Engines die easily with strong winds

[average_pilot]

In very strong winds, and while flying, when turning from headwind the engines are prone to starve. I'm providing a track. Current stable version.

mig29 wind engines die.trk

[bbrz]

Must be a new bug for the MiG-29 because wind has absolutely no effect on an aircraft or its engines in flight IRL and not even on ground.

 

The only thing which is connected to wind and noticeable IRL with some engines is the engine start with a strong tailwind.

[mvsgas]

To be clear to others, you have a 97 knot cross wind on the track you posted. I know the whole wind speed should not affect aircraft and all, but guys 97 knot cross wind? I flew around fine, only with engine at idle and aircraft speed below 260 KPH (140 knots) with 97 knot cross wind did the engine quit.

Edited February 13, 2020 by mvsgas
spelling

[bbrz]

To be clear to others, you have a 97 knot cross wind on the track you posted. I know the whole wind speed should not affect aircraft and all, but guys 97 knot cross wind? I flew around fine, only with engine at idle and aircraft speed below 260 KPH (140 knots) with 97 knot cross wind did the engine quit.

In the air there is no such thing as crosswind. And in a jetstream you routinely see much more than 100kts IRL.

 

And I just considered re-installing DCS...

[mvsgas]

In the air there is no such thing as crosswind. And in a jetstream you routinely see much more than 100kts IRL.

 

And I just considered re-installing DCS...

 

But what do you call it when you start in the taxiway and the wind is 90° from either direction of the runways as the track is?

[bbrz]

But what do you call it when you start in the taxiway and the wind is 90° from either direction of the runways as the track is?

Again, there's no such thing as crosswind for an aircraft in the air.

 

Crosswind exists only when objects on the ground are added to the equation, like TACAN stations or runways.

[mvsgas]

Ok, I get it. But in the track he start in the taxiway, that is why I call it crosswind. So how about this: In the track, the wind is perpendicular to the runway at 97 knot and I was not able to taxi. I change the mission to start in the air. Mig-29 flew no problem in all directions. Only when I tried to land in a 97 knot perpendicular wind did the engine fail.

 

So the problem would be the engine are affected by perpendicular wind at 97 knot if aircraft is going less than 200 knots.

Also

And I just considered re-installing DCS...

If you don't have DCS installed, why do you care? Just curious

Edited February 13, 2020 by mvsgas

[bbrz]

... In the track, the wind is perpendicular to the runway at 97 knot and I was not able to taxi. I change the mission to start in the air. Mig-29 flew no problem in all directions. Only when I tried to land in a 97 knot perpendicular wind did the engine fail.

 

So the problem would be the engine are affected by perpendicular wind at 97 knot if aircraft is going less than 200 knots.

 

If you don't have DCS installed, why do you care? Just curious

 

No aircraft would takeoff or land in a 97kts wind, regardless where the wind comes from. 60kts is the usual limit, but that's mostly due to door/canopy limits.

 

That's extremely weird that the engines fail below 200kts. Makes zero sense.

 

DCS IMO offers by far the most realistic flying experience but the ever increasing number of bugs and unfinished modules is rather frustrating so I've uninstalled it while I'm waiting for the new alpha version of the new MSFS.

 

But I haven't given up on DCS yet!

[mvsgas]

The thing is I doubt anyone that uses the Mig-29 in real life has ever flown it in a situation where a constant 97 knot wind exist so this would be an unknown in term of comparing it to real life aircraft. So the engine shutting down in DCS is strange, does it really matter? How many people on a daily basis crate such strong winds to do missions?

 

So it may be wrong or strange, does it warrant any attention form ED? I think is one of many "quirks" that in the grand skim does not matter that much in my opinion.

[bbrz]

The thing is I doubt anyone that uses the Mig-29 in real life has ever flown it in a situation where a constant 97 knot wind exist so this would be an unknown in term of comparing it to real life aircraft. So the engine shutting down in DCS is strange, does it really matter? How many people on a daily basis crate such strong winds to do missions?

 

So it may be wrong or strange, does it warrant any attention form ED? I think is one of many "quirks" that in the grand skim does not matter that much in my opinion.

Again, in flight there is no wind for the aircraft, if it's 9, 90 or 190kts. That's why this problem is so strange.

 

Since quite a few modules are apparently incorrectly affected by wind this is IMO a serious problem and a real showstopper.

 

E.g. being not able to fly at the same IAS with the same power setting in a head and in a tailwind is simply a very basic error, which doesn't exist in any other simulator AFAIK.

 

Does this problem only occur at 97kts or also at lower wind speed?

Edited February 13, 2020 by bbrz

[draconus]

Nice, didn't know I can hover and Harrier up a Mig :)

 

On the dying engines it must be related to the air flow. You can hear the engines try to airstart when going headwind again. If you keep the speed though engines are fine whatever heading you take.

[average_pilot]

I may clear up a few points.

The extreme winds are only a tool to probe DCS and not that I want DCS aircraft to be able to operate from air bases during a hurricane. (Always fun, though )

As already explained by bbrz, once flying, all the physics of an aircraft, its aerodynamics, energy state, etc, all are referred to the air mass it is travelling through. How the mass of air is moving with respect to the ground below is irrelevant to the aircraft, physics wise. Ground may not even exist to all effects.

As ground bound creatures we have trouble separating the concept of wind from the concept of air blowing on things, but when an aircraft is in flight it is embedded in the mass of air as if air were a giant three-dimensional conveyor belt and thus wind can not blow on the aircraft. Any onboard system that relies on interaction with air to work or any control surface can't tell if the mass of air is moving with respect to the ground below or not. Ground may not even exist to all effects.

While the track I posted still works with the current version of DCS now I see it was a mistake to start from the ground as it only adds confusion to the already confusing concept of frames of reference, the wind blowing on ground-fixed things, etc.

That the engines stall in this particular module is not important. The important matter is that this may show some evidence that DCS at its core may have some inaccuracies regarding this very fundamental concept of the physics of all things flying. I use the specific case of the Mig-29 engines flaming out because it's really easy to reproduce.

I have to admit, as stupid as it may sound, that this topic causes me some mild uneasiness because DCS is nowadays almost my only free time hobby and I wish this specific topic could be cleared up once and for all and thus provide me with some peace of mind.

And lastly as a disclaimer, as years go by I'm increasingly more aware of how little I know about everything, so I welcome corrections, etc from actual experts.

[Ironhand]

@average_pilot

I missed this thread the first time around, so thank you for bringing it back up. To be honest, wind/IAS isn’t something that I spent too much time thinking about. FWIW, wind speed seems to have no significant effect on IAS. Take off directly into a hurricane force wind, set your RPMs and the speed you settle into seems be the speed you stay at regardless of which direction you fly.

The engine stall is another matter. While some in this thread have said that they only got it at slow speed, I’ve had both engines stall while making slow turns at speeds in the 500-600 km/hr range. Not at all sure what’s going on there. But something certainly seem amiss.

[Exorcet]

On 2/13/2020 at 2:55 AM, bbrz said:

Must be a new bug for the MiG-29 because wind has absolutely no effect on an aircraft or its engines in flight IRL.

A small point here. While in flight a constant wind speed is the same as 0 wind speed, changes in wind speed/direction can impact flight.

Is turbulence a factor here? Is it also set to a high value? Is this happening near the ground? DCS doesn't model interactions between the ground and wind besides height as far as I know, but if there is some interaction with the ground it might be a possible explanation.

43 minutes ago, Ironhand said:

The engine stall is another matter. While some in this thread have said that they only got it at slow speed, I’ve had both engines stall while making slow turns at speeds in the 500-600 km/hr range. Not at all sure what’s going on there. But something certainly seem amiss.

If the air is calm, turning should have no effect. With turbulence you might see something, but I doubt it would matter much unless turbulence was so strong that the plane was being tossed around.

[Ironhand]

14 hours ago, Exorcet said:

If the air is calm, turning should have no effect. With turbulence you might see something, but I doubt it would matter much unless turbulence was so strong that the plane was being tossed around

That’s why something is amiss. With the steady state wind that we currently have in the sim, no matter its speed with no turbulence or eddying, I’d might as well be flying with no wind. It only becomes a factor when orienting to the ground. But I was holding a 20* bank and, suddenly, both engines died.