one Week of fun!
Thread Starter
one Week of fun!
Well thought I’d let everybody know about my interesting week.
Just spent two weeks fighting fire, somewhere… And in the span of those two weeks, managed to have 2, nope not one, but 2, unrelated chip lights.
First one, just lifted off a rock outcrop, having dropped off some equipment, the trans chip light flickers, I notice it, and decide to go towards safer climes (i.e. OFF the fire) and start a gentle climb and depart the area. Safe landing is about 20 nm away.
The light flickered a few times, but when it got on solid, I landed. No more for me, as I am already sweating bullets by then.
Sure enough, an engineer pulls a chip of the detector, and we ran the machine under various stress levels, before we returned the machine to service. All fun and games, keeping a close look at the panel, but nothing happes.
Then a few days later, on a different fire, in a different part of the country, out early in the morning, doing scanning, when the ENG CHIP light comes on… (By now I figure I’m cursed so to hell with it, I landed in the first available spot, and did a normal shut down. All is well, other than a light… but pulling the plug there is metal on both of them (this is in a 206B3).
Same thing again, pull the plugs off, clean them and then run for a while, to make sure no more come on. Nothing did, but the officials released us from the contract to go and figure hat is wrong with the machine… lotsa rain anyways, and due for some time off as well.
So now a week later, no more problems, and nothing found in the engine…. What caused the problems?
other than that the trip was uneventful...
so there ya have it, one Week of fun!
Just spent two weeks fighting fire, somewhere… And in the span of those two weeks, managed to have 2, nope not one, but 2, unrelated chip lights.
First one, just lifted off a rock outcrop, having dropped off some equipment, the trans chip light flickers, I notice it, and decide to go towards safer climes (i.e. OFF the fire) and start a gentle climb and depart the area. Safe landing is about 20 nm away.
The light flickered a few times, but when it got on solid, I landed. No more for me, as I am already sweating bullets by then.
Sure enough, an engineer pulls a chip of the detector, and we ran the machine under various stress levels, before we returned the machine to service. All fun and games, keeping a close look at the panel, but nothing happes.
Then a few days later, on a different fire, in a different part of the country, out early in the morning, doing scanning, when the ENG CHIP light comes on… (By now I figure I’m cursed so to hell with it, I landed in the first available spot, and did a normal shut down. All is well, other than a light… but pulling the plug there is metal on both of them (this is in a 206B3).
Same thing again, pull the plugs off, clean them and then run for a while, to make sure no more come on. Nothing did, but the officials released us from the contract to go and figure hat is wrong with the machine… lotsa rain anyways, and due for some time off as well.
So now a week later, no more problems, and nothing found in the engine…. What caused the problems?
other than that the trip was uneventful...
so there ya have it, one Week of fun!
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Chip lights:
Chip lights are designed to be an indication that something is coming apart but doesn't necessarily mean that the failure is imminent.
In many fixed wing turbo prop aircraft the engine chip lights are disabled in flight by the weight on wheels switch. If an engine is making metal you won't get an indication until after you land.
I had an engine once that started to howl (beaing noise) I decided to land and on approach the engine chip light came on; in this case the engine was coming apart. Landing with a chip light is NEVER a WRONG choice and with a gear box chip light it is ALWAYS the RIGHT CHOICE!
Chip lights are designed to be an indication that something is coming apart but doesn't necessarily mean that the failure is imminent.
In many fixed wing turbo prop aircraft the engine chip lights are disabled in flight by the weight on wheels switch. If an engine is making metal you won't get an indication until after you land.
I had an engine once that started to howl (beaing noise) I decided to land and on approach the engine chip light came on; in this case the engine was coming apart. Landing with a chip light is NEVER a WRONG choice and with a gear box chip light it is ALWAYS the RIGHT CHOICE!
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An engineers view
I'm a type rated engineer on 206 & 212.
In the past I spent 3 years in a lab doing nothing else but analyzing debris on chip plugs, filters & SOAP (oil) samples. (very boring).
Engines & gearboxes have hundreds of metal parts rotating at high speed, under enormous pressure, high temperatures & the only thing separating these parts is a microscopic layer of oil.
Under these conditions you can be sure that the metal parts will wear & produce metal debris.
Some designs of engines/gearboxes produce very little debris (jet Ranger falls into this category). Others like the G/boxes on S58/Wessex continuously produce wear debris.
If on your B3 you are going many flight hours between chip lights on the same componant, say (25 hrs +) and when you inspect the chip plug you only find a small quantity of very fine debris or the occaisional small "hair" then you dont have a problem.
If you regularly get a chip light on the same componant or when you inspect the plug there are several pieces of coarse debris.
Or you get more debris on the chip plug during the post maintenance ground run, then you have probably got a problem.
There are clear guidelines for this in the Maintenance Manual.
Sounds like you & your engineer did it by the book, no worries.
Sounds like the officials who released you from the contract were looking for an excuse to save money, or they know nothing about helicopter maintenance, probably both.
In the past I spent 3 years in a lab doing nothing else but analyzing debris on chip plugs, filters & SOAP (oil) samples. (very boring).
Engines & gearboxes have hundreds of metal parts rotating at high speed, under enormous pressure, high temperatures & the only thing separating these parts is a microscopic layer of oil.
Under these conditions you can be sure that the metal parts will wear & produce metal debris.
Some designs of engines/gearboxes produce very little debris (jet Ranger falls into this category). Others like the G/boxes on S58/Wessex continuously produce wear debris.
If on your B3 you are going many flight hours between chip lights on the same componant, say (25 hrs +) and when you inspect the chip plug you only find a small quantity of very fine debris or the occaisional small "hair" then you dont have a problem.
If you regularly get a chip light on the same componant or when you inspect the plug there are several pieces of coarse debris.
Or you get more debris on the chip plug during the post maintenance ground run, then you have probably got a problem.
There are clear guidelines for this in the Maintenance Manual.
Sounds like you & your engineer did it by the book, no worries.
Sounds like the officials who released you from the contract were looking for an excuse to save money, or they know nothing about helicopter maintenance, probably both.
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Chip lights are designed to be an indication that something is coming apart but doesn't necessarily mean that the failure is imminent.
A chip detector can't tell the difference between normal wear 'paste' and an important lump of metal that you can read the part number from.
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Technoprat,
Would you suggest any kit to continously monitor oil? I've seen some chip counters that give a continuous indication of hydraulic system life. This would give pilot a better state of knowledge about machine serviceability if the light came on. It would also help minimise unexpected chip lights...
Would you suggest any kit to continously monitor oil? I've seen some chip counters that give a continuous indication of hydraulic system life. This would give pilot a better state of knowledge about machine serviceability if the light came on. It would also help minimise unexpected chip lights...
Thread Starter
The powers that were, "assumed" I had declared an emergency both times, and thus decided the machine as unfit. only short term hire anyway, and the rains came that day (Guess when... lol). So the release would have come soon regardless.
Still ****ty tho, as I had a good run.
And you were right about not knoing ANYTHING about the operation of the machine... Perhaps I'll tell more later on some of the operational aspects of what we were doing...
Cheers
winnie
Still ****ty tho, as I had a good run.
And you were right about not knoing ANYTHING about the operation of the machine... Perhaps I'll tell more later on some of the operational aspects of what we were doing...
Cheers
winnie
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Graviman,
Seems to me crew have to many guages, lights, horns to monitor already.
If you've got a chip light or any other indication of a malfunction, check all the other indicating systems for that component.
If you've got a transmission chip light but the oil pressures, oil temp & oil temp light are good & you cant hear/feel anything nasty then you're probably not about to fall out of the sky.
When you talk to your Engineer tell him what all the indications were showing, we like information.
Seems to me crew have to many guages, lights, horns to monitor already.
If you've got a chip light or any other indication of a malfunction, check all the other indicating systems for that component.
If you've got a transmission chip light but the oil pressures, oil temp & oil temp light are good & you cant hear/feel anything nasty then you're probably not about to fall out of the sky.
When you talk to your Engineer tell him what all the indications were showing, we like information.
Thread Starter
That is exactly what the engineer told me too...
Also when he pulled the chip of the plug he said "Not big enough for a part number, so you're good to go!"
Turned out OK, but they have now sent the engine in for analysis, because there were LOTS of chips, but they stopped after a while.
Also when he pulled the chip of the plug he said "Not big enough for a part number, so you're good to go!"
Turned out OK, but they have now sent the engine in for analysis, because there were LOTS of chips, but they stopped after a while.
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CAPT:
Chip detectors are not disabled in ALL turbo-props, only some models-early Dash-8s as example.
I guess the logic behind disabling chip detectors in flight is that pilots won’t be distracted by nuisance chip lights.
The Pilatus PC-12, when first certified in Canada was certified with the engine chip detectors disabled in flight. After an accident at Clarencville Newfoundland in 1998- attributed to engine failure- Transport Canada mandated that they chip detectors be enabled in flight in all single engine aircraft engaged in “commercial”single engine IFR operations.
Here’s an excerpt from the 1998 Transportation Safety Board (TSB) report.
“ The design feature of the chip detector installed on this aircraft was such that indications to the cockpit were disabled whenever the landing gear was retracted; therefore, this installation did not meet the requirements of the standard governing the transport of passengers in single-engined aircraft, Commercial Air Service Standard (CASS) 723.22”
Full report here:
http://www.tsb.gc.ca/en/reports/air/...7/a98a0067.asp
Chip detectors are not disabled in ALL turbo-props, only some models-early Dash-8s as example.
I guess the logic behind disabling chip detectors in flight is that pilots won’t be distracted by nuisance chip lights.
The Pilatus PC-12, when first certified in Canada was certified with the engine chip detectors disabled in flight. After an accident at Clarencville Newfoundland in 1998- attributed to engine failure- Transport Canada mandated that they chip detectors be enabled in flight in all single engine aircraft engaged in “commercial”single engine IFR operations.
Here’s an excerpt from the 1998 Transportation Safety Board (TSB) report.
“ The design feature of the chip detector installed on this aircraft was such that indications to the cockpit were disabled whenever the landing gear was retracted; therefore, this installation did not meet the requirements of the standard governing the transport of passengers in single-engined aircraft, Commercial Air Service Standard (CASS) 723.22”
Full report here:
http://www.tsb.gc.ca/en/reports/air/...7/a98a0067.asp
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Technoprat
"If you've got a transmission chip light but the oil pressures, oil temp & oil temp light are good & you cant hear/feel anything nasty then you're probably not about to fall out of the sky".
What a ridiculous statement.Whats the point in having chip lights?You suggest pressure and temp indications are good enough.When you "hear or feel something nasty" it is probably too late to do anything about it.You only have one MGB!
There are also commercial considerations to continuing flying while your engine/mgb disentgrates behind you.Shop repairs/overhaul can be expensive and more so if chip lights are neglected.
I suggest you return to testing oil samples for debris.A business which plays an important role in trend mointoring and fore warning responsible operators of impending $$$$.
"If you've got a transmission chip light but the oil pressures, oil temp & oil temp light are good & you cant hear/feel anything nasty then you're probably not about to fall out of the sky".
What a ridiculous statement.Whats the point in having chip lights?You suggest pressure and temp indications are good enough.When you "hear or feel something nasty" it is probably too late to do anything about it.You only have one MGB!
There are also commercial considerations to continuing flying while your engine/mgb disentgrates behind you.Shop repairs/overhaul can be expensive and more so if chip lights are neglected.
I suggest you return to testing oil samples for debris.A business which plays an important role in trend mointoring and fore warning responsible operators of impending $$$$.
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Chip lights
Some companies have fuzz burners which get rid of small particles and give the pilot an indication as to how serious the chip is while Aerospatial/Eurocopter had a system of measuring the area of debris and changing the box when the limit was reached. Again on a PT6 combining gear box I have had a chip warning that was due to an entire tooth coming off that was so big it prevented the self sealing on the chip detector closing but had no other obvious effect,ie vibration or oil pressure changes so take your pick but landing promptly seems a good idea.
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Here's an example of a MGB coming apart and then getting a chip light.
NTSB Identification: NYC94FA106 .
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
14 CFR Part 91: General Aviation
Accident occurred Thursday, June 30, 1994 in NEWPORT, RI
Probable Cause Approval Date: 3/27/1995
Aircraft: SIKORSKY S-76B, registration: N76UT
Injuries: 3 Uninjured.
AFTER DISCHARGING PASSENGERS ON AN ISLAND, THE S-76 HELICOPTER DEPARTED FOR A RETURN FLIGHT TO THE MAINLAND. ONE MINUTE AFTER TAKEOFF, AT 500 FEET ABOVE THE WATER, A VIBRATION FOLLOWED BY A LOUD BANG OCCURRED. THE MAIN GEAR BOX (MGB) CHIP LIGHT ILLUMINATED AND THE NUMBER ONE ENG DROPPED OFF LINE. A FORCED LANDING WAS INITIATED, THE EMERGENCY FLOATS WERE INFLATED AND A DITCHING TO WATER WAS ACCOMPLISHED. THE NUMBER ONE ENG WAS SHUT DOWN, AND THE ACFT WAS WATER TAXIED ON THE SECOND ENG. AFTER A SECOND BANG WAS HEARD THE NUMBER TWO ENG WAS SHUT DOWN. EXAMINATION REVEALED THAT THE LEFT HAND (NUMBER ONE ENG) HELICAL GEAR IN THE MGB, FAILED FROM FATIGUE CRACKS ACROSS THE 12 ATTACHING BOLT HOLES. THE TORQUE REQUIRED ON THE 12 NUTS WAS 4OO INCH POUNDS. THREE NUTS HAD LESS THEN 60 INCH LBS, THE REMAINING NINE HAD NO TORQUE. BOTH MGB OIL PUMPS WERE SEIZED FROM FOD THAT ENTERED THE PUMPS THROUGH AN ALTERNATE OIL PATH, THAT BY-PASSED THE OIL SCREENS. THE NUMBER TWO ENG PINION GEAR IN THE MGB, FAILED DUE TO OVERHEATING FROM THE LACK OF LUBRICATION. ELAPSED TIME WAS LESS THAN 6 MINUTES FROM INITIAL FORCED LANDING TO SECOND ENGINE SHUT DOWN.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
the failure of the left hand helical gear in the main gear box (MGB), due to undertorqued attaching bolts installed by the manufacturer, which resulted in a partial MGB failure. This failure resulted in the loss of the number one engine, illumination of the MGB chip light and a ditching to salt water on emergency floats.
Full narrative available
NTSB Identification: NYC94FA106 .
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
14 CFR Part 91: General Aviation
Accident occurred Thursday, June 30, 1994 in NEWPORT, RI
Probable Cause Approval Date: 3/27/1995
Aircraft: SIKORSKY S-76B, registration: N76UT
Injuries: 3 Uninjured.
AFTER DISCHARGING PASSENGERS ON AN ISLAND, THE S-76 HELICOPTER DEPARTED FOR A RETURN FLIGHT TO THE MAINLAND. ONE MINUTE AFTER TAKEOFF, AT 500 FEET ABOVE THE WATER, A VIBRATION FOLLOWED BY A LOUD BANG OCCURRED. THE MAIN GEAR BOX (MGB) CHIP LIGHT ILLUMINATED AND THE NUMBER ONE ENG DROPPED OFF LINE. A FORCED LANDING WAS INITIATED, THE EMERGENCY FLOATS WERE INFLATED AND A DITCHING TO WATER WAS ACCOMPLISHED. THE NUMBER ONE ENG WAS SHUT DOWN, AND THE ACFT WAS WATER TAXIED ON THE SECOND ENG. AFTER A SECOND BANG WAS HEARD THE NUMBER TWO ENG WAS SHUT DOWN. EXAMINATION REVEALED THAT THE LEFT HAND (NUMBER ONE ENG) HELICAL GEAR IN THE MGB, FAILED FROM FATIGUE CRACKS ACROSS THE 12 ATTACHING BOLT HOLES. THE TORQUE REQUIRED ON THE 12 NUTS WAS 4OO INCH POUNDS. THREE NUTS HAD LESS THEN 60 INCH LBS, THE REMAINING NINE HAD NO TORQUE. BOTH MGB OIL PUMPS WERE SEIZED FROM FOD THAT ENTERED THE PUMPS THROUGH AN ALTERNATE OIL PATH, THAT BY-PASSED THE OIL SCREENS. THE NUMBER TWO ENG PINION GEAR IN THE MGB, FAILED DUE TO OVERHEATING FROM THE LACK OF LUBRICATION. ELAPSED TIME WAS LESS THAN 6 MINUTES FROM INITIAL FORCED LANDING TO SECOND ENGINE SHUT DOWN.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
the failure of the left hand helical gear in the main gear box (MGB), due to undertorqued attaching bolts installed by the manufacturer, which resulted in a partial MGB failure. This failure resulted in the loss of the number one engine, illumination of the MGB chip light and a ditching to salt water on emergency floats.
Full narrative available
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Waffler
Please re read my previous posts.
I am not suggesting you fly around ignoring the chip light.
I am suggesting you use other indications that are available to you to decide how urgent the situation is.
Depending on which aircraft you are flying the Flight Manual tells you what action to take when you get a chip light.
It will probably say something like "land at the nearest safe place".
By cross checking your G/box chip light with pressure, temp & vibration indications you can make an informed judgment as to wether the water directly below you is a safe place or if it might be safer to fly 10-20 mins to your operating base.
In the example given by IHL, the chip light was accompanied by many other indications that made it clear to the crew that ditching was the only option.
Please take the time to read and understand a post before issueing personal insults. If you dont understand the information given, then ask further questions rather than flaming me.
I am not suggesting you fly around ignoring the chip light.
I am suggesting you use other indications that are available to you to decide how urgent the situation is.
Depending on which aircraft you are flying the Flight Manual tells you what action to take when you get a chip light.
It will probably say something like "land at the nearest safe place".
By cross checking your G/box chip light with pressure, temp & vibration indications you can make an informed judgment as to wether the water directly below you is a safe place or if it might be safer to fly 10-20 mins to your operating base.
In the example given by IHL, the chip light was accompanied by many other indications that made it clear to the crew that ditching was the only option.
Please take the time to read and understand a post before issueing personal insults. If you dont understand the information given, then ask further questions rather than flaming me.
