I was browsing Wikipedia the other day and on the page "Knight banneret" there is a paragraph on the post title. The source for this is listed as page 364 of Sir Llewellyn Woodward's 'Great Britain and War of 1914–1918'. Obviously the names eventually selected for use have a direct comparision to the role that officer plays (a 'Wing Commander' commands a wing, etc) but do we know what names were considered before the final decision?
According to Ian Philpott's The Birth of the Royal Air Force the first list of ranks, proposed in 1917, was: Ensign, Lieutenant, Captain, Major, Commander, Colonel, Commodore, Rear-admiral, Vice-admiral, Admiral, Air Marshal. The War Office were not particularly happy with the lower ranks being military titles and the upper ranks being naval, while the Admiralty objected to the use of naval titles in general, even if preceded by 'Air'. This led to new proposals being more 'suggestive of the air'; from Volume VI of Sir Walter Raleigh's The War in the Air; Being the Story of the Part Played in the Great War by the Royal Air Force they were: Ensign, Lieutenant, Flight-Leader, Squadron-Leader, Reeve, Banneret, Fourth-Ardian, Third-Ardian, Second-Ardian, Ardian, Air Marshal (or an alternative set after Squadron-Leader of: Wing Leader, Leader, Flight Ardian, Squadron Ardian, Wing Ardian). 'Ardian' was apparently derived from the Gaelic ard ('chief' or 'eminent person'), and ian or eun ('bird').
In the end, though, Raleigh says that the new titles were the "last item of a long and tiring agenda", and the easiest option was to stick to the first proposed list; the War Cabinet took on board the objections of the Admiralty and War Office and so when the Royal Air Force was formed on April 1st 1918 RFC officers retained their army ranks, and RNAS officers switched from naval to army ranks. In August 1919 Air Ministry Order 973 introduced the current ranks, only Squadron Leader and Air Marshal surviving from the second set of proposed ranks.