Twins operating without Onshore Diversion Fuel in GOM
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While I understand all these inputs I spent many days out to 100nm and sometimes more in 206Ls with P*I... when I flew the 412 out there I always felt that on a benign day I would be better off doing a controlled ditching than a potentially very hazardous landing on any deck...regardless of its size.
Maybe Im naive but I still wonder about our incessant obsession with S/E performance. The one major thing I like about flying in Europe is the HUMS.... Now Im not an expert but there are so many things that can and do go wrong throughout the drive system that focusing in the engine...something we perceive we can control.. is a far too simple a way of looking at things.
Maybe Im naive but I still wonder about our incessant obsession with S/E performance. The one major thing I like about flying in Europe is the HUMS.... Now Im not an expert but there are so many things that can and do go wrong throughout the drive system that focusing in the engine...something we perceive we can control.. is a far too simple a way of looking at things.
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Decks.
Nice point about HUMS or IHUMS............
They will measure vibration essentially...........what blade failure or rotor failure gives a vibration before failure........???
HUMS may tell you when a Generator bearing MAY fail......great, I have two or three of them and a battery. Or perhaps numerous drive shaft couplings that the engineers already know about.
But I have only one set of blades............[I assume the IHUMS on the S76 last year in the North Sea suggested ZERO prior to dispatch?].......
Many things will put you in the water............and IHUMS KNOWS NOTHING about some of them.
Its only another tool....
They will measure vibration essentially...........what blade failure or rotor failure gives a vibration before failure........???
HUMS may tell you when a Generator bearing MAY fail......great, I have two or three of them and a battery. Or perhaps numerous drive shaft couplings that the engineers already know about.
But I have only one set of blades............[I assume the IHUMS on the S76 last year in the North Sea suggested ZERO prior to dispatch?].......
Many things will put you in the water............and IHUMS KNOWS NOTHING about some of them.
Its only another tool....
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GlsNightpilot
You said
"The technique we use for a single-engine approach is to set up a slightly steeper than normal approach, make a rather slow descent with some power, & put it on the deck".
Why would you set up a diferent approach angle when practising a OEI approach ?, wouldn't you be better placed making your normal approach this steep in case of a real engine failure.
There are to many shallow approaches flown to decks and its only due to better engineering and design that this is allowed to continue unchecked.
Decks
The IHUMS on the AS332 L2 failed to detect any onset of the bearing failure on the engine that failed instantly last saturday dropping the compressor onto the stator and triggering fire bells and whistle,s along with Pwr and Diff Ng warnings luckily this happened in the cruise and the crew responded correctly to the situation. well done to them
Chopperman
Never used a offshore alternate myself as the L2 doesn't have a single engine perf chart, but I was allways curious as to why we didn,t lower the u/c prior to PNR and accept the extra fuel penalty (+6%fuel flow) over the chance of metal to metal landing or ditching.
You said
"The technique we use for a single-engine approach is to set up a slightly steeper than normal approach, make a rather slow descent with some power, & put it on the deck".
Why would you set up a diferent approach angle when practising a OEI approach ?, wouldn't you be better placed making your normal approach this steep in case of a real engine failure.
There are to many shallow approaches flown to decks and its only due to better engineering and design that this is allowed to continue unchecked.
Decks
The IHUMS on the AS332 L2 failed to detect any onset of the bearing failure on the engine that failed instantly last saturday dropping the compressor onto the stator and triggering fire bells and whistle,s along with Pwr and Diff Ng warnings luckily this happened in the cruise and the crew responded correctly to the situation. well done to them
Chopperman
Never used a offshore alternate myself as the L2 doesn't have a single engine perf chart, but I was allways curious as to why we didn,t lower the u/c prior to PNR and accept the extra fuel penalty (+6%fuel flow) over the chance of metal to metal landing or ditching.
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chopperman
Ok............
Playing the Devils Advocate now............
Sure the HUMS may have identified a MGB problem................was that before or after the Chip Plugs did their job???.
Once had a HUMS warning that a Generator was troublesome............44 hours later we changed it when engineering "felt" a problem.
Great.....
Don't get me wrong......................the system is a good aid to safer flight..................but don't put all your eggs in the computer system of IHUMS.
Playing the Devils Advocate now............
Sure the HUMS may have identified a MGB problem................was that before or after the Chip Plugs did their job???.
Once had a HUMS warning that a Generator was troublesome............44 hours later we changed it when engineering "felt" a problem.
Great.....
Don't get me wrong......................the system is a good aid to safer flight..................but don't put all your eggs in the computer system of IHUMS.
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rotordk: Ta!
The Auditor: I agree that HUMS is not too good on rotor blade failures because as you say they work on vibrations. Blade cracks, until the last few minutes tend to expand on start-up, then the loads in the blade stop vibration until the end of the flight.
chopperman hits the nail on the head with MGBs (and other GBs, shafts etc). You only get one of each and there is almost no way of inspecting inside gearboxes in service. Mag plus are only good at picking up wear debris. Fatigue cracks don't produce debris but they do give vibrations so HUMS works like a dream.
Remember the lessons from the fatal HKS accident in 97 - if they had fixed the accelerometer the failure would have been averted - 12 lives saved. What we don't know is how many accidents have been avoided by HUMS.
Have a look at rotorcraft page on http://www.jaa.nl/certification/certification.html to see the JAA policy.
The Auditor: I agree that HUMS is not too good on rotor blade failures because as you say they work on vibrations. Blade cracks, until the last few minutes tend to expand on start-up, then the loads in the blade stop vibration until the end of the flight.
chopperman hits the nail on the head with MGBs (and other GBs, shafts etc). You only get one of each and there is almost no way of inspecting inside gearboxes in service. Mag plus are only good at picking up wear debris. Fatigue cracks don't produce debris but they do give vibrations so HUMS works like a dream.
Remember the lessons from the fatal HKS accident in 97 - if they had fixed the accelerometer the failure would have been averted - 12 lives saved. What we don't know is how many accidents have been avoided by HUMS.
Have a look at rotorcraft page on http://www.jaa.nl/certification/certification.html to see the JAA policy.
Iconoclast
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Keep yourselc clean with SOAP.
HUMS monitors against an established standard for vibration and temperature in lubricated gearboxes. However long before the vibration or temperature reach and exceed this established standard there is a precursor to those conditions. That is the increase in wear metals in the oil. Wear metals are not to be confused with metallic chips. The buildup of wear metals can be detected through the use of a consistent SOAP analysis program, SOAP or Spectrometric Oil Analysis Program monitors the rate of increase of wear metals in the oil and compares this with new oil which is the standard. The analysis program can determine the types of wear metals (steel, bronze, aluminum, magnesium or any other internal working parts bathed in the oil). The only drawback in the use of SOAP is frequent oil changes.
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Lu: SOAP has had a long history or poor results in the North Sea. On the S61 the Sikorsky limits are so high that unless someone has angle ground your gears you'll never get a indication. And just like mag plus have minimal capability against fatigue failures (until really late in the day).
One view of the problem is that civil flying is normally so intensive (a good AS332L2 operation can be close to 2000FH/pa), the time to get results means you are always chasing your tail.
Out in more remote areas (and I don't mean Shetland!) the problems getting the samples back to a lab is even worse.
Another view is all you get back is a mish mash of data that rarely points to a single defect (as opposed to general wear) until the whole thing goes bang. As most gears are made of the same material and all wear its no wonder SOAP rarely provides the insight it does in gas turbines wee the material mix.
At least HUMS can be processed on-site in minutes and can point to the shaft the vibrations are coming from. SOAP was trialled back-back with HUMS in the CAA trials in the late 80s - with HUMS coming out by far and a way superior.
The Canadians have spent a lot of money developing an on-line debris monitor (OilScan ??) which apparently could complement HUMS well.
Don't understand why oil changes are more frequent with SOAP though - surely you don't want to change your oil so you can build up a trend??
Also Lu: IHUMS, NSHUMS, 101AMS and the two EC systems do not measure oil temperatures, these remain standard aircraft instrumentation.
One view of the problem is that civil flying is normally so intensive (a good AS332L2 operation can be close to 2000FH/pa), the time to get results means you are always chasing your tail.
Out in more remote areas (and I don't mean Shetland!) the problems getting the samples back to a lab is even worse.
Another view is all you get back is a mish mash of data that rarely points to a single defect (as opposed to general wear) until the whole thing goes bang. As most gears are made of the same material and all wear its no wonder SOAP rarely provides the insight it does in gas turbines wee the material mix.
At least HUMS can be processed on-site in minutes and can point to the shaft the vibrations are coming from. SOAP was trialled back-back with HUMS in the CAA trials in the late 80s - with HUMS coming out by far and a way superior.
The Canadians have spent a lot of money developing an on-line debris monitor (OilScan ??) which apparently could complement HUMS well.
Don't understand why oil changes are more frequent with SOAP though - surely you don't want to change your oil so you can build up a trend??
Also Lu: IHUMS, NSHUMS, 101AMS and the two EC systems do not measure oil temperatures, these remain standard aircraft instrumentation.
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Max, you make a good point. My normal approaches are pretty much what we're taught for a single-engine approach. However, many fly a flatter normal approach, for whatever reason, so they would need to steepen it for a single-engine approach.
Iconoclast
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SOAPy water?
To: Zalt
SOAP does not contribute to frequent oil changes. The point I was trying to make was that periodic oil
changes mean that you must start over because you are throwing the baby out with the bath water the baby being the wear metals.
On the EH-101 as it was originally designed had a HUMS system built into it which monitored bearing temperature, gear vibration patterns, oil temps and vibratory frequencies at various points on the helicopter.
Regarding the debris monitor being developed by the Canadians Douglas had incorporated a similar system on the original DC-10. This was a part of a precursor to HUMS that was mounted on the aircraft when it originally rolled out in 1968-69. The purpose of the system was to monitor the health of the hydraulics system and down load any problems to a landline in middle America. When the plane landed for turn around the repair crew would be waiting with the replacement parts and the tools necessary to fix the problem. There were so many problems that the system was removed saving a considerable amount of weight.
Regarding fatigue failure without the presence of chips an Italian navy S-61 suffered a fatigue failure in one of its free wheeling units and within twenty seconds the pilot made a safe autorotation into the water. In those twenty seconds the parts of the free wheeling unit were either worn down or welded together. No warning. No chips and no vibration. Most likely HUMS could not have detected it.
SOAP does not contribute to frequent oil changes. The point I was trying to make was that periodic oil
changes mean that you must start over because you are throwing the baby out with the bath water the baby being the wear metals.
On the EH-101 as it was originally designed had a HUMS system built into it which monitored bearing temperature, gear vibration patterns, oil temps and vibratory frequencies at various points on the helicopter.
Regarding the debris monitor being developed by the Canadians Douglas had incorporated a similar system on the original DC-10. This was a part of a precursor to HUMS that was mounted on the aircraft when it originally rolled out in 1968-69. The purpose of the system was to monitor the health of the hydraulics system and down load any problems to a landline in middle America. When the plane landed for turn around the repair crew would be waiting with the replacement parts and the tools necessary to fix the problem. There were so many problems that the system was removed saving a considerable amount of weight.
Regarding fatigue failure without the presence of chips an Italian navy S-61 suffered a fatigue failure in one of its free wheeling units and within twenty seconds the pilot made a safe autorotation into the water. In those twenty seconds the parts of the free wheeling unit were either worn down or welded together. No warning. No chips and no vibration. Most likely HUMS could not have detected it.
It's not just an adventure....
it's just a job!
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Wow!
Is this discussion for real? Am I really hearing Pilots actually considering OEI Landings on a rig?
Someone actually said it is the accepted practice in the North Sea to use another rig as an alternate providing you arrive at OEI performance?
EXCUSE ME that means you dont have enough fuel to reach the beach. And if you think your going to make a successful OEI landing on the rig, GOOD LUCK TO YA. (Unless ofcourse its an aircraft carrier your landing on) BUT I DONT THINK THATS THE CASE, IS IT? My God, what company are you working for anyway?
Have we worked our a$$es off for the past 20+ years to make things better, only to see this kind of "Get the job done at any cost" attitude re-surface?
There's nothing wrong with getting the job done. Just do it safely and that means holding a shore-based OEI alternate. I dont think JAR allows for any less, nor CAA.
Just my two cents worth.
Cheers,
OffshorIgor
Is this discussion for real? Am I really hearing Pilots actually considering OEI Landings on a rig?
Someone actually said it is the accepted practice in the North Sea to use another rig as an alternate providing you arrive at OEI performance?
EXCUSE ME that means you dont have enough fuel to reach the beach. And if you think your going to make a successful OEI landing on the rig, GOOD LUCK TO YA. (Unless ofcourse its an aircraft carrier your landing on) BUT I DONT THINK THATS THE CASE, IS IT? My God, what company are you working for anyway?
Have we worked our a$$es off for the past 20+ years to make things better, only to see this kind of "Get the job done at any cost" attitude re-surface?
There's nothing wrong with getting the job done. Just do it safely and that means holding a shore-based OEI alternate. I dont think JAR allows for any less, nor CAA.
Just my two cents worth.
Cheers,
OffshorIgor
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offshoreigor
There have been occasions where AS332 have been approved to hold offshore facilities as OEI alternates.......but under very strict controls. And also because of the unique OEI capacity of this helicopter.
[I think the B214ST may have also been approved...not sure on this one]
GLSNightPilot works for a company which allows Mediums to hold platforms as OEI alternates.
The wisdom of undertaking such an activity has certainly be questioned by most [if not all] other pilots outside the GOM.
Each to their own standards I guess.........
[I think the B214ST may have also been approved...not sure on this one]
GLSNightPilot works for a company which allows Mediums to hold platforms as OEI alternates.
The wisdom of undertaking such an activity has certainly be questioned by most [if not all] other pilots outside the GOM.
Each to their own standards I guess.........
Thread Starter
The GOM continues to suffer from a lack of oversight by the FAA...they continue to ignore that segment of the aviation industry. One quarter of a million passengers per week moved....pilots making non-precision approaches to precision approach minima....then circling to land......poor weather reporting....terrible comms with ATC (if at all)....no radar traffic separation....flying mediums at MAUW all the time....no onshore diversion fuel....Cat A ignored....."Wunderbar!" One operator is having or has just had the worst year for accidents and the Corporate Safety Officer continues to draw his bonus and exercise his stock options.....what a deal !
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Sassy................
Quarter of a million a week????....250,000???
Thats:
62,500 B206b flights [at least 2 done by Poo Prawn]
20,833 S76 flights
17,857 B412 flights
13,888 AS332 flights
555 B747-400 flights!!!!
Of the 2000 platforms,,,thats an average crewchange of 125 folk/week/platform???
I'll do my 4 a week and enjoy.
Thats:
62,500 B206b flights [at least 2 done by Poo Prawn]
20,833 S76 flights
17,857 B412 flights
13,888 AS332 flights
555 B747-400 flights!!!!
Of the 2000 platforms,,,thats an average crewchange of 125 folk/week/platform???
I'll do my 4 a week and enjoy.
Thread Starter
One must also count the inter-field hops...taking the Beaudreu's to and from lunch....well checking....fetching tools....etc.....that is sorties multiplied by occupants I am sure.....but an impressive number notwithstanding. Well checkers are doing a hundred sectors per day in some fields....that adds up over the week....and by the sheer number of fields in the GOM. Just using some numbers quoted by an industry insider.
Last edited by SASless; 24th May 2003 at 07:55.
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Things have slowed down considerably, but there's still a lot of activity. I used to do 120+ takeoffs every day, guaranteed. I didn't go far, but I did it often. There are still fields where you do 50 or better every day, some more. The average medium makes probably 3 trips/day, and more isn't unusual. There are very few places where you do one trip out, come back, & then have a beer. The limit is usually allowable flight time, 10 hrs/day with a crew of 2, or duty time, which is 14 hours. Timing out in either category is common. Also, keep in mind that there are probably close to 500 helicopters flying out there. PHI alone has close to 200 in the GOM.
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OGP offshore figures are:
3.1mn pax in GoM in 2001 (average flight time 18 mins) i.e. 60000 per week
2.4mn pax in North Sea in 2001 (average flight time 40 mins)
3.4mn pax in ROW for oil industry in 2001 (average flight time 18 mins)
3.1mn pax in GoM in 2001 (average flight time 18 mins) i.e. 60000 per week
2.4mn pax in North Sea in 2001 (average flight time 40 mins)
3.4mn pax in ROW for oil industry in 2001 (average flight time 18 mins)
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Interesting Stats.
Extracted from the May 2003 issue of Time Magazine [Oz Edition].....
The US had [has] 508,000 active Oil Wells producing an average of 17 barrels / well /day.
Iraq had [has] 250 active Oil Wells producing an average of 13,700 barrels / well / day.
[Stats are a tad old....but still proportional]
No wonder there are different rules for the GOM.....or those wells may not be viable. [I accept some of those are "Rocking Horse" wells belonging to the Hillbillies in the backblocks of Texas]
Tell me George......truthfully now......Oil was not really on the agenda...was it??
The US had [has] 508,000 active Oil Wells producing an average of 17 barrels / well /day.
Iraq had [has] 250 active Oil Wells producing an average of 13,700 barrels / well / day.
[Stats are a tad old....but still proportional]
No wonder there are different rules for the GOM.....or those wells may not be viable. [I accept some of those are "Rocking Horse" wells belonging to the Hillbillies in the backblocks of Texas]
Tell me George......truthfully now......Oil was not really on the agenda...was it??
Last edited by Red Wine; 28th May 2003 at 15:10.
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The wells offshore produce much more than many of the onshore wells, or they wouldn't be viable at all. The majority of the offshore wells in the GOM produce gas, not oil, especially in the shallow water. But your main point is well taken - there is a reason we invaded Iraq & not North Korea. Not much profit to be made from North Korea.