Of simple and robust construction , they also had relatively benign flying characteristics .
The Pitcairn Mailwings were developed by Pitcairn to carry air mail for the U.S. Postal Service .
Of simple and robust construction , Pitcairn Mailwings also had relatively benign flying characteristics .
The Pitcairn Mailwings were developed by Pitcairn to carry air mail for the U.S. Postal Service .