The British-built D.H.4 delivered to McCook Field for evaluation in August 1917.

Views of a US-built DH-4 with experimental flotation gear, showing the air bags deflated and inflated.

A US Army photograph said to depict the "last DH-4 at Clermont-Ferrand", about December 1918.

Two views of the DH-4M-1 being manoeuvred into its permanent exhibition site in the USAF Museum.

The DH-4M-1 after completion of restoration by the USAF Museum, showing the colour scheme and markings based on those of the aircraft originally flown by Maj Gen Mason M Patrick.

Another view of the beautifully restored DH-4M-1

Three stages in the life of DH-4M-1: As restored in 1938, with new fabric and a coat of paint, for the Air Mail commemorative flight.

A typical DH-4 mail plane; the Museum example probably looked like this in its mail-carrying days.

Three stages in the life of DH-4M-1: N -489 as it appeared at the Detroit war-bond sales drive in 1944, with its former owner A K Miller in the front cockpit.

Three stages in the life of DH-4M-1: Back in mailplane configuration, N -489 was displayed in this guise at the USAF Museum until January 1982.

General Patrick’s original aircraft, which the restoration has been painted to represent.

The wing assembly shop in the DH-4 production factory at Fisher Body, Detroit, about 1918.