Lizzie fuel burn information

Chris Trott · Post by **Chris Trott** » 22 Sep 2006, 20:11

As requested, here is some of the info out of the manual on the Lizzie -

For a Takeoff Weight of 23,600kg -

Fuel for climb to 15,000 = 93 gallons (I'm guessing this is Imperial but it doesn't specify)

Cruise (1200 SHP @ 15,000) = 155 Gallons per Hour

I will try to run some tests to see how close this is. If anyone can confirm to me that the numbers are Imperial Gallons insead of "standard" Gallons I'd apprediate it since it'll allow me to make the required conversions if it is to make up a "US Gallon" chart for our use in Excel or Word.

Post by **RAF_Quantum** » 22 Sep 2006, 20:35

Hi Chris,

I would hazard a guess it's Imperial gallons. Does it give different SHP power settings for different altitudes or is it just for 15000ft. In the reference notes that downloads with the acft it gives power settings at 20,000ft

Cruise:
Cowl flaps: Closed (Press Ctrl+Shift+C as necessary)

Guidelines at altitudes 20000 ft are

Max cruise (1950 hp per engine): Boost 4 lbs, 2200 RPM. This will give you a true airspeed of approx. 300 mph (267 kts) or more.
Recommended fast cruise (1700 hp per engine): Boost 2 lbs, 2150 RPM. This will give you a true airspeed of approx. 280 mph.
Economical cruise (1300 hp per engine): Boost 0 lbs, 2050 RPM. This will give you a true airspeed of approx. 253 mph (160 kts/180 mph indicated). This was the the norm with BEA.

Rgds

John

Chris Trott · Post by **Chris Trott** » 23 Sep 2006, 00:04

It gives for many altitudes (it's a graph), but it says that 15,000 is typical cruise altitude for the aircraft after a 23,600kg departure. Also, the 1200SHP is listed as "ECA" cruise which I gather to be roughly equivalent to ECON setting which is the engine setting which provides best airspeed for least wear on the engine.

The climb chart is a normal chart which is why I can translate it quickly to an Excel or Word chart since it's just filling in cells. The cruise chart is harder because the quality isn't great (being that it's scanned from old books that have faded and worn) so I don't know that anyone will be able to read it even if I did extract it from the PDF document and post it as a JPG.

I will say one thing, these are the full manuals. The Airspeed manual is worth it alone becuase it has detailed diagrams of many of the major components of the aircraft including the cowlings and their configuration.

Post by **DaveB** » 23 Sep 2006, 00:22

Tks for that Chris

If you'd be willing to make it available to a slightly wider audience, I'd be glad to cover your costs. Alternatively, a pointer to the source would see the originator/s costs covered

I know the Ambassador was pressurised but had my doubts that FL200 was the norm. FL150 does seem a more likely altitude for an aircraft of this type

ATB

DaveB :tab:

Post by **RAF_Quantum** » 23 Sep 2006, 00:32

Hi Dave/Chris,

The flight I did in the Lizzie climbed well to FL200 so if we could get some figures for say 10k, 15k and 20k with a couple of different power settings at those altitudes we can get the fuel scalar sorted I'm sure.

Rgds

John

Chris Trott · Post by **Chris Trott** » 23 Sep 2006, 01:16

I will forward parts of the manual relevant to you and John, Dave, and see.

If anyone's interested in getting full sets of manuals for a lot of airplanes out there, you can go here -

http://www.flight-manuals-on-cd.com/

There are a lot of good manuals available and for $25.00 each (including shipping) it's a good deal. Shipping time from New Zealand to the US is about 1 week, and it's good quality stuff considering the sources aren't always the best. The Ambassador set has 700+ pages total.

Post by **DaveB** » 23 Sep 2006, 01:44

AH!!.. FM on Cd

Yup.. reputable company with some rare info

Tks for that Chris

ATB

DaveB :tab:

Chris Trott · Post by **Chris Trott** » 23 Sep 2006, 13:10

Okay, until I get home this evening (my time) I can't cut up the manual to try and get you guys the Flight Handling and Chart sections for you guys to be able to run tests.

In the meantime, here's something that I don't think was in the model's documentation. This is per the BEA book, so it may be different in the manufacturer's book -

There are 3 climb stages (compared to 4 for most) - 2 power reductions, and a blower speed shift (if climbing above 10,000).

From the book (additions by me in bold italics)

After take-off, make the first power reductionby reducing first the r.p.m. to 2400 and the manifold pressure to 48" Hg. For the second power reduction, reduce r.p.m. to 2200 and then the manifold pressure to 37" Hg. If the takeoff has been made with 20% flap, select flap UP when about 400 ft. above the airfiled level.
The rate of climb should be limited to ensure passenger comfort and allow time for the pressurization drill (checklist) to be carried out. The rate of climb should be controlled by reducing r.p.m. as necesary leaving the throttle levers at the E.C.B position (don't know what this stands for). When pressurization is complete, climb at 135 kts. I.A.S. with r.p.m. up to 2200 as required and throttle at the E.C.B (37 ins. Hg.) position. The maximum rate of climb is obtained at 125 kts. I.A.S. but at this speed engine cooling becomes marginal under high atmospheric temperature conditions. At 135 kts. the cooling is much improved and only a little rate of climb is lost. Above 135 kts. however the fall-off in rate of climb is rapid; use of speed higher than 135 kts. would therefore extend the use of climbing power for an excessive proportion of the flight time.
The climb is begun in LOW supercharger gear. when the manifold pressure falls to 34 ins. Hg. change to HIGH gear. the height at which 34 ins. Hg. is obtained will vary but it will usually be about 12,000 ft. with 2200 r.p.m. and 9,900 ft. with 1900 r.p.m. Thus if the climb is being made only to 10,000 ft., it will not be necessary to use HIGH gear. When continuing the climb in HIGH gear, carry on until full throttle height is reached at 2200 r.p.m. (usually 15,000 ft. to 16,000 ft.) and then increase the r.p.m. to 2,400 for the remainder of the climb. The throttle levers should be left at the E.C.B. (37 ins. Hg.) position throughout the whole of the climb because the small amount to be gained by using the throttle levers to obtain the optimum ignition timing is not worth the trouble it causes during climbing conditions.

As you can see, the Lizzie's climb process is pretty easy compared to other pistons. You simply make your 2 power reductions and blower speed shift and you're done. Once you make the second power reduction to 37" Hg., you leave the throttle in that position for the remainder of the climb. I don't understand yet what "E.C.B." is but suffice it to say, the manual simplifies it too. It's the position of the throttle levers at which you obtained 37" Hg. when you made your second power reduction. Once you do that, you leave the throttles alone and allow the manifold pressure ot fall off.

Next part is cruise. According to the book, 1150 torquemeter B.H.P per engine is the "normal scheduled power" and the maximum B.E.A. cruising power is 1300 B.H.P per engine. The numbers I gave above are techincally for 1160 B.H.P cruise, I rounded up to 1200 as I wasn't aware at the time they were actually using a non-rounded number for cruise HP since it's not "standard" to my training. In the US with any of the Pratt ir Wright powered aircraft (CV-240/340/440, DC-3, DC-4, DC-6, DC-7, etc) your cruise horsepower is in rounded hundreds. This is mainly because it usually results in fairly rounded manifold pressure numbers that are easier to find on the gaunges of the day that weren't usually all that easy to read the fine numbers on due to the vibration.

Okay, enough rambling for now. Will try to get a few Ambassador flights in tonight and/or tomorrow morning (my time) to get some initial impressions on consumption. Hopefully I'll also get John and Dave the numbers and between the three of us we can see how close the FM is and maybe make the required tweaks to get it right.

Post by **DaveB** » 30 Sep 2006, 12:48

Hi Guy's,

Can someone run the Imp/US gallon conversion by my. I really need this tattooed somewhere!

ATB

DaveB :tab:

Post by **Garry Russell** » 30 Sep 2006, 12:53

Hi Dave

US= 0.83267 of IMP Gallon

Garry