Topic: Spacemaster Privateers Vehicle Manual Jet Drive help

[snrdg051306]

Howdy everyone,

I've finally gotten around to looking at the Privateers Vehicle Manual Creation Rules and I'm having trouble with the Jet drive, page 102. I tried to recreate an early model Airbus A320 with an operating weight of about 38 metric tons and an air speed of 650 km/h using two CFM56-5 turbofan engines. My web search indicates that the engine have a dry weight between 1.95 and 3.9 metric tons depending on the series.

Plugging an A320 with a weight of 38 tons with an air speed of 650 km/h built at TL 25 my engine mass works out to be about 73.3 tons. Thinking that I might have a problem using paper, pencil, and calculator, I whipped up an Excel spreadsheet. Unfortunately I'm still getting the engine as massing about 73.3 tons.

My luck with searching for topics relating to my issue of the jet drive has been down right pathetic. Can some kind soul please help me out here. Also are there tutorials for designing various vehicles?

Respectfully,

snrdg

[markc]

snrdg051306;
 I do not know of any tutorials for SM:P VM but I will see right now if we get the same numbers for the Jet Drive. (.15x38)+(38/3x.008x.055)= 5.7557333333 .
 It seems to me that you used the 650 air speed instead of converting to G's on the Acceleration Chart (pg102) below the Jet Drive Tech Level Factors.


Does that help?
MDC

[snrdg051306]

Evening MDC,

Thanks for the reply and yes the use of the Acceleration Chart appears to fix the engine mass problem.

You're correct that, like the conventional drives pages 100 to 101, I'm using the air speed directly in the formula. According to the copy of the Vehicle manual you "Calculate the stats of this engine like a conventional engine." Good call on using the chart which brings the VM engine mass closer to the real world.

Just after I posted my topic I kind of thought about using the Acceleration Chart, but looking at the higher speeds I got cold feet. I guess I should have trusted my hunch.

Thank again for the assistance.

[markc]

Tom;
 If you need any more help just post your question of PM me and I will try and help you out.


MDC

[snrdg051306]

Morning MDC,

Again thanks for the help and the permission to PM you about future needs.