GURPS WW2 Air Combat?

[Gnaskar]

Originally Posted by Rivenshield

1) Re: aerial engines. How do I determine the cost for these? The instructions tell me to multiply the cost by x5, but doing so makes -- for example -- the Zero's engine cost more than the listed price for the Zero. Do I multiply a turbocharged gas engine by x5 *instead* of x2? Or do I just shrug and accept that Imperial Japan could build things more cheaply than my fictional military-industrial complex can?

Not sure where you're getting that x2 from, nor why you think the engine costs more than the the completed vehicle. Unless... are you using the 2$/lbs High Performance Turbocharged Gas engine as a base? The Zero is using a regular (turbo/super-charged) gasoline engine.

Before the aerial modifier, the engine weighs 3,206lbs and costs $1,282.40. With the modifier, the cost is $6,412 and the weight is 1,282.4lbs. Half the total cost and a fourth of the total weight of the vehicle.

[Rupert]

Originally Posted by Ulzgoroth

Real engine performance was strongly dependent on altitude, so you're not going to be able to get sensible values for service ceilings unless your model incorporates that...

And different engines had very different performance profiles, even if they were otherwise similar. Often they behaved in ways that the designers didn't intend or want. Quite a number of WWII 'high-altitude fighters' ended up as ground attack aeroplanes because of this (often quite successful ones).

The usual features of a good high-altitude fighter in WWII were a huge engine with optimisations for high altitudes, and a wing and airframe shape that didn't lend itself well to low altitude dogfights.

[Rivenshield]

Originally Posted by Gnaskar

the engine weighs 3,206lbs and costs $1,282.40. With the modifier, the cost is $6,412 and the weight is 1,282.4lbs.

Edit: Ah, I see. Thanks for your help and your swift response times.

Edit #2: Okay, what about the Me-109? It has an 860 kW aerial turbocharged engine, base weight and cost 2162.5 lbs., $4324. Apply the 'aerial' modifier and it becomes 865 lbs. and a whopping $21,620 -- six grand more than the list price of $15,400 for the complete aircraft. Am I doing something wrong, still...?

BTW, if I can shoehorn a semi-unrelated question in here.... as per the instructions in the Vehicles book for making bombs, does a modest 190mm napalm bomblet (total weight with parachute 30 pounds) REALLY have a 190 yard burst radius? Or am I reading something incorrectly, again? Because if I'm not that seems disastrously broken. Frankly I'd be tempted to shave off a zero.

[a humble lich]

Originally Posted by Rivenshield

BTW, if I can shoehorn a semi-unrelated question in here.... as per the instructions in the Vehicles book for making bombs, does a modest 190mm napalm bomblet (total weight with parachute 30 pounds) REALLY have a 190 yard burst radius? Or am I reading something incorrectly, again? Because if I'm not that seems disastrously broken. Frankly I'd be tempted to shave off a zero.

For your semi-unrelated question, with my quick read I get the same as you. I agree, that is way too high. I would rule that napalm has a much lower burst radius than CHEM rounds.

Here is a thread looking at the area of napalm rounds.
http://forums.sjgames.com/showthread.php?t=138378

They have a link which says the Mark 77 bomb (which weighs 750 lbs), can cover 2500 square yards (i.e. a radius of about 30 yards), although one commentator said looking at footage that number was very optimistic and 2500 square feet is more likely.

[Gnaskar]

Originally Posted by Rivenshield

Edit #2: Okay, what about the Me-109? It has an 860 kW aerial turbocharged engine, base weight and cost 2162.5 lbs., $4324. Apply the 'aerial' modifier and it becomes 865 lbs. and a whopping $21,620 -- six grand more than the list price of $15,400 for the complete aircraft. Am I doing something wrong, still...?

Same thing again. The Me-109 isn't using an HP (High-Performance) engine. It's using the second engine from the top, not the fourth. A lot of WW2 aircraft didn't run on aviation grade fuel, surprisingly enough. The Mustang, the Corsair, and the Catalina are the only aircraft in the core book that use HP engines.

The base weight is 3890lbs and cost is $1,556, which becomes a much more reasonable 1,556lbs and $7,780.