But to my utter surprise I learnt that all the Hurricanes and Spitfires that took part in the Battle of France (May - June '40), and this included basically the entire compliment in the RAF, had absolutely no armour at all.

Armour was hurriedly fitted (after a few lessons were learnt, I imagine) before the BoB got under way about a month or six weeks after the fall of France.

A very fortunate 6 week break for RAF pilots, I dare say.  

Oh how things haven't changed

A 91-YEAR-OLD war hero who has suffered two strokes was left lying on the floor of his Cookham Dean home after paramedics told him they did not have the correct equipment to lift him.
Air Marshall Sir Patrick Dunn, who relies on a walking frame and a wheelchair, fell to the floor as his wife Lady Diana, 90, was helping him into his chair.
Lady Dunn called the emergency services as she was unable to lift her husband, but told the operator he did not need hospital treatment.
She said two paramedics later arrived, but said they needed specialist equipment to pick up Sir Patrick as regulations prevented them lifting him themselves.
Lady Dunn said: “They said they are not allowed to lift anybody from the floor, I did not know what to do, he had been about an hour on the floor.
“He was lying on the floor saying ‘please help me’ and holding up his hands, but they would not.”
Fortunately Sir Patrick’s daily carer, who was not due until the evening, was passing by and came into the house to help the fighter ace – who flew Hurricane and Gladiators in the Second World War before taking command of anti-V2 rocket operations.
Graham Groves, from the Royal Berkshire Ambulance NHS Trust, said a representative of the trust was due to visit Lady Dunn yesterday (Thursday) to discuss the incident and address any failings which may have arisen.
He said: “We apologise if there has been a failing in the service.”