STUPID HELICOPTER WONT START

[wbrady755]

So I was going out for a night flight last night, and our R44 would not start, or even turn over. I get that piston engines have their intricacies, but this is the third flight that I have cancelled in as many months. Does anyone have any suggestions on how to get it to turn over?

 

-IO-540 (fuel injection)

-Started cold, no flights that day

-Tried priming the engine with the AUX pump for 20 seconds after 3 failed starts (in case we made a vapor lock)

-Let the starter cool down, repeated with another 3 start attempts.

[Astro]

What does your mechanic say?

[iChris]

R44 would not start, or even turn over

 

But this is the third flight that I have cancelled in as many months. Does anyone have any suggestions on how to get it to turn over?

 

Let’s clarify your question. “R44 would not start, or even turn over.”

 

The engine won’t start and/or hard to start or the engine won’t crank (turn over). Since you’re talking about priming, I assume the engine is cranking (turning over).

 

You need hands on from your A&P, if this is on-going. Sounds like you may have some sort of intermittent electrical connection issue if the engine will not crank (turn over). When all else fails, get the book out.

 

Edited September 12, 2016 by iChris

[Doug D]

So I was going out for a night flight last night, and our R44 would not start, or even turn over. I get that piston engines have their intricacies, but this is the third flight that I have cancelled in as many months. Does anyone have any suggestions on how to get it to turn over?

 

-IO-540 (fuel injection)

-Started cold, no flights that day

-Tried priming the engine with the AUX pump for 20 seconds after 3 failed starts (in case we made a vapor lock)

-Let the starter cool down, repeated with another 3 start attempts.

 

Well, a 20 sec prime and you most certainly flooded it. Try a 4-5 second prime (cold engine) and then start. A good indication of over prime is fuel dripping from the sniffle drain. If so, let it sit for 5 minutes so the excess fuel can evaporate then try a start. Don't be "that guy" who cranks and cranks and cranks and engine. If it doesn't fire off in a couple seconds then you need to do something else. Engines need air, fuel and spark. On the IO-540 start its most likely too little or too much prime. Too little prime is usually indicated by a backfire due to a overly lean condition in the cylinders. Even though the engines is the same between multiple Raven II's not everyone starts the same. Find what works and roll with it. Also, your not going to have vapor lock on a cold engine.

[wbrady755]

 

Well, a 20 sec prime and you most certainly flooded it. Try a 4-5 second prime (cold engine) and then start. A good indication of over prime is fuel dripping from the sniffle drain. If so, let it sit for 5 minutes so the excess fuel can evaporate then try a start. Don't be "that guy" who cranks and cranks and cranks and engine. If it doesn't fire off in a couple seconds then you need to do something else. Engines need air, fuel and spark. On the IO-540 start its most likely too little or too much prime. Too little prime is usually indicated by a backfire due to a overly lean condition in the cylinders. Even though the engines is the same between multiple Raven II's not everyone starts the same. Find what works and roll with it. Also, your not going to have vapor lock on a cold engine.

 

To clarify, we first attempted just a normal start with that 4-5 second prime. When we hit the starter, we slowly started moving the mixture in, but it didnt seem to "grab". We did this another two times, and THEN we tried a 20 second prime with the mixture out. I think we may have flooded it at that point. I think the biggest issue is we cant find that happy medium of fuel and air, so we start playing with the mixture too much. And then its shot for a while.

[r22butters]

Probably not the same issue, but,...

 

I did some night flying back in snow country and we had to direct a portable heater at the oil pan to get our Robby to turn over.

[Doug D]

 

To clarify, we first attempted just a normal start with that 4-5 second prime. When we hit the starter, we slowly started moving the mixture in, but it didnt seem to "grab". We did this another two times, and THEN we tried a 20 second prime with the mixture out. I think we may have flooded it at that point. I think the biggest issue is we cant find that happy medium of fuel and air, so we start playing with the mixture too much. And then its shot for a while.

Wait until the engine lights off before you advanced the mixture. You should be able to get it to begin to start and then add the mixture in. Priming with the mixture out just circulates fuel but does not inject it into the engine. You will not flood the engine with the mixture out. It could be the retard points timing on your left magneto could be off a bit and making it hard to start as well. Also, when the engine is fully warmed up, what is it idling at on the tach? It should be 58-62% but if its set too low this can make starting tough as well.

[wbrady755]

Wait until the engine lights off before you advanced the mixture. You should be able to get it to begin to start and then add the mixture in. Priming with the mixture out just circulates fuel but does not inject it into the engine. You will not flood the engine with the mixture out. It could be the retard points timing on your left magneto could be off a bit and making it hard to start as well. Also, when the engine is fully warmed up, what is it idling at on the tach? It should be 58-62% but if its set too low this can make starting tough as well.

Ok I can go easy on the mixture for sure.

 

As for the idle, it sits happy in the 58-62% area (once its started). At least thats the way it used to be when I could actually get it running...

[iChris]

You’ve got a problem you’re trying to mitigate with all these gyrations in starting technique. The problem is bound to deteriorate to the point of not being able to start at all. Anytime you have a situation that deviates far outside the normal starting procedures in the flight manual, you need to isolate the true cause for the deviation.

 

Many of the small flight schools people rent from do very little if any preventive maintenance. They struggle just to get by, so what else can you expect. This is an issue you need to take up with whoever you’re renting from. When you pay out-of-pocket at the Robinson Safety Course you don’t expect to have problems starting their R44, so you shouldn’t expect to have problems with any other operator you pay out-of-pocket for. It’s a simple maintenance issue they need to take care of.

 

Many pilots aren't aware magnetos need minor tune-up at least every 200 hours and a major disassembly inspection, cleaning, lubrication and adjustment at least every 500 hours. The 500-hour major maintenance is frequently neglected, and it's not unusual to see an engine reach TBO without the mags ever having been removed. The fact that mags can continue to function in the face of such neglect is a testament to their reliability. Magneto performance deteriorates significantly if routine maintenance isn't done. This usually shows up as hard starting.

 

Again, when all else fails, get the book out. Intermittent ignition switch issues. Remember your ignition switch has multiple contacts and even though your engine cranks, any one of the remaining contacts covered with oxidation or corrosion could cause start problems.

 

Starter vibrator issues, most R44-IIs have the Slick-START module that provides the vibrator function. The Slick-START is a magneto start booster that uses solid-state electronics with capacitive discharge technology. Robinson Helicopters accounted for start issues with this Slick-START that boosts the magneto's electrical output to overcome hard starting issues caused by fouled spark plugs, poor priming, hot engine restarts, and extreme cold weather conditions. Here again, any faulty connections in or out of this module or a faulty module will result in problems starting the engine.

 

Moreover, don’t expect a good start with incorrect retard time. The retard magneto internal timing most be adjusted correctly. That should be all part of the minor mag tune-up.

 

 

 

Edited September 27, 2016 by iChris