Drunk Harrier question

So sitting here haven a few beers, a thought came to me. Since the Harrier makes enough theust to hover, is it possible to rotate the nozzles all the way to the back (180 degrees??) and then hover pointing straight up? Like imagine getting into a hover with the nozzles at 90? (straight down), and then pitching up and moving the nozzles to maintain the same relationship to the ground, and hover around like a dolphin on its tail?

2 Likes

Yes. It’s known as @Gunnyhighway’s Cobra.

3 Likes

Depending on weight (fuel, loadout) then the key thing for any jet to do this would be thrust-to-weight. If that’s greater than 1 then you can be a dolphin on your tail as much as you like. F-15’s, F/A-18’s etc can go ‘up’ at an acceleration rate of 0, to sort of hover for a bit before unbalancing.

The Harrier has four curved engine nozzles in a rectangular formation (see pic), so the only thing I can think of that might spoil the Flipper Dancing would be (a) that the front two interact with the rear two to reduce the magic thrust-to-weight a bit and (b) it might be hard to balance going up like that.

2 Likes

will be my mission in life once its released.

3 Likes

Also, notice the 4 little squares: 1 on the end of the tail, one on the end of each wing and one under the nose. As I understand it, those are little balancing thrust ports that are used to move the jet while it is in a hover. In essence, those are what let the jet balance on the main thrust from the 4 nozzles that are close to the CG/body. If you were to try to go vertical (put the jet in a vertical orientation ‘balanced’ on the tail) those ports would lose all effectiveness and be unable to balance the jet.Without their help, the Harrier would be like any other jet standing on it’s tail with next to no maneuverability or control and I am pretty sure it would quickly be fatal.

EDIT: Not authoritative but from Wikipedia:

Several small reaction nozzles are also fitted, in the nose, tail and wingtips, for the purpose of balancing during vertical flight.

Without those, you do not have control in a hover.

EDIT 2: http://www.harrier.org.uk/technical/How_Hovers.htm

2 Likes

Yeah, I was wondering about the RCS puffers. Maybe in vertical pointing the tail and wing top/bottom could still help a bit - I doubt it (it would be one very confused Flight Control System) :slight_smile:

image

Don’t listen to all that technical rap @Gunnyhighway. Let the force guide you.

5 Likes

The depth of RAZBAMS modeling of said small nozzles will be tested for sure.

Funny that you mentioned it - I was also thinking about it and have already tested it in CAP2 few months ago

Although possible in the sim I’m a bit sceptical about it working in reality. The RCS system was designed with certain airframe orientation in mind i.e. gravity pointing in specific direction in reference to the fuselage. Balancing the jet on it’s tail would be troublesome with the RCS setup as it is.

It should also be noted that engines have a design speed, that is, they are designed to deliver maximum thrust at a certain speed, not at rest. This is due to the additional compression from the inlet duct.

The F-15 when clean and with little fuel, can accelerate inside a certain speed regime when going straight up. As you correctly mentioned, i’m pretty certain though that it can not accelerate straight up from a standstill (even if it wouldn’t tip over).

1 Like

002
You need one of these :slight_smile:

3 Likes

You’re one step closer to becoming Dr.Zebra…

1 Like