Crosswind landing and propwash tests
 

Well, here goes my first tests in CoD while trying to land under strong crosswind.

http://www.youtube.com/watch?v=xuMDBf6DUwE

I've placed an IA to wee what he does, in several tests he landa for the runway that has less crosswind component. Smart guy, uses correctly the crabbing technique, better than me, but his decrabs are tending to crash land the plane since de does not correct the last moment sink.

Landing after him, but with the runway that had more crosswind, I cheched some things:

-Anemometer had an instrument error (not bug, I think that's a real measurement error, caused by some lateral coomponent in advance), The fact is that a stall speed of an E-3 is about 125km/h... and IAS indication was 95 km/h only!

-Decrabbing a 109 under these conditions is extremely difficult, I understand IA's difficulties ;)

-Once stopped on the ground, I was satisfied to chech that, as a good taildragger, the plane tends to face the wind.

-Maybe 30 m/s is a crosswind outside plane specifications, but it is almost impossible to taxi to a desired parking.

-Same for the fact that braks are inefective, and plane goes backwards when faced to wind.

-In the last ground test, wind acts as it should do the propwash, but (and I don't recorded this, soory got no diskspace left), if you stop the engine, the controls are still effective just by the action of the wind, son there's no propwash modelled!


-In general, that was a very challenging test, try it!


PS: Sorry, posted this in the general forum, It should be in FM Sub-Forum, reposted there, this post can be deleted.

how to make a mission with wind?

Full mission builder, and then select conditions, its' the first menu that appears on the video. I'll tell you the excat name, but I have it in spanish...

Good testing Tuckie. :)

hehee 30 m/s is 108 km/h or 67 mph. That wind speed is almost enough to be a level 1 hurricane ! :cool:

Very nice, thanks for the test.

Wouldn't that be a bit extreme simulated? I mean if you would stand there a person you would fly in the sky I bet, seeing the aircraft behaving like a plastic toy..And its possible taxiing with this wind?

In a cross wind landing, cocking the nose into the wind is one technique. Another is the wing low method, in which the nose isn't cocked into the wind nearly as much. The upwind wing is lowered, and rudder keeps the nose headed in the right direction.

Either way, just before touchdown you need to get the nose lined up with the runway. Don't land with the nose still into the wind, or the wing still low.

Some cross wind components (speed/direction) result in an impossible situation to compensate for. It depends on the aircraft as to how far you can go.

binky9

Almost impossible to taxi, that's an extreme situation, where the flight itself would not be reccomended, and plane should be fixed to the ground.

There's an object for that in the mission editor, don't know the exact translation since I have it in spanish, but it's named similat ro "anti-storm attach block"...

I know, I did it the last time I flew the Cessna 152, except for the landing in one wing lowered, that is allowed if the final flare is very smoothly done.

The fact is that my instinct failed me when I performed the test for this video; maybe because in a lowered wing to the wind and nose crabbed, the visibility of the runway is poor and I'm still not so much used with 6DOF.

Must get more training on this... AI makes a perfect final, and a better decrab than me, even with failing on the final flare. :)

My worst fail in this video was to decrab the nose while raising the wing into wind; this is a "how not to land video" instead of a "must do" ;)

As this can be a typical stupidly dramatic end for a sucessful mission, I'll get some more training on this subject... including the aborted landing sequence...

Thanks to youtube, I'll add notes to this video, linking to the video with the correct procedure when I'll get it and upload another video.

PS1: as you can see, smoke is affected by wind so this can be a good visual indication of current wind on the field (in fact often were used Smoke Signal Bombs to do so when there was not an available "T", at least in my country during Spanish Civil War).

PS2: the airfield wind indicator (Windsock) looks like does not work at the moment.

well u'd normally get your wind direction and speed from your ATC :rolleyes:

The wing low method is usually good for high-wing airplanes :D. Seriously, it's much better to crab when you don't want your wingtip to catch the runway on landing. With the Bf it might be okay, large dihedral, wings not too long...

With regards to the crosswind component, some airplanes have limitations, some (high-wing Cessnas :)) have only the demonstrated crosswind value. It's like saying "this is what the test pilot was able to pull off, now let's see what you can do :)". Personally, I landed with about 16kt gusty crosswind in 172s and it's bordering unpleasant. 67kts? I'd consider staying at home :D.

+1 here.

Now, I have to say this having been a flight instructor in Canada. Most europeans won't use the slide technique (wing low) for landing as for north American, it's the first one that's being thaugt. In fact, the slide was apparently removed from the PP training syllabus in France. The low airspeed indicated is normal only as you flare. That is, the crab approach should not cause any different speed indication since the plane has nothing to do with it's trajectory over ground. When you flare and de-crab, you go sideways from what the air around the plane travels, exposing the pitot tube to an angle thus creating the difference in airspeed. That's just another (there are many more) reason why we have two pitot tubes in airliners nowadays.

That decrease in IAS also tells you that the downwind wing is also partly "shadowed" or airflow-obscured by the fuselage. That momentarily affect the aerodynamic wingload and most likely loose so lift. That why, without passengers, you can start decrabbing earlier and set your attitude 1/4 mile before touchdown if you want.

Now, with your 108 km/h wind setting, I would not even think of going up for a spin, let alone trying a wing low landing!!! I'm sure they were all inside, sipping tea with scones and crumpets...
;)
Cheers.

Hey, really good explanation! anyway this can be considered an instrument installation error, ins'nt it?

Will do more suitable tests... in that way :)

67 knot crosswind is no problem in a Cessna 172 or similar because it's above the stall speed. Therefore it's not a crosswind anymore because you effectively have a VTOL capability and so you can always takeoff & land directly into wind. :-P

However, you obviously would have to be very careful about wind gradients & gusts.

Best approach technique would probably be to come in at 80-90 knots with flaps retracted so that your approach angle relative to the ground was shallow enough that you could keep the touchdown point in view.

There therefore a very definite worst crosswind speed for any given aircraft type, such that the wind is strong enough to cause trouble, but weak enough to prevent you from taking off or landing across the runway etc.

The biggest challenge in really strong winds (i.e. those similar to the stall speed of the aeroplane) is moving the aeroplane around on the ground, because the weathercocking tendency and roll due to sideslip forces can be very large.

As a rule of thumb, if you can taxi the aeroplane then you can fly it.

Here's a landing in 45 knot winds. http://www.liveleak.com/view?i=a98_1303334732


There shouldn't be any error in the speedo while crabbed, as the crab itself only relates to relative ground movement, not the aircraft through the air so the speedo error is weird (probably another bug ...).

Also, did anyone else notice the 109's flaperons (drooping ailerons). They dropped 3 degrees (hardly noticeable) with flaps at takeoff position and 11 degrees for full flaps. This feature was discontinued beginning with the F. This wasn't included in IL-2 Mark 1.

Instrumentation error, yes. Is it like that in reality, yes. That is, on single pitot installation, which I believe all WWII era fighters were equipped with.

As for some people saying that the wing low technique is only for high wing aircraft, I must say it isn't true. I personnaly accomplished hundreds of real life landing with the wing low technique on CRJs, B767 and EMJs without even coming close to scrapping a wingtip. Well executed, there should be no reason why your upwind wheel wouldn't touch the pavement (grass) before the same side wingtip. Just for fun, in game of course, record a track of low speed flying above the runway with gear and flaps downs. Not trying to land, just bank until the wingtip strikes the ground, play the track at low speed and you'll notice that you need quite a bit of bank to strike the wingtip. As a matter of fact, the amount of bank would probably be higher than what the rudder would be able to compensate for going straight, which is what you attemp to accomplish in a crosswind landing.

Hope this helps. Cheers.

Could somebody please explain in simple what menu to look at. I cant find the weather options at all in the FMB. There is some menu that says Locales but it´s grayed out and cant be accessed. I would also like to try out the weather. I can use the local weather objects but don´t seem to know how to make the winds as the text is all messed up.

Seriously? Instrument error in straight ahead coordinated flight? So you can't expect a reasonably reliable reading on any given approach? How so?
I've experienced errors during extreme slips and skids but nothing significant (as illustrated in OP's movie) in a simple approach.

That's not what I wrote. Read again mate.

I said, when you de-crab and start side slipping for your flare, you start having IAS error. Straight and level flight should not be affected; apart of course by compressibility and position error.

Guys, I've went on more testing about the anemometer and the result is... it was pitot icing!

Once pitot heater is activated, IAS is back again to the correct indication.

I've simply flown through an icing condicions zone just before landing. Try it; fly into a cloud and play with pitot heater! :)

This simulator is OUTSTANDING!

Brilliant, its unfortunate that most of the reviewers will not bother scraping the surface of this gem and see the rough diamond underneath.

I can't wait to finish my studies and delve into this game, I stuck with il2 for 7 years, no other game I have played has left my fixated for that long.

HA! SAS!!! ncie to see you are alive and kicking!!! jezus, missed you mate!

Haha wow, yeah there would really be no need to crab at all landing in a hurricane like that. Just nose her into the wind and land cross-ways to the runway. You could land at like only 25 kph relative to the ground, almost a hover landing.

So what do they teach? The "Crab and Kick" technique? And what about for those pilots that are flying taildraggers?

In most cases (ignoring very large aircraft with castering landing gear, or extremely robust gear) the ideal situation is one where there is no lateral drift, and the aircraft is aligned with the landing direction to prevent sideloads, this is particularly true in taildraggers/conventional gear airplanes to prevent ground loops. . . most feel that this is best accomplished with the wing low method / side slip.

Great test - excellent data collection and write up.

Thank you very much!

S!

Gunny

(Taildragger here) That's what I do .... crab on final to slip at touchdown, typically wheeling it on.

yeah...i hate to say it, bu your wind speed is WAY too high. lol. That's like flying in a tropical storm. You need to lower it to like 5m/s