Chill31

I did a 6 minute taxi test on the ground, and I didn't detect any over heating issues. I am using an infrared thermometer to check cylinder temps when I shut down. Regarding leaning for temperature control...I run my lycoming on my RV-8 lean of peak EGT during cruise flight. The temperature drops substantially. That engine is fuel injected with a very hot electronic ignition, and it runs quite well that way. The rotary however seems to get rather fussy at really lean mixtures on the ground...obviously I can't speak to how it works in flight yet. And Sephton of the Shuttleworth Collection told me the Clerget can lose temper on the valve springs from getting too hot on the ground, but I am a ways from running the Clerget. Good question! Having talked to 3 Pup pilots who are flying 80 Rhone powered Pups around the world, I dont believe the Pup could achieve the speeds I've seen on the test reports (which FC/ROF have used). One Pup pilot said he achieved about 110 mph in a dive at 1200 rpm trying to chase the 160 Gnome Camel. Maybe they were able to run it really hard for the speed run to get the extra mph? Most pilots say they are happy if they 90 mph out of it... With an 80 Rhone on my triplane, I dont think it will be representative of a "real" DrI since it does not have the 120 Rhone on it. I do think it it be exactly representative of a Dr.I with an 80 Rhone though for FC, I think it has important implications in that we would have a known point on the performance scale. We will know exactly how an 80 Rhone powered Dr.I performs with the propeller specs from mine. My personal guess is that it will be about the same as when it was lycoming powered...in order to approximate the modern equivalent power for a rotary engine, double it. I will likely have the 120 Rhone running within a year, so then we will know exactly how it performs!

I have calculated the CG on it, and it seems to be within acceptable limits compared with other DR1s flying today. I will know early in the takeoff roll if I have enough forward stick to control the tail heaviness. It is at the forefront of my mind for sure! The loaded weight does include me.

Sweet! Keeping my fingers crossed for good weather

My bird is finished! Ready for the first flight on Dec 14th. https://m.facebook.com/events/790165198085427 Weight and balance complete...953 lbs empty, 1232 lbs fully loaded. The original aircraft as tested in WWI was 949 lbs empty and 1,382 lbs loaded. The biggest differences between mine and the original are the engine (the 80 Rhone is about 50 lbs lighter than the 120 Rhone), the guns (my guns weigh about 15 lbs a piece, half of the original), and I have no ammo!

The Camel was a loss https://images.app.goo.gl/aBHUDW7aTGdzzYCp8 Where did you find that bit on the engine acceleration? I wouldn't rule that out, by any means. I did a static engine run up in the chocks, and I didnt notice any tendency for the engine to enrich or cut out. I will definitely be keeping an eye out for that phenomenon until I can figure out if it is real or not.

It is instant. All the blip switch does is ground the magneto, so the spark doesn't go to the sparkplug. Here you can listen to the Fokker D8. I had to blip it going down hill in order to keep it from getting too fast on the ground. Not my plane, so I can't afford to bend it up!

My experience running the rotary is still rather limited at this point, since I haven't flown it... Here is a short video I made of how the carburetor works on Le Rhone, Clerget, Oberursel, and Bentley (I'm not 100% about the Bently) engines: I've found that I can leave the minet valve (the fuel fine adjustment) wide open during anything other than low idle settings. When I run the engine up and lean it out from full rich, I do get more revs, however it still has a lot of power at full rich. This effect is also present in modern day engines found in light aircraft (lycomings, continentals, etc). The throttle response is much faster than I had anticipated due to my experience with ROF/FC. The engine will spin up and down faster than you think. In the following taxi video, I set the minet valve to wide open, full fuel flow, and then I taxied it around. I wanted to see if I could get a rich cut. Alas, I could not. I found that I could taxi successfully (it was a pretty fast taxi though) in that configuration. That being said, if I had used the fine fuel lever in concert with the throttle, I could have achieved a lower idle speed on the engine. Based on my experience at this point, I don't think the minet valve is as critical as it has been made out to be. The engine seems to run well over a range of fuel mixtures, however, there is definitely a "best power" mixture setting. Regarding the "rich cut," I've had rotary pilots tell me it is a myth...BUT in this video, you can definitely see the smoke plume of this engine getting very rich for some reason. As of yet, no one knows why. I suspect that it is a symptom of having a pressurized fuel tank (most WWI fighters did NOT have a pressurized tank, including the Fokker Dr.I). At low power, the pressure in the tank is maintained using a hand pump in the cockpit along with slight pressure from the air driven pump mounted in the propeller slipstream. As you take off, the air driven pump is getting A LOT more air and subsequently adds a lot of pressure to the tank. The increased tank pressure results in higher fuel flow, to the point it causes a rich cut. If my hypothesis is correct, a rich cut should be an impossibility for most WWI aircraft. The way FC/ROF represents rotary engine control is most flawed by the fact that "idle" on the throttle itself should shut off the engine...😯 Other than that, it is believable. Some nuances are missing such as how the engine behaves at low power settings on the ground and how the engine works best if you lead an increase in power with opening the minet valve and lead a decrease in power with closing the minet valve (you can see what I mean in my taxi video below. Listen for the engine run ups to hear the throttle response). In the video, I only blipped once or twice...the rest I did using the throttle alone. So back to the Blip Switch! It is used primarily to get the engine slowed down for landing and during taxi. In the air, and for dog fighting, I can't see it being all that useful. Once I fly it, I will have a better idea though...

Beast of an airplane!

I think we should do air starts...

I hope you guys find this as interesting as I did.

My Dr.I is my test bed where I ultimately plan to use this device to record flight parameters: Levil BOM I've wanted to do this since Rise of Flight came out over 10 years ago! Finally, I am on the brink of accomplishing this. I have to be successful on my own before I can ask someone (perhaps PJ) to allow me to study their aircraft using the same methods. I am in the home stretch of fabrication for the Dr.I prior to flight I have ambitions to fly it before the end of October, but sometimes life has other plans. I am going to Rhinebeck Aerodrome this weekend to learn from their expertise and hopefully build some good relationships that would afford me the opportunity to use the BOM on their aircraft in the future.

The average resting G tolerance for people is about 3.5 Gs. That is just sitting in a chair, no G strain exercise or anything to counter them. For me personally, I have to start doing anti-G strain at 4-5 to keep 100% vision. I've heard of guys (VERY rare) who have a resting tolerance of 6 Gs! Below 5 Gs, I can fight all day, but it is tiring. After a 4-5 G fight, it would probably be challenging to go hammer away at 7 Gs or more. Regarding small radius maneuvers, at these low airspeeds, the maneuvers look very tight! One of my friends watched me looping the DrI and said it was the smallest loop he'd ever seen (this coming from an aerobatic pilot) and I never hit more than 2.5 G doing it. The WWI planes just cant sustain G forces long enough for G forces to be significant. I imagine if you black yourself out in the Camel, it is a pretty short duration? I have yet to try it myself, but I will.

G tolerance on a WWI plane doesn't even need to be modeled. These planes can barely sustain 2 5 Gs.

To see a single WWI plane at low altitude at 2-3 miles would be realistic. To see a formation at 3-8 miles would also be realistic. The longer distance corresponding to larger formations. At high altitudes, you might get 30% improvement.

On these types of engines, yes. When the throttle body is opened all the way (full throttle) that is the maximum amount of air it can put in the cylinder. I asked some friends and it would be possible to over heat a water cooled engine in very hot climates. A rotary would probably not be as susceptible.