ADA AW139 Ditched?

[VEMD]

Any news regarding the ditched aircraft at Abu Dhabi recently?

[Milo C]

Controlled ditching. 5 on board safe.

[mickbates]

The skipper is experienced and he did the right thing, crew is well, passenger is well, it is a good day! Aircraft is expendable. Crew and pax are not!!!! Well done!

[Aser]

Ended up like this:
https://media.licdn.com/media-proxy/ext?w=800&h=800&f=n&hash=Zv1nLoSRk8ChabP%2BCXq36HzBPeo%3D&ora=1%2CaFBCTXdkRmpGL2lvQUFBPQ%2CxAVta9Er0Vinkhwfjw8177yE41y 87UNCVordEGXyD3u0qYrdf3HqesGNKLaouVkReiQclAQxePKhSGTkD8LtLo6 9eN4lipLkcY27dA4BYBI3iSdF_NQ8

[The Sultan]

Any reason?

[noooby]

Is it next to a rig? Just wondered what that crane is on.

[spinwing]

Mmmm ....

Well that would have spoilt their day a bit !!!

[SASless]

Flat water to have gone upside down!"

[Dreviator]

No lives lost....:ok:

[noooby]

One float is deflated Sasless, hence it rolled over.

[gulliBell]

One float is deflated Sasless, hence it rolled over.

To me it looks like all 3 float bags are still inflated.

[Canuck Guy]

The 139 has 4 bags

[Mee3]

oh sasless

[gulliBell]

The 139 has 4 bags

Argh yes, so it does. If fate should have you going for a swim, that is the ideal place to do it.

[Search&Rescue]

Is it next to a rig? Just wondered what that crane is on.

The crane is on a salvage vessel.

[Search&Rescue]

Any reason?

Seems like the crew experienced high transmission temp (assume MGB).
Decided to divert to the closest island. Before reaching the island the transmission started having strong grinding noises... So, the crew decided to ditch it before reaching the island. They ditched 4 NM short of the closest island.
(These details come from UAE RCC.)

[212man]

Seems like the crew experienced high transmission temp (assume MGB).
Decided to divert to the closest island. Before reaching the island the transmission started having strong grinding noises... So, the crew decided to ditch it before reaching the island. They ditched 4 NM short of the closest island.
(These details come from UAE RCC.)
Do you have a link to that information source? My searches come up blank.

[Search&Rescue]

Do you have a link to that information source? My searches come up blank.

Actually I got this info from my colleague who is working there... And he mentioned this source... Maybe, he had a direct connection to UAE RCC?
(But I think that the preliminary info concerning this accident is reliable...)

[TukTukDriver]

The aircraft made a controlled ditching 4 minutes or approx 8NM from the closest island.

[albatross]

Yes ..WELL DONE indeed.

[Canuck Guy]

A shout-out to the Coast Guard for picking our brothers up as well. Thank you! :ok:

[hueyracer]

Four minutes out before touching ground? Tough call......i assume many would have tried to get feets dry....and probably crashed......

[malabo]

Yes, I'll be watching this one close, as the 139 transmission has always been one of its jewels of design that solidly elevated it over the "weaker" 212/412 transmission. Plus the coveted "30 min run dry" halo.

High transmission temps are not uncommon in extended hovering in hot climates, but they come back down at lower power settings and better airflow in cruise. So something odd here with just high temp in cruise followed by "I'm about to self-destruct" transmission noises. No mention of pressure, chips, but early days before maintenance records/HUMS are known.

Anything from Leonardo? Bad year for 139's, but like the 92 the type most used will have the most incidents.

[Mark Six]

I heard from a reliable source that the "grinding noise" was a broken oil cooler fan belt. That would also explain the high temp.

[Wrench16]

There is no oil cooler fan belt on the 139. The fan is driven off a drive quill and shear shaft directly from the MGB. None the less the shaft shearing, or the fan coming apart could explain the high temp and "grinding noise". On two occasions in the past 5 years I have had hums indications of oil cooler drive shaft problems requiring replacing the fan drive shaft. All in all it is to early to speculate the problem and I for one will be looking forward to learning what happened and ensuring it does not happen again.

[Search&Rescue]

I heard from a reliable source that the "grinding noise" was a broken oil cooler fan belt. That would also explain the high temp.

Thanx Mark Six! Good info!:ok:

[driftwood1]

I heard from a reliable source that the "grinding noise" was a broken oil cooler fan belt. That would also explain the high temp.

They don't have an oil cooler fan belt

[212man]

Four minutes out before touching ground? Tough call......i assume many would have tried to get feets dry....and probably crashed......
From my own experience it's not a tough call!

[Non-PC Plod]

Crew actions sound to be iaw RFM. Any gearbox indications accompanied by noise and/or vibration is a "land immediately".
To continue for 4 nm to nearest point of land by comparison would be "as soon as possible" according to the definition.

[BTC8183]

139 does have a MGB driven
drive belt, to the Air con compressor though!.

[ODEN]

I heard it trough the grapevine...

This order...MBG chip then oil temp then vibration/noise....ditch

[SASless]

From my own experience it's not a tough call!

Nothing hard about this...with the first indication get close to the surface....second indication PARK IT!

Unusual noises or vibrations....no brainer...get on the surface no matter the damage to the aircraft!

[donut king]

WELL DONE, to the crew!

[spinwing]

Mmmmm ....

Well my info comes from the 'Horses Mouth' and no mention was made of a MGB Chip light.

Yes there was increasing MGB increasing Temp indications ( and lotsa GRINDING noises) up to and until the Trans was cooled by water !!!

Happily the flight crew were 2 of the best senior captains (and personal friends of mine) in the company with many many years of experience and that paid off for them their passengers and the company ...

How about we now wait for any official notifications and investigations ... the crew did well it was the a/c that broke ... enough said.

Cheers Chaps ..

[hueyracer]

I keep saying iz:
I believe it was a tough call..

One thing to ditch if you have nothing but ocean around you for hundreds of miles....another story when you only need to keep going for another four minutes to get feet dry..

I can imagine the thoughts and considerations running through my brain in a situation like this...
What does the manual say?
What is actually happening?
How bad is it?
Can we make it?


Tough call..
Pilots are good not bevause they do exactly whats in the manual...they are good because they take into consideration every little detail...and come to a conclusion....

At the end all that matters is that they all got out unharmed....now its wait and see until the results of the investigation will be published, so we can learn some valuable lessons...

[ODEN]

Mmmmm ....

Well my info comes from the 'Horses Mouth' and no mention was made of a MGB Chip light.

Yes there was increasing MGB increasing Temp indications ( and lotsa GRINDING noises) up to and until the Trans was cooled by water !!!

Happily the flight crew were 2 of the best senior captains (and personal friends of mine) in the company with many many years of experience and that paid off for them their passengers and the company ...

How about we now wait for any official notifications and investigations ... the crew did well it was the a/c that broke ... enough said.

Cheers Chaps ..

Spinwing, Thank you for sharing that info.

Cheers

[Geoffersincornwall]

As I say in my Day One brief on a TR, the answer to any situation in the air is:

QRH + Technical Knowledge + Airmanship = The Correct Answer

As the trained risk analyst the Captain is the one who makes the call.

G

[rrekn]

Official Word for you....

[The Sultan]

Leonardo knows how to handle an incident. Airbus could learn.

[mexmike]

I came across high MGB Oil temp once. The cooler fan has an aluminium plate riveted in the housing. Two of the rivets on one side had corroded and allowed the plate to be sucked towards the impeller blocking airflow. This caused the mgb temp to rise. Fortunately, the plate could not get pulled completely into the impeller because of the remaining rivets on the opposing side preventing it. Also, the impeller has a small shear type drive shaft. If that fails the temp of the mgb will rise.

[RWing]

Difficult but a good call by the skipper in my honest opinion. Better to be in the water awaiting rescue than in a heap near the land.

[megan]

It is worth noticing that the crew duly implemented the flight manual procedure, safely terminating the mission and confirming the outstanding reliability and modern design of the world-class leading AW139Crew may contend that if it had been in sea state 6, sub zero temps, with SAR a long, long way away. ;)

[SASless]

All's well that ends well!

The Crew and Passengers are safe.

The helicopter is merely a reusable shipping container for its contents!

I might be a scaredy cat but upon the second indication OR hearing odd unusual bad noises from the MGB area......I would have parked it on something solid or on its floats.

Guessing wrong with cast iron failures carries a serious penalty!

[gulliBell]

How many other AW139's have been parked on the water? The only other one I can think of was in Hong Kong, and they had a pretty good reason for parking that one after the tail rotor went for a swim first.

What ever resulted from that Bristow Nigeria S76C++ getting parked in the Atlantic? Discussion on that ran out of steam a long time ago.

[Apate]

Despite the good outcome, there still needs to be an understanding on why one of the floats failed and the aircraft inverted in what must have been pretty benign conditions.

The obvious question is "are the floats up to the job"? As gulliBell points out we don't have much history to go on.

[albatross]

Several helicopter I have flown. RFM States words to this effect:
"Floats are designed to allow enougn time to evacuate the aircraft."
Also activities during evacuation or salvage can easily cause float deflation.

[malabo]

Leonardo knows how to handle an incident. Airbus could learn.

I dunno, Sultan. Leonardo's press release was strategically ambiguous. "Nothing wrong with the transmission", and in the same breath "crew complied with RFM direction and ditched". As an owner or insurance company I could rightly be peeved at such a statement. As far as the whole "ditch the bitch" sentiment, there would be no 92's flying today if all of them followed the RFM on an engine fire warning. Like Megan said, sounds easy in daytime warm flat water, different story where you will statistically lose a few even with a good ditching.

[noooby]

malabo, where are you getting "nothing wrong with the transmission". That is absolutely NOT what Leonardo said.

They only said that there was no sign of oil pressure loss and no sign of leakage.

That is VERY different to what you are stating.

So Sultan is on the ball with what he said.

Was there an earlier revision of this letter that said something different???

I see no reason for owners or insurers to be "peeved". Quite the opposite. They should be happy that a statement of known FACTS was released so soon by the Transmission OEM (Leonardo).

[NomadicMechanic]

To answer Apate's question, we service our own floats at the operation where I work (AW139) and we regularly send them back for repair as they fail the leak checks due to damage/wear/degradation. It's not often we have a full set of floats that pass the annual servicing, at least one or two fail.

[AnFI]

What happened to the certification requirement for sea state 4 with the critical cell deflated? Has that gone?

[albatross]

We do not know when or how the float got deflated. Are not all float bags dual cell?
Just wondering. I don't have a 139 endorsement so am not posting with any knowledge of the float system attached thereto.
Kudos to the crew for their decision to ditch and successfully carry it out.
High temp followed by secondary indications ..Land immediately seems to be the go to procedure.
Second guessing from the comfort of the couch is a PPrune is SOP on this site. Given the inability to climb out of the aircraft in flight, open the cowlings and investigate..the crew had to react to the indications, and secondary indications they were faced with.
I don't think anyone is going to ditch unless they feel that is the best choice regardless of sea state.
The NF 92 accident taught us a lot of lessons.

[Bladestrike]

What happened to the certification requirement for sea state 4 with the critical cell deflated? Has that gone?

Sea state 4 certification only requires that the aircraft remain upright long enough for the pax to disembark into a raft after having ditched in sea state 4, as far as I know.....I read through it years ago....my memory is not what it once was.

[SASless]

I don't have a 139 endorsement so am not posting with any knowledge of the float system attached thereto.

I suspect there is more interest in the one Float Bag that is NOT attached thereto!

[gmrwiz]

AnFi and Bladestrike. For your information ditching equipment of AW139 has been certified fo SS 6.

[albatross]

I suspect there is more interest in the one Float Bag that is NOT attached thereto!
Sorry I thought the bag was deflated not detached.
Darn funny comment in any case. Had a good snortlaugh over it.
Cheers
Albatross

[SASless]

The photo was not very clear....and my advancing senility may have played a role in my confusing the actual situation however in defense there is not much difference in the end result it would seem.

[spinwing]

Mmmm ...

If one views the movie of the ditched a/c near the recovery workboat one can clearly see the deflated LH rear float flapping/slapping against the a/c hull .....

[ec155mech]

Spinwing, do you have a link for that movie ?

[SASless]

And if one had no video to watch....and there was just the one grainy still image to look at....what would one surmise?

Detached or uninflated....or inflated but leaked down to ambient air pressure....is not the effect the same?

The question was raised about certification requirements and an another person reported failure of at least one bag of four as being common.....and even a dull third grader should wonder about the 139 float system's performance when used in a ditching.

[John Eacott]

Even fully functioning floats aren't always going to keep a ditched machine upright; I'd say we're chasing a bit of a red herring to make an issue out of one float failing following a successful ditching and escape by all on board.

http://www.eacott.com.au/gallery/d/1251-1/824+Sea+King+051+ditched+and+inverted+with+diver.jpg

[[email protected]]

Considering the Sea King floats quite nicely upright with no flot bags inflated, that one hasn't gone so well:)

[SASless]

Gives a whole new meaning to the Command "Gear Up!".

[sycamore]

helium in the tyres

[76fan]

That particular Sea King had ditched at top hover weight at about 1 a.m. and had been kept rotors running on the sea for some four hours awaiting daybreak so that it could be craned aboard the carrier . When the crew eventually shut the aircraft down the waves were lapping over the tops of the sponsons. Shortly after, with a lot of water in the nose electrical bay and in the forward part of the cabin, the aircraft dipped its nose and turned over. The bags did their job but it was the taking on of so much water over several hours that caused the capsize.

[John Eacott]

That particular Sea King had ditched at top hover weight at about 1 a.m. and had been kept rotors running on the sea for some four hours awaiting daybreak so that it could be craned aboard the carrier . When the crew eventually shut the aircraft down the waves were lapping over the tops of the sponsons. Shortly after, with a lot of water in the nose electrical bay and in the forward part of the cabin, the aircraft dipped its nose and turned over. The bags did their job but it was the taking on of so much water over several hours that caused the capsize.

Funny how our recollections differ over a span of many years: I was top cover for 051 after the ditching and was also SSEO, responsible for the dinghy and bolt croppers that the ships divers 'borrowed' to go to the machine when it couldn't raise the sonar body, thus preventing an attempt at a SE take off. The cable was duly cut with the bolt croppers; the loss of the stabilising effect of the sonar allowed a roll to build up in the long swell. Eventually the SK was shut down, abandoned and left to its own devices.

Jerry G was my co-pilot, we were instructed in no uncertain terms by Flyco to remain at least 1nm clear in case we turned it over with our downwash :rolleyes:

But we're wandering OT.........

[76fan]

Sorry John, you've got it wrong. There was no attempted SE takeoff... black night, no horizon, too bloody dangerous to try! Yes cutting the sonar body loose made the aircraft lively, so did losing the AFCS, and all other electrical equipment gradually dropped offline but when the intercom went too I decided it was time to vacate and not risk the crew further. Not quite as you remember, but still very clear in my memory ... not the sort of personal experience one forgets!


PM sent.

[[email protected]]

And, as I am sure you know, losing the AFCS is a pretty sure sign that the nose bay is flooding and the C of G will be too far forward in that case for a safe SEWTO.

[John Eacott]

I stand corrected: recollections differ over so many years!

Back to the AW139?

[FC80]

0there would be no 92's flying today if all of them followed the RFM on an engine fire warning.

Complete and utter rubbish.

:rolleyes:

[212man]

Complete and utter rubbish.

:rolleyes:
I assume what he means is that the RFM tells you to ditch or land immediately if the fire warning remains after following the procedure. Had all the crews that have had such warnings followed the procedure in the RFM, there would have been a lot of ditchings, which may not all have been totally successful, and the type may have suffered some of the same loss of confidence we have seen elsewhere. Thankfully, those of us that have had these warnings have used airmanship and captaincy and not ditched! I'm referring purely to the S92 fire warnings issue and not making any comment on this ADA incident!

[Geoffersincornwall]

212 - The 139 has in its ECL for 'Engine Fire in Flight' a unique line that as far as I know does not exist in Bell, Sikorsky an AH helicopters - it says:

"Confirm Engine Fire"

Unfortunately, the simple statement is a trifle ambiguous but I know how I would read it.

G.

[atakacs]

Apparently Leonardo just released another builtin regarding this incident.

Anyone?

[Apate]

The 139 has in its ECL for 'Engine Fire in Flight' a unique line

Geoffers - do you know that to be a fact? Hint - I know it isn't :=

If I could cough "BS" online, I'd be doing it right now to your message :E

[2leftskids]

On affected engine
- ENG MODE switch to IDLE
- Confirm engine FIRE
- ECL to OFF
- Lift FIRE/ARM guard and press illuminated pushbutton
- Set FIRE EXTING switch to BTL1

[Apate]

I was referring to the assertion that "confirm fire" is unique to the 139.

[rrekn]

See follow up bulletin below, confirms it was the oil cooler fan.

[noooby]

They certainly seem to be quick getting information out. I feel and AD or SB for the fan coming though.

[The Sultan]

212man wrote relative to 92 fire warnings: Thankfully, those of us that have had these warnings have used airmanship and captaincy and not ditched!

Then you are saying that the Cougar crew acted with proper airmanship as they relied on Sikorsky propaganda about the 92's 30 minute loss of lube lie instead of following the RFM to the letter. This from you who parked a 92 1 km short of an airfield because of a (later determined) non-event oil pump failure. There you had a safe place to land once you mis-interpreted the criticality of the situation and decided to follow the RFM instead of using airmanship to stay in the air another 60 seconds.

After the second false fire warning the 92 should have been grounded like the 235 after the oil pump drive gear failures which in the end were as serious as the 92 pump failures (which did not result in grounding). The 235 crews showed they were pros by following the RFM to ditch after an erroneous second failure indication said they had backup lube failure, which was caused by gross incompetence by Airbus wiring the sensor backwards. They could have made it to a dry landing, but thought of their passengers instead of future bar roomy war stories.

[malabo]

Geoffersincornwall,
Do you update the training for this? Will Leonardo lift the oil cooler noises from the CVR so you can train pilots on an alternative to ditching from That noise combined with high temps? The QRH for high MGB temp is "land as soon as possible", but the general note applied to Transmission System Failure, of which the high temp is one, adds the proviso that "multiple indications" (there were none) or "abnormal noise and/or vibration" (there was that) changes the action to Land Immediately (ditch). Quite a burden on the pilots to differentiate.

Maybe an engineering guru like noooby can fill us in on the technical consequences of this kind of failure.

BTW, the QRH Engine Fire drill says "confirm", but the Rotorsim interpretation for that has always been for the pilots to simply check for the fire lights on the power levers, none of the Puma visual check of the engines with the eyebrow mirrors, or the 92 doing the same with the tail fin camera (or doing a flyby of a convenient rig). Fortunately the Fire Warning system, like the transmission, is quite reliable. Oh, and all types I've flown have some kind of "confirm" written into the engine fire procedure, at least on the operator ECL.

[tasspook]

The Sultan

Suggest you revisit 212man's post, as he NEVER mentioned ANYTHING about the MGB ECL procedure.

I'm referring purely to the S92 fire warnings issueSlightly off topic, but for an engine fire, in flight, the S76D RFM states:

1. Confirm fire.
2. Attain safe single engine airspeed.
3. Throttle (affected engine) - STOP.
4. FIRE/ARM switch (affected engine) - ARM
5. Fire extinguisher switch - MAIN/RESERVE (as required).
6. Land as soon as possible..

But I digress.....

[rotor-rooter]

Tell us all, oh great, all knowing, Sultan?

What exactly IS a 235?

[Geoffersincornwall]

Apate - I did say "as far as I know' - The S76D RFM is one I have never had the privilege of reviewing. So in that case, I wind my neck in. By way of a word of caution I would differentiate between the RFM and your company ECL. The former - certainly in that part of the past I am familiar with - put an obligation upon the pilot to accept the fire warning as gospel. Some aircraft (S92?, Super Puma series?) have such a poor record in this respect that it would be unusual if the company ECL did not reflect this. There are some societies where absolute adherence to the book is a given and the lack of any room to avoid arriving at the last line in the drill that invites LAND IMMEDIATELY is problematic.

Yes, the 139 system is pretty reliable but I know from an analysis of over 1500 incident reports relating to the 139 that the three fire warning related incidents were all non-events.

We find that those entering the complex world of the latest generation of helicopters for the first time encounter a problem caused the relative scarcity of (serious) system failures.

Managing over and under reaction is an important element of airmanship. That's why Evidence Based Training using scenario type exercises and properly trained sim instructors has a lot to offer our industry.

The guys in AD did the right thing and I would venture to suggest that this was in no small part down to their (apparently) high level of experience.

[gulliBell]

...The guys in AD did the right thing and I would venture to suggest that this was in no small part down to their (apparently) high level of experience.

If a crew with high level experience has followed a checklist to its end point I should hope that the final outcome would be no different to that of a low experience crew faced with the same circumstances following the same checklist.

[212man]

212man wrote relative to 92 fire warnings:

Then you are saying that the Cougar crew acted with proper airmanship as they relied on Sikorsky propaganda about the 92's 30 minute loss of lube lie instead of following the RFM to the letter. This from you who parked a 92 1 km short of an airfield because of a (later determined) non-event oil pump failure. There you had a safe place to land once you mis-interpreted the criticality of the situation and decided to follow the RFM instead of using airmanship to stay in the air another 60 seconds.

After the second false fire warning the 92 should have been grounded like the 235 after the oil pump drive gear failures which in the end were as serious as the 92 pump failures (which did not result in grounding). The 235 crews showed they were pros by following the RFM to ditch after an erroneous second failure indication said they had backup lube failure, which was caused by gross incompetence by Airbus wiring the sensor backwards. They could have made it to a dry landing, but thought of their passengers instead of future bar roomy war stories.
You've written some bollocks in your time but this one takes some beating!

I did not have a pump failure and have never said that. What I did have was a cabin full of smoke and the smell of being in a welding workshop, plus 9 EICAS captions. We were not following any RFM procedure and were not 1km from the airfield (although quite close).

I have never supported the Cougar 491 crew actions and think the 30 minute issue was never in their thoughts and is a red herring.

The 225 Emergency Lube sensors were not 'wired backwards' (although there was a change in pin selection) and the primary issue was the pressure thresholds being too high.

[ericferret]

I seem to remember that the BO105 had an air pressure switch to indicate a fan drive failure. A simple system to give the pilot cockpit information about the fans condition.
The reason being that originally there was no ram air for the coolers (engine and gearbox).
The aircraft was modified to provide a ram air system.

The 139 MRGB has no ram air system (the engine oil systems being fuel cooled). The 139 is not alone in this respect. It seems a little extreme to loose an aircraft for the want of air when it is passing by at 100+ knots.

[212man]

I don't think cooling is the issue, and the MGB will run quite happily much hotter than in this incident. The issue is the sound of mechanical distress and the uncertainty about what its cause is.

[ericferret]

Yes I am sure you are right. Nothing to say that any fan fail (in general) was due to an internal gearbox failure as opposed to a simple fan failure.

[Sid447]

What is the nominal operating tempurature...

For the AW139 main transmission?
The system has an 82c thermostat, so in a sufficiently well-designed system, shouldn't this temp be maintained in normal S&L flight conditions?

The same oil is used in both the engines and the transmission, yet the engines are ''red-lined'' @ 140c and the transmission @ 110c...
.....Reasons?

Someone mentioned the engines having a fuel-cooled oil cooler....this is more of a heat exchanger with the primary purpose of heating the fuel, it does little, or nothing to cool the engine oil. The engine oil temps (in hot climates) run at around 115 to 125c ....and during the two minute cool down after flight can often reach 140c!

[Doors Off]

I had an MGB "Warning, Warning" Oil Temp event in a 139, (reported within company and national system). It was accompanied by an increasing MGB Oil Temp all the way to landing with the highest temp noted by myself at 137c. Of course it happened over water about 11nm from the coast, of course I followed RFM actions however, I briefed the crew to prepare to ditch and gave the ditching plan to all onboard. Whilst, stating that under current situations (normal pressure, no noise or vibration) that we would only ditch if we received secondary indications (vibrations/noise). Altitude was decreased to 200-300 ft over water and speed reduced (all gradually so as to not excite an already excited MGB),

A pan was also declared to ATC and intentions for arrival if we made feet dry (coastal airport). Fortunately, we had no secondary indications however, we were prepared to ditch 50m from shore or Land immediately in the trees short of the strip, if secondary indications presented themselves.

A dynamic situation, and though we suspected a cooling system issue, we didn't know for sure.

My point of this diatribe is; well done to the crew with ADA, they are all alive. Every situation is different yet, they made the tough decision to ditch based upon their situation. I, personally, am grateful for their decision and also believe that the fact they are all still breathing, support it.

[hueyracer]

I absolutely agree...i guess i would have run through the same thought process you did-and deciding to ditch when you are close to the shore is probably one of the toughest decisions one has to make-ever.

The outcome is what proofed them right....all came out alive and unharmed.....

[noooby]

Sid447, the Fuel Cooled Oil Cooler is just that, an oil cooler. There is a separate Fuel Heater for heating the fuel. It just happens to use engine oil for heating the fuel :)

Oil is also cooled by intake air, as the oil tank in the Accessory section has fins that intake air passes over, helping to cool the oil.

Temp limits are not to do with the oil, they are a function of the temp limits of internal components in the engine or gearbox. The oil will not begin to break down until it gets much hotter than the MGB temp limits, but the components are always much hotter than the oil (the oil only carries some of the heat away).

There have been coking issues with some engines, particularly running 2380 oil in high temp locations. The Turbine Scavenge Pump especially was heat soaking after shutdown causing the oil to coke up.

What is the nominal operating tempurature...

For the AW139 main transmission?
The system has an 82c thermostat, so in a sufficiently well-designed system, shouldn't this temp be maintained in normal S&L flight conditions?

The same oil is used in both the engines and the transmission, yet the engines are ''red-lined'' @ 140c and the transmission @ 110c...
.....Reasons?

Someone mentioned the engines having a fuel-cooled oil cooler....this is more of a heat exchanger with the primary purpose of heating the fuel, it does little, or nothing to cool the engine oil. The engine oil temps (in hot climates) run at around 115 to 125c ....and during the two minute cool down after flight can often reach 140c!

[Sid447]

Thanks ''nooby''

appreciate the input.
Though have to say, the engine oil coolers are pretty ineffective. :)

Still asking for someone to give me some insight on nominal MGB temp.
We had a box change on one of our 139's about 18 months ago and that one never goes above 82c, even on (heavy) climb-out with the components only permitted to cool for 30 mins between flights.
I know about the newer boxes having a small oil reservoir above each of the 90-degree input drives, but do they have a revised oil cooler system too?

Ambient temps here (UAE) range from 35 to 45c during the summer, with high RH and the atmospheric pressure as low as 993Mb during July and August.

Digressing: Once had a brand new (US-built) 139 that had it's initial compass swing during August and didn't make the second 8-point turn before both engines hit 140c, the IGB reached 110c and the #2 Hyd System was just above 120c (#1 Hyd hardly affected).

[noooby]

Shouldn't make a difference where the hull is made. IGB's all made at Westland and the engines are all made at the same factory in Quebec.

The new MGB is the same internally as the old MGB with the same oil cooler and blower. Just has the two reservoirs added on top of the most critical element of the 139 MGB, the high speed inputs. Assures 30 minute run dry for O&G, even though the test MGB was run for a total of 1 hour without oil (you can pull it apart on the maintenance simulator in Italy if you are interested and check out the gears :ooh:).

If you're having MGB temp issues, pull the oil cooler and clean out the fins. If your mechanics are over greasing the swashplate (which a lot of Bell mechanics do!!!) then the excess grease gets flung off, clogging the fins on the cooler. You can see a 20C drop if it is very dirty.

As for a nominal MGB temp, anywhere in the green range :) Are you running air con. Are you running an AGB. are you running AC Generators. Are you running Super Silent gears. They all impart a load on the MGB, which will affect temp. Ambient temp also will affect MGB temp. I can tell you that the MGB runs nice and cool when it is -40C.

But the biggest factor I've found is a dirty/contaminated oil cooler. :ok:

[jimcarler]

The preliminary report on this ditching has been issued (fairly promptly) - read it here

Preliminary Report (https://gcaa.gov.ae/en/ePublication/admin/iradmin/Lists/Incidents%20Investigation%20Reports/Attachments/106/2017-2017-%20Preliminary%20Report,%20AAIS%20Case%20AIFN-0004-2017,%20A6-AWN.pdf)

Assume the MGB cooling fan used here (manufactured by Technofan) would be the same in all AW139s? Looks like the fan had detached and one of the bearings had completely degraded after the cooling system had packed in

[rrekn]

While the fan is worrying, the bits that concern me about this report are:



Float punctured due to shear bolts not functioning
Liferaft failed to deploy
Cockpit window panel cracked, and
CPI failed to activate or deploy (again!)


I hereby motion to removal all CPIs for all aircraft, pile them into a ceremonial bonfire and dance around it!

[The Goldfish Club]

Now the dust has settled a little on this incident ... could I remind the crew that they have now qualified to join a most exclusive club and we would like to welcome them to the shoal.

If you know the crew (or indeed any other unfortunate souls to have gone through this experience) please ask them to contact us.

This year we celebrate our 75th Anniversary and the reunion promises to be quite special.

Thanks and fly safely.

The Goldfish Club (http://thegoldfishclub.co.uk/)
(Facebook (https://www.facebook.com/TheGFClub/))

[212man]

I'm a little puzzled why they didn't return to the Dhabi II they'd just departed from? The initial warning came one minute into their climb, and even with a bit of time elapsing thereafter as things developed, I'm sure it would have been closer than the island they chose to route to 16nm away.