Su-27 concrete jungle in 2:44

[g590]

Figured I had better post this before DCS World 2:

 

 

Concrete jungle mission in 2:44, which to the best of my knowledge is the fastest time by far. I turned off the flight computer for the whole thing, because it's very useful to be able to convert energy quickly when turning for the gates. I think it's cool how the Su-27 flies without it; after a while it seems the fly-by-wire implementation makes the Su-27 behave like a 'normal' plane unnecessarily. (The artificial speed trim is one example -- it adds an unwanted characteristic of conventional positively stable aircraft just for the sake of tradition.)

 

Anyway, I'd be interested to see if anyone can beat my time. For me the hardest part was the building near the end, and also being very careful to minimize negative gs throughout (instant loss of consciousness).

[Erdem]

That was very impressive. How do you not suddenly break up and die in an irrecoverable stall when you disable the FC though? :)

[Ironhand]

Figured I had better post this before DCS World 2:

 

 

Concrete jungle mission in 2:44, which to the best of my knowledge is the fastest time by far. I turned off the flight computer for the whole thing, because it's very useful to be able to convert energy quickly when turning for the gates. I think it's cool how the Su-27 flies without it; after a while it seems the fly-by-wire implementation makes the Su-27 behave like a 'normal' plane unnecessarily. (The artificial speed trim is one example -- it adds an unwanted characteristic of conventional positively stable aircraft just for the sake of tradition.)

 

Anyway, I'd be interested to see if anyone can beat my time. For me the hardest part was the building near the end, and also being very careful to minimize negative gs throughout (instant loss of consciousness).

 

G590,

 

Very impressive! Enjoyed watching that. :)

 

 

Erdem,

 

At the very least, you need to flick the stick back quickly as you take direct control. Best is to be neutrally trimmed prior to touching that switch.

[g590]

That was very impressive. How do you not suddenly break up and die in an irrecoverable stall when you disable the FC though? :)

 

Because the plane is neutrally stable, pilots used to conventional aircraft tend to mislabel it as overly sensitive. But there is a better way to think about it:

 

imagine you are controlling a marble by tilting the floor. as you fly now, you tend to keep the floor tilted and the marble will hit the walls (of controlled flight) very quickly.

 

instead: to "recover" from a "stall," push the stick quickly and abruptly and return it to the center position. you can use very small deflections. this is like tilting the floor quickly to one side and returning it to center, to reevaluate where the marble is.

 

I think that most of the control difficulties are because pilots used to convention will tend to overcompensate and induce oscillations, which quickly leads to either: 1. loss of consciousness or 2. a state where the controls aren't effective (in the video I lose control in this manner, right before I eject :D)

 

Once you learn to balance, the word "stall" loses its meaning; these jet fighters have enough thrust to make gravity a nuisance and enough control authority to allow you to stick and unstick the air around the whole airplane. In a (109 / Cessna) you can only unstick it around the wing roots, before the nose plops back towards the earth.

[DarkFire]

Figured I had better post this before DCS World 2:

 

 

Concrete jungle mission in 2:44, which to the best of my knowledge is the fastest time by far. I turned off the flight computer for the whole thing, because it's very useful to be able to convert energy quickly when turning for the gates. I think it's cool how the Su-27 flies without it; after a while it seems the fly-by-wire implementation makes the Su-27 behave like a 'normal' plane unnecessarily. (The artificial speed trim is one example -- it adds an unwanted characteristic of conventional positively stable aircraft just for the sake of tradition.)

 

Some VERY impressive flying there! I couldn't come close to that even on my best day.

 

The reason for the FCS being on though was evident from your video: you were getting the 'over G' notification almost continuously. In reality flying like that would nearly kill you and would damage the aircraft beyond use. Still, awesome time through the gates :thumbup:

[g590]

Some VERY impressive flying there! I couldn't come close to that even on my best day.

 

The reason for the FCS being on though was evident from your video: you were getting the 'over G' notification almost continuously. In reality flying like that would nearly kill you and would damage the aircraft beyond use. Still, awesome time through the gates :thumbup:

 

The audio notification is not an effective indication of g force physiologically. I think it repeats for too long after g force peaks above a threshold, and the times are uncertain and flawed.

 

Consider that when FCS is enabled, its purpose is to correlate stick travel with g force, which is the limiting factor, above a certain speed. When I disable FCS, I may be able to achieve more gs, but only momentarily, otherwise I would black out.

 

Basically, neutral stability requires a metric for control magnitude, which is the human physiology. IIRC, only at one section (long left hand turn before the reversal and road) was sustained g forces enough to make blacking out a factor.

 

Of course, with the FCS off you can induce unsurvivable g forces almost instantly, but this rate of turn is not necessary to get through the gates at the speed I achieved. Maybe if you were faster, gloc would become your limiting factor.