That... did seem really weird to me to be honest. I mean the plane itself didn't look at all like something Amazons would have designed on their own, and I have a hard time imagining how it even came to exists considering what we have seen of the Amazons so far. I mean, even Rucka's YO Amazons were going 'whoa' at a simple pistol. And the alternative is that the plane came out of Hephaestus' forge... which I dont think is cheap.
That said, I think it's fine if the various Titans add something unique to the teams equipment pool... I'm just sad that Donna's might as well have been built by Wayne Tech.