Pre-1916 could recruit well off people who had already obtained a pilot's licence.
From mid 1916 they took anybody, transferring out of infantry, cavalry or artillery into RFC.
Often used to get rid of misfits and disreputable types!

Ground School

1 - 4 weeks of drill
then 4 weeks of classroom training e.g. making engine parts, theory of barometers, mess room etiquette, but not theory or mechanics of flight
Exams at that stage, but so easy that over 95% passed.

Training Aircraft

Maurice Farman MF.II (aka Shorthorn).
Very underpowered, could only fly in <5kts of wind

Training Squadron

Dual Controls

2 - 5 hour in dual controls. Hands and feet on 2nd set of controls whilst the instructor flew. No communications between pilot and trainee as too noisy, and too much drag if one stood up to tap the other on the shoulder.

Going Solo

In a typical day 1 trainee was killed and several more hospitalised. E.g. at one airfield 1 died, 5 in hospital, and 17 crashes.
Some sources say 8000 trainees killed in training - but that's a huge over estimate.
Instructors were pilots no longer mentally capable of flying at the front, and didn't want to get killed in training, so they spent as little time as possible teaching before sending them off solo.
Very much a "teach yourself" environment.
Training completed after 10 - 20 hours in the air, both 2 up and solo.

In Action

Life of new pilots measured in days, not weeks.

Smith-Barry's Gosport Training

In Autumn 1917 they finally introduced a new training process, a vast improvement
Earning Their Wings: British Pilot Training, 1912-1918