BOAC
You are correct - he should read the BOI in its entirety.
Equally he should also read the evidence of the Duty Exec at Aldergrove (as given to the HOL Committee) in respect of the concern he expressed to Flt Lt Tapper regarding the extended Crew Duty limits he had requested and the probability that those limits would be exceeded. It should be remembered that when they Took Off on that fatal sortie they were already some 10 hours into their Crew Duty Time with 3 sectors still to be flown which would require a refuelling stop at Kinloss later that night.
In his evidence to the HOL Committee the Duty Exec stated that he counselled Flt Lt Tapper that it would not be acceptable for Tapper to call in from somewhere in Scotland seeking permission to nightstop out of Theatre.
The BOI stated that "Detatchment Crews preferred to operate on a "Day On/Day Off rota". In my opinion what the Crews preferred to do is irrelevent. They were in NI to assist the Civil and Military Forces of the Crown in the face of Armed Insurrection. Personal preferences had no part to play in that Duty.