I'm not trying to Hijack this thread, but Tecnico66 asked "...i remember there was a similar plane with in-line engines...."
Here's my attempt to answer his question ...
The in-line engined plane was the "little brother" of the Goose called the Grumman G-44 Widgeon or J4F in Navy service. Smaller all around and powered by two 200HP Ranger inline engines.
This plane could also carry a 200lb. Depth Charge. With this depth charge in place the plane was flown a crew of two and was said to have a "negative rate of climb" on one engine ... which some thought would keep it from being employed as a patrol aircraft. Try telling that to the crew of the U-166 which was sunk in 1942 by a J4F-1 just off the Mississippi Delta in the Gulf of Mexico.
And finally the specifications for the G-44 a.k.a. J4F and the G-21 Goose
Enjoy ...TS