Correct answer is... 3068 kg. It is equal to 6764 lbs. Empty weight of Douglas Dolphin is total weight of the airframe, engine, avionics and all other systems installed by manufacturer. It is higher weight then empty speed of other aircrafts of a similar size. Average is about 1938 kg (4273 lbs).
The biggest civil aircraft has empty weight of 250,000 kg (628,000 lb), so Douglas Dolphin has 1% percent of it's weight. Typical jet airliner has about 39,500 kg (87,100 lb), so in the comparision Douglas Dolphin has 8% of aircrafts like B737 or A320.
Disclaimer: Our articles and data connected to empty weight of Douglas Dolphin are based on public data from various sources. We are very picky to select an reliable data providers, but we cannot guarantee that everything is 100% error-proof. We recommend for any serious purpose - as a rule of thumb - to request offical data about empty weight from manufacturer of Douglas Dolphin.