Sky Shuttle AW139 ditches in HK Harbour
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Some of the speculation in this thread is pretty bizarre regarding this incident! Thought I might add a couple of facts.The AW139 has quite a 'nose up' attitude even during level flight and particularly during flare into hover, which often brings about a 'tail low' audio alert to the crew. If the crew has encountered some sort of bird strike to the T/R and the large vibe that would have accompanied it, the pilot may have elected to ditch if he was already well over water. The floats would have been armed and can be deployed from the collective head prior to contact with the water.
If the tail was as low as it normally is, and with a bit of a swell in the harbor, in goes the tail rotor possibly leading to the seperation of the gearbox and rotor due to the sudden stoppage hitting the water. It would also have easily ripped off the rear fairing which is hollow and only made of thin honeycomb sandwich material and secured with 10/32 screws. What you see in the photos is the spar of the fin at the rear, which is far more substantial. The tailplane is still intact but is well secured at the base of the fin, so it has not departed, however the tip is missing on one side, although these are a fairly flimsy construction and hollow.
The failure of the previous Gulf Helis AW139 is not related to this incident. The AW139's PT6C-67C engines are over powered and an engine loss would rarely call for a ditching in any weight configuration. Losing one normally means continue the flight, burning half the gas! With only 12 pax and the fuel for a harbor hop, I don't think so. Turbine blades departing the engine (what??) would have destroyed the engine cowls, which are remarkably intact.
Give us a break.The AW139 tail rotor blades are also incredibly strong as are most modern european rotor blades, and the 'issues' of 'cracking' mentioned in one post has been cosmetic cracking of the filler around the root end elastomeric/spar attachment area caused by the normal twisting of the blades in operation, all normal and to be expected. The spar itself is solid woven fibreglass around 3/4 inch thick and literally bulletproof. Cracking in some instances of an outer layer or two would not effect the integrity of the entire blade. The tail gearbox is attached to the upper end of the fin to a solid alloy fitting with four large bolts. Everyone is interested in the circumstances of the ditching, the performance of which is a credit to the crew involved and everyone is relieved there were no casualties.
It's also a fine example of the safety systems built into this helicopter working as their designers intended them. Hats of to both parties.
If the tail was as low as it normally is, and with a bit of a swell in the harbor, in goes the tail rotor possibly leading to the seperation of the gearbox and rotor due to the sudden stoppage hitting the water. It would also have easily ripped off the rear fairing which is hollow and only made of thin honeycomb sandwich material and secured with 10/32 screws. What you see in the photos is the spar of the fin at the rear, which is far more substantial. The tailplane is still intact but is well secured at the base of the fin, so it has not departed, however the tip is missing on one side, although these are a fairly flimsy construction and hollow.
The failure of the previous Gulf Helis AW139 is not related to this incident. The AW139's PT6C-67C engines are over powered and an engine loss would rarely call for a ditching in any weight configuration. Losing one normally means continue the flight, burning half the gas! With only 12 pax and the fuel for a harbor hop, I don't think so. Turbine blades departing the engine (what??) would have destroyed the engine cowls, which are remarkably intact.
Give us a break.The AW139 tail rotor blades are also incredibly strong as are most modern european rotor blades, and the 'issues' of 'cracking' mentioned in one post has been cosmetic cracking of the filler around the root end elastomeric/spar attachment area caused by the normal twisting of the blades in operation, all normal and to be expected. The spar itself is solid woven fibreglass around 3/4 inch thick and literally bulletproof. Cracking in some instances of an outer layer or two would not effect the integrity of the entire blade. The tail gearbox is attached to the upper end of the fin to a solid alloy fitting with four large bolts. Everyone is interested in the circumstances of the ditching, the performance of which is a credit to the crew involved and everyone is relieved there were no casualties.
It's also a fine example of the safety systems built into this helicopter working as their designers intended them. Hats of to both parties.
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stacey_s
Yes - could the out of balance force after a lost blade do that?
The Black Dragon
The crash was in Hong Kong so the HKCAD are in charge of the investigation. I read a very comprehensive report on a HK EC155 accident a few years back.
Yes - could the out of balance force after a lost blade do that?
The Black Dragon
The crash was in Hong Kong so the HKCAD are in charge of the investigation. I read a very comprehensive report on a HK EC155 accident a few years back.
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sox6 ,, Hope your correct. but
Its my understanding that Macau (AACM) would have the rights on this report. Hopefully both Dept. will get along to make this quick for all the 139 Pilots out their waiting.
Its my understanding that Macau (AACM) would have the rights on this report. Hopefully both Dept. will get along to make this quick for all the 139 Pilots out their waiting.
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Both are ICAO contracting states, and so the investigation would follow the law and guidance of ICAO Annex 13.
In short, the state in which the accident occured (State of Occurance) will lead the investigation. (Para. 3.2)
In addition, the State of Registry, State of the Operator, State of Design or State of Manufacture (as involved parties) have the right to appoint reps (Accredited Representatives) to the investigation, who have the right to participate in all aspects of the investigation.
Once the incident evidence is no longer needed it will be released to the State of Registry or State of Operator. (para. 3.4)
FYI
http://www.airsafety.com.au/trinvbil/C619icao.pdf
In short, the state in which the accident occured (State of Occurance) will lead the investigation. (Para. 3.2)
In addition, the State of Registry, State of the Operator, State of Design or State of Manufacture (as involved parties) have the right to appoint reps (Accredited Representatives) to the investigation, who have the right to participate in all aspects of the investigation.
Once the incident evidence is no longer needed it will be released to the State of Registry or State of Operator. (para. 3.4)
FYI
http://www.airsafety.com.au/trinvbil/C619icao.pdf
Last edited by Chi Sin Gei Si; 4th Jul 2010 at 23:37.
Q:Would this variant have push out passenger windows and liferafts ?
If so, I note in the photos that all (the pax windows) appear to be still in situ and the cabin door was slid open, fine until there's a rollover before everyone egresses ?
If so, I note in the photos that all (the pax windows) appear to be still in situ and the cabin door was slid open, fine until there's a rollover before everyone egresses ?
So B- is a Macau registration marking? I thought the Macau helicopters had CS- registration marking? I wonder if Pansy will get out the cheque book and write out a big number for six new S76's in light of this?
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"So B- is a Macau registration marking? I thought the Macau helicopters had CS- registration marking? I wonder if Pansy will get out the cheque book and write out a big number for six new S76's in light of this? "
Really, it doesn't take much to these days to use Google for something like this, (probably as long as it took you to post) to find that B- is the mark for China. B-Mxx is generally reserved for Macau, being part of China.
BTW no liferafts, and pop-out windows - confirmed.
Really, it doesn't take much to these days to use Google for something like this, (probably as long as it took you to post) to find that B- is the mark for China. B-Mxx is generally reserved for Macau, being part of China.
BTW no liferafts, and pop-out windows - confirmed.
Last edited by Chi Sin Gei Si; 4th Jul 2010 at 23:51.
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CSGS, I don't think you are so Chi Sin. However:
The HKCAD has in previous accidents stated they can choose to interprete ICAO rules in whatever way they like, as ICAO rules are just a guideline and not strictly binding legislation on member states.
As soon as the tail departed from the aircraft, it immediately belongs to the insurance company and they can do whatever they like with it, but would normally allow the regulators to inspect it. After the investigation, the insurers usually sell written off aircraft parts piecemeal as scrap, but would allow the original operator the first right of refusal to purchase before offering and disposing on the open aviation market.
Wild Chicken, that speculation was made before clear photos were made available by the media. It is presently certain it was a TR problem. Thanks for your observation.
In addition, the State of Registry, State of the Operator, State of Design or State of Manufacture (as involved parties) have the right to appoint reps (Accredited Representatives) to the investigation, who have the right to participate in all aspects of the investigation.
Once the incident evidence is no longer needed it will be released to the State of Registry or State of Operator.
Turbine blades departing the engine (what??) would have destroyed the engine cowls, which are remarkably intact.
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Tail Boom Stress
The AW139 ((could)) be pushing into a unknown area of tail boom stresses, Due to the large number of Vertical Cat-A departures flown everyday with this company. Approx every 30min, from 9:00 am to last dept at 23:00.
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For DECUFAULT and Ned
Yes, the Gray Haired Plague continues to infect EAA and it's people. Best part is he will have no doubt been instrumental in "convincing" the 16/F pop-out windows and life rafts were not needed. Hope they hang him.
Pilots, am told, claimed they heard a bang resulting in the pedals becoming ineffective. Both engines pulled back immediately and into the water they did go.
I'm going to speculate here (my opinion only) that assuming the aircraft entered the water WITH the T/R et al still attached to the airframe, it wouldn't have been turning under any real amount of power. Therefore, any notion that a sudden stoppage on contact with the water resulted in not only the T/R and gearbox separating from the aircraft, but also that much of the vertical stab structure, is somewhat difficult to believe. Again, just my opinion.
So that leaves us with the only other likely scenario, in-flight structural failure which, if true, is scary indeed. And you have to admit, from looking at all the posted photos, there appears to be an awful lot of structure missing from the vertical stab assembly.
JW
Yes, the Gray Haired Plague continues to infect EAA and it's people. Best part is he will have no doubt been instrumental in "convincing" the 16/F pop-out windows and life rafts were not needed. Hope they hang him.
Pilots, am told, claimed they heard a bang resulting in the pedals becoming ineffective. Both engines pulled back immediately and into the water they did go.
I'm going to speculate here (my opinion only) that assuming the aircraft entered the water WITH the T/R et al still attached to the airframe, it wouldn't have been turning under any real amount of power. Therefore, any notion that a sudden stoppage on contact with the water resulted in not only the T/R and gearbox separating from the aircraft, but also that much of the vertical stab structure, is somewhat difficult to believe. Again, just my opinion.
So that leaves us with the only other likely scenario, in-flight structural failure which, if true, is scary indeed. And you have to admit, from looking at all the posted photos, there appears to be an awful lot of structure missing from the vertical stab assembly.
JW
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Thank God this occured right off the end of the Shun Tak pad where there are literally hundreds of boats and ferries that could help rescue the pax and crew. Would hate to think what the result would have been had it been at cruise flight somewhere between HK and Macau and up high. 
Well done to the crew
Well done to the crew
The AW139 could be pushing into new a unknown area of Airframe stress here, Due to the share number of vertical Cat-A depts everyday,
will be? Seems the bird in the tailrotor theory is no longer in vogue.
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Some of the speculation in this thread is pretty bizarre regarding this incident!
Turbine blades departing the engine would have destroyed the engine cowls, which are remarkably intact.
As in this case, why the tail rotor took a holiday will only be ascertained by investigation, despite the scenarios we may dream up. History shows the reasons are diverse and many. Our operation had one, all due to a washer not being installed. Upper half of the fin on a 204 fell off, along with the gearbox.
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From today's South China Morning Post
"A bird strike might be one issue investigators will look into when they investigate the emergency landing of a Macau-bound helicopter in Victoria Harbour on Saturday.
And the Civil Aviation Department said the operator of the helicopter service had provided sufficient life jackets for those on board, after claims there were not enough.
The department said 14 life jackets were in the aircraft. It is believed some passengers panicked and could not find life jackets.
The crash into the sea happened about noon on Saturday when the helicopter was forced to make an emergency landing in the harbour shortly after it took off from the Sheung Wan helipad due to "technical difficulties".
The 11 passengers and two pilots on the 15-seat helicopter were rescued from the harbour. No serious injuries were reported.
The department is investigating the incident in co-ordination with authorities in Macau, where the helicopter was registered, and the AgustaWestland AW139's Italian manufacturer.
The helicopter was transported to a depot at Chek Lap Kok airport for inspection after it was salvaged from the sea and put on a barge overnight. Some components of the aircraft were disassembled yesterday. There had been claims there were not enough life jackets on the helicopter, according to newspaper reports quoting a passenger who had been unable to find one.
Media reports also said a bird strike could have caused the accident, quoting witnesses saying they had seen birds flying near the helicopter shortly before the accident occurred.
A department spokeswoman yesterday said an investigation was under way and it was too early to speculate about causes. She said investigators had found 14 life jackets "so, it seems there were enough life jackets on board for the 13 people."
Lo Wai-yan, of the Hong Kong Bird Watching Society, said: "I am not really sure if a bird strike could be a cause. Eagles can sometimes be seen hovering over the harbour. But they should be able to avoid colliding with a helicopter, especially when the aircraft has just taken off and the speed might not be very high."
The helicopter came into service last year. Its owner, Sky Shuttle, was ordered to suspend its helicopter service until safety checks are completed on the five other aircraft of the same model that it owns.
Sky Shuttle's ticket counters at the Macau ferry terminal in Sheung Wan remained closed yesterday. But there was no notice about the suspension of service or Saturday's accident. A duty officer at the company's customer service telephone hotline said it was unknown how much longer services would be suspended.
One traveller returning from Macau yesterday said she was not worried by the accident because she would not travel to the city by air. "It is too expensive. It is for rich people only. Us ordinary travellers usually take the ferry," Jane Chung said.
Sky Shuttle has six medium-twin engine AgustaWestland AW139 helicopters. It operates 54 flights daily between Macau and Hong Kong, between 9am and 11pm. Each flight takes 15 minutes. A one-way ticket costs HK$2,600."
JW
And the Civil Aviation Department said the operator of the helicopter service had provided sufficient life jackets for those on board, after claims there were not enough.
The department said 14 life jackets were in the aircraft. It is believed some passengers panicked and could not find life jackets.
The crash into the sea happened about noon on Saturday when the helicopter was forced to make an emergency landing in the harbour shortly after it took off from the Sheung Wan helipad due to "technical difficulties".
The 11 passengers and two pilots on the 15-seat helicopter were rescued from the harbour. No serious injuries were reported.
The department is investigating the incident in co-ordination with authorities in Macau, where the helicopter was registered, and the AgustaWestland AW139's Italian manufacturer.
The helicopter was transported to a depot at Chek Lap Kok airport for inspection after it was salvaged from the sea and put on a barge overnight. Some components of the aircraft were disassembled yesterday. There had been claims there were not enough life jackets on the helicopter, according to newspaper reports quoting a passenger who had been unable to find one.
Media reports also said a bird strike could have caused the accident, quoting witnesses saying they had seen birds flying near the helicopter shortly before the accident occurred.
A department spokeswoman yesterday said an investigation was under way and it was too early to speculate about causes. She said investigators had found 14 life jackets "so, it seems there were enough life jackets on board for the 13 people."
Lo Wai-yan, of the Hong Kong Bird Watching Society, said: "I am not really sure if a bird strike could be a cause. Eagles can sometimes be seen hovering over the harbour. But they should be able to avoid colliding with a helicopter, especially when the aircraft has just taken off and the speed might not be very high."
The helicopter came into service last year. Its owner, Sky Shuttle, was ordered to suspend its helicopter service until safety checks are completed on the five other aircraft of the same model that it owns.
Sky Shuttle's ticket counters at the Macau ferry terminal in Sheung Wan remained closed yesterday. But there was no notice about the suspension of service or Saturday's accident. A duty officer at the company's customer service telephone hotline said it was unknown how much longer services would be suspended.
One traveller returning from Macau yesterday said she was not worried by the accident because she would not travel to the city by air. "It is too expensive. It is for rich people only. Us ordinary travellers usually take the ferry," Jane Chung said.
Sky Shuttle has six medium-twin engine AgustaWestland AW139 helicopters. It operates 54 flights daily between Macau and Hong Kong, between 9am and 11pm. Each flight takes 15 minutes. A one-way ticket costs HK$2,600."
JW
The AW139 could be pushing into new a unknown area of Airframe stress here, Due to the share number of vertical Cat-A depts everyday
The only extra "stress" is spinning the rotor at 102% instead of 100%.
Pull hover Tq plus 7% (from memory??), and climb vertically. That certainly doesn't sound stressful to me, and when sitting inside it certainly doesn't feel stressful.
I know of one African operation where a 139 was doing 10 Cat A departures everyday with no issues or problems.
Keep in mind this airframe, tailboom, and rotor head are now flying at 8000kg on the AW149! I'm sure there is some beefing up of structure there, and I'd love to know where, and if they will back track those mods to the 139.
Doors will normally be used to egress if the aircraft is stable. Unlike some other helicopters, all passenger rows have clear access to the door opening, so why not use the biggest hole available to get people out, just like Bristow did with their 332 in Nigeria recently.
All 139's have pop out windows, even the double glazed VIP windows, but they are can be a prick to use!
It will be very interesting to see what exactly happened with this aircraft.
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noooby
Perhaps we should be saying "unknown composite airframe stress".
I used to stand at the hangar door in Macau, watching the aircraft (C+) depart using our vertical departure procedure. I would essentially be almost directly underneath the aircraft and so had an amazing view of the stresses the entire tail section was enduring using this procedure. Trust me when I say, it made me cringe to see just how much bending and twisting was going on all up and down the entire tail boom. Lets remember this was all happening on an airframe design with many, many years of service already behind it.
Somehow I don't think the same can be said where the 139 and its composite structure(s) are concerned.
JW
Perhaps we should be saying "unknown composite airframe stress".
I used to stand at the hangar door in Macau, watching the aircraft (C+) depart using our vertical departure procedure. I would essentially be almost directly underneath the aircraft and so had an amazing view of the stresses the entire tail section was enduring using this procedure. Trust me when I say, it made me cringe to see just how much bending and twisting was going on all up and down the entire tail boom. Lets remember this was all happening on an airframe design with many, many years of service already behind it.
Somehow I don't think the same can be said where the 139 and its composite structure(s) are concerned.
JW
noooby, you must be one of those Canadian guys that doesn't feel obliged to fly Class 1 on every takeoff. Class 1 Helipad departure profile calls for pulling hover Tq plus 23%, not 7% that the Class 2 guys use.
I don't think 102%NR is any extra stress except that any vibration damping is tuned for 100% so as soon as you go to 102% your eyeballs jiggle. A lot. The "profiles" you are told to use will usually guarantee that your eyes are in jiggle mode for an extended period. Most of you VFR guys think transition vibration is something you accelerate and decelerate quickly through, like on an S61 or Bell 407, and you never think to linger in it to stay on a "profile".
I don't think 102%NR is any extra stress except that any vibration damping is tuned for 100% so as soon as you go to 102% your eyeballs jiggle. A lot. The "profiles" you are told to use will usually guarantee that your eyes are in jiggle mode for an extended period. Most of you VFR guys think transition vibration is something you accelerate and decelerate quickly through, like on an S61 or Bell 407, and you never think to linger in it to stay on a "profile".
Avoid imitations
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Unknown Airframe stress? Seriously??
The only extra "stress" is spinning the rotor at 102% instead of 100%.
The only extra "stress" is spinning the rotor at 102% instead of 100%.