Su-27 wings falling off?

[lucien]

 

in a recent encounter on the open conflict server i found myself with a missing wing. Fortunately I made the best of the situation, but I just didn't know why my wing went in the first place. It is to my understanding I would have had to exceeded 8gs for this to have happened, and the AOA seemed fine too(apparently not lmao). I don't doubt there is a reasonable reason for this to have happened, but at first I thought it was the enemy's missile

[Pocket Sized]

Depending on total weight, Mach number, and rolling motions the max allowable G can be as low as 5.5ish.

[Ironhand]

...

 

in a recent encounter on the open conflict server i found myself with a missing wing. Fortunately I made the best of the situation, but I just didn't know why my wing went in the first place. It is to my understanding I would have had to exceeded 8gs for this to have happened, and the AOA seemed fine too(apparently not lmao). I don't doubt there is a reasonable reason for this to have happened, but at first I thought it was the enemy's missile

Judging from what I could see from your fuel gauge and airspeed indicator, I'd say you were flying an aircraft that weighed roughly 25,000 kg with an airspeed in the Mach 0.7 range. Gien the Gs you were pulling, those numbers would cause you to stress the airframes several times until, finally, something gave.

[lucien]

Judging from what I could see from your fuel gauge and airspeed indicator, I'd say you were flying an aircraft that weighed roughly 25,000 kg with an airspeed in the Mach 0.7 range. Gien the Gs you were pulling, those numbers would cause you to stress the airframes several times until, finally, something gave.

 

Depending on total weight, Mach number, and rolling motions the max allowable G can be as low as 5.5ish.

 

Ah, makes sense. As little as 5.5 is scary :cry: had to jink my aircraft back down when I lost track there too, I think that was at least a contributor, in that it forced(not really) me to increase my speed slightly, and make a higher strain maneuver to get over the incoming missile. I've probably just got to take better care.

 

If there is some kind of graph for wing load for the extremely aerodynamic and agile su-27

[DarkFire]

This is what you need:

 

 

The vertical axis is maximum rated G and the horizontal axis is mach number. A couple of things to bear in mind:

 

1) The graph and the aircraft are calibrated for an all-up weight of 21,400Kg. Heavier will result in lower maximum safe G loading and lighter --> higher safe G loading.

 

2) Actual airframe destruction will not take place immediately if you exceed the amount shown on the graph. The airframe seems to have a built-in safety margin of between 1.4x and 1.7x (depending on weight & speed) rated maximum G. Destruction of your airframe will take place if you exceed the safety margin.

 

3) G loading applied slowly is safer than G-loading applied quickly. If you give it time to work the AOA / G limiter will usually prevent you from entering an over-G condition.

 

4) The Su-27 really, really doesn't like negative G. If you watch videos of real Su-27s the pilots almost always roll inverted & pull rather than pushing over.

 

5) At the point at which your wing broke it looked like you were rolling as well as pitching. Multi-axis inputs cause significantly higher G than single-axis inputs. Instead of rolling & pulling, roll then pull. One of the few times that the AOA / G limited will not save you is during over-G caused by multi-axis inputs.

 

6) Feet off the rudder!! The Su-27 performs co-ordinated turns for you. The only time you need to use the rudder is during cross-wind landings.

Edited November 14, 2016 by DarkFire

[Esac_mirmidon]

Even the real manual describes that the exit from every acrobatic maneouver must be done with positive G.

[ShuRugal]

6) Feet off the rudder!! The Su-27 performs co-ordinated turns for you. The only time you need to use the rudder is during cross-wind landings.

 

Not quite true. The Su-27 ASC will mix in some rudder with aileron, but will not hold a coordinated level turn for you. Watch the ball indicator when you turn: you will still need to step on the ball a bit to keep it centered (just not nearly as much as, say, the P-51)

[DarkFire]

Not quite true. The Su-27 ASC will mix in some rudder with aileron, but will not hold a coordinated level turn for you. Watch the ball indicator when you turn: you will still need to step on the ball a bit to keep it centered (just not nearly as much as, say, the P-51)

 

True, it does need a little finesse for absolute accuracy, but "feet off" is good advice for those suffering from wild rudder gyrations, as seen all too frequently in YouTube videos of Su-27 pilotage. There is a good argument to be made that performing proper co-ordinated turns is part of 'getting the basics right', but I think the default behaviour is close enough that concentrating on other things like maintaining steady altitude in turns is more important to start with :)

[Stuge]

I find myself using a lot of rudder when in extreme AoA slow-speed rolling scissors or something similar (S key engaged obviously) and trying to find a proper balance between high AoA and roll rate (you know the thing doesn't roll at all when you exceed a certain amount of AoA). I feel maximum rudder into the roll helps a bit with the roll. Not sure how much of it is actual effect and how much placebo, but hey as long as it kills the bandit...

 

For pretty much everything else (excluding engine failure and the aforementioned crosswind landing) I don't see the need for rudder use. Maximum performance sustained turns work just fine without it.

Edited November 15, 2016 by Stuge

[GGTharos]

In high AoA maneuvers, rudders should produce higher roll rate than ailerons for the typical modern jet fighter.

[esb77]

True, it does need a little finesse for absolute accuracy, but "feet off" is good advice for those suffering from wild rudder gyrations, as seen all too frequently in YouTube videos of Su-27 pilotage. There is a good argument to be made that performing proper co-ordinated turns is part of 'getting the basics right', but I think the default behaviour is close enough that concentrating on other things like maintaining steady altitude in turns is more important to start with :)

 

Coordinating will give some pretty good returns in both turn rate and energy retention at low speeds in the Su-27. The problem is that where in a real plane you'd FEEL sideslip, we only have the gauges in DCS, so it's not very practical to coordinate and have eyes out of the cockpit at the same time.

 

I think probably the ideal procedure for DCS is to coordinate your turns if either of the gauges are in your field of view, but don't change zoom or look into the pit just for the sake of coordinating. In general there are more important things to be looking at.

[DarkFire]

I find myself using a lot of rudder when in extreme AoA slow-speed rolling scissors or something similar (S key engaged obviously) and trying to find a proper balance between high AoA and roll rate (you know the thing doesn't roll at all when you exceed a certain amount of AoA). I feel maximum rudder into the roll helps a bit with the roll. Not sure how much of it is actual effect and how much placebo, but hey as long as it kills the bandit...

 

For pretty much everything else (excluding engine failure and the aforementioned crosswind landing) I don't see the need for rudder use. Maximum performance sustained turns work just fine without it.

 

In high AoA maneuvers, rudders should produce higher roll rate than ailerons for the typical modern jet fighter.

 

Agreed. Personally I find that for AOA above say 23-25 degrees the rudders produce much more roll than the flapperons do. As a bit of an aside, I'm quite looking forwards to what the Su-33 will bring to the table once it gets its PFM. Low speed, high-AOA jinking & jiving should get a little more interesting. Maybe not in terms of roll rate but I'm thinking that in the pitch plane high-AOA stuff should be a little more stable than with the -27.

[DarkFire]

Coordinating will give some pretty good returns in both turn rate and energy retention at low speeds in the Su-27. The problem is that where in a real plane you'd FEEL sideslip, we only have the gauges in DCS, so it's not very practical to coordinate and have eyes out of the cockpit at the same time.

 

I think probably the ideal procedure for DCS is to coordinate your turns if either of the gauges are in your field of view, but don't change zoom or look into the pit just for the sake of coordinating. In general there are more important things to be looking at.

 

Yep, pretty much what I find myself doing. If I'm just wandering around looking at the scenery on the VA server I'll try to keep things precise, but if I'm in a furball with the limiter off or god forbid in direct mode there are more pressing things to be worrying about :)