Complex sentence: First run in 1951 the engine was flight tested during 1953 using an Avro Lancaster provided by Air Service Training, the engine being installed underneath in a nacelle faired-in to the Lancaster's bomb bay.
Split into simpler sentences: First run in 1951, the engine was flight tested during 1953 using an Avro Lancaster provided by Air Service Training. The engine was installed underneath in a nacelle faired-in to the Lancaster's bomb bay.