What is the right way to perform a barrel roll?

[Gloom Demon]

In the F-15C I raise the nose to 30 degrees and then start rolling it with a slight backward movement of the stick. However what I accomplish by that hardly resembles a barrel roll - more like a traditional roll. What I fail to understand is how to make the nose of my F-15 make a circle around a certain point on the horizon - once the wings come close to vertical, the plane, predictably, looses lift and starts slipping to the ground. If I fight that slipping by increasing the roll rate - the barrel roll becomes a plain roll - what am I doing wrong?

 

Here is an explanation from Wikipedia:

To do a barrel roll in its purest form, from the pilot's perspective, it may best be thought of as a roll around a point on the horizon that is 45 degrees off the flightpath.[9] Starting from a level flight, the pilot will usually pick such a point on the horizon as a reference, which is typically between the nose and the wing-tip, out the side window (if the plane has side windows). This point can be anything in that area, like a distant lake, mountain peak, or cloud. The pilot will then pull back on the stick, bringing the plane up into a brief climb. As the nose passes through the horizon, the pilot begins to apply aileron input, which is accomplished by easing the stick to either the right or the left. As the airplane rolls it will continue to pitch in the direction of the lift vector. The pilot will need to carefully control the roll rate, keeping the nose 45 degrees off the reference point on the horizon as the nose traces a circle around this spot. Some planes may require rudder input, while most high powered planes will only need to be guided by aileron and elevator control.

 

When the aircraft has rolled 90 degrees, and the wings are vertical, the nose should be angled about 45 degrees directly above the reference point. As the plane continues to roll upside-down it will begin to level out, and the horizon will appear to rise to meet the nose. When in the completely inverted position, the aircraft should be level and the nose should still be 45 degrees to the side of the reference point, putting it 90 degrees off the original flightpath. As the nose drops through the horizon, the pilot may need to reduce the elevator pressure, to avoid altitude loss by counteracting the force of gravity and the loss of lift. Still keeping the nose 45 degrees off the reference point, the plane should roll into level flight along the same flightpath and at the same altitude at which the maneuver began. If properly performed, the reference point should appear to remain in a fairly stationary position, relative to the plane, while the horizon spins around it.

Edited January 6, 2015 by Gloom Demon

[HellToupee]

its supposed to let drop down as much as you raised it up you fly a spiral, apply more back pressure at start ease a little bit when you going inverted

[FoReIgNeR]

A barrel roll is a perfect 1G roll without sideslip. The easiest method is to trim the plane for stationary horizontal flight (no horizontal acceleration or vertical speed), raise the nose slightly and start the roll (do not push back too much on the stick once in the roll), zero the sideslip by using rudder and maintain 1G by using slight stick inputs. Before you know it you'll be pouring iced tea =)

 

[Aginor]

Good old Bob Hoover again! :)

I love how he always said "I don't think I am doing stuff that anybody else can't do." shortly after flying such maneuvers. :D

Edited January 6, 2015 by Aginor

[flyco]

The Wiki description is just about perfect, except for the insistence on using a 45 degree angle-off to define the central axis. In fact you can choose any angle you like - if you use an angle of 90 degrees it's a loop, if you choose 0 degrees (i.e. Straight ahead it's a slow roll (in theory).

 

It is called a barrel roll because the aircraft follows a path around the surface of a large barrel (or more accurately an oil drum, or tube), with the cockpit pointing toward the central axis of the barrel. With a lower powered aircraft it helps to chose a point a little above the horizon to roll around, and always ensure that you have passed the wings level inverted position before the nose drops below the horizon. Many pilots have died trying to continue with a descending barel roll instead of relaxing the pull, accepting defeat and rolling out as soon as it looks nasty.

 

I found that the barrel roll was the most poorly flown manoeuvre by student pilots, until you explained that they were just driving the nose around a big circle centred on the horizon. The aircraft should always have positive(but varying) 'g' and the ball should always be in the middle. It requires good coordination because in most aircraft the speed varies throughout the manoeuvre, requiring you to adjust both back pull and aileron deflection all the way round.

 

Practice by flying level, or a slight climb, choose a clearly defined spot on the horizon (about 20 to 45 degrees off the nose) and fly the nose in perfect circle around it. Check that you are at 90 degrees angle of bank above the spot, inverted before you let the nose go below the horizon, at 90 degrees aob directly below the spot, and end up wings level flying in the direction you started. Throughout try and keep the roll rate constant. By choosing different angles off the centre axis for different rolls, you will quickly get a feel for what you are trying to do.

 

Good luck, and 'Many Happy Rolls of the Day'

 

Flyco

(Once a know-it-all QFI, always a kitQFI)

[Cali]

I don't recall how high or if the pilot raised the jet up when I got my ride, but I know it was over before I even realized it....it happened that fast. I'd have to go back and look at the video to see what happened.

[MiG21bisFishbedL]

Double Tap the R or Z button.

[Sneak69]

Aileron roll...its called an aileron roll.. damn star fox messed it up for everyone.

[Aginor]

Nope, it has been called that since WWI. It is just another word for aileron roll.

[BitMaster]

As a boy I had the chance to sometimes fly in my Dad's friend MBB single prop craft and we did many barrel rolls, among other stuff up to +3G and -1G, I was glad he did not do more LoL

 

I did not feel any G forces during the roll but I thought someone is turning the horizon 720°.

 

If it is done well, you won't even notice that your plane is moving. It all depends on the pilots skill and the plane being capable of, but looking at Bob, I guess they all can do it, at least when he flew them.

 

Bit

[BitMaster]

AN aileron roll and a barrel can be the same but don't need to be the same.

 

The barrel roll, looked from outside, has a clear shape of a barrel or circle or whatever you call it but the G-Force +1G does not come from nowhere, it comes from the centripedal forces induced due to the speed at which you roll and the diameter of your circle, that should match 1G.

 

 

Bit

[NeilWillis]

Are you using rudder? It's not all stick you know. There is a rudder component to every maneuver you can think of. Don't forget those pedals!

 

To keep the roll coordinated, with the ball in the centre on the turn and slip gauge, you will always have to use the rudder.

[FoReIgNeR]

G remains close to 1 and certainly positive =)