Knights of the Sky Foundation

[Chill31]

I finally got the stick throttle working on the Fokker. I think it may be the only one in the United States configured this way right now.  Here's a short video showing its operation: 

 

 

Edited May 22, 2019 by Chill31

[Chill31]

I am nearing completion of the cockpit mods required for running the rotary. Most recently, I installed the fuel and along with the necessary fueltank and oil connections to the engine.   For your viewing pleasure...

 

 

Edited July 14, 2019 by Chill31

[Chill31]

This has been a long road! Finally starting to see light at the end of the tunnel.

 

[LesG]

Maybe you can explain something to me:

 

The left and right movement of the joystick is going up (at first) with a single wire

 

 

but somewhere between the full ammo case and the empty ammo case the single wire is splitted in two wires for the left and right rudder movement

 

 

i cant find a picture of these connection / mechanic to split it

 

Is it a single wire for both rudders (going from the left wing to right wing)?

 

 

or is every wire firmly screwed like this

 

 

i hope you can help me

 

greets from germany

LesG

 

Edited August 8, 2019 by LesG

[Chill31]

@LesG

 

The 3D animation is inaccurate.  2 wires came from the control stick. Each aileron ("wing rudders") was controled by a completely independent wiring circuit so that one could be shot away.  Hope that helps!

Edited August 9, 2019 by Chill31

[Cynic_Al]

On 7/14/2019 at 6:16 PM, Chill31 said:

 

Could you explain the purpose of the curved rails fitted below the rudder bar? From several months of gaming with a centrally-pivoted rudder bar, I've found it desirable for the floor under one's heels to be as slippery as possible. Is that the function of the material between the rails?

[Chill31]

@Cynic_Al the metal plate in beneath the pedals is diamond plate, so it is tough with plenty of friction.  I don’t know if that is exactly how it was originally or why they put anything there at all.  If it was to prevent wear, it is a pretty ambitious goal to have the plane last long enough during the war for wear to be a concern.  

 

When taxiing on on the ground, that is the most my feet move on the pedals/floor. In flight, I can get away with simply rocking my feet on their heels to have adequate control for basic flying. Some “extreme” maneuvers require me to move my whole foot, but it isn’t too often.  When I have it flying again, I’ll try to get a video of the cockpit so you can see what goes in to controlling it.

[LesG]

18 hours ago, Chill31 said:

@LesG

 

The 3D animation is inaccurate.  2 wires came from the control stick. Each aileron ("wing rudders") was controled by two complete wiring circuits so that one could be shot away.  Hope that helps!

 

This is exactly what i dont understand. Look here at the pictures of the Dr.I cockpit in Rise of Flight

 

One wire

 

One wire

 

 

One wire

 

 

Two Wires to the aileron (upper and lower mechanic for the movement - joystick to the right / left wing rudder down - right wing rudder up)

 

 

but only one is going up

 

 

replica - MHM Rechlin

 

 

i have a good contact to the restoration team in Rechlin and i will also ask them how the aileron system is made in the replica

 

i would like to make a animation for the aileron of the Dr.I too (here a picture of my explanation of the rudder mechanics of the Pfalz D.XII)

 

 

but in the moment i cant say that i am sure that my informations are exact or plausible

 

 

but many thank you for your help

greets

LesG

 

Edited August 9, 2019 by LesG

[Chill31]

@LesG I should have said it this way (I will go edit the post in order to reduce confusion for anyone who reads this later): each aileron is controlled by it's own independent circuit. On aileron or its controls can be shot away, and the other will still work.

 

The ROF/FC 3D model of the wires coming from the control stick is inaccurate. There should be two wires coming from the stick. Here is a picture of how it should be:

 

The replica you posted appears to be a Sands plans airplane. Some of the details I can see in the picture are inaccurate (normal if you build it strictly according to those blueprints), so I will be surprized if the aileron system is accurate. 

[LesG]

Thanks a lot - this is exactly what i mean (it wasnt easy to see it on your picture - i have enlarged a part of the image)

 

 

Both wires are going directly up.

 

Now i am a big step further

Thanks and greets from Cologne / Germany

LesG

 

 

 

 

Edited August 10, 2019 by LesG

[DakkaDakkaDakka]

On 8/8/2019 at 5:20 PM, Chill31 said:

If it was to prevent wear, it is a pretty ambitious goal to have the plane last long enough during the war for wear to be a concern. 

 

I chortled audibly. Thanks! ?

[Chill31]

It will run by the end of the month!

 

[Chill31]

I am not an expert on these engines yet, but I am officially on the learning curve now!

 

[Zooropa_Fly]

Love the matching chocs ?

[Chill31]

1 hour ago, Zooropa_Fly said:

Love the matching chocs ?

haha, one cannot simply go half zebra...it must be done ALL the way

 

Here is a little more Fokker fodder for you

 

[Cynic_Al]

2 hours ago, Zooropa_Fly said:

Love the matching chocs ?

 

 I didn't know Toblerone make that size. It's certainly the right shape for the job.

 

 

 

Edited September 24, 2019 by Cynic_Al
The preposterous merging feature.

[Cynic_Al]

22 hours ago, Chill31 said:

I am not an expert on these engines yet, but I am officially on the learning curve now!

 

 

It seems to have a safe 'idle' speed without being blipped, but this leads me back to something I asked a while ago:, namely what minimum ground crew do you think it will need to operate it?

[Chill31]

7 hours ago, Cynic_Al said:

 

It seems to have a safe 'idle' speed without being blipped, but this leads me back to something I asked a while ago:, namely what minimum ground crew do you think it will need to operate it?

 

One of the guys there in the video has done it for his own Dr1 completely on his own!  However, 1 or 2 other people helping is a more comfortable way to run it.

 

[Chill31]

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

 

 

[=IRFC=Jorri]

Congratulations, Chill, and thanks for sharing, this is great to see! 

 

 

[No.23_Starling]

Fantastic video on the Se! Thanks for sharing Chilli. Have you read his book? He went on to help found the BBC! What a life!

Edited October 16, 2019 by No56_Hotwing

[No.23_Gaylion]

It's part of a longer series:

 

Original only available in the UK: 

https://www.bbc.co.uk/programmes/p01tczfx

But I found this mirror on vimeo: 

Also these:
https://www.bbc.co.uk/sounds/play/p016w3nc
https://www.bbc.co.uk/sounds/play/p0093z71

Edited October 16, 2019 by US103_Talbot

[Chill31]

Beast of an airplane!

[Chill31]

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!   

[No.23_Gaylion]

I plan on being there!

[Chill31]

2 hours ago, US213_Talbot said:

I plan on being there!

Sweet! Keeping my fingers crossed for good weather 

[HagarTheHorrible]

3 hours ago, Chill31 said:

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!   

 

Given that DR1’s tend to fly nose high anyway (constant stick forward pressure) and the weight discrepancy, between original and yours,  is all up front (engine and guns) what will you do to balance out the trim, if needed ?  Does the loaded weight include you ?

Edited December 2, 2019 by HagarTheHorrible

[Chill31]

6 hours ago, HagarTheHorrible said:

 

Given that DR1’s tend to fly nose high anyway (constant stick forward pressure) and the weight discrepancy, between original and yours,  is all up front (engine and guns) what will you do to balance out the trim, if needed ?  Does the loaded weight include you ?

 

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. 

[1PL-Husar-1Esk]

Fingers crossed for good and save flight, looking forward for detailed review how real rotary handle in the sky

BTW you did texi test runs , it's is true that those rotary need to be in the air up to 3-4 minutes after engine start do to the raising temperature and no save/practical way to reduce tkat heat by bleeping/ reach or lean mixture ?

[BMA_Hellbender]

What kind of difference in performance are you expecting between your 80hp Le Rhone and the original 110/120hp Oberursel? A 30hp difference on a rotary seems to be of far less concern than the actual weight difference.

 

For instance, the Pup (80hp Le Rhone) and Camel (130hp Clerget) have close to similar top speed at sea level, while the Pup is obviously a much lighter machine which sports only a single machinegun.

 

In other words: do you think your Dr.I will be representative of a historical one?

[Chill31]

5 hours ago, 1PL-Husar-1Esk said:

Fingers crossed for good and save flight, looking forward for detailed review how real rotary handle in the sky

BTW you did texi test runs , it's is true that those rotary need to be in the air up to 3-4 minutes after engine start do to the raising temperature and no save/practical way to reduce tkat heat by bleeping/ reach or lean mixture ?

 

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. 

 

54 minutes ago, J5_Hellbender-Sch27b said:

What kind of difference in performance are you expecting between your 80hp Le Rhone and the original 110/120hp Oberursel? A 30hp difference on a rotary seems to be of far less concern than the actual weight difference.

 

For instance, the Pup (80hp Le Rhone) and Camel (130hp Clerget) have close to similar top speed at sea level, while the Pup is obviously a much lighter machine which sports only a single machinegun.

 

In other words: do you think your Dr.I will be representative of a historical one?

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! 

[1PL-Husar-1Esk]

Thanks for answer,  I'm really interested how centrifugal forces and gyroscopic effect and adverse yaw will have effect on the airfare with rotary engine during yours test  turns with and without rudder.  Present very good rotary airplanes FMs  by those findings could be  yet more  authentic and accurate if shared with devs.

S!

[BMA_Hellbender]

Thank you for your very complete answer, Chill!

 

1 hour ago, Chill31 said:

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...

 

This pretty much confirms what I suspected for a long time, meaning that the performance figure of the Sopwith Pup is close to that of the Nieuport 11, which sports the exact same engine, close to the same weight, has a sesquiplane arrangement and has a top speed of around 160km/h.

 

My best guess is that there was a misprint or poorly written note somewhere down the line where a 6 turned into an 8, giving rise to the 180km/h figure of the Pup.

 

Ironically, with the 1.034 FM changes, we now likely have an accurate Pup in RoF (as well as a busted Triplane and Camel — but hey, small victories!).

 

 

P.S. Please fly safe!

Edited December 3, 2019 by J5_Hellbender-Sch27b

[SeaW0lf]

On 12/3/2019 at 12:40 PM, J5_Hellbender-Sch27b said:

Ironically, with the 1.034 FM changes, we now likely have an accurate Pup in RoF (as well as a busted Triplane and Camel — but hey, small victories!).

 

Mikael Carlson's Fokker Dr1 (Le Rhône 110hp) and Fokker D.VII (DIIIaü, 200hp) both have the cruise speed of 86/85knots (about 160km/h). Since the D.VII can go over 200kmh in the right conditions, the Fokker Dr1 should scale nicely around WEP / 1400rpm (although no one would get to that with these rare engines nowadays), so I'm interested in seeing Chill's results at cruise speed with the *80hp version.

Edited December 7, 2019 by SeaW0lf

[Chill31]

https://www.facebook.com/KOTSWWI

 

If you want to see a few new videos of ground runs...here ya go

[unreasonable]

On 12/3/2019 at 10:40 PM, J5_Hellbender-Sch27b said:

Thank you for your very complete answer, Chill!

 

 

This pretty much confirms what I suspected for a long time, meaning that the performance figure of the Sopwith Pup is close to that of the Nieuport 11, which sports the exact same engine, close to the same weight, has a sesquiplane arrangement and has a top speed of around 160km/h.

 

My best guess is that there was a misprint or poorly written note somewhere down the line where a 6 turned into an 8, giving rise to the 180km/h figure of the Pup.

 

Ironically, with the 1.034 FM changes, we now likely have an accurate Pup in RoF (as well as a busted Triplane and Camel — but hey, small victories!).

 

 

P.S. Please fly safe!

 

No misprint required, just examination of contemporary documents.   Bruce's British Aeroplanes 1914-18 gives two test reports for a Pup, with the sea level top speeds given at 111.5 mph (80 hp Le Rhone) and 110 mph (100hp Monosoupape)

 

111.5 mph = 179.4 kph.

 

 

[Chill31]

4 minutes ago, unreasonable said:

 

No misprint required, just examination of contemporary documents.   Bruce's British Aeroplanes 1914-18 gives two test reports for a Pup, with the sea level top speeds given at 111.5 mph (80 hp Le Rhone) and 110 mph (100hp Monosoupape)

 

111.5 mph = 179.4 kph.

 

 

I remember when they made the Pup in ROF. They matched it to the data pretty well.  Based on talking to Pup pilots today, I am skeptical of the test data.  It seems like there must be something...tricky...about it to achieve those numbers.  

[J5_Adam]

11 minutes ago, Chill31 said:

I remember when they made the Pup in ROF. They matched it to the data pretty well.  Based on talking to Pup pilots today, I am skeptical of the test data.  It seems like there must be something...tricky...about it to achieve those numbers.  

 

Same thing with the numbers for the camel I'm sure

[unreasonable]

10 minutes ago, Chill31 said:

I remember when they made the Pup in ROF. They matched it to the data pretty well.  Based on talking to Pup pilots today, I am skeptical of the test data.  It seems like there must be something...tricky...about it to achieve those numbers.  

 

Anyone who has been studying this subject for a while knows that measuring aircraft speeds in those days was a problem for a number of reasons, so I do not rule that out.

 

Comparing the Pup with an N.11, however, is also a problem. The N.11 has much higher wing loading,  (36.1 kg/m^2 compared to 23.6), so more AoA required at a set speed to fly level = more drag. It is questionable whether the sesquiplane arrangement is more or less efficient. It may create less drag, cet par, but if the lower wing is warping because it only has one attachment on the V -strut, maybe not.  It had a wing mounted gun instead of one flush to the fuselage = more drag. It lacked a vertical stabilizer and had a much more tapered fuselage than a Pup: much harder to fly consistently without sideslip. 

 

All in all, the Pup was a much better design that the N.11 and I would be extremely surprised if it did not show a measurable improvement in actually achieved top speed over the N.11    Hence my objection to Hellbender's comparison. 

[ZachariasX]

1 hour ago, unreasonable said:

All in all, the Pup was a much better design that the N.11

I‘d be careful going that far on the base of your original assumption about wing size, as it lacks critical issues.

 

The lower wing is less efficient than the top wing, as the top wing shields part if the lift mediated by the lower wing. The closer the wings are together (in relation to thei chord length) the more pronounced the effect. In this sense, you can see the lower wing mostly as a rigging aid to create a safe top wing arrangement.

 

The sesquiplane arrangement is just that. It makes the lower wing what it really is, a rigging aid, with least drag. At normal flight speeds, AoA is so small anyway that there that I would be very surprised if there was a difference in induced drag with such light aircraft. At least for practical purposes. Albatros did just that in newer models, reduce the lower wing to the rigging aid it essentially always was.

 

 

Regarding top speed, my bets are still that @Chill31‘s Dr.I will go as fast (TAS) as fast as his prop pitch x rpm give.

 

I know, this simplification is frowned upon in these realms (an exchange with @AndyJWest IIRC comes to mind), because a realistic world is a complicated one, but let‘s make it about something material.

 

I bet this will be the case, prop pitch times rpm will produce the Dr.I‘s (TAS) flight speed by a tolerated margin of 5%. 

 

Let us bet for or against that hypothesis. The loser must gift a copy of FC1 to an RoF remainer (or any aspiring soul) of his choice. It‘s Christmas, so why not.

 

I can edit this and list the participants in this message below.

 

I hope a lot of folks will bet against me.