Fuel consumption.

[cbrn]

Hi,

I need some info here.
What is the fuel consumption you get on the DHC-2 and on the C-206 on floats?

If you have the figures also for the take off run, climb and taxi will be greatly appreciated.

Thx!

cbrn

[Slats]

Same as on wheels really.
206 with a 520: 15 gph
206 with a 550: 17 gph
DHC-2: around 20 gph if I recall correctly

[Cat Driver]

Why would you need to know the fuel burn on the take off run?

[Colonel Sanders]

Every CPL should know this rule of thumb:

To estimate your fuel burn at WOT at takeoff, drop a zero off your horsepower.

Seriously. 200hp, 20 gph at WOT. 300hp, 30 gph at WOT.

You probably cruise at 65% power. Without leaning very well,
take 2/3 of the above WOT fuel burn.

For example, 300hp takeoff burn is 30 gph, cruise 20 gph.

Obviously if you pull the throttle (and the mixture) back, you can
do better. But the above rule of thumb gets you in the ballpark.

See BSFC if you care to learn more.

[rapid602]

Thanks for that Colonel. GREAT STUFF !!!

I have been away from flying for a while, and most of my flying was turbines.

But

Thanks .... great to know.

[Colonel Sanders]

You're welcome!

As an example, sometimes I fly a Beech 18, which has 450hp
R-985's on each side.

So, as a rule of thumb, 45 gph per side (90 gph total) on takeoff,
and 2/3 of 90 (65% power) is 60 gph in cruise, at say 30 inches
and 20 turns. Call it a gallon a minute in cruise. You can tell I'm
not buying the 100LL!

I fly so many different types of aircraft, these sorts of calculations
come in handy.

[wang dang doodle]

in a 206 try thinking a liter per minute....makes it simple....a 40 min flight= 40 liters.


in a beaver 20-22 gal per hour.. for simplicity call it 90 liters an hour =1.5 liters per min...so a 30 min.flight...you need 45 liters since most fuel tanks read in liters. And don't forget that little extra bit for your kids that are waiting for you to come home..

[Cat Driver]

That is a pretty safe method to use colonel, for sure it is ball park.

Over the thousands of hours I flew long interconental ferry flights with the P&W R1830's I could take it to the bank my average fuel burn would be 72 GPH for the trip.

The longest trip I ever did non stop was 19 hours and ten minutes.......

We were real serious about our fuel burn on that one and got a lower over all fuel burn.

[Cat Driver]

Aaaaaaahhhhh, the what measurement should we use when planning any flight conversation.......be careful....real careful when converting from one measurement to another....it can be a real gotcha.

For instance coming back to the Socialist Republic of Canada I have to be careful thinking of take off and landing visilibities......I'm so used to meters your miles and feet confuse me.

[Lost Lake]

You're welcome!

As an example, sometimes I fly a Beech 18, which has 450hp
R-985's on each side.

So, as a rule of thumb, 45 gph per side (90 gph total) on takeoff,
and 2/3 of 90 (65% power) is 60 gph in cruise, at say 30 inches
and 20 turns. Call it a gallon a minute in cruise. You can tell I'm
not buying the 100LL!

I fly so many different types of aircraft, these sorts of calculations
come in handy.

Are you saying that the beach burns 50% more fuel per side than a beaver? What is the reason for that?

[Colonel Sanders]

the beach burns 50% more fuel per side than a beaver? What is the reason for that?

How the guy in the left seat positions the levers in the engine control quadrant!

The Beaver burning 20 gph is not running 30/20.

[flyinthebug]

the beach burns 50% more fuel per side than a beaver? What is the reason for that?

How the guy in the left seat positions the levers in the engine control quadrant!

The Beaver burning 20 gph is not running 30/20.

I gotta agree with you Colonel. I used to plan around 28 GPH on the DHC2. We ran 31/20, and rarely leaned below 4000'.

[Colonel Sanders]

Fuel burn is determined by horsepower produced (power setting) and mixture setting - BSFC.

For comparison, I also fly a Stearman with an R-985, 450hp. I NEVER cruise at high power settings because with all that junk hung out in the breeze, all you're doing is shuffling air around.

In the Stearman I like 25 inches - no more - and 18 or even 17 turns.

The lowest possible RPM without exceeding your max allowable BMEP will yield the lowest gph for the same horsepower.

[Lost Lake]

the beach burns 50% more fuel per side than a beaver? What is the reason for that?

How the guy in the left seat positions the levers in the engine control quadrant!

The Beaver burning 20 gph is not running 30/20.

I gotta agree with you Colonel. I used to plan around 28 GPH on the DHC2. We ran 31/20, and rarely leaned below 4000'.

Wow, those are high setting IMHO. I used to run 28/18 in Northern Ont, 29/19 in the arctic. Why would you use those settings uless you are at high altitude, which would require leaning? In the arctic, 29/19 yeilded a legit 20 gph. We also leaned , even though at sea level. Company SOP. Fuel cost was a definite factor.

[rigpiggy]

in a 206 try thinking a liter per minute....makes it simple....a 40 min flight= 40 liters.

.you need 45 liters since most fuel tanks read in liters.

Maybe as a check when buying the fuel. I don't think I have ever flown an aircraft that had litres on the guages. Pounds, imp Gals, or Gals

[zeppelin]

of course the guages aren't in liters,Cessna's are built in the States where they can't even spell "leetur."I don't trust the guages anyway,and for all my 206 time they were actually taped with electric tape over them.And since all the fuel tanks/pumps in Canada are in "leeturs",why not think in liters...still 30 liters =30 min.You don't have to do a conversion,and better yet,the brand new CPL dock guy does'nt have to do a conversion when he fuels you...Simple...just trying to help...Or you could goto the fuel guy and say..I need a half hour fuel...let's see that's 15 gall per hour divided by 2 = 7.5 gall,but the pump is in liters so let's see 7.5 gall times about 4.5=30. so I need 30 liters please....I'm not trying to be a smart ass here but .. DUHH....And it took me years to figure what a liter was,cause I'm of the Gallons age....I'd better add make sure you have your reserve before I get pounced on for not mentioning it..

[Lost Lake]

Turbines are simpler, but you could use the same formula. Simply multiply the # of pounds required X 6 = leetours required.
Pt27 -6 burns 300 lb/hr= 180 leetours/hr. Of course that's at 1 gal= 7 lb.

[rapid602]

Lost Lake Question for you !!!

Those fuel burn numbers are they for a specific cruise altitude. say below 10,000 ft.

Reason I flew a Turbine usually around 210, 220, 230, and we used 600 pph hour #1, 400 pph hours #2,3,4 example long Xcountry's

[Lost Lake]

Sea level

[Slats]

Sadly, it has been a couple years since my last trip in a piston beaver and so I don't recall the exact tank capacities, but it seems to me that some wildly high numbers are being tossed around here. I do recall ballparking that I could count on full bellies for around 4 hours of endurance depending on how horrific the combination of load+canoe+OAT+highest mountain ridge was on that particular day, even with deploying standard Beaver tricks of cracking some cruise flap and running 29/19 or 30/20. I DO know for sure though that if I had been burning 8 gph (20 vs 28!?!?) more than I had planned I surely would have ingloriously run out of fuel more than once. I also do recall quite confidently that leaning a Cessna 185 or 206 by the book will certainly not yield 20 gph in cruise, even with the 550 as opposed to the 520. Your average altitude of 3-5000' will get you roughly 15 gph and 17 gph for the 520 and 550 respectively, and you can do considerably better than even those numbers if the circumstances warrant going up high. Oh, and for what it is worth: never once experienced ANY issues or problems related to engine mismanagement-no cracked jugs, no nothing-ever. It's something I still take great pride in.

Or maybe all my memories of my first few thousand hours are all askew.