Chaps,

The wearing of parachutes by British pilots was not an outright ban, I understand.

Higher authority recommended against such equipment which might encourage pilots to abandon their machines prematurely. No pilot would wish to be accused of that which became known as LMF in WWII, although the enemy had no such qualms. In those days, official recommendations were generally interpreted as direct orders and only observation balloonists were expected to dive over the side in the face of air attack, poor things.