Fuel consumption rate.

[Minquanlu]

Hello folks.
I am looking at helicopters and powerplants, and they have data.
I am however curious with fuel consumption.

1. How do we know if a fuel consumption rate is high, low or good, not-so-good, and so on?
2. Is it even significantly important?
3. What powerplant has the best fuel consumption rate?

[admikar]

Those questions are hard to answer.
1. Good fuel consumption based on what? Engine power? Helicopter weight? Speed? Range?
For example, AW101 burns ~3.5 l/km. AS 350 burns ~1 l/km. But 101 carries a hell of a lot more payload.
2. see above.
3. IDK and can't be bothered to google it, so I'll go with one that is shut down.

[MightyGem]

Litres per kilometre ? Not kilograms per minute?

[Ascend Charlie]

A 200l drum can run a B206 for 2.5 hrs with a bit left over.

[Hughes500]

A 200l drum can run a B206 for 2.5 hrs with a bit left over.
Cant be doing much work with the 206 then !

[OvertHawk]

load-lifting (short lifts) the 206 burns half a barrel an hour (102lts). so that equated to 2 hrs of hard work with nothing left over.

[Ascend Charlie]

It was on powerline inspections, bopping along at 20-30kt at powerline level. Mostly the 2.5 hr limit was my bladder.

[Agile]

What powerplant has the best fuel consumption rate?
The smallest powerplant working the hardest.
Arrius at 100% ~500Hp
Arriel at 50% ~500hp
in that case would guess Arrius use less fuel

[Hilife]

1. For an engines efficiency, look no further that its specific fuel consumption (SFC) and use the lb/(shp-h) as a comparison from one engine to another.
2. In principle, a reduction in SFC, means more range or better payload and of course reduced operating costs.
3. As for the most efficient engine type. It is going to be a recent design, incorporating the very latest technologies. Something like the GE38 on the 53K is around 0.4 lb/(shp⋅h), but I would hazard a guess that the GE T901 is even better and likely in the region of 0.3? lb/(shp⋅h).

[Sir Korsky]

Nick Lappos told me once in order to extend endurance time in a multiengine helicopter, fly at max endurance speed and bring one engine back to idle and watch your fuel flow decrease. So we tried it briefly and there was a discernible reduction in the total fuel flow. Pertinent here ? No idea, thought it was an interesting experiment from a long while back.

[ShyTorque]

A turbine engine at idle is using quite a lot of fuel to self sustain yet provides no useful power. A better option is to shut one engine down completely.

[Minquanlu]

Thank you for taking out to respond to this thread.

Looks like these days even aircraft powerplants are going hybrid too.
Fuel consumption is really like an outdated term.

[RMK]

R44 (Lycoming I0-540) burns 15 USG/hr of AvGas. R66 (RR300) burns 23 USG/hr of JetA.