No other has such bearing upon precisely those qualities of aerodynamic efficiency, fuel economy, and reliability of airplane and powerplant that most affect commercial usefulness.
"The First Airplane Diesel Engine: Packard Model DR-980 of 1928"
Robert B. Meyer
The ship was found to be within the bounds of aerodynamic laws for operations in our atmosphere.
"The Flying Saucers are Real"
Donald Keyhoe