chn6 Posted January 10, 2015 Posted January 10, 2015 (edited) I tested last version 1.2.14.35734 MiG-21Bis landing in Crosswind, For example, cross wind of 8m/s. The aircraft can be smooth landing and normal running, but when Drag Chute activate, The aircraft must out of the runway and certainly, can't correction through the rudder . I read about the air force manual data, MiG-21 can easily land in 90 degrees crosswind 15m/s, also did not mention the use of Drag Chute can not be in such a crosswind manifold. So, now the physical Drag Chute calculation may be some problems, the lateral force Drag Chute produced in a crosswind when the effect is too big? My Crosswind landing trk: http://forums.eagle.ru/attachment.php?attachmentid=111118&stc=1&d=1420879440Crosswind_chute.rar Edited January 10, 2015 by chn6 [sIGPIC]http://forums.eagle.ru/signaturepics/sigpic87046_1.gif[/sIGPIC]
Mike Busutil Posted January 10, 2015 Posted January 10, 2015 Same results here... [sIGPIC][/sIGPIC] Checkout my user files here: https://www.digitalcombatsimulator.com/en/files/filter/user-is-Mike Busutil/apply/
Badger1-1 Posted January 10, 2015 Posted January 10, 2015 If a big chute like this one, is facing 8m/s crosswind, dont you think it will somehow behave exactly like that and move an object on only 3 wheels easily into the direction of the wind?
chn6 Posted January 12, 2015 Author Posted January 12, 2015 If a big chute like this one, is facing 8m/s crosswind, dont you think it will somehow behave exactly like that and move an object on only 3 wheels easily into the direction of the wind? I asked J-7 (Chinese version MiG-21) pilot, landing in such a crosswind, the release of Drag Chute does not occur after it is impossible to control nose pointing problem. With respect to the high speed aircraft, crosswind caused Drag Chute produce lateral force on the plane should be relatively weak. [sIGPIC]http://forums.eagle.ru/signaturepics/sigpic87046_1.gif[/sIGPIC]
Hadwell Posted January 12, 2015 Posted January 12, 2015 (edited) yeah, when it starts getting too uncontrollable, get rid of the chute and stop the rest of the way with brakes... only real solution for now.... but it's definitely a bug... Edited January 12, 2015 by Hadwell My youtube channel Remember: the fun is in the fight, not the kill, so say NO! to the AIM-120. System specs:ROG Maximus XI Hero, Intel I9 9900K, 32GB 3200MHz ram, EVGA 1080ti FTW3, Samsung 970 EVO 1TB NVME, 27" Samsung SA350 1080p, 27" BenQ GW2765HT 1440p, ASUS ROG PG278Q 1440p G-SYNC Controls: Saitekt rudder pedals,Virpil MongoosT50 throttle, warBRD base, CM2 stick, TrackIR 5+pro clip, WMR VR headset. [sIGPIC][/sIGPIC]
Dolphin887 Posted January 12, 2015 Posted January 12, 2015 In RL, use of drag chute is limited to max 10m/sec cross-wind due to strong effect on directional control (decreased) and stability (increased, turning). Drag chute behavior is not a bug. Power through superb knowledge, training and teamwork. [sIGPIC][/sIGPIC]
Flagrum Posted January 12, 2015 Posted January 12, 2015 In RL, use of drag chute is limited to max 10m/sec cross-wind due to strong effect on directional control (decreased) and stability (increased, turning). Drag chute behavior is not a bug. Can we have this info added to the manual ("Operational Limitations") then? :D
atsmith6 Posted January 12, 2015 Posted January 12, 2015 Hi chn6 I've found that if you touch down, then keep the nose up 5-6degrees to air-brake to around 200 (no wheel brakes yet), then deploy the chute, you can keep the jet straight with about 1/2 rudder deflection while braking. Make sure the nose wheel braking is enabled and prepare to drop the chute as soon as you hit around 50km/h. This works for me in some pretty intimidating crosswinds. Hope that's useful
billeinstein Posted January 13, 2015 Posted January 13, 2015 When speed = 0, drag force of the chute will larger than the thrust. The aircraft will go backward when releasing brakes with max throttle. [sIGPIC][/sIGPIC]
chn6 Posted January 13, 2015 Author Posted January 13, 2015 Hi chn6 I've found that if you touch down, then keep the nose up 5-6degrees to air-brake to around 200 (no wheel brakes yet), then deploy the chute, you can keep the jet straight with about 1/2 rudder deflection while braking. Make sure the nose wheel braking is enabled and prepare to drop the chute as soon as you hit around 50km/h. This works for me in some pretty intimidating crosswinds. Hope that's useful Thank you atsmith6, I will try.. [sIGPIC]http://forums.eagle.ru/signaturepics/sigpic87046_1.gif[/sIGPIC]
chn6 Posted January 13, 2015 Author Posted January 13, 2015 In RL, use of drag chute is limited to max 10m/sec cross-wind due to strong effect on directional control (decreased) and stability (increased, turning). Drag chute behavior is not a bug. Thx for reply, I will try again. [sIGPIC]http://forums.eagle.ru/signaturepics/sigpic87046_1.gif[/sIGPIC]
billeinstein Posted January 13, 2015 Posted January 13, 2015 When speed = 0, drag force of the chute will larger than the thrust. The aircraft will go backward when releasing brakes with max throttle. Zero wind trk here:mig21chutebug.trk [sIGPIC][/sIGPIC]
billeinstein Posted January 13, 2015 Posted January 13, 2015 :doh: If there is a 1 m/s cross wind:mig21chutebug2.trk [sIGPIC][/sIGPIC]
chn6 Posted January 15, 2015 Author Posted January 15, 2015 I agree with your point of view, the conversion of kinetic energy efficiency of drag chute may not be 100%, so should not appear big thrust engine case, drag chute can take the plane took the reverse glide problem. [sIGPIC]http://forums.eagle.ru/signaturepics/sigpic87046_1.gif[/sIGPIC]
Fishbreath Posted January 15, 2015 Posted January 15, 2015 With 100% thrust, it's certainly plausible that a parachute placed directly behind the engine could pull the plane backward. (Thrust reversers operate on exactly the same principle, and they work well enough.) It's less plausible that the parachute would stay attached, but I don't think the forum has ever reached a consensus on that. Black Shark, Harrier, and Hornet pilot Many Words - Serial Fiction | Ka-50 Employment Guide | Ka-50 Avionics Cheat Sheet | Multiplayer Shooting Range Mission
billeinstein Posted January 15, 2015 Posted January 15, 2015 The reversal of a jet engine make most fan and/or core exhaust flow go forward. Parachute is NOT a thrust reversal. The force of cable pulling the tail can never larger than the thrust at 0 speed. Because only very small part of air flow is stopped or reversed by the chute. Most of the thrust airflow is bypassed. There is also a very long distance between the nozzle and parachute. Airflow is slowed down. This means the parachute must stop more mass of air than that blow out from the engine. The other bug about this is ground spin with cross wind. Brakes can't stop it. [sIGPIC][/sIGPIC]
Chief1942 Posted January 16, 2015 Posted January 16, 2015 Not a physics person, but I usually think of air/wind forces being somewhat akin to water. In that comparison, a drag chute in a relatively strong wind (cross or otherwise) would have a similar effect as a sea anchor on a boat in the water. I would anticipate it would turn the craft into the direction the wind(current) is coming from, providing considerable drag in the process. I will leave it to the more scientifically astute to be more precise, but that analogy helps me prepare for and adjust to the effects of the winds. Intel i5-4690K Devil's Canyon, GForce TitanX, ASUS Z-97A MB, 16GB GDDR3 GSkill mem, Samsung SSD X3,Track IR, TM Warthog, MFG Crosswind pedals, Acer XB280HK monitor,GAMETRIX KW-908 JETSEAT
Hadwell Posted January 16, 2015 Posted January 16, 2015 Not a physics person, but I usually think of air/wind forces being somewhat akin to water. In that comparison, a drag chute in a relatively strong wind (cross or otherwise) would have a similar effect as a sea anchor on a boat in the water. I would anticipate it would turn the craft into the direction the wind(current) is coming from, providing considerable drag in the process. I will leave it to the more scientifically astute to be more precise, but that analogy helps me prepare for and adjust to the effects of the winds. yes, air and water both follow the rules of fluid dynamics. My youtube channel Remember: the fun is in the fight, not the kill, so say NO! to the AIM-120. System specs:ROG Maximus XI Hero, Intel I9 9900K, 32GB 3200MHz ram, EVGA 1080ti FTW3, Samsung 970 EVO 1TB NVME, 27" Samsung SA350 1080p, 27" BenQ GW2765HT 1440p, ASUS ROG PG278Q 1440p G-SYNC Controls: Saitekt rudder pedals,Virpil MongoosT50 throttle, warBRD base, CM2 stick, TrackIR 5+pro clip, WMR VR headset. [sIGPIC][/sIGPIC]
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