sikorskys29a

Not a "Grumman Bomber," but actually the Sikorsky S-29 (S-29-A, reg. no. NC-2756, c/n 1) painted in German markings, as it portrayed a Gotha Bomber in the Howard Hughes movie "Hell's Angels" (1930). As per Wikipedia,

The Sikorsky S-29-A was an all-metal, twin-engine biplane airliner, first flown in 1924. It was the first aircraft that aviation pioneer Igor Sikorsky designed and built after coming to the United States, hence the special "-A" suffix signifying "America".

en.wikipedia.org/wiki/Sikorsky_S-29 Ultimately the aircraft would crash during filming on March 22, 1929. The S-29 was placed in to a spin to portray the Gotha being shot down, but went out control. Tragically, while pilot Al Wilson was able to bail out of the aircraft, a mechanic, Phil Jones, who was in the rear of the aircraft setting off smoke bombs, was unable to and perished in the crash. Nevertheless, the footage of the aircraft spinning out of control was used in the movie.

An S-29 as a Hollywood (fake) "bomber actually", for a Howard Hughes movie

Sikorsky S-29, a not so well documented plane, thanks for the nice image.

Sikorsky S-29 See: en.wikipedia.org/wiki/Sikorsky_S-29-A