AS332 Main Gear Box run dry 30min ?
Thread Starter
AS332 Main Gear Box run dry 30min ?
Hi !
I fly the Super Puma (AS332 M1). We had a discussion about if it has the '30 min run dry' feature ? There was some different opinions about this...
Would be a good idea the be good d****d sure about this, if being IMC and loosing all oil pressure.
(I did some searches on pprune, but could'nt find the info)
I fly the Super Puma (AS332 M1). We had a discussion about if it has the '30 min run dry' feature ? There was some different opinions about this...
Would be a good idea the be good d****d sure about this, if being IMC and loosing all oil pressure.
(I did some searches on pprune, but could'nt find the info)
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,573
Received 413 Likes
on
218 Posts
They used to claim this for the military Puma. My personal strategy would be to put the aircraft on the ground asap in case it's only 29 minutes...
The answer is a definitive NO !!
There is no dry running capability at all on the 332 Super Puma. You have the ability to bypass the oil cooler if the pressure starts to fall, but if the leak is elsewhere and you continue to lose gearbox oil (and pressure) you have to land immediately.
If that means ditch in the sea, then so be it. I'm sure the Cougar S-92 accident has created a lot of debate on this issue as to how far you can expect to travel - I dare say a few weeks ago, pilots may have flown perhaps 10 minutes to reach a suitable landing spot, but now I would be revising that estimate downwards to be sure of a safe touch down, even if it means in the water.
As someone said on another thread - The checklist says Land Immediately. If you extend that a few minutes and land successfully, you'll get a pat on the back - If he gearbox seizes with 2 miles to run, then people will question why you didn't ditch. Its a tough call, but anecdotal evidence will tell you that your flight time with zero lubrication is really very short.
There is no dry running capability at all on the 332 Super Puma. You have the ability to bypass the oil cooler if the pressure starts to fall, but if the leak is elsewhere and you continue to lose gearbox oil (and pressure) you have to land immediately.
If that means ditch in the sea, then so be it. I'm sure the Cougar S-92 accident has created a lot of debate on this issue as to how far you can expect to travel - I dare say a few weeks ago, pilots may have flown perhaps 10 minutes to reach a suitable landing spot, but now I would be revising that estimate downwards to be sure of a safe touch down, even if it means in the water.
As someone said on another thread - The checklist says Land Immediately. If you extend that a few minutes and land successfully, you'll get a pat on the back - If he gearbox seizes with 2 miles to run, then people will question why you didn't ditch. Its a tough call, but anecdotal evidence will tell you that your flight time with zero lubrication is really very short.
In my previous company, we had a spate of MGB Oil Cooler Leaks through cracked pipe/welds (in fact I discovered one on deck, and we used some very creative interpretation of the FTL scheme to eventually fly home after the repair!) Another crew had one at about FL80, I recall, and when they got to the nearest deck (Clyde?) things had got pretty hot and interesting.
The company test pilot (MB) used to produce an excellent fleet newsletter, and in one issue he described Aerospatiale test data for the MGB on a test rig. I forget the precise details, but it described how, with the rig running, the 'plug' was pulled out of the base and the clock started. Within a very short time white smoke was coming out of the mast bearings and not long after that the whole thing seized. It was of the order of 11 minutes I think. certainly it was sobering.
I'm sure HC can provide more detail and explain how the 225 alleviates these problems.
The company test pilot (MB) used to produce an excellent fleet newsletter, and in one issue he described Aerospatiale test data for the MGB on a test rig. I forget the precise details, but it described how, with the rig running, the 'plug' was pulled out of the base and the clock started. Within a very short time white smoke was coming out of the mast bearings and not long after that the whole thing seized. It was of the order of 11 minutes I think. certainly it was sobering.
I'm sure HC can provide more detail and explain how the 225 alleviates these problems.
Join Date: May 2005
Location: Europe trying to enjoy retirement “YES”
Posts: 372
Likes: 0
Received 0 Likes
on
0 Posts
Absolutely correct Special 25, no inferred run dry time was ever intended when I was involved in AS 332L1 flight training.
I was lucky enough to witness the RUN DRY test on the L2 MGB at EC during a visit, also to view the MGB strip down after it had been completed. Enough to say the NF over speed shut down system worked on both engines and the ensuing leaking hydraulic fluid fire was extinguished.
Outhouse.
I was lucky enough to witness the RUN DRY test on the L2 MGB at EC during a visit, also to view the MGB strip down after it had been completed. Enough to say the NF over speed shut down system worked on both engines and the ensuing leaking hydraulic fluid fire was extinguished.
Outhouse.
What is important to realise though, is that whenever you are confronted with a problem which the RFM requires you to LAND IMMEDIATELY from, any and every moment you elect to stay airborne is potentially a moment closer to your maker. If you know and understand that and accept because of the particular situation you are faced with, then all well and good. However, the phrase "continued flight may prove more hazardous than the consequences of landing in an unsuitable location" should always be ringing in your ears.
I am with 212Man on this one.....sometimes you pay your money, take yer chances, and roll the dice!
As you are taking a gamble with steep odds favoring the house....it is not one to take except in the very worst of choices.
There are times ditching is not going to be conducive to a long life or a very pleasant termination of it....landing in a forest full of very tall trees has some downsides as well.
Riding a raging white water river down through the mountains could be a bit sporty.
Perhaps "Immediately" should be written...."At the absolute first opportunity with consideration of loss of life only".
I would suggest the aircraft is merely a re-usable container for the contents....as far as I am concerned it is just a large engine can. When it comes to using it up to save my own hide....I have priority over all other considerations.
As you are taking a gamble with steep odds favoring the house....it is not one to take except in the very worst of choices.
There are times ditching is not going to be conducive to a long life or a very pleasant termination of it....landing in a forest full of very tall trees has some downsides as well.
Riding a raging white water river down through the mountains could be a bit sporty.
Perhaps "Immediately" should be written...."At the absolute first opportunity with consideration of loss of life only".
I would suggest the aircraft is merely a re-usable container for the contents....as far as I am concerned it is just a large engine can. When it comes to using it up to save my own hide....I have priority over all other considerations.
AKEE
Absolutely not, no 30 min dry running timefor the AS332L. I believe some tests carried out at Aerospatiale years ago showed that the actual dry run time was very variable - one box lasted nearly 20 mins, another less than 5, making it pot luck and impossible to give any approved dry running time, and certainly never 30 mins.
Its the same for the L2, however in order to meet the latest certification requirements for the EC225, Eurocopter added an emergency lubrication/cooling system, consisting of a glycol reservoir, pump and engine air supply, and a complicated manifold of pipes that sprayed the atomised glycol/air mixture into the hot parts of the gearbox. The primary function of this is apparently to cool, rather than to lubricate the parts.
The tank in fact has enough glycol for 50 minutes, but the system is certified only for 30 minutes of flight at Vy (80 kts).
But you have to bear in mind the probability of a complete loss of gearbox oil on a 332L. Bristow has nearly 30 of them, operated them since 1983, and must have millions of flight hours on them, but I don't think there has ever been a case of complete loss of oil pressure in flight. We did have one leak that might have resulted in complete loss of oil (crack in gearbox), but the aircraft landed before all the oil was lost. So don't fret about it too much!
A oil cooling failure such as fan drive failure, low gearbox oil level or main pump failure is a more realisitic possibilty (though rare) and with those, provided you still have the minimum pressure you can continue flight for up to 2 hours at Vy.
HC
Absolutely not, no 30 min dry running timefor the AS332L. I believe some tests carried out at Aerospatiale years ago showed that the actual dry run time was very variable - one box lasted nearly 20 mins, another less than 5, making it pot luck and impossible to give any approved dry running time, and certainly never 30 mins.
Its the same for the L2, however in order to meet the latest certification requirements for the EC225, Eurocopter added an emergency lubrication/cooling system, consisting of a glycol reservoir, pump and engine air supply, and a complicated manifold of pipes that sprayed the atomised glycol/air mixture into the hot parts of the gearbox. The primary function of this is apparently to cool, rather than to lubricate the parts.
The tank in fact has enough glycol for 50 minutes, but the system is certified only for 30 minutes of flight at Vy (80 kts).
But you have to bear in mind the probability of a complete loss of gearbox oil on a 332L. Bristow has nearly 30 of them, operated them since 1983, and must have millions of flight hours on them, but I don't think there has ever been a case of complete loss of oil pressure in flight. We did have one leak that might have resulted in complete loss of oil (crack in gearbox), but the aircraft landed before all the oil was lost. So don't fret about it too much!
A oil cooling failure such as fan drive failure, low gearbox oil level or main pump failure is a more realisitic possibilty (though rare) and with those, provided you still have the minimum pressure you can continue flight for up to 2 hours at Vy.
HC
We did have one leak that might have resulted in complete loss of oil (crack in gearbox), but the aircraft landed before all the oil was lost. So don't fret about it too much!
However, I think we are all in violent agreement on this subject!
Thread Starter
Thanx for all replies. Seems that I have the same idea as you guys about how quick I would want my feet on the ground...
Even if it is very unlikely to happen, I think we should have have thought about it. I guess a good MCC concept inludes to be prepared for this, and that we perhaps dont have the time to use 10 minutes to discuss it onboard 'when' it happens.
Do anyone know there is a difference between the civil and military version in the MGB ? (AS332L, L2 vs AS332M1?9)
Even if it is very unlikely to happen, I think we should have have thought about it. I guess a good MCC concept inludes to be prepared for this, and that we perhaps dont have the time to use 10 minutes to discuss it onboard 'when' it happens.
Do anyone know there is a difference between the civil and military version in the MGB ? (AS332L, L2 vs AS332M1?9)
Thread Starter
Big bump for an old thread.
We had an partial loss of oil in MGB a few Days ago.
Oil filler cap O-ring failed/ wrong mounting wich caused the oil to dissapear that way.
One hour of flight since oil filled it lost 7L (out of about 20L?) and the MGB main pump pressure started dropping with a resulting short 'flash' warning MGB C / MGB COOL -warning.
The warning iluminated just Before landning, looks like it at least would have gotten to a MGB C/ Cooling problem if the flight had been longer.
We had an partial loss of oil in MGB a few Days ago.
Oil filler cap O-ring failed/ wrong mounting wich caused the oil to dissapear that way.
One hour of flight since oil filled it lost 7L (out of about 20L?) and the MGB main pump pressure started dropping with a resulting short 'flash' warning MGB C / MGB COOL -warning.
The warning iluminated just Before landning, looks like it at least would have gotten to a MGB C/ Cooling problem if the flight had been longer.
