The fourth aircraft owned by the CAB was another De Havilland D.H.50A, G-AUAY (c/n 137). It was built by De Havilland Aircraft Co., Stag Lane Aerodrome, Edgware, Middlesex, UK, and powered by a 330hp ADC Nimbus engine. Shipped to Australia, it was registered new to the CAB on 1 March 1928, Certificate of Registration number 190. The aircraft was reportedly “fitted with DH-9A type external tanks (later removed).”

G-AUAY was damaged at Cook, SA, after overturning on landing on 15 Sep 1928.

In line with the general change-over in registration markings, the aircraft was required to change markings to VH-UAY 1928, change to be completed by 31 Aug 1930.

It was given the name Warrego, but it is unlikely it wore this name in CAB service.

The aircraft crashed and was withdrawn from service, being struck off register 24 December 1934. However, as was common in those days the remains were sold to Northern Airlines Ltd, Sydney NSW, two days later and rebuilt.

The aircraft then had various owners. It moved to New Guinea in about 1937 where it was fitted with a more powerful Bristol Jupiter VI engine of 450hp.

VH-UAY was extensively damaged on 21 December 1941 when the aircraft swung on take-off at Wau, New Guinea. Pilot H. Harvey got the D.H.50 airborne to avoid a ground collision with another aircraft, but stalled and crashed. Harvey was unhurt but his sole passenger suffered from shock and a minor injury to one leg.

The aircraft probably would have been re-built again if not for the Japanese invasion of New Guinea shortly afterward. It was struck off the Register on 11 March 1942.