Agusta AW139
Platinumpure, I feel for you. Nothing worse than having a machine with good potential not living up to the hype.
js0987, while Shell control Bristow (oh yes they do!!!), Bristow can't buy AW139's. Shell demand that a simulator is available, and for the 139, that won't be until late this year, early next.
Bell bailed on the 139 because they were losing sooooo much money on the V-22 and BA609, that they had to sell out of the 139 because they needed the money so bad (so I heard).
If Honeywell would step upto the plate and fix the f
CMC to get rid of the phantom maintenance messages, and fix the other elec gremlins, and if Agusta would sort out the main rotor and tail rotor scissors, it would be a fantastic machine.
I still think it is better than the competition though, especially where passenger safety and comfort is concerned. You don't sit on the floor in the back like a 365, and everyone can get out the doors easily in an emergency, unlike the 76.
My 2 cents
js0987, while Shell control Bristow (oh yes they do!!!), Bristow can't buy AW139's. Shell demand that a simulator is available, and for the 139, that won't be until late this year, early next.
Bell bailed on the 139 because they were losing sooooo much money on the V-22 and BA609, that they had to sell out of the 139 because they needed the money so bad (so I heard).
If Honeywell would step upto the plate and fix the f
CMC to get rid of the phantom maintenance messages, and fix the other elec gremlins, and if Agusta would sort out the main rotor and tail rotor scissors, it would be a fantastic machine.I still think it is better than the competition though, especially where passenger safety and comfort is concerned. You don't sit on the floor in the back like a 365, and everyone can get out the doors easily in an emergency, unlike the 76.
My 2 cents
Fuel planning for EMS and SAR would be closer to 1000 lbs/hr - I agree
Common problems
Air conditioning. - Yes
Hyd servo CAS messages due to moisture and faulty switches. - Yes
Fuel probe CAS messages (mostly due to cannon plugs). - No
Fire warnings due to exhausts cracking and in some cases collapsing. - Not the warning but yes on the cracks
AHRS failing. -No
GPS antenna failures (not a whole lot of fun when 150 miles offshore as the FMS D/R mode isn’t so hot) -No
Not so common problems –
Gear dropping magically by itself.- No
Engine starting to spool up when hyd electrical pump turned on ??? -No
Parking brake sticking. -No
And more recently an un-commanded shutdown of an engine followed by a EEC failure. - Hell No!
Common problems
Air conditioning. - Yes
Hyd servo CAS messages due to moisture and faulty switches. - Yes
Fuel probe CAS messages (mostly due to cannon plugs). - No
Fire warnings due to exhausts cracking and in some cases collapsing. - Not the warning but yes on the cracks
AHRS failing. -No
GPS antenna failures (not a whole lot of fun when 150 miles offshore as the FMS D/R mode isn’t so hot) -No
Not so common problems –
Gear dropping magically by itself.- No
Engine starting to spool up when hyd electrical pump turned on ??? -No
Parking brake sticking. -No
And more recently an un-commanded shutdown of an engine followed by a EEC failure. - Hell No!
Aser
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
The 139 sounds like it is doing as expected on initial introduction, the stories of cracked exhausts and the like are somewhat "normal" and quite likely to be fully ironed out very quickly. I would also bet that stories from pilots that I respect about its good vibrations, good handling and such are all quite true.
The pilot preferences for a full Cat A capability are answered by the 139, it literally has no Dead Man's curve at normal altitudes, so it meets the ppruner's most basic wish (proven by lots of interesting threads!)
The real story behind the scenes is the "cost" of the super engine power that the design brings to the table. By "cost" I mean the fuel consumed, the extra purchase price and the extra maintenance expense incurred by a drive train that would normally go into a 20,000 lb helo, but is stuck in a 15,000 lb one. Similarly, is the fuel burn of 1000 lbs per hour acceptable when compared to the 550 to 700 pph for helos with the same pax load by more "normal" engine power? If the helo loads full pax and then flys 200 miles, does it leave 3 pax home to make it, due to the extra fuel consumed?
These questions are on the lips of every operator who faces the purchase decision. I am sure the questions about support are not about whether parts will be available, they ask how much per hour the machine costs, and if the manufacturer will provice a competitive "power by the hour" guarantee.
In short, when you have no HV curve in a 15,000 lb helo, what you actually have is a 20,000 lb helo in every way (purchase price, cost to operate, fuel burn, overhaul costs) except one - payload. And less payload means less revenue generation. The market will decide if the trade-off is worth it!
The pilot preferences for a full Cat A capability are answered by the 139, it literally has no Dead Man's curve at normal altitudes, so it meets the ppruner's most basic wish (proven by lots of interesting threads!)
The real story behind the scenes is the "cost" of the super engine power that the design brings to the table. By "cost" I mean the fuel consumed, the extra purchase price and the extra maintenance expense incurred by a drive train that would normally go into a 20,000 lb helo, but is stuck in a 15,000 lb one. Similarly, is the fuel burn of 1000 lbs per hour acceptable when compared to the 550 to 700 pph for helos with the same pax load by more "normal" engine power? If the helo loads full pax and then flys 200 miles, does it leave 3 pax home to make it, due to the extra fuel consumed?
These questions are on the lips of every operator who faces the purchase decision. I am sure the questions about support are not about whether parts will be available, they ask how much per hour the machine costs, and if the manufacturer will provice a competitive "power by the hour" guarantee.
In short, when you have no HV curve in a 15,000 lb helo, what you actually have is a 20,000 lb helo in every way (purchase price, cost to operate, fuel burn, overhaul costs) except one - payload. And less payload means less revenue generation. The market will decide if the trade-off is worth it!
With due repect Nick, the market won't decide for much longer. When the new JAR regs come into effect (2008??) most helos flying offshore ops will have payload limitations put on them, whereas the 139 will not. 76D may address this with more power, as it is the power margins that will be the determining factor with regard to payload. PM me with the purchase price of an offshore equipped S-76, IFR, with 3 axis autopilot, and I'll PM you the 139 price back. You might be surprised how close it is!!!
As for windscreens, yep, the early ones cracked. All the time!!!! New windscreens are out now, and all new machines should have them. If they don't, the retrofit is simple. They come predrilled for the screws, and all the holes actually line up!!!!
So far, no problems with the new screens. Optics are better, and the frame is much stronger. One thing that I don't like however, is the fact that the anti-scratch coating is not as scratch resistant on the new screens as it was on the old ones.
Why is it that manufacturers persist with plastic/acrylic windscreens!!! I even hear that the S-92 has acrylic screens. What was the reasoning behind that Nick? I personally prefer glass, even with a weight penalty
As for windscreens, yep, the early ones cracked. All the time!!!! New windscreens are out now, and all new machines should have them. If they don't, the retrofit is simple. They come predrilled for the screws, and all the holes actually line up!!!!
So far, no problems with the new screens. Optics are better, and the frame is much stronger. One thing that I don't like however, is the fact that the anti-scratch coating is not as scratch resistant on the new screens as it was on the old ones.
Why is it that manufacturers persist with plastic/acrylic windscreens!!! I even hear that the S-92 has acrylic screens. What was the reasoning behind that Nick? I personally prefer glass, even with a weight penalty
Thats completely true (had it clarified from a source at Bell). Its a bit of a shame if you ask me. The first 50ish aircraft are still AB139s though, Bell wouldnt let them change to AW139.
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
nooby,
Your logic is a bit flawed, the amount of power that is in the 139 is far beyond the needs of a full Cat A from a rig. As the PM on the S92, I was intimately aware of the JAR OPS needs, and several helos meet full Cat A from rigs at weights that allow good payloads and good range. The 139 carries even more power, to the detrement of its payload at even medium ranges.
Note that the 15000 lb 139 has the same power (2 x 2000 HP engines) installed as the 21500 lb Black Hawk.
Your logic is a bit flawed, the amount of power that is in the 139 is far beyond the needs of a full Cat A from a rig. As the PM on the S92, I was intimately aware of the JAR OPS needs, and several helos meet full Cat A from rigs at weights that allow good payloads and good range. The 139 carries even more power, to the detrement of its payload at even medium ranges.
Note that the 15000 lb 139 has the same power (2 x 2000 HP engines) installed as the 21500 lb Black Hawk.
Nick, you are assuming that 6400kg will be the final weight of the 139. I'm thinking that Agusta will be upping the MTOW at some point. Won't be for a while yet though, they don't have anywhere near enough fleet hours to be able to fully assess how the airframe would handle it. Interesting to note however that the 149, using same basic frame with different undercarriage, is rated for 7000kg. Word from a contact at Agusta was that some of the design improvements being made to the 149 (simpler retraction sequence on the main gear for instance), could be carried across to the 139. I certainly hope so.
jimma, I agree that it was a shame that Bell had to withdraw. With their product support behind it, things would be better than they are now!!!
jimma, I agree that it was a shame that Bell had to withdraw. With their product support behind it, things would be better than they are now!!!
Join Date: May 2002
Location: Italy
Posts: 37
Likes: 0
Received 0 Likes
on
0 Posts
AE139 Power
Nick
the 139 has tha power that it needs. It has 1872 SHP at the 2.5' rating (OEI) and 2x1122 SHP AEO at T.O.
Cat A for rig operations are unbeatable allowing a Take Off weight of 6400 kg (max) for zero wind and OAT up to ISA+25 (40ºC) with no drop down!.
This the first helicopter that has exceptional margins either in power and controllability up to 14000 ft HD that is the Cat A/B take off envelope.
I'm an engineer and I love these characteristics but I also think pilots love it.
This also a TRUE JAR OPS Class 1 Performance Helicopter.
Just to mention, it also provides for the first time a Power Index (not a FLI), the only power plant gauge that substitutes all traditional engine/transmission gauges, reducing considerably pilot workload and enhancing safety.
the 139 has tha power that it needs. It has 1872 SHP at the 2.5' rating (OEI) and 2x1122 SHP AEO at T.O.
Cat A for rig operations are unbeatable allowing a Take Off weight of 6400 kg (max) for zero wind and OAT up to ISA+25 (40ºC) with no drop down!.
This the first helicopter that has exceptional margins either in power and controllability up to 14000 ft HD that is the Cat A/B take off envelope.
I'm an engineer and I love these characteristics but I also think pilots love it.
This also a TRUE JAR OPS Class 1 Performance Helicopter.
Just to mention, it also provides for the first time a Power Index (not a FLI), the only power plant gauge that substitutes all traditional engine/transmission gauges, reducing considerably pilot workload and enhancing safety.
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
bpaggi says, " I'm an engineer and I love these characteristics but I also think pilots love it." Yes, but only when pilots carry the checkbooks does that make sales.
I think you have read me wrong. I think the 139 has lots and lots of power, in fact, perhaps too much, since it now has less range and the payload is reduced due to the high fuel burn. With the power you describe, the helo could weigh 21000 lbs, and have about 2 tons more payload than it does. In other words, for the fantastic single engine performance, the operator carries thousands of pounds less revenue-paying load!
Regarding how pilots believe that engine power makes more safety, if you look at the accident statistics, you will see that engines are not the problem, people are. Since the biggest single block of accidents, (about 25 to 40% of all helo accidents) involve perfectly healthy machines that are flown into the water or mountains, exactly how will doubling engine power solve this?
noooby,
Have it your way, add gross weight to get payload back. But as you do, the marvelous OEI performance reduces. Cannot have it both ways!
I think you have read me wrong. I think the 139 has lots and lots of power, in fact, perhaps too much, since it now has less range and the payload is reduced due to the high fuel burn. With the power you describe, the helo could weigh 21000 lbs, and have about 2 tons more payload than it does. In other words, for the fantastic single engine performance, the operator carries thousands of pounds less revenue-paying load!
Regarding how pilots believe that engine power makes more safety, if you look at the accident statistics, you will see that engines are not the problem, people are. Since the biggest single block of accidents, (about 25 to 40% of all helo accidents) involve perfectly healthy machines that are flown into the water or mountains, exactly how will doubling engine power solve this?
noooby,
Have it your way, add gross weight to get payload back. But as you do, the marvelous OEI performance reduces. Cannot have it both ways!
C'mon Nick,
Why can't we have great OEI performance plus a JAR 29 helicopter and THEN add HEGWPS,TCAS,HUMS etc.etc.?
I don't get your point with too much power...
We continue using b412/S76 or we buy Blackhawks?
Any other alternative (in the medium range)?
It's not my money
Why can't we have great OEI performance plus a JAR 29 helicopter and THEN add HEGWPS,TCAS,HUMS etc.etc.?
I don't get your point with too much power...
We continue using b412/S76 or we buy Blackhawks?
Any other alternative (in the medium range)?
It's not my money
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
Aser,
Months ago I posted the performance of three hypothetical helos, a one-engine one, a conventional two-engine one, and a two-engined one that could hover on one engine. The cruise range hit that you take to have OEI hover is not at all understood by pilots, I have nearly given up trying to explain why. But here goes!
Turbines are awful at part power, so the less power you are pulling in cruise, the very much worse your fuel burn is. For a given cruise power, the fuel used is at least 40% higher if the helo has OEI hover, I said. Thus, the 100 pph fuel flow for the 139 vice the 600 to 700 for a 412 or 76.
More power does NOT mean better cruise performance!! Thus the "cost" of having scads of power in an OEI condition is paid for on every cruise mile, and in the loss of revenue for meduim distance flights, as well as every overhaul, and every insurance payment (you pay for the cost to replace). For no measurable increase in safety.
Months ago I posted the performance of three hypothetical helos, a one-engine one, a conventional two-engine one, and a two-engined one that could hover on one engine. The cruise range hit that you take to have OEI hover is not at all understood by pilots, I have nearly given up trying to explain why. But here goes!
Turbines are awful at part power, so the less power you are pulling in cruise, the very much worse your fuel burn is. For a given cruise power, the fuel used is at least 40% higher if the helo has OEI hover, I said. Thus, the 100 pph fuel flow for the 139 vice the 600 to 700 for a 412 or 76.
More power does NOT mean better cruise performance!! Thus the "cost" of having scads of power in an OEI condition is paid for on every cruise mile, and in the loss of revenue for meduim distance flights, as well as every overhaul, and every insurance payment (you pay for the cost to replace). For no measurable increase in safety.
Yet again when these discussions on full CAT A arise, I firmly agree with Nick and I find it almost incomprehensible that the argument goes around so many times.
It appears straight forward.
Risk = Frequency X Consequence. As engine failure rates are not accurately recorded, statistics are very hard to argue without significant flaws being apparent, so I will avoid the statistical minefield in terms of frequency of engine failures.
Examining three types of aircraft (single engine, Twin engine with limited CAT A, Twin engine with OEI hover), we can assume that engine failures are relatively consistent between the three types of aircraft and thus, we can assume that frequency of engine failure is the same across the three types. Except of course, frequency is doubled in a twin because they have two engines!
Given frequency is a constant; we need to measure risk in terms of consequence. .
If you want a single engine aircraft you are vulnerable to engine failure 100% of the time. Consequence is generally severe for all but clear area ops and experienced pilots. Thus generally, singles have high risk (due high consequence).
If you go for the Twin engine with limited CAT A, then I concede that your frequency of engine failure could be considered double that of a single in this simplified analysis, and the highest consequence is also similar to the single (i.e. severe) but not as likely to be severe due the other engine being available to reduce severity of the forced landing. Accordingly, the risk is still high, but less than that of a single.
The third type is the AW 139 – “Full CAT A” OEI hover capable with no deadman’s curve. Frequency is double the single, same as limited CAT A, but consequence is low. Thus over all risk is low.
Now the tricky bit – exposure to risk. This is a function of how often the aircraft is exposed to the negative consequence, or in other words, exposure is the amount of time that the frequency (number of engine failures) of the risk can become involved and cause the consequence (crash landing). If you are exposed for longer, the chances of an in-frequent event occurring are higher than if the exposure time was very low. Thus when we assess risk, we should also consider exposure to that risk in order to assess it’s real impact.
There are two extremes. The single is exposed nearly all the time from hover to hover. Lets say for about 80% to be conservative. The twin with hover OEI is not exposed.
The middle ground is actually not very middle at all! The twin with limited CAT A is exposed for less than 0.17% (illustrative only - Nick – can you recall the exact number here? I will amend when I have the correct figure). The aircraft is only exposed when operating in very narrow time segments of take off and landing over adverse terrain. It is not exposed enroute, nor during those narrow time segments when operating over terrain that would sustain a landing, albeit with minor aircraft damage (as opposed to human damage).
Many corporate owners happily fly around in singles because they are cheap and they assess engine failures as remote, but they almost universally fail to consider consequence. Similarly, many corporate owners want full CAT A because they either do not understand exposure, or because they don’t want any exposure to the same risks that many corporate owners consider negligible.
Now cost: singles are cheaper, twins with OEI hover are very expensive (20,000 lbs operating costs to haul 15,000 lbs of goods). The limited CAT A fits nicely in the middle BUT it allows compromise. If you want to have full CAT A, fit the aircraft with less seats and voila! You have it. If you then accept the exposure rate of 0.17% to a possible (not likely) consequence, you can load it up and operate cost effectively. I agree that limited CAT A is a smart (and probably a mandatory) step to make away from singles for high net worth individuals and work place safety reasons for fare paying passengers because it significantly reduces exposure (80%ish to 0.17%) for a more reasonable cost increase, but I cannot justify spending considerably more on reducing a mere 0.17% to about zero.
The outcome of making all new twins hover OEI is that more and more people will buy singles because cost effective operations are no longer viable in twins given that there is no aircraft available for those who accept the occasional 0.17%.
But what is most surprising to me about all this pprune (pilot as opposed to owner) demand for hover OEI twins that will actually drive people to singles is that a crucial piece of the puzzle always seems to escape the argument: it is NOT ENGINE FAILURES THAT ARE RESPONSIBLE FOR THE LARGEST CHUNKS OF OUR ACCIDENT STATISTICS.
Revolutionary idea follows; lets push owner funding into anti CFIT devices like multi axis autopilots, synthetic and night vision devices, 3D nav equipment, wire detection and avoidance capabilities, advanced weather radar and ground to air situational information linking, terrain and traffic detection and avoidance capabilities, and lots more motion simulator training for the pilots. CFIT risk is proven to be much more than the 0.17% exposure to possible risk that we are trying to overcome by demanding OEI hover capable twins and driving people back to singles. Why do we stay so obsessed by such an insignificant risk when the meanest monster gets so little attention???????
It appears straight forward.
Risk = Frequency X Consequence. As engine failure rates are not accurately recorded, statistics are very hard to argue without significant flaws being apparent, so I will avoid the statistical minefield in terms of frequency of engine failures.
Examining three types of aircraft (single engine, Twin engine with limited CAT A, Twin engine with OEI hover), we can assume that engine failures are relatively consistent between the three types of aircraft and thus, we can assume that frequency of engine failure is the same across the three types. Except of course, frequency is doubled in a twin because they have two engines!
Given frequency is a constant; we need to measure risk in terms of consequence. .
If you want a single engine aircraft you are vulnerable to engine failure 100% of the time. Consequence is generally severe for all but clear area ops and experienced pilots. Thus generally, singles have high risk (due high consequence).
If you go for the Twin engine with limited CAT A, then I concede that your frequency of engine failure could be considered double that of a single in this simplified analysis, and the highest consequence is also similar to the single (i.e. severe) but not as likely to be severe due the other engine being available to reduce severity of the forced landing. Accordingly, the risk is still high, but less than that of a single.
The third type is the AW 139 – “Full CAT A” OEI hover capable with no deadman’s curve. Frequency is double the single, same as limited CAT A, but consequence is low. Thus over all risk is low.
Now the tricky bit – exposure to risk. This is a function of how often the aircraft is exposed to the negative consequence, or in other words, exposure is the amount of time that the frequency (number of engine failures) of the risk can become involved and cause the consequence (crash landing). If you are exposed for longer, the chances of an in-frequent event occurring are higher than if the exposure time was very low. Thus when we assess risk, we should also consider exposure to that risk in order to assess it’s real impact.
There are two extremes. The single is exposed nearly all the time from hover to hover. Lets say for about 80% to be conservative. The twin with hover OEI is not exposed.
The middle ground is actually not very middle at all! The twin with limited CAT A is exposed for less than 0.17% (illustrative only - Nick – can you recall the exact number here? I will amend when I have the correct figure). The aircraft is only exposed when operating in very narrow time segments of take off and landing over adverse terrain. It is not exposed enroute, nor during those narrow time segments when operating over terrain that would sustain a landing, albeit with minor aircraft damage (as opposed to human damage).
Many corporate owners happily fly around in singles because they are cheap and they assess engine failures as remote, but they almost universally fail to consider consequence. Similarly, many corporate owners want full CAT A because they either do not understand exposure, or because they don’t want any exposure to the same risks that many corporate owners consider negligible.
Now cost: singles are cheaper, twins with OEI hover are very expensive (20,000 lbs operating costs to haul 15,000 lbs of goods). The limited CAT A fits nicely in the middle BUT it allows compromise. If you want to have full CAT A, fit the aircraft with less seats and voila! You have it. If you then accept the exposure rate of 0.17% to a possible (not likely) consequence, you can load it up and operate cost effectively. I agree that limited CAT A is a smart (and probably a mandatory) step to make away from singles for high net worth individuals and work place safety reasons for fare paying passengers because it significantly reduces exposure (80%ish to 0.17%) for a more reasonable cost increase, but I cannot justify spending considerably more on reducing a mere 0.17% to about zero.
The outcome of making all new twins hover OEI is that more and more people will buy singles because cost effective operations are no longer viable in twins given that there is no aircraft available for those who accept the occasional 0.17%.
But what is most surprising to me about all this pprune (pilot as opposed to owner) demand for hover OEI twins that will actually drive people to singles is that a crucial piece of the puzzle always seems to escape the argument: it is NOT ENGINE FAILURES THAT ARE RESPONSIBLE FOR THE LARGEST CHUNKS OF OUR ACCIDENT STATISTICS.
Revolutionary idea follows; lets push owner funding into anti CFIT devices like multi axis autopilots, synthetic and night vision devices, 3D nav equipment, wire detection and avoidance capabilities, advanced weather radar and ground to air situational information linking, terrain and traffic detection and avoidance capabilities, and lots more motion simulator training for the pilots. CFIT risk is proven to be much more than the 0.17% exposure to possible risk that we are trying to overcome by demanding OEI hover capable twins and driving people back to singles. Why do we stay so obsessed by such an insignificant risk when the meanest monster gets so little attention???????
Join Date: Jun 2006
Location: vancouver
Posts: 81
Likes: 0
Received 0 Likes
on
0 Posts
IGB at 100 hours, and at 300+ it looks like I may need to change it again.
Agusta parts are very slow, even when they say 2 days it could mean a week or two before you have that part in your hands. I highly recommend
the operator keeps spares on the shelf, or you will definity go AOG once and a while. One cannot rely on Agusta for Overnight Parts Availability here in North America. You are going to have to buy some over priced Agusta tooling also to maintain this aircraft. The pratt -67C engines are great and the customer support is very good, no issues with the engines so far.
CHC and other North Sea operators will be pleased about that, the aircraft is 400Kg heavier than what Agusta told them so they are currently limited to 10 pax. Rumour has it that when Agusta weighed the aircraft, they forgot about all the extra North Sea equipment.
Join Date: Jul 2006
Location: Jankara
Age: 64
Posts: 377
Likes: 0
Received 0 Likes
on
0 Posts
The big problem for the 139 seems to be that outside Europe, with its need for full Class 1 performance offshore, it has a pathetic baggage capacity for its size and the huge fuel burn means that an S76C+ will probably take more passengers, further and at a lower cost. The oil companies in general are not interested in Class 1 performance offshore, no matter how much we pilots may like it, and unless something is done to improve the payload/range and baggage capacity of the 139 I can't see it succeeding commercially against helicopters like the S76. It may be an old design and the Arriel 2 series engines may give lots of problems, but at the moment, and probably for the next few years, it's almost unbeatable on range/payload/performance/cost.
Don't misunderstand me, I'd love to fly the 139, it looks great and has some interesting new features, but it doesn't seem to be a serious competitor in the long range offshore market as yet. Just my own opinion.
Don't misunderstand me, I'd love to fly the 139, it looks great and has some interesting new features, but it doesn't seem to be a serious competitor in the long range offshore market as yet. Just my own opinion.
Most of the 139 pilots I know are ex-S76 aircrew and they all seem to be happy with the switch. The biggest complaint I have heard is the lack of a cupholder. In fact, several of the pilots have requested their maintenance crew to retro fit them.
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
Mamaput,
You see it exactly as I do, I think. It is important to realize that the excellent Cat A performance and the very high fuel burn are actually two facets of the same design decision!
Noooby,
I do see that the increased MGW will help the useful load (and thus either tange or payload) but it will harm the OEI performance to some extent. This actually proves my point - too much engine power means less useful load.
AB139engineer,
I have no doubt that the 139 will end up as a relatively easy to maintain helo, but it will be a helo with a drivetrain and powerplant that can carry 21000 lbs of helo in a 15000lb package, so it will cost 30% more to maintain, even if it is easy to maintain, since cost is directly related to horsepower, and the transmissions, shafts, gearboxes, engines and rotors are "too big" for its payload by about 30%. Is this a problem? Only if operators don't buy it because of these costs.
helmet fire,
Wow, you said what I was trying to, thanks for the clarity. The statistics that are used by JAR to determine rig landing compliance is that the aircraft has good OEI performance virtually all the time, except during a few seconds on takeoff and landing, and probability of engine failure during those critical portions of the flight (typically about 6 to 10 seconds during a 1 hour flight - about 0.2% of the time) is less than the demonstrated probability of a major component failing. In other words, why make the engine failure safety lots of times better than the safety of the rest of the helo, especially when engine power has such a strong influence on economics of operation.
All,
Remember, we are not talking about Cat A from a rig, several helos have that capability, but not to the massive extent of the 139. We are talking about no HV curve limitations at all, and asking iof the market wants to pay the price for that increase in capability (I do not call it an increase in safety, because it is not.) I believe the dollar cost for extra performance is very very high, and that if we spent these dollars on what causes accidents, we would get more safety by far. It can be said that if we put too much power into the helo, we make it less safe, since we now have less money to spend on real (not imagined) safety items.
Let me not sound like bad-mouthing any particular helo. The 139 by all accounts is a fine machine, smooth, fast and powerful. I however do challenge the basic premise that "power equates to safety", and that "you can't have too much power."
You see it exactly as I do, I think. It is important to realize that the excellent Cat A performance and the very high fuel burn are actually two facets of the same design decision!
Noooby,
I do see that the increased MGW will help the useful load (and thus either tange or payload) but it will harm the OEI performance to some extent. This actually proves my point - too much engine power means less useful load.
AB139engineer,
I have no doubt that the 139 will end up as a relatively easy to maintain helo, but it will be a helo with a drivetrain and powerplant that can carry 21000 lbs of helo in a 15000lb package, so it will cost 30% more to maintain, even if it is easy to maintain, since cost is directly related to horsepower, and the transmissions, shafts, gearboxes, engines and rotors are "too big" for its payload by about 30%. Is this a problem? Only if operators don't buy it because of these costs.
helmet fire,
Wow, you said what I was trying to, thanks for the clarity. The statistics that are used by JAR to determine rig landing compliance is that the aircraft has good OEI performance virtually all the time, except during a few seconds on takeoff and landing, and probability of engine failure during those critical portions of the flight (typically about 6 to 10 seconds during a 1 hour flight - about 0.2% of the time) is less than the demonstrated probability of a major component failing. In other words, why make the engine failure safety lots of times better than the safety of the rest of the helo, especially when engine power has such a strong influence on economics of operation.
All,
Remember, we are not talking about Cat A from a rig, several helos have that capability, but not to the massive extent of the 139. We are talking about no HV curve limitations at all, and asking iof the market wants to pay the price for that increase in capability (I do not call it an increase in safety, because it is not.) I believe the dollar cost for extra performance is very very high, and that if we spent these dollars on what causes accidents, we would get more safety by far. It can be said that if we put too much power into the helo, we make it less safe, since we now have less money to spend on real (not imagined) safety items.
Let me not sound like bad-mouthing any particular helo. The 139 by all accounts is a fine machine, smooth, fast and powerful. I however do challenge the basic premise that "power equates to safety", and that "you can't have too much power."