Defining safe airspeed tolerance "calls" by support pilot.
Without over-doing it to the irritation of the other pilot, there are airspeed tolerances to be called by the PNF, if outside company limits. These limits before the support call is made, often vary - and this can cause standardisation problems when pilots change jobs to another operator. Of course, that is his problem and he has to stick with the new procedures
Advice on the subject in the Boeing 737 Flight Crew Training Manual is a case in point. There is not much help there - except one line which recommends the pilot monitoring calls out significant deviations from command speed. But it does not define significant deviations, leaving that apparently to individual operators. Then, every man is a critic.
There needs to be certain published airspeed tolerances before a call is made during normal flight and perhaps different airspeed tolerances once the aircraft is in the final landing configuration. For example, an "outside tolerance" call would be made by the support pilot on final approach if the speed was more than ten knots above the selected approach speed or less than VREF. After all, VREF is a safe speed and it can be quite unproductive (irritates the other pilot) if unnecessary "support" calls are being made providing conditions are normal.
Comments/suggestions invited. Thanks.