Dornier Do. Q (circa 1925)

[Pelzig]

I found this two page German document within a 1925 Japanese collection of official papers. In this document, which was sent to Kawasaki, it mentions a Do. Q aircraft. Problem is, I can find no reference to this designation. In fact, it seems that Dornier jumped "Q" in their aircraft names. Kawasaki did produce the Do. J, however.

 

[Stargazer]

Now THAT is some find of historic significance! A Dornier designation believed to have been skipped and found to have actually existed. Thanks a lot for sharing.

 

[Pelzig]

The first paragraph reads, roughly:


"To their request, regarding the work progress of the Do. Q - (machine with Siemens motor), [would] like to share with them [Kawasaki?] that we will be expecting such a motor from the delivery company and then try to make it [Do. Q]. We assume that with this engine, a better performance of the Do. Q will be achieved."


The second paragraph:


"[As far as] flying the Do. Q, built [using the] Le Rhone engine is concerned, it was executed some time before another flight with the maximum payload. The engine of the [Do. Q] started effortlessly in 20 seconds, however, the speed [was] very low, which was detected by [comparison to the Dragonfly (Do. A)] and it found that the rate [speed?] of the Do. Q was [inferior] to the Dragonfly. Also on the water, the rotating mass of the motor [required] that the turn down the Le Rhone engine [to] only 800 [Touren?] and the pilot is forced to temporarily turn off the ignition to the engine. The consequences of this is that the boat [was] pretty jerky and restless and rolls up after turning the ignition [on]. The flight tests were, therefore, with the Do. Q [using the] Le Rhone."


Third paragraph:


"So we must ask them [Kawasaki?] to be patient in this affair, until we try our exports [engines] with [the] built-in Siemens motor [note: Siemens engines powered the Do. A] [as we regret that opposition to ] the Le Rhone engine [has] stiffened. It will be understandable to them that the Do. Q [will] only achieve good results and for this reason [we must]refrain from [using] the Le Rhone engine.


Your faithfully,


Dornier-Metallbauten G.m.b.H."

 

[Arjen]

'Typenhandbuch der deutschen Luftfahrttechnik' by Lange, von Gersdorff & Schliephake mentions the Do Q as a submarine-carried aircraft. No further information.

 

[Pelzig]

AFAIK, the Germans pretty much gave up on sub-launched aircraft following WW1 and only returning to it after the 1920s. It is plausible, though, that since the Japanese were enamored with sub-launched aircraft, that Dornier would seek to produce one for the Japanese to evaluate. Japan's first aircraft carrying submarine was the I-5 that was completed in 1932. It would explain the problems the Do. Q had on the water in terms of rough alighting.


But, Dornier used the Do. A (called the Libelle, meaning "Dragonfly") as a comparison aircraft and it would seem to me that a more diminutive aircraft (assuming the Do. Q was built smaller) would not compare favorably with a larger aircraft that could use more powerful engines.


I imagine the mystery deepens.

'Typenhandbuch der deutschen Luftfahrttechnik' by Lange, von Gersdorff & Schliephake mentions the Do Q as a submarine-carried aircraft. No further information.