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Hi, IMHO, the engine startup time and rotor revs increasing on startup as well, is little bit lower, than IRL. You can check and compare it on vids with the module in game.

 

 

 

 

please note the airframes, we have the Mi-8MTV-2, the ones in the videos you provided show a Mi-17 which is a much more updated and modern airframe compared to the Mi-8MTV-2 we can fly in DCS

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Mi-17 and Mi-8MTV-2 have the exact same engines and APU and the startup times should be the same.

 

While the Mi-8MTV-2 in DCS uses the TV3-117MT turboshaft engine, the mi-17 model in the videos your provided is not defined hence it could be use any of the following engines: TV3-117MT, VK-2500, TV3-117VM, VK-2500PS-03 or VK-2500-03 (engine models from wikipedia)


Edited by BlackFoxNZ
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in the second vid they don't wait the 40 seconds between engine stars to let the APU cool down.

so it is probably a different APU?

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40 seconds

 

Isn't it a full minute actually? Or that's the limit I've been using between engine starts myself since I seem to recall the manual says so.

The DCS Mi-8MTV2. The best aviational BBW experience you could ever dream of.

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While the Mi-8MTV-2 in DCS uses the TV3-117MT turboshaft engine, the mi-17 model in the videos your provided is not defined hence it could be use any of the following engines: TV3-117MT, VK-2500, TV3-117VM, VK-2500PS-03 or VK-2500-03 (engine models from wikipedia)

 

First of all, the DCS Mi-8MTV-2 has TV3-117VM engines, not TV3-117MT engines.

 

Second, all of the engines you listed (and at least two others that can be found installed in the Mi-8/Mi-17 that you/wikipedia failed to list) have the exact same starting parameters in the context of this post. That is, they all have the exact same "Engine startup time", which is the title of this thread.

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in the second vid they don't wait the 40 seconds between engine stars to let the APU cool down. so it is probably a different APU?

 

Regardless of the APU installed, the flight manual calls for a minimum of 1 minute between engine starts. However, nothing prevents the crew from ignoring that limitation and starting the second engine immediately after the start sequence for the first engine is completed.

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nothing to prevent the crews from ignoring the limitations?

 

don't you have officers :)

 

the apu in dcs used to squeal like a pig if you started the other engine to early.

does it not do that anymore?

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How long does it take in game from starter light illumination to rotors starting to turn?

 

The bottom light (about starter), not the upper one between buttons (about auto-ignition)?

 

I checked with scripted auto-start procedure, which opens overhead valves before doing anything else (I was surprised to see that - do you do the same in your ships? I had an impression looking at youtube vids that engineers tend to open these valves after pressing the startup button, but maybe it's different drill between various operators).

 

In that case, the time is about 10-11 seconds.

 

At what engine RPM do the rotors start to turn?

 

18-19'ish %

 

All tested in default Nevada instant cold-start mission.


Edited by Art-J

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

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  • ED Team
Hi, IMHO, the engine startup time and rotor revs increasing on startup as well, is little bit lower, than IRL. You can check and compare it on vids with the module in game.

 

 

 

The time for different aircraft depends on atmosphere pressure and temperature as well as on start-uo automatic governor tuning.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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The bottom light (about starter), not the upper one between buttons (about auto-ignition)?

 

I was really referring to the AUTO IGNITION light, but they should be pretty close to each other. The AUTO IGNITION light means that the auto start process is working and comes on as soon as you press the start button. The STARTER ON light illuminates when the air pressure inside the engine compressor reaches around 8.5 psi. I very rarely get to watch that light sequence, since I'm always outside the helicopter during engine start. So I don't remember how long that takes. Maybe 3-4 seconds? I hate to guess because I'm probably wrong.

 

In the videos, it's about 7 seconds from the time you hear the starter whine until you see the rotors turning. If that same process is taking 11 seconds in the game, then that's probably a touch slow but certainly within an acceptable time frame. Maybe in DCS they timed it when it was cold outside so it starts a little slower, and the game maybe doesn't take that into account. I don't know for sure.

 

As far as opening the cutoff levers go... We open the cutoff levers above the pilot's head when there is an rpm indication on the engine rpm gauge. There is a spring-loaded valve that must be overcome by fuel pressure inside the fuel control, so no fuel will actually go into the engine until that's reached, which should happen between 15-20% N1. Which is when lightoff is supposed to take place as well, since the igniters are already firing just waiting for fuel (they started firing 4 seconds after pressing the start button and continue to fire until 29 seconds into the sequence, by which time the combustion process should already be self-sustaining). There is nothing bad going to happen if you open the cutoff levers early, but they should really be opened before 15% N1 in my opinion, just to prevent the possibility of a slow or hung start because the start sequence is now waiting on a human to introduce fuel rather than letting the fuel control do that.

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Thanks for the info. Levers surprised me, because as you probably remember, in both DCS manual and training mission players are tought to flip them after engine starts rotating indeed. So it's only the auto-start script that uses unusual procedure.

 

Both lights are close to each other in the sim as well, I didn't measure, but it's maybe 2-seconds -ish delay.

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During my combat start up I put both engine stop levers forward before I activate the engine starter, then once engine 1 has reached 40% the engine becomes self staining and I stop the engine starter and switch to engine 2 and begin starting that, then full throttle and as soon as main rotor rpm gets up I’m lifting off while engine 2 rpm is still climbing up past 70ish percent

 

Not sure if such a quick start is possible irl but can be done in game

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can be done in game

 

I'd guess it's too hard on the engines and/or the APU and thus prohibited. Shortens the MTBF considerably.


Edited by msalama

The DCS Mi-8MTV2. The best aviational BBW experience you could ever dream of.

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