investigating Landing gear damage model - too weak

[CF104]

Hello,

Getting used to the paddle brakes and had a very slow excursion off the side of the taxiway during which the left main gear was damaged and partially collapsed with a flat tire. The Mig-29 was designed and built with unimproved strips in mind so a gear collapse with a slow excursion over flat frozen ground should not have happened. I didn't save a track but I'll test again and post it if I get the same results.

Regards,

John

 

[CF104]

I see this has been marked as "correct as-is". I have attached 2 track files and will respectfully disagree with the assessment. In both tracks the gear didn't collapse but I was unable to retract them successfully.

I also noticed that this has been tagged as "VVI to(sp) great". This was not due to high sink rate on landing but on taxi out from parking.

The Mig-29A has very robust landing gear and should be able to take short excursions from paved surfaces without causing damage to the gear.

Although this is a video of Mig-21's operating from a grass field, the principle is the same. 

Regards, John

 

Mig-29 gear damage-2.trk Mig-29 gear damage.trk

 

Edited yesterday at 03:51 PM by CF104
spelling

[BIGNEWY]

Hi, 

you are taxing onto soft ground, off the taxi way, and then on the take off you are over speeding your gear. 

Please also check your bake axis 

thank you 

[CF104]

I did post that I had an excursion off the taxiway which caused the initial issue. Thus I replicated it on the tracks. The landing gear should be able to withstand unprepared surfaces.

On track "Mig-29 gear damage", the left main gear already indicated unsafe after taxiing on the unprepared surface. 

I did not overspeed the landing gear on takeoff. The max indicated airspeed I reached was 290 KIAS with the gear retraction initiated well below 200 KIAS. The ED supplied flight manual has no reference to landing gear operation airspeeds. According to the German Air Force Mig-29G (Mig-29A to NATO standard) approved flight manual (GAF T.O. 1F-MIG29-1), the landing gear operation maximum speed is 370 KIAS. I didn't come near that speed.

Regards,

John

 

Edited yesterday at 04:44 PM by CF104
clarification

[Convoy]

48 minutes ago, BIGNEWY said:

Hi, 

you are taxing onto soft ground, off the taxi way, and then on the take off you are over speeding your gear. 

Please also check your bake axis 

thank you 

Same thing happened to me and my wingman multiple times today. No excursions, hot start, straight from the hanger to the runway, airborne by 150 knots, gear retracted immediately. 

[CF104]

1 hour ago, BIGNEWY said:

Hi, 

you are taxing onto soft ground, off the taxi way, and then on the take off you are over speeding your gear. 

Please also check your bake axis 

thank you 

Just to confirm I didn't overspeed the gear, I flew a test flight using the Mig-29G numbers. I retracted and extended the gear at several KIAS points up to and including 400 KIAS. The gear didn't fail at all which tells me the development team has the correct 370 KIAS gear operation speeds modelled. Track attached.

Regardless of the above, the gear is too weak on the ground as currently modelled.

And please remove the "overspeeding gear" tag as it doesn't reflect what I'm reporting.

Regards,

John

Mig-29 gear speeds.trk

Edited yesterday at 05:16 PM by CF104
clarification

[NineLine]

Hey all I am gonna have the team review one of these tracks, it does seem like the gear might be a little soft when you leave prepared surfaces. That said, especially the Caucasus, nothing good comes from leaving the tarmac

[Raven (Elysian Angel)]

MiG-29 and other Soviet aircraft were of course designed to deal with rough surfaces (this likely will be irrelevant in the DCS environment), but obviously trying to taxi on grass won't end well:




That being said, a lot of people complain about "soft" landing gear in DCS where they are simply using poor technique: the Hornet forum had a long thread about it as well.

[Art-J]

DCS has always been simplified/limited in this regard and doesn't differentiate between ground properties in winter or summer, wet or dry conditions, so there's no such thing as "frozen", "pepared/unprepared grass" etc. Maybe with a bit of exception re. grassy aifields on 3 WWII maps.

Real life examples are irrelevant then - a more detailed implementation is needed (someday maybe?) and for now all we can do is being more careful and avoiding taxiing onto the dirt in anything newer than WWII planes. With that being said, gear collapse when taxiing seems too much - in other DCS jets one usually just gets "stuck" without such extensive damage.

Edited 2 hours ago by Art-J