With the introduction of the Pegasus, many articles remind us of the history of the Flying Flea (see here, here, here and here for some examples). They refer to the bike being dropped by parachute. In reality very few were, most of them were transported by gliders. There aren't many explanations as to why, though complexity was probably one of the reasons. A Flying Flea with its cradle fitted in a bomb bay would take precious space on a bomber. It would also require locating it once it landed (apparently they had a locating device). In contrast many could be fitted without the cradles in gliders that were easily located.
A more serious error is that most articles refer to the Flying Flea being produced in the underground factory in Westwood. This probably adds to the mystique of the bike. I consulted with Graham Scarth of the Royal Enfield Owners' Club and he kindly confirmed that the underground factory did not produce motorcycles during the war. The cradles for the Flying Flea were manufactured in the Calton Hill factory Royal Enfield had in Edinburgh, the bikes probably there or in the other overground factories. The underground factory produced war materiel, like oil motors for anti aircraft guns and predictor-correctors for them (a sort of analog computer to correct for the bullet travel time).