Lizzie fuel burn information

Post by **RAF_Quantum** » 30 Sep 2006, 12:53

Hi Dave,

Here you go, all the conversion factors you could dream of :-

http://www.onlineconversion.com/volume.htm

Rgds

John

Post by **DaveB** » 30 Sep 2006, 13:12

Tks for that guys. I normally use my trusty BEA Tech Pub (518-1) to get me out of the do-do but it doesn't consider US gallons (and why should it)

John.. I've been running the Ambassador using more info I've received which gives typical figures for a typical load. Range 1266nm.. 8,298lbs.. Spd 194kts.. Alt FL150.. Fuel 986imp gall. Recommended cruise is given at 209kts.. FL150.. weight 49,500lbs.. consumption 150imp gph. I'm trying to find a compromise somewhere in between these speeds (which must be TAS/GS) and have pulled the scalar down from 1.0 to 0.8 as a starting point. This has shown a marked reduction in burn from over 800 to a little over 500kgh. Speed is being controlled purely through the joystick control as I don't have my throttle quad on this system

Will look at it some more this afternoon.

Tks again for that conversion

ATB

DaveB :tab:

Chris Trott · Post by **Chris Trott** » 30 Sep 2006, 13:39

Dave, I'm currently running around 0.75 on mine as it was showing way high (on the order of nearly double) during climb. Haven't had much chance to test fly it since (trying to finish up a few projects before the FSX release), but I have a document lying around that said that most pistons should use a scalar of ~0.75 if they're supercharged, so I figured that was a good starting place.

Post by **DaveB** » 30 Sep 2006, 14:50

Rgr that Chris

Nothing so tech as knowing supercharged engines are around .75.. more a gut feeling to throw it into the ballpark

IF you work on the assumption that her reasonably high cruise speed is TAS(or GS without wind component) and fly to 209kts/168kias, she's only short of the typical figures above by around 400nm +/- with the caveat.. using full tanks. It's a pity the team didn't put a quad with prop pitch on too as it's impossible with the default to try and match their rpm/boost figures as this may have an ultimate effect on fuelburn. I know there are a few out there with hardware throttle quads but many that don't hence my using the stick alone as a point of reference

Does that FM of yours give a max ZFW?? I have so many variations on a theme here it's difficult to nail it down to give her a max payload range of around 720statute miles. I have an empty equipped weight of 16230kg and mtow of 23814kg (from one pub) but MZFW would be most helpful

ATB

DaveB :tab:

Chris Trott · Post by **Chris Trott** » 30 Sep 2006, 15:40

It does have a MZFW, but unfortunately I don't have the manual CD with me today (it's at home and I won't be there until this evening).

The biggest problem I have with their panel is that it uses Boost at all. The real aircraft doesn't have a Boost gauge; it has a torquemeter. Since they don't have the torquemeter, I can't find out how close their power output is to the real figures (I have a flight dynamics testing program that allows me to view things like HP in realtime while flying the plane to determine if the gauges are reading correctly). Since I fly with the quad throttles, it's easy to get the prop RPM right, I just need to find a way to integrate the Auto Rich / Auto Lean gauge from the MAAM-SIM DC-3 or the L-049 panel I have to work on their panel to allow me to set Rich or Weak mixture as on the real aircraft. Their "mixture" lever is actually the prop lever, the mixture only had 3 settings - Cutoff, Rich, & Weak and (from the manual) seemed to be switch controlled and not lever controlled.

Post by **DaveB** » 30 Sep 2006, 16:09

Hi Chris..

Rgr that. The shot I have here does show a boost gauge as the top LH instrument with an RPM gauge below that. Both are dual-needle.. there being only one of each.
Yup.. with you on the missuse of the prop lever too. The picture I have (although quite small) clearly shows these as prop levers (I'd have thought the knob shape would have given it away too)! :roll:

EDIT...
Having read your .75 Chris, I've thrown the scalar straight to .70 and it now gives 187gph (US) at the recommended cruise 209kts(GS)/168KIAS/FL150/150gph. Given the conversion a couple of posts back.. I reckon 150gph(imp) equates to 180.1gph(US) so 7gph is certainly close. Indicated range for this setting is approaching 1200nm. Is it worth taking it any closer??

ATB

DaveB :tab:

Chris Trott · Post by **Chris Trott** » 30 Sep 2006, 16:40

For the routes we run on CBFS, I wouldn't think so. Engines do tend to get a bit thirstier as they get older, so a 7GPH change isn't totally unbelievable. Most charts were considered to be a bit optimistic too, even with the "adjustments" for temperature variations, so the book probably isn't right anyway.

Anyways, can you send me that image you have if possible? I do a little bit of panel tweaking and I know a good gauge programmer and we may be able to throw together a modified panel with more accurate gauges and levers, maybe even with the proper mixture control too.

Post by **DaveB** » 30 Sep 2006, 17:41

Hiya Chris,

It's not a very large phot but I'll try and scan it at the highest my scanner will go to give you a fighting chance

Since my last post, I've been up a bit and down a bit with the scalar but in the event, I reckon .70 is about as realistic as it can be got.. all things considered. You can only go so far without needing to resort to tweaking drag e t c and that simply isn't worth it. My last run was scheduled to run from Seatac to Minneapolis (a tad over 1200nm) with full fuel and 8300lbs payload. As soon as the aircraft was clean, I pulled the boost/map down to a 'tooltip' figure of .5 and left it there. Eventually, the speed rose to 170/172KIAS by the EOC and fuelburn up to that point was between 245gph/668kgh and 250gph/681kgh. Boost/map (what a horrible guage that is!!) had fallen to .35 (again.. tooltip/mouselook figure as what it reads does not coincide with what it shows!!) so a gentle backing off to maintain 169/170KIAS (209/210Kts GS) gave me an indicated 182gph/495kgh and an estimated range of 1274nm with 75nm already gone. The reference figure I have with the partiulars in a previous post are for a 'no reserve' flight so that works pretty well for me.

Of course, it opens the question.. what would the mtow/mzfw have been with the aircraft kitted out as 'Sardine Class' (how we're gonna operate them I think)?? The model does come with 1001lbs/454kg of freight as standard so we could strip out the posh bits, fit deckchairs and take less freight to fit em all in!!

ATB

DaveB :tab:

Post by **DaveB** » 30 Sep 2006, 22:35

Chris,

The AS57 FD shot I have hasn't scanned particularly well despite trying at various resolutions. However, what I consider to be the best of the bunch is HERE . Hope it's of some use anyway

ATB

DaveB :tab:

Chris Trott · Post by **Chris Trott** » 01 Oct 2006, 01:00

What is the source of the photos. May have a better chance that way.

It gives me a clue, but that gauge in the upper left is definitely the torquemeter and not a boost gauge. If it was a boost gauge, it would have negative readings, it doesn't. It goes from 0 to 60 (and I imagine it says "x10" on it somewhere as well making the readings in 100's of inch- or foot-pounds of torque).