Thread: Piloting question - Snap roll and recover.

Hey all. Got a question that I'm not sure of. Since I've never had to do this, I'm unsure if it's possible. But basically, here's what I'm looking to do. I'm writing about a dogfight and the friendly pilot is in front of the enemy who's about to get tone on him and put a missile up his afterburners. To avoid this he does a snap roll, then quickly does a second to return to the vertical. Is this possible in a jet fighter, and if so, what is the maximum speed this can be achieved?

Or would he need to do a half roll and full pitch up with afterburner to recover the vertical after the snap roll? And if he can't snap roll, what other maneuver could he do that would give the equivalent result (ie, get him completely out of the way of the enemy fighter, and slow him very rapidly) and what speed is the limit for such a maneuver? I have my ideas based on my own experiences, but I want to be as accurate as possible. Thanks.

The aircraft I'm using is not currently in any military arsenal, but for close reference, you could refer to the F16 or F18 for the list of capabilities as it's very similar to those.

Are you talking about a complete "barrel" roll, where you rotate the aircraft a complete three hundred and sixty degrees by banking the right or left wing down, and continue the roll until the plane is back in its stationary position? Or do you mean that he pitches his nose down, dives for a short bit, and then comes back up?

I think a snap roll is where you bank your wing either left or right until the two wings are pointing up and down respectively, and then quickly bank back to your original position. In a fighter jet, it is definitely possible. If it's done in a Harrier, it's even more possible.

Other manoeuvres depend entirely on the construct of your fighter jet. If it has afterburners that are adjustable, i.e. that tilt from facing backwards to facing downwards (for hovering purposes) then you can actually use the afterburners to slow you down rapidly, leaving the pursuing jet flying past you at excessive speed. You can then readjust the afterburners, come up behind him, and blow him out of the sky. You do this by moving the thrusters downward while flying at full speed. The aircraft will come to an almost immediate stop and hover. The only danger with that manoeuvre is that it's very easy to stall.

Or, alternatively, he could pitch the nose upward, do a vertical roll, and come in behind the other fighter that way.

These manoeuvres, done by a pro, can all be completed at high speed, though I'm not sure what speed, exactly.

Jeeez Sam, my cat Riley makes more sense than you.

Any members of the RAF who stumble across this would be pissing themselves laughing.

Fer fuck’s sake:

You do this by moving the thrusters downward while flying at full speed. The aircraft will come to an almost immediate stop

Quite apart from the risk of the pilot losing his false teeth the plane would likely disintegrate around his ears.

Why don’t you stick to repairing blocked sewer pipes?

A harrier's top speed is just shy of 550 mph, OX. That's on full afterburner. Here's a little piece of information for you:

Originally Posted by Wikipedia

The Harrier has two control elements that a fixed-wing aircraft does not usually have. These are the thrust vector and reaction control system. The thrust vector refers to the slant of the four engine nozzles and can be set between zero degrees (horizontal, pointing directly back) and 98 degrees (pointing down and slightly forwards). The 90 degree place is generally used for VTOL maneuvering. Thrust vector is adjusted by a control next to the thrust lever. The reaction control is achieved by manipulating the control stick and is similar in action to the cyclic control of a helicopter. While irrelevant during forward flight mode, these controls are essential during VTOL and STOL, and are used together during these maneuvers. Wind direction and the point of reference of the aircraft to this is also crucial during VTOL maneuvers (in this sense operation is limited compared with a helicopter, which can take off and land in side winds). The Harrier's landing gear configuration also complicates normal landing; it is necessary to ensure that the wing-mounted stabiliser struts contact the runway simultaneously; bounce or tilt to one side can result if this is not achieved.

In forward flight, the Harrier is at an advantage compared with fixed wing aircraft in that in the event of stalling, recovery is possible by quickly adjusting the thrust vector and throttle. For STOL and VTOL landing, it is necessary to drop below the normal stall speed and apply this method (against all the instincts of the trained fixed wing pilot). The thrust vector control allows for the engine nozzles to be adjusted to a maximum stop of 98 degrees. This facilitates backward motion as needed but is not normally applied during VTOL as the heading into the wind tends to require some forward thrust via attitude control to maintain a fixed hovering position.



The technique of VIFFing ("Vectoring In Forward Flight"), i.e. rotating the vectored thrust nozzles into a forward-facing position during normal flight, was developed as a dog-fighting tactic for both (a) higher turns rates than would normally be possible for an aircraft with such a short wing-span and (b) SUDDEN BRAKING. The latter causes a chasing aircraft to overshoot and present itself as a target for air-to-air missiles.

Here's the entire article if you're interested, Raiden: Harrier Jump Jet - Wikipedia, the free encyclopedia

Sam, you and SevenWritez should get together.

You and your Harrier and its VIFFing and him and his chainsaw and its Vring….Vriing….Vriiiing would make a great song-and-dance act.

Ps: Don't believe everythig you read on the Internet

Backward Ox, stop being an @$$.

SamW: Here's an explanation of what a snap roll is. The explanation starts about a third of the way down the page where its says "The classic example of this is the snap roll".

Essentially, the cliff notes version of this is that it's a high speed stall of the wings (snap stall), followed by a 180 degree roll that puts you into the vertical nose down position. WW2 pilots used to do it a lot as a way to flip a U turn quickly or brake very rapidly to allow another aircraft to overshoot them, setting them up for the kill shot. You'll sometimes see this used in air shows to impress the audience. But it's best used to essentially suck a ton of momentum out of the aircraft to slow it rapidly and turn you in a hurry.

The idea you have listed with the Harrier is more or less a snap stall done with thrusters. It works well to slow you rapidly, but still leaves you in the kill zone until the pilot can catch up to you and fly by. If he's a couple miles out, closing on you at mach 1, by the time you recover your snap stall, he'll have gotten tone on you and shot your butt out of the air. It's really only good when the other pilot is less than half a mile behind you. Snap stall allows them to be much farther out. Especially since missile engagements can easily happen at 5, 10, even 20 miles out. All he's gotta do is get you sitting in his site long enough to get tone and your bacon is cooked. Snap roll is also very useful for getting to the deck in a bloody hurry to avoid incoming missiles as a missile approaching at mach 4 will have a heck of a time turning quickly.

If it's a radar guided missile, you can break tone and get away from them. If not, and they're a self tracking missile, you can loose them in the ground clutter by hitting the deck as close as you can. However, what I'm trying to do is nothing that fancy or desperate. I just need to get him behind the enemy fighter (a Mig in this case) and out of a position where the enemy pilot would have any hope of getting guns on target or tone. Especially guns. If he's paying attention and you snap stall, he could very easily pump a few feet of 20mm into your afterburners on the way by. I should know. I've seen it done before. A pilot worth his salt will be able to react to your snap stall and switch over to guns before he passes you, allowing him to rake you with guns, which more or less defeats the purpose of snap stalling in the first place.

Hence why I was looking into the snap roll instead. I just didn't know if it was possible in a mainline fighter such as the F16 or F18, especially given the speeds they operate at. Now Harrier I can easily see doing that, since it's meant to be a lower speed fleet footed dogfighter. Honestly, if I had my choice between going up against a Mig and a Harrier, I'd rather test my fate against a Mig, because a Harrier in the right hands makes even the scariest Mig look like a tonka toy.

http://www.rctoys.com/pr/wp-content/...-stallturn.jpg

AHA! I might have a solution. A half roll to a reverse hammerhead (ie, a hammerhead like what's pictured above, but aiming for the ground rather than the sky), then half roll again to a horizontal hammerhead, and bingo, he's behind the guy and right where I want him. The only thing that's gonna be a kicker is the amount of Gforces something like that would exert. At just under mach 1, he's gonna be pegging 9+ G's easily. o_0;;

The Red Baron will shit himself if Snoopy learns that trick

I think I have more expertise than most here, since I am a single engine pilot trying to become a jet pilot(although I wouldn't consider myself an expert in flying).

So here's my take:

Flying at full speed, while trying to turn would be a disaster in a dogfight just because the faster you go the slower your rate of turn (this is more physic dynamics than dogfighting). When you drive you slow down in a turn for the exact same reason; you have both a vertical and horizontal component of your velocity, which means that going faster will extend your turn as fast forward as much as it's going in the direction of your turn. However, that being said the steeper the angle of bank the greater amount of speed you need to keep the airplane from stalling in the turn (stall speed increases as the angle of bank increases), so it' probably adjusted accordingly.

Aswell, the plane will not be going at full speed unless the pilot knows he can get out of range in a burst of speed; the amount of fuel and wear on the engine from afterburners makes it impractical to operate at full speeds all the time. Also, the maximum speeds of any aircraft are misleading; they are usually max cruising speeds in ideal conditions (which only occurs when the plane is in the hands of a veteran pilot and during some sort of test run), or the never exceed speeds (speeds which can only be achieved in some sort of dive with full power and lots of balls).

Anyways, in regards to a hammer head stall I don't understand what you (Radien) mean by doing it towards the ground. I've done one before (well really it was technically a chandell, but that's the closest you'll get in a non-high performance a/c without over stressing it), and what's usually done (or how it was taught to me) is that you gain alot of speed (afterburners, or the old fashion way of pointing the nose down) and then pull up to vertical then, right before the aircraft stalls, you slam on the rudder pedal to push the plane in the direction you want to go and recover from the resulting stall. I don't think it's possible to stall going towards the ground unless you reef back quickly (snap stall like you said), but even then it would defeat the purpose of doing the maneuver (you'd look up for a second then fall back towards the ground).

Well, the primary objective is to get below and behind the guy as fast as possible to put him in a perfect missile shooting angle. Thus I'm trying to come up with something that'll allow him to more or less leapfrog the other pilot (the mig) and put him on the defensive right before he (the good guy) puts a missile up his tailpipe.

The other reason for this maneuver is also to force the Mig into a climb to avoid him, while eliminating any chance that the Mig pilot might actually have a chance to switch to guns and rake him with machine gun fire on the way by. I know it's a slim chance that the guy would be able to pull that off, but why not find a way to avoid that entirely?

The other option is a barrel roll, full air brake, throttle back, and a partial snap stall to drastically reduce air speed?

Well, the only thing I can really think of without putting the a/c in some sort of maneuver, would be to go into a snap stall while reducing the power (so the stall happens alot quicker) and then recover by applying power and either a) recover from the spin that might result from a wing drop, which, if timed properly (need to be a good pilot whose recovered alot of spins), would make the a/c face the tailing jet while under it or b) recover from the snap stall and do a bit of a barrel roll turn at a high power.

Then again I have no training in dog fighting and only slight training in aerobatic maneuvers, so this guess is only slightly more educated than most.