Airco DH.2 Research Project

[Kerbalnout]

Hey guys,

I’ve decided to start studying the Airco DH.2 in-depth to reverse engineer the aircraft to the best of my abilities. I have no formal engineering background, and I’m currently teaching myself how to use SolidWorks, so my work might contain errors, but hopefully, this will be improved in time. This project will take place entirely within CAD, and as of now, I am only seeking to create an accurate CAD model. I’m only 19 right now, but I would like to build an Airco DH.2 reproduction sometime when I’m older, so this CAD model will serve as the initial research to support this long-term goal.

I’ll try to post to this thread whenever I make progress with the 3D model or just its sketches. As of now, I’m waiting for the NASM to get back to me about their higher-quality pre-production DH.2 blueprints. I also welcome any assistance with the project, criticism, and suggested improvements to certain parts I create. Since there is very little material to use for this project, the end result will in no way be 100% accurate, but I hope I can do the best job currently possible!

I also want to mention the real Airco DH. 2 reproductions that have been made. Most of this information is pulled from previous threads and my communications with some people involved. Sky Sports Engineering was working on a Nacelle of a DH.2, and photos of this can be found in other DH.2 threads. This reproduction was passed onto Flying Restorations, which they're still engaged with. The second Airco DH.2 reproduction I’m aware of was acquired by TVAL. Footage of these reproductions can be found using this link to a YouTube documentary made on TVAL:

https://www.youtube.com/watch?v=7gmZ9X9Aplk

It is shown at 1:03 into the video but can also be seen numerous times throughout the documentary and in the bonus TVAL videos posted by the same channel where Peter Jackson goes into a bit more detail about it. In the videos, there is one almost complete DH.2 and another DH.2 Nacelle off to the side.

I’m not sure how much more material these reproductions used, but I would love to know if they had more than my sources listed below.

I’ll list the material I’m currently working with here:

Airco DH.2 Spare Parts Manual (Simplified Full Book)
Airco DH.2 Spare Parts Manual (Detailed Partial Book)
Notes on De Havilland Fighting Scout (NASM)
Hand Drawn Airco DH.2 Field Rigging Notes
Airco DH.2 Rigging Notes (WW1 Aero)
1916 Rigging Notes De H.2
Air Board October 1915 Airco DH.2 Blueprints Three View (Low Quality)
NACA Report No. 93 (Contains DH.2 Aerofoil)
WW1 Aero #146
WW1 Aero #147
Wind Sock Datafile No.48 Airco DH.2
Cross & Cockade DH.2 Study Parts.1-5
De Havilland In Action (Squadron)
Photographs from Wingnut Wings and Other Online Sources

Sources I still need:
De Havilland Aircraft of World War I (Colin Owers)
DeHavilland DH2 and the Men Who Flew Them (GWAS) On Order

Please let me know if you are aware of any other sources I should include!

Kind Regards,
Ethan

[John McKenzie]

Hi Ethan ,

I think you got it wrong about TVAL making the 2 reproduction DH2's .
They bought ,.. or "otherwise obtained " , them ... as is often the case there .

JM.

.

[Kerbalnout]

Hi John,

Thanks for clearing that up! I changed the post a little so as not to spread false information. By the way, Tim Moore told me that the Sky Sports' reproduction had been passed on to Flying Restorations.

Kind Regards,
Ethan

[John McKenzie]

Hi Ethan,

Yes , the guys there at Flying Restorations Ltd. , used to work for Tim ,...after which starting up on their own " down the road " .

Have a look at their web sight & you will learn more about their customer & find also photos of the pair of the aforementioned , DH2 reproduction work .

Over on TVAL sight you will see that many of the aircraft clearly originated elsewhere , although they would like you to think otherwise .

JM

[Kerbalnout]

Here are some pictures of my very early DH.2 tailplane and mainplane general arrangement drawings that are still a work in progress. I'm currently waiting on some extra material to use that can help to confirm or create more accurate dimensions.

I'm also looking for high-quality photos of the mainplanes and tailplanes without fabric. Feel free to private message me if you can help!

Kind Regards,
Ethan

[Spoonfrog]

A great project, I hope you stick it through to the end. Do original DH.2 drawings still exist?

[Kerbalnout]

Thanks, Spoonfrog! I'll do my best to stick with this project and see it through!

There are three known original Air Board general arrangement DH.2 drawings dated October 28th, 1915, that show the pre-production version, with some small differences from the actual production model. From what I know, these drawings are available at the UK National Archives KEW and the NASM. I'm waiting on my DH.2 drawings from the NASM right now.

I've heard rumors that other original DH.2 drawings exist and that they are kept in private hands and difficult to obtain. Judging by the progress of the DH.2 acquired by TVAL, I personally think there are most likely more original drawings that exist, but who knows where they are now? It might be possible that Flying Restorations Ltd has some.

Kind Regards,
Ethan

[Kerbalnout]

Hey guys,


I wanted to make a post about the Airco DH.2s spar thickness to explain the measurements I’ve arrived at and maybe get some feedback on my educated guesses.
After researching today and performing some calculations, which I’ll explain below, I believe that the DH.2's overall front spar thickness is 1.4”, and the rear spar thickness is 1.5”, just like the SE5a.


I’ve come to these numbers by taking all of the British WW1 fighters I have blueprints for and creating a list that includes their total wingspan and front and rear spar thickness and finding the spar thickness to wingspan percentage. I found several fighters with wingspans similar to those of the DH.2, and the spar thickness is approximately 0.45% of the overall wingspan. That number has been rounded. But 0.45% of the DH.2s front spar wingspan being 312.5” is 1.40625”, and 0.45% of the rear spar wingspan is 1.514”. So by rounding again, we get the front spar thickness of 1.4” and the rear spar thickness of 1.5”. These numbers are also similar to what I measured from multiple general arrangement drawings and sketches from the spare parts manual.


Many WW1 fighters have used similar or exactly the same thickness for their spars. These fighters also had a similar wingspan overall compared to the DH.2. Below, I’ll post the list I’ve been using to compare spar thickness between British fighters.


Please, if you have evidence to suggest that the spars were slightly thicker such as 1.75” to 2” thickness, I would love to be corrected in order to find a more accurate measurement.


There is also a possibility that the DH.2 front spar was 1.5” and the rear spar was the same thickness or 1.75” or 2.25" but this is another guess using less reliable data. The numbers I’ve arrived at are also rounded to the nearest quarter inch, as this is what I’ve seen in almost every other fighter and larger aircraft as well. Usually, spar thickness measurements don’t include sixteenth-inch fractions (some do, though). They seem to end at .25”, .5”, and .75” on average but can sometimes have ⅛ inch fractions like .125”, .375”, and so on.



Sopwith Snipe Wingspan 31’-3”
Front Spar Thickness is 0.4% of Wingspan
Rear Spar Thickness is 0.47% of Wingspan
1.5” Front Spar is 2.92% of 60” Chord
1.75” Rear Spar is 2.5% of 60” Chord

Sopwith Camel Wingspan 28’
Front Spar Thickness is 0.45% of Wingspan
Rear Spar Thickness is .63% of Wingspan
1.5” Front Spar is 2.78% of 54” Chord
2.125” Rear Spar is 3.94% of 54” Chord

Sopwith Tripe Wingspan 18’-10”
2.25” Front Spar is 5.77% of 39” Chord
2” Rear Spar is 5.13% of 39” Chord
(The Triplane is an odd one out, so I didn’t include it for the measurements)

Sopwith Pup Wingspan 26’-6”
Front Spar Thickness is 0.4% of Wingspan
Rear Spar Thickness is 0.66% of Wingspan
1.25” Front Spar is 2.03% of 61.5” Chord
2.125” Rear Spar is 3.45% of 61.5” Chord

Bristol Scout Wingspan 24’-7”
36mm Front Spar is 2.63% of 1370mm Chord
40mm Rear Spar is 2.92% of 1370mm Chord

FE8 Wingspan 31’-6”
Spar Thickness is 0.4% of Wingspan
1.5” Front Spar is 3.125% of 48” Chord
1.5” Rear Spar is 3.125% of 48” Chord

SE5a Wingspan 26’-7”
Front Spar Thickness is 0.44% of Wingspan
Rear Spar Thickness is 0.47% of Wingspan
1.4” Front Spar is 2.5% of 60” Chord
1.5” Rear Spar is 2.33% of 60” Chord

Kind Regards,
Ethan

[Kerbalnout]

Hey guys,

I thought I would make a quick post showing a basic DH.2 rudder outline drawing that I quickly whipped up. The drawing was made using the DH.2 spare parts manual and related drawings.

I have the higher quality NASM Air Board Airco DH.2 drawings officially on order, so I hope to get those in a week. Once I get those drawings scanned on my computer, I can begin working on the Nacelle, which I expect to be a particularly difficult part to model.

Kind Regards,
Ethan

[Kerbalnout]

Some slight news: I was just looking through the Wright Field Technical files on the NASMs archival website, and I found two new DH.2 sources. I'll have to make an appointment to document them sometime soon.

Here they are:

"Rigging chart for de Havilland 2 airplane with 100 H.P. Mono engine." Source: Air Service
April 13, 1918
D587D52.1 D.H.2 / 21

"Dwg [drawing] and brief description of the de Havilland D.H. 2." Source:
1915
D587D52.1 D.H.2 / 23

Hopefully, they'll have some more dimensions and other useful material.

Kind Regards,
Ethan