BELL 412 Transmission Oil Leak , Offshore
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ATTENTION BELL 412 OFFSHORE PILOTS
1.On 27 July 2010 I was flying a Bell 412 for offshore crew change in support of a floater about 100 miles away with 7 passengers on board.The co-pilot was on controls at cruise 2000 ft AMSL . Around 54 miles outbound the Transmission oil pressure light came ON, crosschecked with the oil pressure guage and found oil pressure at 30 psi and dropping. I immediately took over the controls and reduced power to approx 45%,commenced descent to 500 ft and turned towards the nearest landing site available, the coast line fortunately 17 miles away.Completed actions as per the RFM and warned the passengers of the emergency and likelyhood of landing on water.
2. Continued ,constantly monitoring the transmission temeprature which remained steady at 60 celsius and looking for any signs of further deterioration in terms of vibrations and increase in temeprature.Continued passing the the GPS position frequently to nearest control tower and other company aircrafts to make SAR easier. The pressure continued dropping and last noted was around 0 psi. Landed safely at the coastline away from the high tide line and switched off.
3. On inspection found last about 500 ml oil flowing from the hell hole.The inspection windows were empty and tail boom splashed all over.The GPS position was passed and within 5 minutes a dornier aircraft of indian navy who was monitoring the calls flew overhead and reported all safe to the control tower.Mobiles came in handy and within 5 minutes all concerned were contacted. The police and local help came soon thanks to 108 service of Andhra Pradesh (akin to 911 of USA).
4. Later it was found that a flexible hose in the system had given way.The hose was 24 yrs old ,8 yrs on shelf and 16 yrs on the aircraft.
5.Good CRM and cool Captain, Copilot and passengers saved the day and lives of all. Above all not to forget the GOD Almighty who blessed us with those crucial 16 minutes.
5.Weather was as in monsoons in India,Sea state could have been anything between 4-6 and landing on water would have had its connected problems. A word of CAUTION you may not always get 16 minutes ,will depend upon how fast the system gets drained out.
1.On 27 July 2010 I was flying a Bell 412 for offshore crew change in support of a floater about 100 miles away with 7 passengers on board.The co-pilot was on controls at cruise 2000 ft AMSL . Around 54 miles outbound the Transmission oil pressure light came ON, crosschecked with the oil pressure guage and found oil pressure at 30 psi and dropping. I immediately took over the controls and reduced power to approx 45%,commenced descent to 500 ft and turned towards the nearest landing site available, the coast line fortunately 17 miles away.Completed actions as per the RFM and warned the passengers of the emergency and likelyhood of landing on water.
2. Continued ,constantly monitoring the transmission temeprature which remained steady at 60 celsius and looking for any signs of further deterioration in terms of vibrations and increase in temeprature.Continued passing the the GPS position frequently to nearest control tower and other company aircrafts to make SAR easier. The pressure continued dropping and last noted was around 0 psi. Landed safely at the coastline away from the high tide line and switched off.
3. On inspection found last about 500 ml oil flowing from the hell hole.The inspection windows were empty and tail boom splashed all over.The GPS position was passed and within 5 minutes a dornier aircraft of indian navy who was monitoring the calls flew overhead and reported all safe to the control tower.Mobiles came in handy and within 5 minutes all concerned were contacted. The police and local help came soon thanks to 108 service of Andhra Pradesh (akin to 911 of USA).
4. Later it was found that a flexible hose in the system had given way.The hose was 24 yrs old ,8 yrs on shelf and 16 yrs on the aircraft.
5.Good CRM and cool Captain, Copilot and passengers saved the day and lives of all. Above all not to forget the GOD Almighty who blessed us with those crucial 16 minutes.
5.Weather was as in monsoons in India,Sea state could have been anything between 4-6 and landing on water would have had its connected problems. A word of CAUTION you may not always get 16 minutes ,will depend upon how fast the system gets drained out.
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rupigill
Many thanks for taking the time to saher your experience. Perhaps you could post this in the Rotorheads section where this would get far more exposure to helicopter crews.
The crew of the Cougar S-92A on 12 March 2009 had less than 10 minutes before there gearbox failed after an oil loss.
Many thanks for taking the time to saher your experience. Perhaps you could post this in the Rotorheads section where this would get far more exposure to helicopter crews.
The crew of the Cougar S-92A on 12 March 2009 had less than 10 minutes before there gearbox failed after an oil loss.
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Shell Management,
Thanks a lot ,put it under rotorheads. Just thought wide publicity may come in handy to someone , someday and save precious lives.
Rupi Gill
Thanks a lot ,put it under rotorheads. Just thought wide publicity may come in handy to someone , someday and save precious lives.
Rupi Gill
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Hello.
Well done boys!!
Some years ago my coworkers were flying a 1200TT AB412EP on water when suddenly XTMS light press went ON with XMSN press zeroed in seconds.
The captain and copilot were alone on board; they headed onshore and landed after 17' oil pressure was lost.
The flight was released after a 600hrs overhaul, the helo being flight tested for TEN hours before releasing the ship back to her Hems base.
Oil was lost in flight after 4 flight hours from start up, tail was totaly oil soaked, temperatures never went up over red line; it was wintertime.
By the way this XMSN is actually certified for sure with 30' run dry capability and operator went on with it for other 300 hours being cleared by Agusta for that.
Despite that we were forced to stop after a while after daily sump chip detection and Agusta decided to withdraw the trasmission.
Some time after the incident we discovered the cause of the sudden leak: the main trasmission oil chip detector in the low sump (known as "the big CHIP") has been istalled upside down after inspection by the flight engineer, letting the oil to go out after 10 hours of duty.
Normally I use to go for 24/7 140Nm trips in deepwater with EP's and ditching is a big concern even in the center of the warm, low waved, SAR well covered mediterranean sea.
Actually I rely deeply on the rugged old style Bell alluminium B412 trasmission AND on PNR & windtemps route calculations.
A bit of luck never hurts, also.
Cheers
Maeroda
Italy
Well done boys!!
Some years ago my coworkers were flying a 1200TT AB412EP on water when suddenly XTMS light press went ON with XMSN press zeroed in seconds.
The captain and copilot were alone on board; they headed onshore and landed after 17' oil pressure was lost.
The flight was released after a 600hrs overhaul, the helo being flight tested for TEN hours before releasing the ship back to her Hems base.
Oil was lost in flight after 4 flight hours from start up, tail was totaly oil soaked, temperatures never went up over red line; it was wintertime.
By the way this XMSN is actually certified for sure with 30' run dry capability and operator went on with it for other 300 hours being cleared by Agusta for that.
Despite that we were forced to stop after a while after daily sump chip detection and Agusta decided to withdraw the trasmission.
Some time after the incident we discovered the cause of the sudden leak: the main trasmission oil chip detector in the low sump (known as "the big CHIP") has been istalled upside down after inspection by the flight engineer, letting the oil to go out after 10 hours of duty.
Normally I use to go for 24/7 140Nm trips in deepwater with EP's and ditching is a big concern even in the center of the warm, low waved, SAR well covered mediterranean sea.
Actually I rely deeply on the rugged old style Bell alluminium B412 trasmission AND on PNR & windtemps route calculations.
A bit of luck never hurts, also.
Cheers
Maeroda
Italy
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Here since tranmission never ran dry, the defective part was replaced & the aircraft was flown next day by me again . A day later after the necessary checks it was off again for revenue sorties.My eyes scan the gauges more often now.
thanks & happy landings
thanks & happy landings
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I always understood that the transmission oil temperature sensor required oil flow work properly. if there is no oil pressure and no flow the temperature will not increase. If you lose oil pressure don't rely on the temperature gauge to let you know how hot transmission is.
JHR
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I always understood that the transmission oil temperature sensor required oil flow work properly. if there is no oil pressure and no flow the temperature will not increase. If you lose oil pressure don't rely on the temperature gauge to let you know how hot transmission is.
Top result, well done, especially for the quick posting on Prune, but....
weren't you loading yourself up somewhat in CRM terms? the other pilot is described as Capt therefore capable so as commander you took on the handling and decision making role?
I immediately took over the controls and reduced power
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I spent a year flying a 212 out of Vizag, Rajah, Yanam & Juhu; very interesting during the monsoon season!
You did the right thing because, to be honest, that was the obvious option. Unfortunately too many pilots don't take the best option.
You did the right thing because, to be honest, that was the obvious option. Unfortunately too many pilots don't take the best option.
JHR
Tend to agree gear box temp is normally taken from the oil flow not casing temp, have seen a few gear boxes (not rotary) wired with thermocouples to check individual bearing\ shaft temps, usually for development purposes, the problem with this is there can be large variations in temp due to heat sink and air flow.
Tend to agree gear box temp is normally taken from the oil flow not casing temp, have seen a few gear boxes (not rotary) wired with thermocouples to check individual bearing\ shaft temps, usually for development purposes, the problem with this is there can be large variations in temp due to heat sink and air flow.
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Oil temp
I think ur correct JHR - oil temperature gauge is meaningless as to actual temperature & thermodynamic situation inside the transmission. Don't rely on the gauge in this situation.
The temperature probe is measuring oil temp i.e wet line, on the pressure side of the system, up towards jets 6 or 7 - the higher portion of the txmsn casing. No oil pressure = no oil carrying heat away from all the nasty moving metal bits = no meaningful reading from the oil temp probe, thats just residual heat u r seeing on the gauge which will cool down in time.
Also, perhaps more important is that the input bearing on the main driveshaft is not getting any lubrication! Jets 5&6 if I recall - again, no oil pressure = no lubrication and no heat dissippation, and that bearing is running around 6000 rpm with no lube!
Have lost the txmsn oil (pressure & the oil itself) in a 412EP at 4500' in cruise. Was due to same problem as maeroda mentioned in his incident below; had happened once before at same company. Worth checking that debris monitor & knowing which way the part plate should be! Ran ours dry for 12 mins during decent and emerg landing - thank goodness for Bell's rugged engineering. Longest 12 mins of my life.
FYI - I was also under the impression that there was a "30 minute run dry certification". Response from Texas in my subsequent investigations was "sorry, no such FAA requirement for civilian machines......" Good food for thought - again, don't be misled on the time you have available to run without oil - think ditch/land as soon as possible but as mentioned already, sea state & SAR situation will influence risk of ditching versus pushing the transmission to a hard surface landing.
We were all lucky and can thank the design team that over-engineered the transmission so well. Another captain I flew with lost the oil in a 212 many years ago - from a 1000' he'd hardly got down to the water before the txmsn failed catastrophically & they went in, he was the only survivor.
Get it down low & slow IMHO and don't be afraid of ditching.....
The temperature probe is measuring oil temp i.e wet line, on the pressure side of the system, up towards jets 6 or 7 - the higher portion of the txmsn casing. No oil pressure = no oil carrying heat away from all the nasty moving metal bits = no meaningful reading from the oil temp probe, thats just residual heat u r seeing on the gauge which will cool down in time.
Also, perhaps more important is that the input bearing on the main driveshaft is not getting any lubrication! Jets 5&6 if I recall - again, no oil pressure = no lubrication and no heat dissippation, and that bearing is running around 6000 rpm with no lube!
Have lost the txmsn oil (pressure & the oil itself) in a 412EP at 4500' in cruise. Was due to same problem as maeroda mentioned in his incident below; had happened once before at same company. Worth checking that debris monitor & knowing which way the part plate should be! Ran ours dry for 12 mins during decent and emerg landing - thank goodness for Bell's rugged engineering. Longest 12 mins of my life.
FYI - I was also under the impression that there was a "30 minute run dry certification". Response from Texas in my subsequent investigations was "sorry, no such FAA requirement for civilian machines......" Good food for thought - again, don't be misled on the time you have available to run without oil - think ditch/land as soon as possible but as mentioned already, sea state & SAR situation will influence risk of ditching versus pushing the transmission to a hard surface landing.
We were all lucky and can thank the design team that over-engineered the transmission so well. Another captain I flew with lost the oil in a 212 many years ago - from a 1000' he'd hardly got down to the water before the txmsn failed catastrophically & they went in, he was the only survivor.
Get it down low & slow IMHO and don't be afraid of ditching.....
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Jet,
My view follows yours, the temp sensor and over temp switch are showing oil temp, and as long as they are in oil then the delivery of information is accurate (to calibration limits). Once they are out of the oil stream then NO. I have experienced a decrease of temperature indications after oil loss, bulb now measuring air temperature at sensor. You can smell increase of case and internal bits temp and stress as it increases when you see the indicator increase it's to late. Secondary indications vibration, and stress noise, decrease in NR (hunting and unstable) increase in TQ (unstable and hunting with engine power indications) and engine trying to maintain power you should be not be flying and awaiting collection by friends.
My view follows yours, the temp sensor and over temp switch are showing oil temp, and as long as they are in oil then the delivery of information is accurate (to calibration limits). Once they are out of the oil stream then NO. I have experienced a decrease of temperature indications after oil loss, bulb now measuring air temperature at sensor. You can smell increase of case and internal bits temp and stress as it increases when you see the indicator increase it's to late. Secondary indications vibration, and stress noise, decrease in NR (hunting and unstable) increase in TQ (unstable and hunting with engine power indications) and engine trying to maintain power you should be not be flying and awaiting collection by friends.
jtA1
"FYI - I was also under the impression that there was a "30 minute run dry certification". Response from Texas in my subsequent investigations was "sorry, no such FAA requirement for civilian machines......" Good food for thought - again, don't be misled on the time you have available to run without oil - think ditch/land as soon as possible but as mentioned already, sea state & SAR situation will influence risk of ditching versus pushing the transmission to a hard surface landing.
We were all lucky and can thank the design team that over-engineered the transmission so well. Another captain I flew with lost the oil in a 212 many years ago - from a 1000' he'd hardly got down to the water before the txmsn failed catastrophically & they went in, he was the only survivor."
maroda
"By the way this XMSN is actually certified for sure with 30' run dry capability and operator went on with it for other 300 hours being cleared by Agusta for that.
Despite that we were forced to stop after a while after daily sump chip detection and Agusta decided to withdraw the transmission."
Again 2 professionals who have a totally different understanding of the gear box they fly, I presume they are talking about the same type Helicopter
"FYI - I was also under the impression that there was a "30 minute run dry certification". Response from Texas in my subsequent investigations was "sorry, no such FAA requirement for civilian machines......" Good food for thought - again, don't be misled on the time you have available to run without oil - think ditch/land as soon as possible but as mentioned already, sea state & SAR situation will influence risk of ditching versus pushing the transmission to a hard surface landing.
We were all lucky and can thank the design team that over-engineered the transmission so well. Another captain I flew with lost the oil in a 212 many years ago - from a 1000' he'd hardly got down to the water before the txmsn failed catastrophically & they went in, he was the only survivor."
maroda
"By the way this XMSN is actually certified for sure with 30' run dry capability and operator went on with it for other 300 hours being cleared by Agusta for that.
Despite that we were forced to stop after a while after daily sump chip detection and Agusta decided to withdraw the transmission."
Again 2 professionals who have a totally different understanding of the gear box they fly, I presume they are talking about the same type Helicopter