Training for RAF Bomber Command aircrew followed a more-or-less standard sequence.

Early in the war, the United Kingdom, Canada, Australia and New Zealand had set up a massive, joint military aircrew training program called the British Commonwealth Air Training Plan (BCATP).

It was modelled on the RAF system, but operating in the broader, safer skies of Canada. 

Under the agreement, air crews received elementary training at home before travelling to Canada for advanced courses and then travelling to the U.K. for final operational training.

1. Initial Training School (ITS) or Initial Training Wing (ITW) or Ground School, undertaken by all air crew,

Budding airmen usually undertook basic, introductory ground training in their home country. 

The photo above was taken at ITW Rotorua in February 1943 – Gerry Newey (far right, middle row) and Jack Pauling (4th from left, front row) were in the same ITW graduation class.
– NZBCA archives, Clive Estcourt collection.

2. ‘Trade’ training schools – specialist training for pilots, observers (navigators & air bombers), flight engineers, wireless operators and air gunners.


– Elementary Flying School (EFTS) – single-engine aircraft
– Service Flying School (SFTS) – multi-engine aircraft, graduate with “wings”

Pilot training took place in England, Canada, Australia and New Zealand.


– Air Observers School (AOS) – navigator and air bomber training
– Air Navigation School (ANS) – advanced navigator training

Mostly in Canada.


– Air Observers School (AOS)
– Bombing & Gunnery School (B&GS) 

Mostly in Canada.


– Wireless School 
– Bombing & Gunnery School (B&GS) 

Mostly in Canada.


– School of Technical Training (SoTT) 
– Flight Engineers School (FES) 

Almost all flight engineers were trained by the RAF in England.


– Bombing & Gunnery School (B&GS)
– Gunnery School 

 Canada and England.

Down Under- and Canadian-trained airmen were then given further training in the U.K. to get them used to the very different flying conditions:

3. Advanced Flying Unit (AFU)  – acclimatisation to European conditions.

Up to this stage, airmen were trained as individuals.

Because of the different trades pathways, and because they took place before the crew formed up, details of Initial and Trade training are covered separately under each member of The Crew.

4. Operational Training Unit (OTU) – training as a six man crew, transitioning to twin-engined bombers, readiness for war operations.

This phase of training saw the men form into crews, learn to fly the RAF’s bombers, and practice all the operational skills required to go to war.

The crew’s time at No.12 OTU is covered here.

5. Heavy Conversion Unit (HCU) – transitioning to four-engined ‘heavy’ bombers.

By mid-1944, the four-engined Avro Lancaster was the RAF’s main heavy bomber, so crews destined for those required extra training and an extra crew member.

A flight engineer joined each crew at the beginning of heavy conversion, making a crew of seven.

Read about the crew’s time at HCU here.

Due to frontline requirements in 1944, valuable Lancasters were not used for the bulk of this training. Obsolete Short Stirlings were used instead, and crews finished off their heavy conversion with a brief stint at Lancaster Finishing School (LFS)

The crew’s time at LFS is covered here.

Ground crew

Most RAF Bomber Command ground crew were RAF personnel trained wholly in the U.K., although a few individuals trained as armourers, fitters, etc., in New Zealand, Canada and Australia and then sailed to England to serve with RAF squadrons.

Each Lancaster had its own dedicated four-man team of ground crew; fitters, riggers and engine mechanics.

Other services such as armourers, instrument repairers, radio technicians and radar mechanics were supplied by the Flight.

1. Recruit Centre or Initial Training – introduction to service, discipline and basic ground training.

2. ‘Trade’ training schools – specialist training for aircraft maintenance – armourers, electricians, instrument repairers, radio technicians, radar mechanics, engine mechanics, fitters and airframe riggers.

Engine Mechanics, Airframe Fitters/Riggers and Armourers:

School of Technical Training (SoTT) 

Read more about ground crew training under the individual members of The Ground Crew.