To quote from our manual in Normal Procedures, Approach, ILS Approach, CAT I:
Quote:
Prior disengaging the A/P, the A/T should be left in the ARM mode by deselecting the SPEED-Mode on the MCP.
The instructions in your company operations manual directly contradict the Boeing philosophy published in the B737 Flight Crew Training Manual which states: The autothrottle ARM mode is not normally recommended because its function can be confusing. The primary feature the autothrottle ARM mode provides is minimim speed protection in the event the airplane slows to minimum maneuvering speed. Other features normally associated with the autothrottle, such as gust protection, are not provided. The autothrottle ARM mode should not be used with Non-Normal checklists. Some malfunctions that affect maneuvering speed cause the autothrottle to maintain a speed above approach speed.
In a previous statement, the Boeing advice is that autothrottle use is recommended during take off and climb in either automatic or manual flight. During all other phases of flight, autothrottle use is recommended only when the autopilot is engaged.
Having read all that, there is no doubt that many 737 operators deliberately choose to disregard the Boeing advice and with the autopilot disengaged, leave the autothrottle always in the ARM mode by de-selecting SPEED. As Sir Humphrey Appleby would say "that is a courageous decision"
...Now about that class action after a prang..