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Starting 206L4


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It's not hard. Insure the throttle is closed, press the starter button, watch the N1 wind up to 12%, open the throttle very slightly until it lights off, and watch closely, moving the throttle slightly as necessary to control the temp. At 58% N1 release the starter button and insure the throttle is above the idle detent.

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I was told there was something that modulates? I don't think he said fadec.

 

​There is no FADEC on the L-4. The pilot modulates the start by controlling the fuel being introduced into the burner via the throttle.

 

Do keep keep adding fuel to keep a certain temp?

 

Yes, Rolls Royce advocates a fast, hot start. You will need to SLOWLY add more fuel at the N1 increases.

 

So if temp spikes retard throttle?

 

YES! In my experience(2000+ hrs L-4 time), if it appears to be getting hot, just close the throttle and abort the start. You can reduce the fuel and lower the TOT, but at least in our aircraft, the throttle is very sensitive and most times you will reduce the fuel to the point that the fire quits. Don't chase the start. Just close the throttle and cool the engine with the starter. Wait 60 seconds for the starter to cool and re-attempt the start. A little wait and embarrassment is way cheaper than chasing the start and cooking the engine.

 

Also, I had a Bell instructor show me years ago, watch the fuel pressure gauge as you add that initial fuel to the start. If you crack the throttle just enough to make the gauge "flicker" just a little, that will be about right.

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There are 2 types of fuel controls on the LR. A ceco, and a bendix as I recall off the top of my head. One auto modulates the fuel for start, the other is manual as has been described.

The manual start is easy once you have mastered it, but until then not so much.

It is easy to introduce too much fuel that would precipitate a hot start.

But you can back the fuel off to prevent it from going hot.

On that backing off move it's not hard to flame the engine out.

The ideal start with a healthy battery should be 30 seconds from lightoff, and around 45 seconds from starter engagement.

The optimum temperature band is in the yellow arc of the temperature gauge.

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The CECO and Bendix fuel controls are on the BIII, not the L series.

 

On an L*, if the temp seems to be going too high too quickly, you can back off the throttle just a touch, about as much as you can feel movement, and usually be OK. If it's going to be a hot start, the temp will usually climb very fast, and with experience you can tell what it's going to do before it even hits the yellow range by the rate of increase. If it's increasing slowly, I just let it go, as long as I don't think it will exceed 927. If you have a TOT gauge with the triangle, you don't even start your 10 second count until the temp is above it. I've done probably 10,000 starts or more over the years, and never had a temp exceedance. Close a few times, but never an exceedance. I have shut it down a few times, but that's to be expected once in awhile, if the fuel control settings aren't right, the engine is hot, and/or the battery is weak. Always check the battery voltage before starting, and if it's low, either get an external power source or don't initiate the start. Make sure you get the TOT below 150 before introducing fuel. Do all this, and the start should be unexciting. Just increase or decrease the throttle to keep the TOT near the low end of the yellow. If you're experienced, you can keep it in the high yellow, but for newbies, in the low yellow is fine.

 

The video start is poor technique, and can give a hot start. You want to start moving the throttle before you reach 12%, to insure you light off by 12%. Waiting until you have 14 or 15% or more to light can give you a very hot start. IME it's better to light off a little below 12% than above it. If the fuel control is properly adjusted, and few are, all should be fine in any case, but every control is different, and adjusted differently, and if you're not familiar with the start characteristics of the ship you're starting, be conservative. Don't wait too long to light it off. If the N1 gets too high, abort and start over.

Edited by Gomer Pylot
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Ahh... gotcha. Im sure you know this... but if you got the job, you are in. You'd probably be better to just show up being the guy they hired. Not trying to come in with information gained off of the internet. You would be better served teaching yourself how to do a W&B and studying the POH.

 

Here is a personal example... where I work now, we have a Huey. I had flown Hueys before left seat but I had never started one. I watched Youtube videos and watched in detail trying to see what every finger was doing so I could show up at least having an idea. One thing I never caught was the Idle stop button on the collected. Prior to start, roll the throttle to full, then back to the stop, then press the idle stop button and then just squeak the throttle back past the stop just a smidgen. I never noticed that being done in the videos or even read about it. There were other things too that i was taught when I went through the course.

 

So what I am saying is by watching and self teaching, there could be one critical step you miss that could be catastrophic because you didnt notice the guy in the video do something with a finger.

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Makes complete sense. But I wouldn't worry about trying to learn to start it. There is a lot of anxiety when you learn to start turbines that doesn't exist in pistons. (or maybe that was just me?) several gauges to watch all at once. It wont be a big deal at all. Your brain will figure out where to look and when to look there.

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How is starting an L4 different from starting a B3? Is it just the 12% N1 for introduction of fuel vs. 15%?

 

On that note, how is starting the civilian B3 different from starting a TH-67? How about an OH-58A/C?

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How is starting an L4 different from starting a B3? Is it just the 12% N1 for introduction of fuel vs. 15%?

 

On that note, how is starting the civilian B3 different from starting a TH-67? How about an OH-58A/C?

The differences between a B3 and L4 are big. Ceco's are pretty much a thing of the past. There are a few still out there though. On a B3 with a Bendix you roll on throttle to idle and just monitor. If it's setup right the TOT will rise pretty quick to the top of the yellow and the start will be quick.

 

On a L4 it's modulated start which means your in control of the fuel. Every long ranger I've flown is different. Some you barely move the throttle to light the flame. Others you have to roll on allot more. The L4 we have is aboauletly the easiest starting L model I've flown. We also have 2 L3's. One is almost as good as the L4 the other one is a b@**#. I have 700+ hours and prob 250 ish starts in it and it still tries to fire me every once in awhile. ;).

The only advice I have is go slow and easy until you get comfortable. As you get more turbine time you will learn the little quirks of each machine. Good luck!

Edited by helipilotm
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Even with a CECO, you start a B the same way - roll the throttle to idle and watch it. You can supposedly modulate slightly from the idle position with a CECO, but I never had much luck with it. If the start isn't right when you roll to idle, get maintenance to adjust it. But I doubt there are many, if any, CECO fuel controls left in use. We used to have a number of them, and in practice there is no difference in starting. Run it up to 15%, roll the throttle to idle, press the idle detent to make sure you can roll the throttle off if necessary, and watch. Kill if if you have to.

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