valid question!!!
i am preparing for ATPL principles of flight and performance first week of Jan and the practice tests asked that question.
problem is Oxford says one thing and Bristol says just the opposite.
i emailed Bristol and they said they will get back with me on that one. they saw the conflict as well.
can't help you at all, but i am there waiting with you. i tried the thai technic but it wouldn't fly for me.
chairs