J-20 5th Generation Fighter - Page 28
I think the J-20 has two landing parachutes instead of one like single engined J-10, so that each chute catches part of the thrust from each of the two engines.
If you only have one chute, it might deviate and catches jet exhaust from one of the two engines predominantly, making it dangerous for the plane during landing.
J-20 5th Generation Fighter - Page 28
Are drag chutes design to catch engine thrust? I thought they were just there to increase drag (therefore slowing it down).
J-20 5th Generation Fighter - Page 28
Or one could install a larger chute instead of two. I'm guessing it's easier to install with two smaller ones. Wouldn't the chute catch on fire if catching jet exhaust?
J-20 5th Generation Fighter - Page 29
I think two smaller chutes is used because of room/clearance constraint, and the fact that the chute opening is close to the engine nozzle.
Military cargo planes use one large chute, but they are larger and their engines are situated under the wings and do not interfere.
They are not designed to catch the immediate exhaust leaving the engine but I think the backwash from the engine exhaust extends for quite some distance behind the plane.
Anyway it's my pet theory so don't look too deeply into it.
J-20 5th Generation Fighter - Page 29
There could be something to it. One large chute would collapse if two stream of thrust is directed at it.
Boys, stop it. You are talking nonsense.
First...There is a difference between a 'drogue' chute, which is a subcategory of the parachute, and the parachute itself.
Drogue parachute - Wikipedia, the free encyclopedia
A drogue parachute is more elongated and has a far smaller area than a conventional parachute, and thus provides less drag. This means that a drogue parachute cannot slow an object as much as a conventional parachute, but it can be deployed at speeds at which conventional parachutes would be torn apart.[1]
The drogue parachute's simpler design allows for easier deployment. Where a conventional parachute could get caught in itself while unfolding and fail to inflate properly (thus not slowing the falling object as much as it should), the drogue parachute will inflate more easily and more reliably to generate the expected amount of drag.
A drogue chute can be easily distinguished by the fact that one can literally see through it because it has many openings to allow air pass through, that is why a drogue chute does not slow down a speeding body, like an aircraft or a race car, as much as a full parachute. This pass through feature also make the drogue chute more stable once deployed, especially for any high speed body, like an aircraft or a race car.
Second...Even though the drogue chute is more stable, that does not mean it is completely immune from being collapsed by turbulence and when it is deployed behind a moving body like an aircraft or a race car,
IF it is directly behind the body, as in being inline with the centerline of said body, the aerodynamic wake created by the body can cause oscillation, which increases the odds of the oddity 'the tail wagging the dog' effect and cause a crash during the landing run. The closer the deployed drogue chute to the body, the greater the odds of oscillation.
Project Excelsior - Wikipedia, the free encyclopedia
...a multi-stage parachute system to facilitate manned tests. This consisted of a small 6 feet (2 m) stabilizer or "drogue" parachute, designed to prevent uncontrolled spinning at high altitudes, and a 28 ft (8.5 m) main parachute that deployed at a lower altitude.
The highlighted is significant in that in the skydiving environment, there is a relatively equal amount of 3D air flow around the body as it travel. The danger of the speeding body going out of control still exists. But now with a landing aircraft, especially when the aircraft is as small and quite near the ground as a fighter, the asymmetrical air flow will create differential pressures that will come into contact with the drogue chute and will increase the risk of the aircraft going out of control.
One solution is to increase the distance between the deployed drogue chute and the aircraft. Another solution is to increase the ground clearance between the deployed drogue chute and the ground, which for as small an aircraft like a fighter, this solution is not possible. The better solution is to use two drogue chutes that when deployed, each will be off the aircraft's centerline to reduce the odds of oscillation (or swaying) and turbulence induced collapse. The decision to use a single parachute or drogue chute or two drogue chutes depends on the aircraft itself and how much study was involved before the decision.
This has nothing to do with catching engine exhaust. What the heck for?
, they are on page 20 of this forum and they display the flight control system, there are a few images ranging from mechanic FCS to FBW FCS.
Typical exaggeration.
