1 stripe is lance corporal in the army. Did you note the uniform change in the 2 pictures, think the change was about 1933 but am not good on uniform history.
In those days the first rank that you wore on the arm in the RAF was corporal. He would get more pay for each rank going up though.
These days ranks have altered slightly and its AC as you join up with no badge, then LAC (leading aircraftman) with a 2 blade propeller badge and SAC (senior aircraftman) with a 3 blade propeller, then corporal. There is a technical rank in between these days as well.
Today's ranks
http://www.raf.mod.uk/organisation/ranks.cfmFor the transport - remember flying was still in it's relative early days and getting men in large numbers around the world would be easier by ship. There would be other RAF and army personnel being taken to Egypt and perhaps the ship would then carry on to India, Middle East or Far East. There was a huge Royal Navy at the time and civilian ships were also charted for troop movements. Regiments get posted together whereas RAF personnel are posted individually so he might find himself on a ship full of army and very few RAF aboard.
The large transport planes were a thing of the future - Sunshine Airlines (RAF joke) for transporting people around the world was also in the future. In fact Transport Command didn't come into being until 1943.
The Royal Air Force came into existence in 1918 so will soon be 100 years old. There may be lots written about it's history then, there may also be programmes on the TV if you are in UK.
