Fuel figures please
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Fuel figures please
Can anybody help me with fuel consumption figures for the following types, preferably in tropical temps but I can interpolate if req.
Bell 412 SP
Super Puma L1
Super Puma L2
EC 135 P2
Thanks
Bell 412 SP
Super Puma L1
Super Puma L2
EC 135 P2
Thanks
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Please do not use these for flight planning purposes, I suggest the actual numbers from the FM for appropriate conditions, but some rough averages based on somewhat normal ops....
332L 470kg
332L1 490kg
332L2 490kg
135 225kg
212 310 kg
412 320 kg
MIL26 2700kg
2700kg.......that still cracks me up
332L 470kg
332L1 490kg
332L2 490kg
135 225kg
212 310 kg
412 320 kg
MIL26 2700kg
2700kg.......that still cracks me up
Nigerian In Law
I flew a 412 SP in a hot tropical place not too long ago and we were burning around 340 kg/hr, which isn't that far off what the FM quotes (albeit in lbs) unless I'm very much mistaken.
Cheers,
NEO
In deference to Nick's post below, we averaged 125 kts IAS
Cheers,
NEO
In deference to Nick's post below, we averaged 125 kts IAS
Last edited by Nigerian Expat Outlaw; 16th Oct 2005 at 23:49.
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IMHO the fuel flow is meaningless without the cruise speed at which it is taken, unless you believe all those machines on your list cruise at the same speed.
Suggest pairing speed with flow, or use the lbs fuel / NM (flow/speed).
Suggest pairing speed with flow, or use the lbs fuel / NM (flow/speed).
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Not exactly tropical, but close enough, in the GOM the 412 burns about 800 lb/hr at whatever speed it can reach, figure 115 kts for an average. Being so slow, the 412 is very sensitive to windspeed, so your groundspeed will vary a lot. I've never seen one vary much from the 800 lb/hr figure, though.
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Nick,
I believe that Geoffs question was a simple one. What are these aircraft burning in normal cruise. It was not specific hence neither was the answer.
I believe that Geoffs question was a simple one. What are these aircraft burning in normal cruise. It was not specific hence neither was the answer.
Last edited by Mikila1A; 17th Oct 2005 at 11:05.
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From a short experience with the 135T2 the present cruise fuel burn is 205 kg/hr...250 lt/hr. I have never managed less than 200 kg/hr and therefore the flight manual is misleading suggesting a greater range than is possible. Cruise is at 130 kts or 9 bananas on the FLI.
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Makila1A,
Yes, your answer was precisely what was asked for, but the figures he asked for are not useful in any meaningful way, unless one believes the speeds are identical, which they certainly are not.
I have always used the typical cruise speed divided into the fuel flow to arrive at the lb/nm, which is a great way to flight plan, because it also tells you how much payload is lost as range increases.
For the 76A 520 lb/hr divided by 140 knots yields 3.7 lb/nm, so a trip of 200 nm requires 3.7 lbs/nm times 200 nm = 740 lbs.
For a 332L2, 490 kg/hr divided by 145knots = 3.37kg/nm (7.46lb/nm)
I even do this in flight, as a quick way to check range, by using actual ground speed. Most pilots "think" in fuel flow, but the aircraft uses fuel per mile. The difference is quite meaningful, the 212 and 412 have virtually identical fuel flow, but the 412 is at least 15 knots faster, thus about 10 to 15% more range, a fact buried in oblivion if you think fuel flow.
Yes, your answer was precisely what was asked for, but the figures he asked for are not useful in any meaningful way, unless one believes the speeds are identical, which they certainly are not.
I have always used the typical cruise speed divided into the fuel flow to arrive at the lb/nm, which is a great way to flight plan, because it also tells you how much payload is lost as range increases.
For the 76A 520 lb/hr divided by 140 knots yields 3.7 lb/nm, so a trip of 200 nm requires 3.7 lbs/nm times 200 nm = 740 lbs.
For a 332L2, 490 kg/hr divided by 145knots = 3.37kg/nm (7.46lb/nm)
I even do this in flight, as a quick way to check range, by using actual ground speed. Most pilots "think" in fuel flow, but the aircraft uses fuel per mile. The difference is quite meaningful, the 212 and 412 have virtually identical fuel flow, but the 412 is at least 15 knots faster, thus about 10 to 15% more range, a fact buried in oblivion if you think fuel flow.
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Nick et al
The aim of the exercise is to quantify the effects on overall payload of changing the fuel planning to JAROPS 3 standards whereby you add 10% route fuel to the out and back calculation plus 30 mins res. At this stage I'm doing the equivalent of using the 10nm thumb that all helicopter pilots are equipped with and the numbers seem to work out at an overall reduction in payload of between 5% and 7%.
Next step is to find out just how accurate I need to be. If I need more than a 'good calculated guess' then I also have to get into how many of each type are in our overall fleet of nearly 50 machines and what the future (because we are talking future planning) fleet make-up will be. On top of that each fleet has it's particular mix of routes/payloads so the definitive calculation will of course feature Nick's suggestion to ensure lbs/nm are taken into account.
By the way has anybody come across a published explanation supporting this additional 10% route fuel? What was in the authority's minds when they ratified what had hitherto been a UK requirement?
Next step is to find out just how accurate I need to be. If I need more than a 'good calculated guess' then I also have to get into how many of each type are in our overall fleet of nearly 50 machines and what the future (because we are talking future planning) fleet make-up will be. On top of that each fleet has it's particular mix of routes/payloads so the definitive calculation will of course feature Nick's suggestion to ensure lbs/nm are taken into account.
By the way has anybody come across a published explanation supporting this additional 10% route fuel? What was in the authority's minds when they ratified what had hitherto been a UK requirement?
