Free Flight, Free Speech

I started to play around with it for the upcoming USA Tour

Lester, in your endless archive about WWI planes, do you have anything about idle rpms for the Oberursel II or the LeRhone 9ja? The current model of the DR.1 we have runs on the Oberurlse, but it demands 300 rpm idle which is too high for zero throttle, it just dies off. And 300 is a lot of such an engien, I think. So, any idea?

I'd love to join the tour as the Red Baron

ah look at those 4 wings..... tri-plane my arse

J-wocky, can I take it this is a yasim job ?

Simon

no. JSbsim job.

JSB, flies fine. Landing is also surprisingly good. Taking off, she is a bitch.

She should take off in 50 yards and climb at 2200ftmin.
Yes this plane should be hard work...

jwocky wrote:I started to play around with it for the upcoming USA Tour

Lester, in your endless archive about WWI planes, do you have anything about idle rpms for the Oberursel II or the LeRhone 9ja? The current model of the DR.1 we have runs on the Oberurlse, but it demands 300 rpm idle which is too high for zero throttle, it just dies off. And 300 is a lot of such an engien, I think. So, any idea?

If this is the JSB sim engine are you sure you don't have too high a fixed pitch on the propeller?

Most if not all throttled WWI rotary engines had a limit to their 'tick-over' idle speed mainly due to their not aspirating fuel reliably below 500~700RPM's. That is what a "coupe" switch is for, it shuts the ignition electrical circuit momentarily to 'idle' the engine more on approach The only way to get a rotary aircraft engine of this class to idle. This video illustrates the VA Oberusal testing in New Zealand.



Note that it doesn't 'idle' while all cylinder's sparkplugs are lit off, they have to actually cut the ignition, just like they do in the historic versions. The only WWI engines that really and reliably idled well were the Mercedes and Benz 6 cylinder inline water-cooled engines. They could be idled down to about 190 rpm, which is damn slow.

You will also note that my YASim DRI is perfectly fine for landing with it's adjusted throttling. I don't get the need to rebuild the FDM on something that is already functioning well.

I tested it near EGOD yesterday, quite difficult for beginners to takeoff/land but with some practice (and crashes :-X ) you can control it, but i don't know how chaotic can be online with some trying to take off at the same airfield. in flight was flawless, nice plane thanks all involved!!

Catalanoic wrote:I tested it near EGOD yesterday, quite difficult for beginners to takeoff/land but with some practice (and crashes :-X ) you can control it, but i don't know how chaotic can be online with some trying to take off at the same airfield. in flight was flawless, nice plane thanks all involved!!

It's short coupled and has small moments of inertia in all axis', with a full flying rudder/Vstab, large elevators and ailerons on the upper wings. Fokker was trying to emulate the Sopwith Triplane's climb speed and maneuverability. The DRI was actually a lot different in flight manners in many ways to the Tripehound, most of them were not really an advantage. For one it was really slow, and you couldn't dive out of a fight to escape.

The Sop Tripe was longer and had a bigger 130 hp engine that performed better at higher altitudes, it was also faster. The DRI's advantages were that it had a supreme manuverability and climb rate. It was touchy like the Camel in yaw and pitch, but for different reasons.

Tactically in 1917~1918 the playing field for fighter aircraft was going more to the boom and zoom tactics of the SE5a and SPAD, turn fighting, especially the type that the DRI excelled at was falling out of favor. Pilots were starting to understand energy conservation and using long attack approaches also known as "E" fighting.

bomber wrote:ah look at those 4 wings..... tri-plane my arse

J-wocky, can I take it this is a yasim job ?

Simon

Armstrong Whitworth had a plane that was a quad wing

the F.K.10

There also was the *Pemberton Billings Nighthawk ( *became Supermarine )