Boeing specific
Guys , thanks for responses.
I am after info on the Boeing specifically as the airbus hatch is within the flight deck ...on the Boeing it is in the pax cabin ...
My reasons for asking is to get an idea of why / how / what precipitated operators to install some sprt of lock and how they did this given airworthy authorities normally have to approve modifications if they involve any physical changes to the aircraft as delivered...
I had designed certain fixes to this myself and now find that others may have used my ideas ... Which is fine as yet I dont have any patent protection , but might have precedence on the ideas down the track... Without knowing how various folks have done it I am guessing.. That is why I am after info ... Its a bit like the guy that designed the intermittent wiper .. Ford took it on as their own ( ie stole the idea) and he took years to get them to admit they had pinched it... Not that I thinkI have anything like that... Just researching..