INU and the ADI

[iceden]

Question: The manual states it takes about 30 minutes for the INU to calibrate. How do you know when this calibration is complete? Also, how do I bind the INU to the ADI? Ive waited more than 30 minutes and when I move the helo I get a 'Helo operating on battery' and always a Navigation failure warning? What am I doing wrong? Ive been thru the manual over and over and am maybe not seeing how this is supposed to function!!!

[EtherealN]

Do you have the generators active?

Have you set the throttles to auto to give the generators enough power?

[ericinexile]

Question: The manual states it takes about 30 minutes for the INU to calibrate. How do you know when this calibration is complete? Also, how do I bind the INU to the ADI? Ive waited more than 30 minutes and when I move the helo I get a 'Helo operating on battery' and always a Navigation failure warning? What am I doing wrong? Ive been thru the manual over and over and am maybe not seeing how this is supposed to function!!!

 

The ADI SHOULD get its information from the INU. I say "should" because in modern aircraft (and at 20 years the Ka50 qualifies as modern) the inertial system provides all attitude, heading, and (usually) VVI data--except for standby, of course. The 30 minute alignment process is, fortunately, ignored in the game. Don't forget the INU heater in your preflight.

[GGTharos]

It isn't ignored - rather it's a non-factor. There is a 3 or so minute alignment process which you can do if you are taking off from the same coordinates you stopped at, AFAIK.

 

The 30 minute process is the 'precise alignment', but you aren't required to use it.

[REL]

It isn't ignored - rather it's a non-factor. There is a 3 or so minute alignment process .

 

Is there a way to change it in the LUA files ? maybe that's going to help you guys .

[EinsteinEP]

Question: The manual states it takes about 30 minutes for the INU to calibrate. How do you know when this calibration is complete? Also, how do I bind the INU to the ADI? Ive waited more than 30 minutes and when I move the helo I get a 'Helo operating on battery' and always a Navigation failure warning? What am I doing wrong? Ive been thru the manual over and over and am maybe not seeing how this is supposed to function!!!

icenden,

 

As EtherealN posted above, the "helo operating on battery" warning is probably due to the generators not generating enough power to operate the electrical equipment. This could be caused by the engines not being run at a high enough rpm (i.e., your throttles aren't set to 'auto') or the generators not being turned on (switches are near the fuel pump switches on the right wall panel). You may also get the warning if you pull up too violently on the collective, which slows the rotor rpm, which causes the generators to stop producing power, etc. Make sure your throttles are set to auto (pgup x2), although the system some time to settle (watch your engine RPM needles, wait until they settle down), then, when you're ready to takeoff, gently pull back on the collective until you start to climb. If you're still seeing "operating on battery" warnings, post a track so we can take a look at it.

 

The NAV failure you're getting is likely related to the power issue (e.g., not enough juice to run the nav system) but double check that the following switches are ON: INU power, NAV, K-40 Power (on targeting panel). If you've solved your power issue (above) you should have any NAV issues.

 

The ADI is by design, always "bound" to the NAV system. If you're talking about the Standby ADI on the right side of the cockpit, it has a separate power switch on the right wall panel.

 

Good luck!

[enigmatics]

It isn't ignored - rather it's a non-factor. There is a 3 or so minute alignment process which you can do if you are taking off from the same coordinates you stopped at, AFAIK.

 

When should the (3 minute) alignment process be used, is it manually started? I don't remember seeing anything about it in the developer vids or the training missions, is it something to even worry about?

[sobek]

When should the (3 minute) alignment process be used, is it manually started? I don't remember seeing anything about it in the developer vids or the training missions, is it something to even worry about?

 

Yes, it starts the minute you turn on the INU switch.

[iceden]

TY gentlemen, that was quick. I'll check when I get home from my real life job. Thx.

[enigmatics]

Yes, it starts the minute you turn on the INU switch.

 

I take it you have to remain stationary during that time?

[Kwill]

I take it you have to remain stationary during that time?

 

You won't be moving anyway since you flip the INU switch pretty much at the beginning of the start-up procedure.

[enigmatics]

Hey, the tutorial claims it can be done in 30 seconds, 45 blindfolded :P. And there is always the cheat startup, Home-LWin. I've never timed myself, but I bet I could cut it fairly close to the three minute mark after the several dozen manual cold starts I've done if I tried. It would be good to know if I had to wait those three minutes or face inaccurate motion detection if I was making a scenario where take-off time was a top priority.

[sobek]

What most people forget is that going to auto on the condition lever is absolutely prohibited until the engine oil temps have reached the lower red marker (30°C i think, or is it 60°C?) in the real aircraft. That makes starting in under 3 minutes practically impossible.

[AlphaOneSix]

Correct, you are not supposed to advance the throttle levers past idle until both engine oil temps are above 30 degrees.

 

Also, there are several built-in time sinks that are ignored, such as waiting one minute between APU start and the first engine start, to ensure that the APU has reached a stable operating temperature, and waiting one minute between first and second engine start, to give the APU time to cool down a bit. That's two minutes right there. Add in the time for the engine oil to warm up on the second engine prior to advancing the throttle, and you've got almost three minutes on the ground and that doesn't even include flipping a single switch.

[EinsteinEP]

Within the constraints of the DCS game, about 120 seconds is as fast as I can start her up using my QuickStart procedure (I get that down to about 100 seconds, if using a macro). In comparison the LWin+Home cheat takes about 3 minutes (180 seconds), and it takes me 5-6 minutes when using my full ColdStart checklist. With the QuickStart, the HUD, ABRIS, and velocimeter need a few more moments to come online, but you don't really need those systems during the ingress. The assumption is that you're in a hurry and need to get wheels up NOW, so those systems can initialize en route.

 

In the game, I don't see any lasting negative effects from the QuickStart procedure (NAV error, AP dysfunction, etc.), and it helps me get back in the fight quickly in multiplayer matches. However, as AlphaOneSix points out, there are a number of time considerations that aren't enforced in the game or that don't have the same negative consequences in real life. Starting the engines immediately after one another, for example, or not waiting until the engines and gearbox have sufficiently warmed up before putting loads on them could result in immediate catastrophic failures. This sort of practice would definitely result in long term damage. You just don't treat multi-million dollar toys like that!

 

That said, this *is* a sim, so... ;)

Edited June 15, 2009 by EinsteinEP

[Boulund]

I've experimented a bit with speeding up the startup procedure and I've managed to get down to around 90sec if you really only start the systems necessary for spooling up the engines and getting the bird aloft. The rest of the equipment can be started enroute ;)

 

Here I was thinking it was dreadfully slow because I was aiming at that 45sec blindfolded =) Guess this is nowhere near possible IRL though...

[EinsteinEP]

I've experimented a bit with speeding up the startup procedure and I've managed to get down to around 90sec if you really only start the systems necessary for spooling up the engines and getting the bird aloft.

Boulund,

 

The APU takes 12 seconds to start and each engine takes 38 seconds which results in 88 seconds just to get the engines up to IDLE speed. The best I've been able to do from cold start to liftoff is about 100 seconds. Can you actually take off at "around 90 seconds"?! If so, would love to see a track of that, and/or whatever procedure you use! Are you able to start one engine while the other one is still starting? I couldn't get that to work... Whatever it is, I'm missing something!

[Boulund]

Boulund,

 

The APU takes 12 seconds to start and each engine takes 38 seconds which results in 88 seconds just to get the engines up to IDLE speed. The best I've been able to do from cold start to liftoff is about 100 seconds. Can you actually take off at "around 90 seconds"?! If so, would love to see a track of that, and/or whatever procedure you use! Are you able to start one engine while the other one is still starting? I couldn't get that to work... Whatever it is, I'm missing something!

 

Unfortunately I'm working out of town for the entire summer and don't have my computer with my saved tracks here with me. Maybe it was more like <100 sec rather than ~90, can't remember exactly. I timed my liftoff using the FPS-counter-feature in BS and thus started counting directly from pressing Pause/Break to unpause the simulation and stopped the timer when I got "Flight" on the EKRAN.

 

As far as I can remember I only flipped the battery switches, instantly flipped the fuel pumps and then brought up the APU, during the start of that I flipped the shutoff and cutoff and EEG for the other engines and brought them online one by one, only I didn't wait for the first to go to full idle (began starting the other ~60% instead of the regular 70+ or what it is). All other systems where started in flight later on. I surely forgot something in the procedure now because I'm a bit stressed to get off to work =) Catch you later

[AussieFX]

The twin squirrel (AS355F) needs two minutes in ground idle on each engine before they can be advanced to full power. Quickstart igniters in the engines can lower these times but they are very expensive. The only civilian helos (Gas turbine) I have seen that use them are medivacs although I would be surprised if the military didn't use them.

They have the added advantage of being able to shutdown immediately as well without having to wait for the 2 minute cooldown.

Edited June 15, 2009 by AussieFX

[EinsteinEP]

As far as I can remember I only flipped the battery switches, instantly flipped the fuel pumps and then brought up the APU, during the start of that I flipped the shutoff and cutoff and EEG for the other engines and brought them online one by one, only I didn't wait for the first to go to full idle...

 

OK! I use basically the same procedure, Boulund! I found that the fastest I can start the next engine is to watch the "START VLV" light on the starter panel: once it goes out you can flip to the next engine, but not a moment earlier. While the main engines are starting up, I go through the rest of the checklist (e.g., INU, NAV, Weapon, ABRIS, K-041 on, etc.), so that by the time the engines are up to full power, I can takeoff and not have any more button pushing/switch flipping to do in the air.

 

I'll post my checklist up, let me know if you can cut any corners off of it...

 

[edit: QuickStart procedure has been uploaded]

Edited June 16, 2009 by EinsteinEP

[EinsteinEP]

The twin squirrel (AS355F) needs two minutes in ground idle on each engine before they can be advanced to full power.

Aussie, is there some sort of control lockout that prevents the pilot for advancing the engines to full power? If not, what would happen if an impatient pilot stepped an engine up to full power as soon as he/she could (BTW, I'm not recommending you do actually try this!)?

[ericinexile]

Aussie, is there some sort of control lockout that prevents the pilot for advancing the engines to full power? If not, what would happen if an impatient pilot stepped an engine up to full power as soon as he/she could (BTW, I'm not recommending you do actually try this!)?

 

Assuming that you are talking about the real thing: your own sense of professionalism and career preservation.

[EinsteinEP]

Assuming that you are talking about the real thing: your own sense of professionalism and career preservation.

... because in the pilot-world, stepping a throttle forward on an engine that hasn't warmed up for some arbitrary time limit is equivalent to embezzling money from the Orphan's Fund?

 

Perhaps my earlier posts weren't clear, but I was trying to understand what would *actually* happen if the condition levers were prematurely advanced, not to determine whether or not it was a sensible thing to do. I concur it's not a sensible thing to do and am not proffering an opposing argument.

 

For example, in combustion engines, a "warm-up" period is to ensure adequate lubrication coverage within the moving parts of the engine as well as to help improve combustion efficiency (hotter chamber = more complete combustion). The short-term effect of not waiting for warm-up is reduced gas mileage, reduced performance, while the long-term effect is reduction of overall engine life including earlier degradation of performance due to wear. In older engines, performance was so bad during the warm-up period that they couldn't carry much of a load at all without bogging down or even stalling. Because of better design and computer-controls most people don't worry about warm-up time in their cars anymore.

 

Are these the same concerns in turbine engines?

[ericinexile]

^^^

 

Even more than IC engines, turbines depend entirely on lubricants to keeps moving parts from immediate failure. These fluids must reach an optimum temperature before further stress is placed on the engine.

 

...And that's just the engine. The gearbox has the same issues.

[sobek]

AFAIK it's not just the lubricant that has to warm up but the entire engine. For example, the A-10A manual states that if the engines have not been running for an adequate time before takeoff, the engine will suffer a thrust droop when going to takeoff power, because the housing and turbines will expand with different speeds and this causes the fan to not run up to takeoff RPM (at least that's my understanding of the manual ;)).