BY ORDER OF THE SECRETARY OF THE AIR FORCE AIR FORCE ...

18
AFMAN 11-217V1 3 JANUARY 2005
lag is due to inertia of the aircraft and the operating principles and mechanisms of the
performance instruments. Therefore, some lag must be accepted as an inherent
factor. This factor will not appreciably affect the tolerances within which you control
the aircraft; however, at times a slight unavoidable delay in knowing the results of
attitude or power changes will occur.
1.2.6.2. Lag in Performance Instruments. Lag in the performance instruments should
not interfere with maintaining or smoothly changing the attitude or power indications.
When the attitude and power are properly controlled, the lag factor is negligible and
the indications on the performance instruments will stabilize or change smoothly. Do
not be lured into making a flight control movement in direct response to the lag in the
indications on the performance instruments without first referring to the control
instruments. Sufficient reference to the control instruments will minimize the effect
of lag on the performance instruments and nullify the tendency to "chase" the
indications.
1.2.6.3. Location of Flight Instruments. Another factor influencing crosscheck
technique is the location of the flight instruments. In some aircraft the flight
instruments are scattered over a wide area of the instrument panel, making it difficult
to bring several instruments into your crosscheck at the same time. Therefore you
must rapidly scan each instrument individually back and forth across the instrument
panel. More advanced instrument systems, such as the flight director and integrated
flight instrument systems have reduced the required scan to a small area so you can
see more of the flight instruments with one look. The task of crosschecking these
instruments is much easier because you can simultaneously observe the attitude
indicator and the proper performance instruments.
1.2.6.4. Pilot's Ability. An important factor influencing crosscheck technique is the
ability of the pilot. All pilots do not interpret instrument presentations with the same
speed; some are faster than others are in understanding and evaluating what they see.
One reason for this is that the natural ability of pilots varies. Another reason is that
the experience levels are different. Pilots who are experienced and fly regularly will
probably interpret their instruments more quickly than inexperienced pilots will.
Pilots who interpret their instruments quickly and correctly do not have to refer back
to them for information as often as pilots who are slow to interpret. They are also
able to bring several instruments into their crosscheck with one glance, interpreting
them simultaneously. Therefore, the speed with which they divide their attention
does not have to be as rapid as the pilot's with less ability who must scan the
instruments rapidly to stay ahead of the aircraft.
1.2.6.5. Observing Attitude Indicator. The attitude indicator is the only instrument
that you should observe continuously for any appreciable length of time. Several
seconds may be needed to accomplish an attitude change required for a normal turn.
During this period, you may need to devote your attention almost exclusively to the
attitude indicator to ensure good attitude control. The attitude indicator is the
instrument that you should check the greatest number of times. This is shown by the
following description of a normal crosscheck. A pilot glances from the attitude
indicator to a performance instrument, back to the attitude indicator, then a glance at
another performance instrument, back to the attitude indicator, and so forth. This