The Piasecki PA-97 Helistat was an American experimental heavy-lift aircraft, built by Piasecki by fastening four obsolete helicopters to a framework beneath a helium blimp....
To meet the US Army's requirement, Piasecki's design featured two tandem, three-blade ducted rotors, with the crew of two seated between the two rotors. Power...
The Piasecki H-21 Workhorse/Shawnee is an American helicopter, the fourth of a line of tandem rotor helicopters designed and built by Piasecki Helicopter (later Boeing...