Yes Blacksheep, they are fully certified, and yes you are right again in your statement that some airlines leave 'em on permanently.
But OTOH, when these same airlines are confronted with cracks in the patches, they get very defensive. Recall in one carrier, the F/E during walkaround (crew change) found a rather longish (three inch) split in the patch 'round the forward outflow valve, the company denied any responsibility. But then it got expensive, pax to hotac, aeroplane ferried to base, for you guessed it, another patch.
And jokeair, I suppose for "standards" you mean the events described in the first post...yes?
