[4] A number of companies expressed interest in the Sapphire, and it was considered as either the main or backup powerplant for most British designs of the late '40s and early '50s.

The Sapphire compressor operated well, free from surging,[6] over its complete RPM range without the need for variable inlet guide vanes (VIGV) or bleed.

However, early compressor stages suffered from fatigue due to rotating stall at low RPM and various fixes, such as lacing wire, were incorporated.

Curtiss-Wright introduced variable ramps on the Wright J65 at the entry to the compressor[7] to prevent the stalling and blade excitation.

[8] Caygill[9] states that one of the most serious problems encountered throughout the life of the Gloster Javelin was caused by "centre-line closure" on the Sapphire engine.

12% boost was required at high altitudes to regain the bomber intercept performance that had been lost carrying the new de Havilland Firestreak missiles.

[13] An Armstrong Siddeley Sapphire is on static display at the Midland Air Museum, Coventry Airport, Warwickshire.