

Must have been a step in the tomcat ejection process, haha.

Raptorman · by **Raptorman** » 05 Jul 2005, 21:45

The Raptor canopy is heavier on one side so when the pilot punches out it flips out of the way

Infinity16 · by **Infinity16** » 06 Jul 2005, 18:30

MikeMan wrote:4. Speed = life, so why slow down?

Something similar to that move is actually taught in top gun. It’s been used once in air to air. I can’t remember the specific details but I think (THINK) that a single Phantom was engaged with a MiG-23. They were trading advantages very often until the guy in the F-4 did something similar while he was inverted. I’m sure it was not as glorious as “fly right by” but he did get kill. If anyone can give a little more info or even correct mine that would be great.

EDIT: I agree with you that Speed is VERY important and this was probably not the right time to pull that crap in Top Gun, but none the less it does exist.

Kosmos · by **Kosmos** » 06 Jul 2005, 20:16

There is no way you can crash into your own canopy, not matter how hard you try. And even if you should make it somehow, the ACES seat is higher then my head/helmet (this goes for all seats that I have ever seen). So it would crash into (or through) the canopy, and protect my head (if needed).