Did WW2 RAF Bombers have Airworthiness Certificates?

[Observer1940]

In an Archives I came across some 1940 British Government Load Sheets (released under the Public Record Act of 1958) which apparently indicate that the Bomb Load was increased from the maximum load stated by Armstrong Whitworth Aircraft the manufacturer of the bomber.

Then later the bomb load was increased yet again and all of the crew would need to be forward of the centre of gravity (CG), near/in the cabin when taking off. Certain aircraft manoeuvres could not be carried out until 400 gallons of fuel had been used.

I had to pinch myself (so as to speak) as I could not believe what I was reading

I presume that once an RAF bomb load exceeded the maximum load specified by the aircraft manufacturer, the aircraft would no longer have a Certificate of Airworthiness?

Although, it seems the RAF went to the RAE for testing and the aircraft bomb load was increased and therefore overturned the maximum manufacturer loading?

Mark