A-star: Low Eng.oil Pressure & Engine Shutdown

[Skidz]

The FM always assumes you're flying the a/c in a way that will always allow for a "safe autorotation" at all times. In practical terms, if you're not in a situation where you can safely autorotate, I think you'll want to keep the engine going long enough to get to that point, after which you should shut 'er down. Cost of overhaul would be the least of my pre-occupations in that situation. I wouldn't want to keep her going until she siezed up either though. Too many "ifs" in that situation. The last thing you want is to be autorotating AND on fire, or having damaged MR or TR blades... :down:

[sirlandsalot]

Skids and H to the Y, excellent points. If you are on top of 100' trees on a 60Dergree slope, you might wanna at least get over a better auto spot...PDM! You could however have a problem with sudden stoppage and loose your rotor RPM and then it's going to hurt! I remember asking a high timer would you really shut your engine own if you expected a fire? and he said "**** ya! that's better than having your whole tail burn off on the way down"

[as350]

as350: 3rd time lucky w/ yer post, eh?. Thanks for being persistent!

 

Fer shur, look on the bright side. However, it's in the FM and seems kinda stupid to me. Does it seem stupid to you? Why shut down the engine? Maybe I'm stupid. Maybe that's what yer tryin' to tell me... t Am I talking to myself? Are you all laughing at me? ;)No... not being humourous at all very valid question just have confidence in the people around you. 90% of accidents/incidents are pilot error take care of things in the air and others will take care of things on the ground so you arent anticapating unforeseen disasters. fly safe

Cheers!

 

D'ick

[helidude]

This is just a thought but seeing as how the freewheel unit is lubed with engine oil, wouldn't running the engine until the oil is gone affect the freewheel unit's ability to properly operate? Maybe the residual oil inside it would be enough to do the job................. maybe not.........................

Do you keep her going and hope the freewheel holds up or do you shut her down and "successfully" autorotate in a less than ideal spot?

Think fast!!

[as350]

This is just a thought but seeing as how the freewheel unit is lubed with engine oil, wouldn't running the engine until the oil is gone affect the freewheel unit's ability to properly operate? Maybe the residual oil inside it would be enough to do the job................. maybe not.........................

Do you keep her going and hope the freewheel holds up or do you shut her down and "successfully" autorotate in a less than ideal spot?

Think fast!!

unlike other machines an astar ie bell will autorotate a long ways to safety

[Phil Croucher]

We had such a problem in a 355 in UK once. The book says to shut down the engine (Allison 250) within 30 seconds to avoid an inspection if the oil pressure goes, but this was not done - it is unknown how long it actually was. Anyhow, it was eventually shutdown successfully and it was discovered that most of it was on the verge of seizing, and not exploding.

 

I guess it's like anything else - you don't really know what's going on behind there. I work on the basis that as soon as something goes wrong it belongs to the insurance company, so I'll do whatever it takes to get it down safely. That is, sacrifice the machine to save the passengers. Having said that, my autorotation training is better than that for nursing sick engines. My personal choice is that if I can autorotate, shutting down the engine if it's likely to fail imminently gives me one less thing to worry about and secures the fuel system, etc. If it can give me that little bit extra when I need it, then try to use it.

 

Phil

[dimit]

Good discussion, gents. Let's keep the ideas/info coming!

 

Thanks,

 

DM

[Roger]

Very good thread!

 

For myself I can't imagine shutting down the engine. For me, the airframe and engine are now the property of the underwriters and I don't work for them.

 

All that counts now is saving my mothers 2nd eldest son and any occasional juggie/hooker that may be following me around.

 

On the rare occasions I fly a S/E helo. It's always a B3 and I admit the thought of engine/drive train malfunctions does cross my mind, mostly over 'Indian country'

 

I've adopted (against my will) the possibly false sense of security two engines normally gives me.

 

My personal planning in the AS350 oil pressure scenario is power to idle for the descent, and power recovery earlier than normal (Vs a training flight power recovery).

 

If it comes back long enough for a normal flare and landing..... Great! But I'd bring the power in long enough before the flare to know if it's going to play along.

 

If it doesn't, I'd inhale the seat cushion yet further, and do the best I can with what I have to work with. Which is basically the same as if you lost the engine during a normal flare to land.

 

I don't claim its the only or best answer. But I prefer this than to auto into a hostile environment engine out...

 

All this predicated on having some height. Low level (normal environment) I'd just take it down at the first suitable or semi suitable site available with whatever power I still have...Just my 5 cents...

 

Best Rgds..Rog

[skullcap]

This is just a thought but seeing as how the freewheel unit is lubed with engine oil, wouldn't running the engine until the oil is gone affect the freewheel unit's ability to properly operate? Maybe the residual oil inside it would be enough to do the job................. maybe not.........................

Do you keep her going and hope the freewheel holds up or do you shut her down and "successfully" autorotate in a less than ideal spot?

Think fast!!

 

 

Even though the freewheel unit is supplied by engine oil it would not matter if you lost oil pressure as the freewheel unit is like a reservoir that is being replentished by engine oil. There is no flow. So unless the freewheel was leaking like a sieve you'd still have oil to do the auto.

 

Personally. the situation would drive the procedure, if high over open flat terrain with a bit of wind. would shut it down. If low over trees, going for the landing power on.

[TwistedSpar]

I think common sense will prevail, unfortunately, i think many have forgotten that extra carry on bag where they packed all of it...

 

anyway....over 100ft trees, I think most would avoid an engine shutdown and the ensuing auto, and would opt for the landing at the next possible location asap, basic common sense.....some would do otherwise :shock: ....I believe they are connected to darwin in some way shape or form.

 

 

To comment further in regards to Skullcaps post....yes, the freewhell will retain some oil, depending of course the where and why you lost it in the first place....the question is how much, and do you really want to find out what the result would be??? we're back at square one...just wondering if we want to roll the dice or not....