Landing rollout

[Kroll]

I was able to play A-10C for the first time online about a week ago. My buddy and I are both pilots in real life and have flown everything from J3 cubs - 747s. This sim is awesome! However there are a few areas that could be tweaked. Now the two of us are just getting started here with this amazing sim and neither of us flew the A-10 but have friends that do.

 

The landing roll out: We both noticed that we chew up huge amounts of runway on landing. There is a bit of iceskating rink feeling. Flaming cliffs had the same problem with the SU-25T. We also notice this in the yaw while rolling out if you put a little rudder. Now this side action dew to rudder/ nose wheel steering could be my joystick and curves. The point of all this is the tires should grab a little better with reguards to sideload to prevent side skidding. Also the brakes should be more effective. In real airplanes you can honk on the peddles harder if need be. He and I are just using the W key. So maybe this is the problem. Reguardless with steady braking a jet like the A-10 should not eat up more than half the runway. The only aircraft I've flown that could chew up runway because of weak brakes was the Lear 60.

 

I'm not trying to being critical I just want this sim to be more realistic in this area.

[FreeFall]

This is a good brakes related thread:

http://forums.eagle.ru/showthread.php?p=1375574#post1375574

 

I asked this question to our pilots a few months back and both that I asked said the same thing...

 

- As soon as you touchdown speed brakes full open

- Use the ENTIRE runway to slow to taxi speed

- Use wheelbrakes as needed as you approach the end of the runway.

 

 

And normal procedure would be to use the full length of the runway, not try and get off at the first taxiway.

 

You would be surprised how much the brakes heat up just in normal braking. One of the first items we have to check when recovering a jet is for hot brakes.

 

ACFT tires are made so the should (key word being should) deflate themselves if they overheat but that doesn't always happen. If an A-10 main or nose tire blows and your not directly in front or rear of the tire there is a good chance you won't be alive after.

 

Actually, in the military world, braking to exit the runway quickly will actually cause the guy coming in behind you to have to execute a go around. As well as other potential issues.

 

Fighters/Attack aircraft generally land with an overhead pattern and you can easily have 4 aircraft (all from the same flight) on the runway at the same time at various stages between touchdown and exiting at the end of the runway.

 

Additionally as has been said before, when you are in an armed aircraft, exiting at anywhere other than the designated taxiway (generally at end of runway) will cause problems as there will be no arming crew there to put the safety pins back in to any remaining weapons, guns and flare dispensers. And without pins you're not going ANYWHERE near the ramp.

Edited March 3, 2012 by FreeFall

[Slayer]

A couple of questions:

 

Are you using the airbrakes?

 

Did you have the NWS engaged? You shouldn't turn it on until you are down to safe taxi speed and vice versa when you are taking off.

 

Have you tried rudder pedals with a toe brake function? The toe brakes would give you a proportional input to the brakes verses a digital one being full on/full off with W key.

 

I've seen a video from I think Tiger from the 74th instructional video he never even touches the brakes at all.

[SimFreak]

If we had dash-1 for a10C, we would be able to test max braking... but. Usually pointy nosed aircraft do not brake well...

Here's how none-pointy-nose aircraft does it...

Edited March 3, 2012 by SimFreak

[jeffyd123]

Ahhhh, a real world pilot feels the landings are a bit off. I ve been wondering this myself for quite a while.

 

After reading a bit on landings and slowing, i recently changed my technique which is working pretty well.

 

I usually dont flare much during landing anymore. I try to level and touch down near the front of the runway at 125kts (no weps on the plane ~ 1/2 tank fuel), open the air brakes, then gently pull up on the nose to add more aero braking. usually by about 2/3 of the runway Im at a comfortable speed that i can use my brakes.

 

I havent broken my gear with this new technique. previously, i would come in at about 140kts and try to flare and then land long and slam on "W" (white knuckled! teeth gritting! eyes squinting!) and barely make a stop and break my gear a lot due to landing hard.

 

Paullkillirll (snoopy) has a lot of great info on what A-10's can and cant do so I follow his info. and he said that braking at high speed is too hard on the equipment... "the "MAN has spoken LOL

 

So I know my technique isnt real world but it is working well so far and my blood pressure is down 40 points.

[Dejjvid]

This is how it's done.

 

 

But then again, we're Swedes ;)

[joey45]

I've always liked the 37.

[mvsgas]

I was able to play A-10C for the first time online about a week ago. My buddy and I are both pilots in real life and have flown everything from J3 cubs - 747s. This sim is awesome! However there are a few areas that could be tweaked. Now the two of us are just getting started here with this amazing sim and neither of us flew the A-10 but have friends that do.

 

The landing roll out: We both noticed that we chew up huge amounts of runway on landing. There is a bit of iceskating rink feeling. Flaming cliffs had the same problem with the SU-25T. We also notice this in the yaw while rolling out if you put a little rudder. Now this side action dew to rudder/ nose wheel steering could be my joystick and curves. The point of all this is the tires should grab a little better with reguards to sideload to prevent side skidding. Also the brakes should be more effective. In real airplanes you can honk on the peddles harder if need be. He and I are just using the W key. So maybe this is the problem. Reguardless with steady braking a jet like the A-10 should not eat up more than half the runway. The only aircraft I've flown that could chew up runway because of weak brakes was the Lear 60.

 

I'm not trying to being critical I just want this sim to be more realistic in this area.

 

Hard to compare the stopping in the sim to RL when you are using the keyboard. At what speed at you landing? What load out? Fuel?

[mvsgas]

This is how it's done.

 

 

But then again, we're Swedes ;)

 

So the 39 can do that...after all, it is Swedish right?:D

[159th_Viper]

Last time I looked you could stop in 800-odd metres, give or take a few - Also depends heavily on your landing configuration.

 

Tracks will help analysis greatly.

[july865]

So the 39 can do that...after all, it is Swedish right?

i bet it can parallel park too.

that was cool.

[PeterP]

STOL DCS:A10C

 

This is how it's done.

 

 

But then again, we're Swedes ;)

 

Pfff...! Who needs reverse thrust when you have a GAU-8 !? :D

 

 

Full stop in 500m/1640FT

Edited March 14, 2012 by PeterP

[effte]

My initial reaction was that this was sorted a long time ago.

 

However, I have been feeling that the brake performance was more abysmal than I would expect in the latest versions, so I decided to have another go at verifying them:

 

Test setup and procedures

 

GW 37500 lbm

 

Flaps 20° -> Vref 135 KIAS (125 for minimum run)

 

Batumi 13 used, flown on ILS GP for nominal TCH. Dash one procedures used. Idle after crossing threshold, three second free run following touch down before applying full braking utilizing the A/S.

 

Flown on normal Vref.

 

No wind.

 

No significant runway slope (<0.3%)

 

15°C, 1013 hPa -> Landing index 100

 

Watch towers placed as placemarks along the R/H side of the RWY, at approximately the anticipated T/D point and at the anticipated stop points for the three configurations listed in the -1.

 

Published data

 

As per A-10A dash one:

Air distance (normal Vref) 1270’ (387 m)

 

Flaps 0°/no speed brakes: 2200’ (670 m) gnd roll, LDR 981 m

Flaps 20°/Full speed brakes: 1650’ (502 m) gnd roll, LDR 890 m

Flaps 20°/no speed brakes: 1950’ (594 m) gnd roll, 1058 m

 

RCR 23 (dry hardened runway) assumed.

 

Results

 

See the attached picture for results. To my surprise the ground roll distances are twice the published figures.

 

 

Speculation

 

I think the abysmal braking is due to the A/S still (again?) being over-active.

 

Further work

 

See if better results are possible using manual braking, thus confirming that the A/S modelling is at fault.

 

(And yes, A/S should by far outperform a human when it comes to maximum effort braking - check the dash one in general and figure A2-9 in particular if in doubt.)

 

Peer review to see if I made any mistakes.

 

Potential issues

 

No regard given to brake cooling.

Something seems to be amiss with the threshold crossing heights.

Slight bounces on two landings, TD measured where the wheels contacted the runway and stayed down.

I never braked to a full stop on the first attempt, so actual stopping position estimated. Good correlation with second attempt in the same configuration though.

I could have screwed up - please check my data.

Landing distance test.miz

Landing distances.trk

Edited March 3, 2012 by effte
Results inline

[159th_Viper]

Track/s?

[effte]

Track/s?

 

Yes. Now.

 

D'oh! :doh:

 

Please have a look. With any luck, I'm doing something wrong...

 

Also started a thread in the appropriate forum.

[159th_Viper]

Ta - I'll have a look. Again, not trying to be difficult with a track request - just makes life easier as well as having a baseline for comparison.

[PeterP]

:huh:Which configuration do you want to see ?

I will do four tracks with effte's mission

 

1.clean - barley fuel

2.clean - full fuel

3.full load - with barely fuel

4.full load - full fuel

 

-is this OK ?

or tell me what exactly you would like to see and what kind of payload.

(I have enough time this weekend - my wife is visiting her parents ;))

 

EDIT:

sorry- to slow

Edited March 3, 2012 by PeterP

[159th_Viper]

Config as effte mentioned should do, in the absence of official numbers (37500 pounds gross weight with empty pylons).

 

Then the three tracks with the listed flaps/speedbrake configurations.

 

:)

 

Edit: Peter - I did not edit my post above.

[effte]

Ta - I'll have a look. Again, not trying to be difficult with a track request - just makes life easier as well as having a baseline for comparison.

 

I know. I planned to include the track as well as the .miz but forgot when I rushed off to prep dinner. Saffron cod with aspargus! :thumbup:

[Frostiken]

So it's not just me who felt that you seemed to roll too easily on landing... I'm working on landing without relying on my wheelbrakes as much as I used to, and the rate at which the end of the runway suddenly shows up is surprising, and I'll be lucky to have dropped below 60 knots by the time I find myself standing on the brakes to try to stop.

[sobek]

Speculation

 

I think the abysmal braking is due to the A/S still (again?) being over-active.

 

Simple check whether you are in the right ballpark:

 

As friction when skidding should be way more than half the optimum braking friction, simply turn off A/S and slam the brakes. If the model is correct, that should put you a little over the numbers from the -1, no?

[BlueRidgeDx]

Sobek,

 

If you turn off the anti-skid and jam on the brakes, you're going to blow the mains within about 2-3 seconds.

 

I too have always felt that brake effectiveness is too poor, but without a precise way to measure in-game performance, I've never been able to bug it.

 

Are you guys adding objects at fixed intervals in the ME? I haven't tried that...is it precise enough?

[PeterP]

Simple check whether you are in the right ballpark:

 

As friction when skidding should be way more than half the optimum braking friction, simply turn off A/S and slam the brakes. If the model is correct, that should put you a little over the numbers from the -1, no?

>>>

Track/s?

:)

[Kalahari]

Pfff...! Who needs reverse thrust when you have a GAU-8 !? :D

 

 

Full stop in 500m/1640FT

 

 

Good one :lol:

[effte]

sobek,

that has to be tried. Now, problem is - you should be skidding on the rims rather quickly, and they'll have a lot lower friction than the tyres...

 

Slamming her down at the threshold rather than at the TDZ at 15 below Vref (10 below recommended for minimum run) gets you down to around 1000 m LDR... but it's hardly recommended procedure. I think I recall being able to do a lot better in earlier versions.

 

On a sidenote, checking the relative performance of maximum performance braking and AD braking (about the same, which probably feeds the forum infatuation with aero braking as the end-all, be-all for stopping), I found an interesting capability to do loooooong wheelies when you leave the speed brakes closed - see attached track. 2500 m wheelies down to 60 KIAS. :D

Wheelie.trk