North Sea heli ditching: Oct 2012
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If it is 1 year, there are not enough spare 332Ls with functioning MGBs or S-92s around to make up the deficit. The oil companies will be looking for a way to not continue to pay the operators, who won't be making enough revenue to pay the banks. How long before some jobs may have to go?
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false warning of emlube failure gets convincingly sorted out.
"EMLuBe Fail(ed to fix the problem) - Ditch"
then in fact it is working properly, If I were writing the software, I might well decide to not have a host of different error messages when the conclusion is the same.
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As it stands, that message from the StepChange website is out of date. If I understand the effect of the CAA Operational Directive, it will prevent the use of any UK-Reg Pumas and variants offshore, if they have the relevant part number shaft.
The "Step Change" party line is really just the view of the offshore installation operators. It is clear they wanted Puma shuttles to resume with limited restrictions. I wonder whether this will change, in the light of the CAA action?
The "Step Change" party line is really just the view of the offshore installation operators. It is clear they wanted Puma shuttles to resume with limited restrictions. I wonder whether this will change, in the light of the CAA action?
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Is relying on HUMS acceptable?
CAP 753 (8.3) states that HUMS must detect no less than 70% of failure modes that it is directly monitoring. The oil pump shaft is not directly monitored so presumably the rate of detection may be less than 70%.
At what percentage do you say the risk is mitigated and it's OK to fly?
Can EC or an operator demonstrate 225 HUMS will always give an early warning of impending failure?
CAP 753 (8.3) states that HUMS must detect no less than 70% of failure modes that it is directly monitoring. The oil pump shaft is not directly monitored so presumably the rate of detection may be less than 70%.
At what percentage do you say the risk is mitigated and it's OK to fly?
Can EC or an operator demonstrate 225 HUMS will always give an early warning of impending failure?
As it stands, that message from the StepChange website is out of date. If I understand the effect of the CAA Operational Directive, it will prevent the use of any UK-Reg Pumas and variants offshore, if they have the relevant part number shaft.
The "Step Change" party line is really just the view of the offshore installation operators. It is clear they wanted Puma shuttles to resume with limited restrictions. I wonder whether this will change, in the light of the CAA action?
The "Step Change" party line is really just the view of the offshore installation operators. It is clear they wanted Puma shuttles to resume with limited restrictions. I wonder whether this will change, in the light of the CAA action?
Why is the EC225 still suspended?
The helicopter operators took the decision to continue to suspend the EC225 until further guarantees can be provided on its safety. Independent of this, the UK aviation regulator, the Civil Aviation Authority (CAA) has since issued an operational directive forbidding its use for offshore transport. This continued suspension of the EC225 is fully supported by the Helicopter Safety Steering Group and the trade unions.
Last edited by Bravo73; 26th Oct 2012 at 09:38. Reason: Edited HTML formattting
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Exactly the point Sanus. You have answered the question yourself.
This failure of the defective part is known and at the moment has an apparent return period of 6 months in the UK fleet. Apparently the HUMS has only a relatively small chance of preventive detection, so the frequency of further undetected failures is pretty significant if the affected aircraft continue to fly.
Its only a satisfactory resolution, if you are happy with a reasonable prospect of North Sea "controlled" ditching, in the winter months.
We have been very lucky so far, that the outcomes have not involved injury or worse. What is the conditional probability of benign conditions in a North Sea winter? It gives the expression "wing and a prayer" new resonance.
B73 - thanks for pointing me at the second link. However, is it not less to do with the aircraft type/variant but more with the gearbox shaft batch part number/method of manufacture?
This failure of the defective part is known and at the moment has an apparent return period of 6 months in the UK fleet. Apparently the HUMS has only a relatively small chance of preventive detection, so the frequency of further undetected failures is pretty significant if the affected aircraft continue to fly.
Its only a satisfactory resolution, if you are happy with a reasonable prospect of North Sea "controlled" ditching, in the winter months.
We have been very lucky so far, that the outcomes have not involved injury or worse. What is the conditional probability of benign conditions in a North Sea winter? It gives the expression "wing and a prayer" new resonance.
B73 - thanks for pointing me at the second link. However, is it not less to do with the aircraft type/variant but more with the gearbox shaft batch part number/method of manufacture?
Last edited by Helinut; 26th Oct 2012 at 09:54. Reason: To add acknowledgement of B73's last post
The return to flying will see an additional one AS332L1 and eight AS332L2 aircraft amongst the three Aberdeen-based operators.
So, in essence, the CAA directive effects all but 9 Super Pumas in ABZ.
I wonder what the time scale is for going back to original design shafts on the L and L2 models. I also wonder if it is possible to rework the existing new design shafts which are in service now or will EC have to start from scratch. I assume it takes a long time to make a shaft due to the manufacturing, chemical treatment and ageing processes involved so the North Sea (and other areas) is probably in for a lengthy disruption.
The loss of a significant proportion of O & G helicopter support worldwide is bound to cause serious concern at the highest levels of the oil companies management and governments.
The loss of a significant proportion of O & G helicopter support worldwide is bound to cause serious concern at the highest levels of the oil companies management and governments.
To think all those S-61's that got flogged off for junk prices!
Why are some Super Pumas flying and others not?
The difference is down to a certain type of component – the main gearbox vertical shaft. For ease, these have been labelled below as shafts 1 and 2.
Type of shaft.......Can be fitted in.......What is it?.........Approved for use?
“Shaft 1”......L, L1 and L2 models........This is the original design of shaft. Has accumulated 4.5 million flight hours without incident......Yes
“Shaft 2”...... L, L1, L2 and EC225 L, L1 and L2 aircraft can be fitter with either Shaft 1 or Shaft 2 If not already so, these will now be re-fitted with shaft 1 in order to be fly again. All EC225s feature shaft 2 and cannot be fitted with Shaft 1........... A change in the manufacturing process of specific batches of Shaft 2 was originally thought to be the cause of the G-REDW ditching in May. New evidence is coming to light which suggests that the scope of the problems associated with Shaft 2 are wider. Use of aircraft which feature this shaft is not supported by the aircraft operators and is also no currently permitted by the CAA.
First introduction a little bit less than 8 years ago so the answer is : no
G-TIGC, a 332L from Bristow for sale (up to now...) is 30 years old with about 34000 Hrs TT.
.
G-TIGC, a 332L from Bristow for sale (up to now...) is 30 years old with about 34000 Hrs TT.
.
I'm just using Eurocopters own data:-
Puma helicopter, super puma - Eurocopter helicopters - Eurocopter, an EADS company
which says:-
The EC225 has evolved from the vast experience accumulated by some 100 Super Puma operators; some 900 helicopters have been ordered in 52 countries. The in-service Super Puma fleet has logged more than 4,4-million hours and the fleet leader has flown 39,300 hours.
One assumes therefore that they are now being clever with the mix and match of types.
Puma helicopter, super puma - Eurocopter helicopters - Eurocopter, an EADS company
which says:-
The EC225 has evolved from the vast experience accumulated by some 100 Super Puma operators; some 900 helicopters have been ordered in 52 countries. The in-service Super Puma fleet has logged more than 4,4-million hours and the fleet leader has flown 39,300 hours.
One assumes therefore that they are now being clever with the mix and match of types.
ha yes but Bravo I think we are seeing that some Super Puma's are more Super than others...
One truely wonders how that approach was used in the approval process. Over simplification no doubt but do you just take AS332L2 then say you've ran the new gearbox on a rig for X hours and therefore we are good to go with the EC225?
The focus on the emergency gearbox cooling system is all well and good but remember thats just the short term fix if you have one type of in flight issue. As has been said before when parts of the gearbox are departing through the fuselage a cooling system isn't going to save you.
The only real solution short term is limit the torque of the 225 to protect the gearbox that it has and for the manufacturer to give a strict limits on checks. Although one might note that in the case of REDL the suggestion was that existing detection methods wouldn't have provided further indication of issues.
Now I know the failures are different but with no explaination why a 3000hr gearbox shat itself which was lifed to 6000hrs and with 2 further gearbox issues in 2012 I think an engineering solution is needed not just a software update and the responsibility dumped on the operator or worse maintenance for the operator. Would you want that on your conscious?
One truely wonders how that approach was used in the approval process. Over simplification no doubt but do you just take AS332L2 then say you've ran the new gearbox on a rig for X hours and therefore we are good to go with the EC225?
The focus on the emergency gearbox cooling system is all well and good but remember thats just the short term fix if you have one type of in flight issue. As has been said before when parts of the gearbox are departing through the fuselage a cooling system isn't going to save you.
The only real solution short term is limit the torque of the 225 to protect the gearbox that it has and for the manufacturer to give a strict limits on checks. Although one might note that in the case of REDL the suggestion was that existing detection methods wouldn't have provided further indication of issues.
Now I know the failures are different but with no explaination why a 3000hr gearbox shat itself which was lifed to 6000hrs and with 2 further gearbox issues in 2012 I think an engineering solution is needed not just a software update and the responsibility dumped on the operator or worse maintenance for the operator. Would you want that on your conscious?
Last edited by Pittsextra; 26th Oct 2012 at 17:00.
The only real solution short term is limit the torque of the 225 to protect the gearbox