| Home | Privacy | Contact |

Instrument Flying Handbook
Airplane Basic Flight Maneuvers Using an Electronic Flight Display
Straight-and-Level flight

| First | Previous | Next | Last |

Instrument Flying


Table of Contents

Chapter 1. Human Factors
Chapter 2. Aerodynamic Factors
Chapter 3. Flight Instruments
Chapter 4. Section I
Airplane Attitude Instrument
Using Analog Instrumentation
Chapter 4. Section II
Airplane Attitude Instrument
Using an Electronic Flight

Chapter 5. Section I
Airplane Basic
Flight Maneuvers
Using Analog Instrumentation
Chapter 5. Section II
Airplane Basic
Flight Maneuvers
Using an Electronic Flight

Chapter 6. Helicopter
Attitude Instrument Flying

Chapter 7. Navigation Systems
Chapter 8. The National
Airspace System

Chapter 9. The Air Traffic
Control System

Chapter 10. IFR Flight
Chapter 11. Emergency

Trim Technique
Trim control is one of the most important flight habits to
cultivate. Trimming refers to relieving any control pressures
that needs to be applied by the pilot to the control surfaces to
maintain a desired flight attitude. The desired result is for the
pilot to be able to take his or her hands off the control surfaces
and have the aircraft remain in the current attitude. Once the
aircraft is trimmed for hands-off flight, the pilot is able to
devote more time to monitoring the flight instruments and
other aircraft systems.

In order to trim the aircraft, apply pressure to the control surface
that needs trimming and roll the trim wheel in the direction
pressure is being held. Relax the pressure that is being applied to
the control surface and monitor the primary instrument for that
attitude. If the desired performance is achieved, fly hands off if
additional trimming is required, redo the trimming steps.

An aircraft is trimmed for a specific airspeed, not pitch attitude
or altitude. Any time en aircraft changes airspeed there is a
need to re-trim. For example, an aircraft is flying at 100 knots
straight-and-level. An increase of 50rpm will cause the airspeed
to increase. As the airspeed increases, additional lift will be
generated and the aircraft will climb. Once the additional thrust
has stabilized at sonic higher altitude, the airspeed will again
stabilize at 100 knots.

This demonstrates how trim is associated with airspeed and
not altitude. if the initial altitude is to he maintained, forward
pressure would need to be applied to the control wheel while
the trim wheel needs to be rolled forward to eliminate any
control pressures. Rolling forward on the trim wheel is equal
to increasing for a trimmed airspeed. Any time the airspeed
is changed, re-trimming will be required. Trimming can be
accomplished during any transitional period; however, prior
to final trimming, the airspeed must be held constant. if the
airspeed is allowed to change, the trim will not be adjusted
properly and~ the altitude will vary until the airspeed for which
the aircraft is trimmed is achieved.

Common Errors in Straight-and-Level Flight

Pitch errors usually result from the following errors:

1. Improper adjustment of the yellow chevron (aircraft
symbol) on the attitude indicator.
Corrective Action: Once the aircraft has leveled off and
the airspeed has stabilized, make small corrections to
the pitch attitude to achieve the desired performance
Cross-check the supporting instruments for validation.

2. Insufficient cross-check and interpretation of pitch
instruments. [Figure 5-61]

Insufficient cross-check.
Figure 5-61. Insufficient cross-check. The problem is power and not nose high. In this case, the pilot decreased pitch inappropriately.