Insights

For Your Safety And Efficiency

Most pilots comply with airport departure and arrival procedures, but I frequently observe some who deviate. These pilots compromise flight safety, and when questioned they usually admit that they have forgotten the applicable procedures spelled out in the Aeronautical Information Manual. Knowing and using proper procedures is important, but there are additional considerations that reflect good judgment and enhance flight safety and aircraft operating efficiency.

The objective of every departure is to reach a safe altitude quickly. This means an altitude that provides a reasonable forced landing option in the event of an engine failure. Because a 180-degree, power-off descending turn can use up almost 800 feet of altitude, traffic pattern altitude is usually the lowest safe altitude.

To reach the safe altitude in minimum time, you must control pitch attitude judiciously. As speed increases during the takeoff roll and elevator control becomes positive, you select the takeoff pitch attitude. At liftoff, you must maintain this attitude in order to quickly accelerate to the best-rate climb speed or V_y. This action requires continual forward yoke movement because the pitch attitude will try to increase as a result of three factors - the increasing airspeed, the increased elevator moment arm that of- ten occurs when the main gear lifts off the runway, and the airflow change over the horizontal stabilizer as the airplane leaves ground effect.

The airplane will quickly accelerate to V_y, at which point you should establish and maintain the best-rate climb attitude. At the safe altitude, you should establish the cruise-climb attitude and select climb power, if applicable.

Arrivals require proper descent planning and a cruise descent. This descent maintains cruise power, a vertical speed of approximately 500 feet per minute - a comfortable rate for passengers who are unaccustomed to flying - and all the airspeed you can get - within the limitations of the airframe, the engine, and the conditions, of course. Airplanes are time machines, and I always cringe when I see a pilot reduce power and slow down for the initial descent to the destination.

If the airplane has a fixed pitch propeller, rpm will increase as airspeed increases, so you must reduce power slightly to maintain cruise power. You would also reduce power in order to reduce airspeed if it exceeded the maximum structural cruise speed, V_no (the intersection of the green and yellow arcs on the airspeed indicator), or if it exceeded the maneuvering speed (V_a) when turbulence was significant.

Pilots will often say that airspeed can be in the yellow arc providing the air is smooth, but I believe the FAA only allows momentary airspeed excursions into the yellow arc. If you were flying in the yellow arc and encountered sudden, moderate to severe turbulence - frequently associated with aircraft vortices and mountainous terrain - the structural integrity of your airplane could be suddenly and totally compromised.

During a cruise descent, you can expect to travel approximately four miles for every 1,000 feet of descent if your ground speed is 120 knots. If you are flying at 5,500 feet and your destination airport's traffic pattern altitude is 1,200 feet, the 4,300-foot descent will take approximately 16 miles. Decrease this distance if groundspeed is less than 120 kt, and increase it if groundspeed is faster.

It is important that you descend to traffic pattern altitude and slow down before entering the pattern, so add three or four miles to your descent mileage. In the previous example, I would start my descent when 20 miles from the airport, terrain permitting.

Upon reaching pattern altitude and the 45-degree entry leg, you should reduce to slow cruise power, the normal downwind-leg power setting. The airplane will now decelerate to its slow cruise speed before you reach the traffic pattern, and you are in an ideal position to look for traffic because your visual background is the sky, not the earth's surface. A background of sky makes it much easier to observe other aircraft. To descend onto the downwind leg compromises flight safety and makes traffic observation difficult if not impossible.

Safe and efficient airport departures and arrivals require proper procedures, proper planning, and proper attitude and power control. Always remember the five Ps - prior planning prevents poor performance.