Why did I just flame-out?

[scott heger]

Ok, after watching Cody's inspirational armchair piloting skills cartoon:

http://worteldrie.com/flash/emergency.swf



here goes another........

You are flying along at 120 knots at 5800 feet MSL in a turbine Bell (Jet or Long Ranger) Helicopter. What (combined or by itself) switch, circuit breaker, flight control, or enviormental condition(weather or other) will/can result in a engine flameout within a few seconds? Hint, there are many answers.


Scott Heger, Laguna Niguel, Ca N85SH

[WVLeTendre]

In regards to an engine flameout in a Bell 206 B-3, L-1, or L-3, with a Rolls Royce (used to be Allison) 250-C20, C28 or C30 engine, as far as switches or engine controls go, the fuel valve switch being turned to the off position, or throttle control being shut off comes to mind and maybe icing conditions (if the anti-ice is not functioning). Not much else I can think of with that much information in the Bells (configured for Gulf coast oilfield operations) the company I work for operates.
Did you have a flameout?

[brett s]

Really heavy precipitation, fuel pump turned off/breaker pulled/failed, fuel shut off, fuel selector set on wrong tank, perhaps the aircraft attitude if really low on fuel unporting a fuel pickup all come to mind - never flew or worked on the 206 though so these are generic things that affect many types :)

[WVLeTendre]

Yup, lots of ways to get in some autorotation practice!:D

[Al_Hammer]

Some guesses, since I have only a few minutes of time in the Jet Ranger.

Flying in snow, engine de-ice turned off or bleed air breaker pulled. Auto relight kit not installed. one or both boost pump switches off, idle detent pushed and throttle rolled off.

[scott heger]

Brett, your the first one caught wrong.
There is no fuel tank selector switch on these helicopters. Jet rangers have one tank behind the back seat, L-Models have 3 tanks(two extra under each middle seat).

The helicopter has three fuel pumps, two electric "booster" pumps and a engine driven fuel pump. The helicopter can be legally(but not very smart) flown with both electric fuel boost pump failed below 6,000 feet MSL. Over that altitude at least one booster pump has to be funtioning.

There are other conditions not yet mentioned, you guys have got the obvious ones so far.

Scott heger, Laguna Niguel, Ca N86SH

[Cobra Doc]

Scott, every OH-58 I recovered due to flame out had the same cause: The cover over the pilot's faceshields on the SPH-4 helmet snagged the fuel pump circuit breaker. It took us a long to to figure out why those circuit breakers were "popping" with out an electrical fault! We only figured it out when one of the taller pilots actually broke the circuit breaker and it stayed in the cover on his helmet.

[scott heger]

Cody, mine are push-pull types, hitting them would have no effect on causing a failure(in position is on). Were they toggle type ones on OH-58's?



Scott heger, laguna Niguel, Ca N86SH

[Cobra Doc]

No, push-pull. If you are familiar with the old style SPH-4, the the lip on the breakers would catch on either the shield cover or the knob itself. When I did it, I got the landing light breaker caught in the slot on the shield cover. Stupid WO pilot just laughed at me. No help at all.

[scott heger]

I have a SPH-5, I will keep that in mind. Stiil those guys must have been high to flame-out the engine, even without the boost pumps on. Or they had a bad engine driven pump, but that should have made it quit before they took off on a normal preflight or postflight check.

Scott heger, laguna Niguel, Ca N86SH

[Al_Hammer]

I'm out of ideas, but maybe these photos will help those still pondering Scott's question.

[Cobra Doc]

Scott, I don't think the hard-hat has as many open spaces as the -4. It was always on the OH-58A. High altitude for the Army is 50' above the trees. They usually had just enough time to recognize a power loss and park it. Flying NOE you don't care about how or why, just what and get down. My most interesting recovery was a night landing in the top of a huge oak tree. Once we actually found the helicopter, 30' up, it was easy to figure out how the pilot broke his ankle! Naturally the fuel breaker was "popped". Since the 58s didn't have ECUs, I don't know how that could affect the engine. The Snake ECU is powered by bleed-air. Almost everything on the G-Snake was bleed-air. ECU, rain control, TOW rack jacks, etc.

[scott heger]

Ok, Ill give up a enviormental condition answer.......
Hovering over or flying close above a power plant smokestack can/will result in a flameout do to lack of oxygen for the motor. Several helicopter pilots have found this out the hard way.


Scott Heger, Laguna Niguel, ca N86SH

[Cobra Doc]

That's a good one Scott. Makes you wonder about the word fire attack pilots pilots fly in, both fixed and rotorwing. In most of my flying, my pilots only had enough time to figure out if the aircraft would get us to safe LZ or identify the softest tree that would give us the best chance at survivability. From the descriptions I see about most gyro flying, gryo pilots may need to take a few pages from the Army's handbook.

[Al_Hammer]

How about this:

According to historical records, there have been a series of engine flameout related accidents and incidents related to this engine make and model. Controlled tests have demonstrated that should entrapped air migrate through the fuel system to the engine, an engine flame out can occur.
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001208X08415&key=1

After a water drop which involved an abrupt pull up and turn after the water was released from the bucket, he reported hearing the words 'May Day,' 'I have a flame out'

[scott heger]

There are alot of mechanical reasons for a engine to quit. Most flameouts are fuel starvation related (thats a Hint for another answer). Another common one is broken fuel (air)control line or throttle bolt. This normally causes the engine to go to flight idle, which doesnt help you fly very well. For the purposes of this discussion, lets keep to the ones that are pilot induced.

Cody, most brush fires are very inefficient users of oxygen, which leaves alot still in the air. On the other hand, power plants get a much "cleaner' complete burn, not leaving much oxygen above the smokestacks. It is not much different than a poor burning campfire, which is smoky. Get it really hot , and there is almost no smoke.

Scott Heger, Laguna Niguel, Ca N86SH

[Al_Hammer]

Well, my point was that the flameout was pilot induced, in part.
the report says,
"Also causal was the ingestion of entrapped air that occurred during an abrupt maneuver "

[Cobra Doc]

As long as it wasn't Crew Chief induced!! Can a 206/58 maneuver abrutly enough to cause an entrappment?

[Al_Hammer]

Cody , I don't know.

Along with smokestacks...Don't fly over active volcanos.

Glass from melting volcanic ash will coat fuel nozzles, the combustor, and turbine, which reduces the efficiency of fuel mixing and restricts air passing through the engine. This causes surging, flame out, and immediate loss of engine thrust. Ash may also seriously erode moving engine parts, including the compressor and turbine blades, which reduces the efficiency of the engine.
http://volcanoes.usgs.gov/Hazards/Effects/Ash+Aircraft.html

[Cobra Doc]

Al, I've heard that from the heavy metal guys and Piper Meridian drivers. I also saw an AH-64 burp an engine during a snap-roll at TOI. Long story behind how and why, but he was at tower cab altitude. The choice was roll it or smack a NORDO Pawnee. Good thing the 64 has two engines. I'm still curious about the fire dogs.

[Al_Hammer]

NORDO=no radio. TOI= target of interest. Pawnee= Ag plane, OK, got it. :D

[Cobra Doc]

TOI: LA; Lower Alabama. Where David Holmes hangs out with Wiley's crew and drinks Wliey's beer and watches, uhmmm.., sattelite TV. Also know for the place that Sikorsky fixes some of the Army's more spectaular UH-60 screw-ups. Also the no-mans land between Maxwell AFB and Ft Rucker. Where the Whitting T-34C instructors go to hide from Ops. Also know for a spectaular volleyball pit courtesy of the USAF for ordering way too much sand for the NAVAID upgrade installation. Also where all the Trojans come from. The university there also used to have a decent football team, named for the towns #1 product. Or was it the other way around?

[WVLeTendre]

One of the maintenance checks we do at work on 206's is to run them at 100% on the ground with no boost pump pressure for 2 minutes. That way the engine drivin fuel pump is feeding the engine by sucking the fuel out of he tank. It doesn't take much of a leak to flameout the engine!

[scott heger]

Ok, here is another one........

If you fly with a low fuel condition, (even if still legal minimims) steep banking and turning can empty both the front and rear fuel pickups to suck just air, with the flameout not far behind.

I am on my way to Texas tomorrow to pick up a car with my son. I will be back Saturday night. I will post The VERY BEST(dumbest)flameout I have ever heard of then. See what else you guys can up with before.

Al H., I am very familar with the accident you mentioned. I am in the hanger that the pilot involved used to have. Bell Helicopter was ordered to pay 8.6 million to his family from this incident. Floyd Hiser owned a successful flight school in Corona before his death. The check valves were a known problem to Bell that had not been corrected. Very sad.

Scott Heger, Laguna Niguel, Ca N86SH

[Cobra Doc]

Sucking snow in a UH-1 from a rotor induced white-out, Hwaaksan, ROK. Never try to land a Huey in 18" of fresh powder unless you really know what you are doing.

[karlbamforth]

Not a flame out but an embaressing incident.
Military twin helo, pilot getting a check ride from an instructor. At some point the instructor closed both throttles to simulate double engine failure, the pilot duly entered auto rotation and chose a suitable field. Everything was going as planned when the instructor said words to the effect of "OK I seen enough, climb away" As the pilot pulled in collective the rotor rpm drooped and everyone realised way too late that the throttles were still at Flight-idle. The pilot transmitted a mayday whilst attempting to cushion the inevitable landing. The aircraft landed upright but slow rolled destroying the rotors and causing major damage. The good news is there were no injuries other than ego and those sustained from ribbing in the bar.

[scott heger]

Ok, back from Texas. Here is a good reason to destroy a helicopter, it needs washing.....

NTSB Identification: LAX92LA159 .
The docket is stored on NTSB microfiche number 46200.
14 CFR Part 91: General Aviation
Accident occurred Tuesday, March 31, 1992 in KAAAWA, HI
Probable Cause Approval Date: 8/13/1993
Aircraft: BELL 206BIII, registration: N3200N
Injuries: 1 Uninjured.
THE PILOT SAID THAT AFTER CONCLUDING THE DAILY TOUR CONTRACT WITH THE HELICOPTER IT WAS TO BE PARKED AT A HANGAR NEAR THE ACCIDENT SITE. ENROUTE TO THE HANGAR THE HELICOPTER WAS INTENTIONALLY FLOWN NEAR A FARM IRRIGATION SPRINKLER SYSTEM IN AN ATTEMPT TO WASH OFF THE ACCUMULATED DIRT. AFTER THE SECOND PASS THROUGH THE WATER STREAM, THE ENGINE OUT WARNING LIGHT AND AUDIO WARNING WAS ACTIVATED AND THE ENGINE QUIT. THE HELICOPTER LANDED HARD DURING THE SUBSEQUENT AUTO ROTATION TO AN UNIMPROVED DIRT ROAD.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:

AN ENGINE FLAME OUT DUE TO THE PILOT'S INTENTIONAL FLIGHT THROUGH AN IRRIGATION SPRINKLER SYSTEM WATER STREAM IN ORDER TO WASH THE HELICOPTER.

Sometimes you have to wonder. Bet you never heard a JetRanger crashing while taking a bath.


Scott Heger, Laguna Niguel, Ca N86SH

[Al_Hammer]

Scott, that's a good one.

[Cobra Doc]

Can you imagine the loss of revenue for having a dirty tour helicopter?