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DCS World Right Eng Start Problem


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That was easy to spot :) you left the apu generator off and went straight to starting engines. Need to review your startup checklist :)/

 

edit: not exactly certain that would cause the engine not starting or not, but definitely need the apu generator on.

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You'd be stupid if you'd not ask...

 

Here, there are no stupid question and you'll always find someone to help.

 

And yes, Welcome :thumbup:

DCS Wish: Turbulences affecting surrounding aircraft...

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The the left/right Main and Wing Boost Pumps are inoperative when the Left/Right AC Busses are not powered. The AC busses are not powered until APU or External power is applied. Turn the APU GEN switch ON, and all should be fine.

 

The left engine starts normally because there is an auxiliary fuel pump powered by the DC Essential Bus. The DC ESS BUS is available any time the BATTERY switch is ON.

 

You can diagnose your error by noting that there was no rise in ITT. If the Fuel Flow gauge idicates that fuel is flowing, you would know that its an ignition problem...i.e., there's fuel in the engine, but its not being burned.

 

In your track, there was no ITT and no FF...i.e., there's no fuel in the engine to be burned. This is verified by the presence of the R-FUEL-PRESS caution light. The L-FUEL-PRESS caution light is not on because the DC Fuel Pump is supplying pressure to the left side of the fuel system. If you open the Crossfeed Valve, the DC Fuel Pump will provide pressure to the right side as well, allowing the right engine to be started normally.

 

Two other notes, based on other comments made earlier in the thread:

 

1) A hung start is not universally caused by a lack of ignition. It typically occurs as a result of insufficient pneumatic duct pressure, resulting in the engine's inability to accelerate to idle RPM, despite successful "light off" indicated by positive ITT/EGT and FF indications. A hung start may, or may not result in a subsequent hot start. A hot start is when the ITT/EGT runs away due to insufficient airflow through the engine, or a major fuel control failure.

 

2) Motoring the engine does not burn off excess fuel, it simply blows it out the exhaust by using the starter to turn the engine without introducing ignition to ignite the fuel. Motoring the engine is something you would do after an unsuccessful start attempt, in which you observed a positive FF, but ignition did not occur.

 

In such a case, the unburned fuel can sit in the combustion chamber and ignite the next start. The result is not usually detrimental, but does produce a very large flame out the back of the engine. These flames have been cause for ground personnel to mistake them for an actual engine fire, and for flight attendants and passengers to initiate unnecessary evacuations of airplanes.

"They've got us surrounded again - those poor bastards!" - Lt. Col. Creighton Abrams

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Yes, but... I'm pretty sure something like this has happened to me as well when I've already put the power on, inverter on, fuel pumps on and APU ON AS WELL and still only managed to get the left engine starting. What's up with that?

 

Gotta make a track the next time it happens, if ever. And *AHEM* will gladly come clean as well if the problem actually turns out to be one existing between the chair and the keyboard ;):music_whistling:

 

PS. No random failures on ever, either.

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

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To add to what I already wrote, the playing around I was doing before hand was checking system dependencies for start up (actually I was trying to melt the engines, but anyway). The first thing I did was try a start with the inverter off (APU gen on) with the obvious result. I then tried cranking both engines at once (inverter still off). I then motored both engines individually. Then I wanted to actually get going, so I did my last experiment, and cranked #1 but only turned the inverter to standby when the engine was at max motoring RPM (trying for some kind of hot start). The engine lit normally. So, the status is: APU running, gen on. Inverter to SBY. Engine #1 running, but gen off the bus. Fuel boost pumps on. I then tried to start # 2, no joy (cranked, but no light up). Tiny daughter then demanded attention (she who cannot be denied!) and I had to stop. Wish I'd thought to record the track. Still don't know if I did something stupid. No random failures.

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Yep... I feel so stupid, Thanks everyone!

 

If you hadn't asked, I would have. Trying to give up the Win Home cheat startup and was encountering the same problem (faulty checklist I found in the forums was the culprit..and me for not following the training mission first!)

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Only because I'm sitting next to an ex-Alconberry a10 tech, I want to ask, are the circuit breakers modeled? He gave me an idea to test, to see what would happen in the sim:

 

1. start apu

2. pull igniter circuit breaker

3. start left engine (won't start) let motor a minute or so

4. push igniter circuit breaker in

5. profit :)

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Yes, the circuit breakers are functional in DCS.

 

You'd need to pull two circuit breakers, actually, but DCS doesn't simulate the torching/tailpipe fire you'd see if you tried such a stunt in the real jet.


Edited by BlueRidgeDx

"They've got us surrounded again - those poor bastards!" - Lt. Col. Creighton Abrams

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