ben123
18th May 2003, 18:47
hello everyone, doing some work on mach trim systems at college at the moment and I am fairly sure the answer to the question below would be 'C' but I do not have any experiance or information on working on mach trim systems, so if anyone could could help me with this question I would be very greatful
Q) Mach-trim operating threshold values are:-
a) Adjustable by flight-deck control
b) Adjustable during normal maintenance
c) Pre-determined by the airframe manufacturer
Thankyou for your help, Ben
Mad (Flt) Scientist
19th May 2003, 02:45
Mach Trim is generally included in a design to meet the certification lengitudinal stability requirements (25.171, for example). As such it forms part of the certification standard of the aircraft, and so (c) is the obvious answer. However, it's not quite that straightforward....
There is nothing to prevent one certifying an aircraft where there is an element of flight deck control: most systems, after all, can be disabled by the pilot, the ultimate level of 'control' over the system. Provided appropriate limitations are noted within the flight manual there could be some cockpit control.
Similarly, I can envision (rare) circumstances where it might be appropriate to adjust the operation of the system during, or as a result of, maintenance. To compensate for known characteristics of a specific air data system or control system, perhaps.
But the single answer, if you have to pick only one, is (c).