Geoff Wilde

Rolls-Royce Avon; he designed the innovative multi-stage compressor

He did much of the design work for R-R's compressors. In 1938 he joined Rolls-Royce Limited in Derby. While working on test beds for the Merlin engines, he proposed a variable-speed supercharger, to increase the performance at altitude, that was subsequently incorporated in the Merlin XX. He helped Stanley Hooker to design and develop the Merlin two-stage supercharger used in the Merlin 60-series.

Early jet engines were being developed at Lutterworth in Leicestershire, which were having problems with surging. He tested the centrifugal compressor at Derby, and found a solution to the difficulties of surging.

In 1943 he was put in charge of the supercharger and compressor department at Derby.

In 1947 he was put in charge of the design and development of the AJ65 Avon axial-flow jet engine. It had had difficulties with compressor blades breaking. He produced solutions for the design for the multi-stage compressor of the Avon, one of R-R's most successful jet engines.

He later oversaw the development of the compressor for the Conway, the world's first turbofan (by-pass) engine.

In 1956 he set up the Advanced Projects Design Office. Work from this department produced the Medway (cancelled) and Spey engines.

In 1960 he formed a new department to investigate new projects. He chose a new three-shaft design, which was launched as the RB-211. He proposed its wide chord fan blade to obtain maximum aerodynamic efficiency. He was not responsible for all of the project, and when Hyfil carbon-fibre (developed at the RAE) was chosen for the fan blade, he said that this material would not be strong enough in the case of a bird strike. This was found to be experimentally true, at great cost to the project and to Rolls-Royce.

He made great improvements to the design of the high-pressure (HP) turbine blade, and this design is still in R-R's engines today, and other manufacturers. He had set up the High Temperature Demonstrator Unit (HTDU) in 1972 to investigate cooling of turbine blades and thermal fatigue. All airliners today carry this technology.