Takeoff mystery

[Speed_2]

Hello all,

I am having a problem in a mission I made. I cannot take off! As soon as I go to increase collective, I get about 5 meters off the ground before my RPM drops and I fall back down. I am well aware of how the throttles work, my engines are at full RPM. The FARP is at an altitude of 1400 meters, I have a full loadout, and I CAN get in the air by telling the ground crew to reduce my fuel load to 50% or 25%, increasing the thottles to emergency, and then, after lifting off and holding at about 15 meters, I can build forward airspeed to get moving. YES, I know how to put my throttles on the auto position (two pageups). Never seen anything like this. Is it working as intended, or a bug?

 

PS,

Moderators, can you PLEASE activate Speed's posting privaledges? I had never posted anything on these forums before, but it will not allow me to post on my primary account. I'm guessing because I bought the Russian version of BS first, it thinks I can't post on english BS forums?

Edited August 25, 2009 by Speed_2

[miguez]

Hi Speed,

 

Sounds like you are well informed regarding throttle and helicopter weight, so we'll skip the basics. But before we continue, could we get some more data? What's the outside temp? Wind? Can you post the track?

 

Just another idea, you are not jamming the collective up all at once, but smoothly moving it up, correct, leaving enough time for the engine to attempt to maintain the same rotor RPM?

[joey45]

or post the mission for us to test...

 

EDIT: what miguez said.

[Boulund]

It isn't because of the high altitude making hover and vertical take off impossible with full load? You mentioned that taking off with lower fuel load and building forward momentum helped - this increases lift and reduces the load on the engines...

[miguez]

Yes, it could very well be, but we won't know for sure until we see what his payload/fuel load are exactly, and what the weather looks like.

[Speed_2]

Ok to make things weirder, I just took off no problem, didn't even have to set the throttles to emergency. Another guy who is flying with me (this is a multiplayer mission) had the same problem, then went back to briefing, and jumped back in the same chopper and had no problem.

 

How do I post the mission?

[miguez]

Speed, the mission file should have an extension of .miz, can't recall in which folder, but when you save the mission, you can use that window inside the editor to actually see in what folder you're saving.

[Speed_2]

Yea, I know that, my question is, how do I post it HERE for you guys to fly?Just find some file sharing site?

[Speed_2]

Ok, more info on the lift off difficulties. EGT is normal for both engines, tachometer is also reading normal for both engines (near 100%). The guy who I am flying this in multiplayer with also is having the same intermittant take off issue. It could be we are taking battle damage, but if battle damage is preventing us from taking off, how comes all the gauges read normal?!?!

[159th_Viper]

Turn on your Anti-Ice system ;)

[Speed_2]

Turn on your Anti-Ice system ;)

Nope, that's part of my normal ramp start procedure. It's irrelavent anyway cuz the outside air temp is 20 deg C, clear skies.

 

Furthermore, after starting the chopper manually and having this problem, I used the cheat start and had the problem as well.

 

I just got airborne using engine emergency power and asking ground crew to reduce fuel load to 25%. I reduced throttle after taking off to auto. The chopper flew pretty normal after that.

 

The real mystery to me is why I can do NOTHING different and have two complete different outcomes.

[Cp]

Nope, that's part of my normal ramp start procedure. It's irrelavent anyway cuz the outside air temp is 20 deg C, clear skies.

 

Furthermore, after starting the chopper manually and having this problem, I used the cheat start and had the problem as well.

 

Then that might be your problem ;)

 

The engine de-ice uses bleed air from the engine to prevent ice from building up, this takes a chunk off the engines performance though, same with the dust protector, so try avoiding using the de-ice and dust protector (which the cheat start turns on) when not needed.

 

still a track would be appreciated, IIRC multiplayer tracks are saved in the temp folder inside your main DCS folder automatically.

[159th_Viper]

 

IIRC multiplayer tracks are saved in the temp folder inside your main DCS folder automatically.

 

Correct.

 

All your Multiplayer Tracks are saved in your Temp Folder as per the following:

 

client-200908**-133048.miz.trk (or thereabouts)

 

Choose the relevant tracks, upload them and post the link for us to have a look at.

[Speed_2]

THANK YOU! I thought multiplayer didn't have tracks!! Ok, let me get back to you guys later, got something going on right now.

[Speed_2]

This mission occurs during an attack on your FARP, with incoming arty rounds, and 7.62x39 flying around. Though I can see nothing wrong on the gauges, hear no sounds of impacting rounds/shrapnel, and see no sign of battle damage, it's possible I am taking small amounts of it. I didn't believe this was possible at first and didn't even think it was important because I could hear and see nothing wrong with anything... until I tried to lift off. ERKRAN has NO warnings on it when this problem occurs. Give me time to replicate the problem. I'll get a track up if I can, maybe you guys can see WHAT gauge is telling me my aircraft is screwed up?

 

By the way, part of what has been keeping me occupied is a brand new, shiny TrackIR that just came today!!! Woohoo!

[joey45]

Yea, I know that, my question is, how do I post it HERE for you guys to fly?Just find some file sharing site?

 

go 'advanced reply' > scroll down to 'Manage Attachments' > click 'browse' > find your file > then 'up load'

[Zorrin]

Certainly from the symptoms you describe it sounds like you are trying to lift off and are too heavy.

 

The fact that you can get it to work more often than not by reducing the fuel capacity. But still be interesting to see the track.

 

By clear weather do you also mean zero wind? A tailwind can play havoc with your lifting capabilities at heavy weights.

[Speed_2]

It does seem to have been slight battle damage, but I'm still trying to figure out how such battle damage could damage my choppa and not show up on gauges or give me warnings? I moved the arty barrage a little further away, and I don't seem to have the problem any more.

[miguez]

Hi Speed,

 

It would still be helpful to get your mission in here for us to try, especially with the artillery closer as it was before. Or at least a track if you have a recording of when you encounteredthis problem.

 

There is damage that would not cause any lights or alarms to go off and still degrade helo performance. For example, you may have been missiong a portion of one or more of your main rotor blades. No warning lights, although the chopper would shake pretty violently, and that would be your indicator.

 

You could also have worn out your engine(s),as the damage modelling allows for degraded performance based on use/abuse, and up to a certain point, you would just have less power, with no warnings.

[Inseckt]

I have my finger on Cp's suggestion... Could you take off when Engine anti dust/ice were off?

[Kenan]

Or maybe you switched on the Electronic Governor Test switch. If it's on, your engines won't have enough power to lift and fly the chopper properly.

[Speed_2]

It had nothing to do with anti-dust/ice. I'm 100% sure it was battle damage. I wish I had a track for you guys, but they aren't saving for some reason.

[vortex360]

Might be the flight stick is configured wrong.

[Svend_Dellepude]

Unplug all controllers you dont use. sometimes more axis are mapped to the same function, ie two axis mapped to the collective will make the collective behave wierd.

[Inseckt]

It had nothing to do with anti-dust/ice. I'm 100% sure it was battle damage. I wish I had a track for you guys, but they aren't saving for some reason.

 

Have you heard of tachview? You can find it at lockonfiles.com. As I understand, the new version even records shell rounds, so you could use it to proove/disproove the battledamagetheory.

 

Anyway, I have never encountered performance degrading damage, that does not consequently also generate a warning/Instrument readings...

 

And, before letting totally go of the Anti Ice-theory, I must just make sure you know the difference between rotor and engine anti-ice functions... (Huge operational difference)