Insights

Nothing beats common sense

To reduce the cost of flying, you must fly efficiently, which is a prerequisite for anyone who plans to fly professionally. Here are five worthy techniques:

• When the intended direction of flight is opposite the direction of takeoff, make a downwind departure. Climb to 300 feet below traffic pattern altitude, turn onto the crosswind leg, clear the area for traffic, turn onto the downwind leg and continue climbing. If in controlled airspace, request your desired heading; if in uncontrolled airspace, turn to your desired heading when well above traffic pattern altitude.
• Fly faster into a headwind, slower with a tailwind. Many rules of thumb apply, but in light airplanes, I use 75-percent power when the headwind component exceeds 10 knots and 65-percent or long-range cruise power when the tailwind component exceeds 10 knots. When either component is less than 10 knots, it's personal choice--best power or best economy.
• If flying under instrument flight rules (IFR) in mountainous terrain and visual meteorological conditions, I can avoid a long, slow climb to a high minimum en route altitude when it's obvious that I can fly at a lower altitude and safely clear the terrain. I ask air traffic control for a VFR-on-top clearance at my desired VFR altitude and then state, "I'll maintain terrain separation." No publication states that you can do this, but then again, there's no rule that says you can't. I've never been turned down, and any altitude is legal when flying at 3,000 feet above ground level or below.

Never do that, however, when winds aloft are stronger than 20 to 25 knots. In that case my minimum altitude is at least 50 percent or more above the highest terrain. If terrain is 5,000 feet, minimum altitude is at least 7,500 feet. High winds and high terrain mean turbulence and compromised performance for light airplanes. You won't be smiling if you're performing a best-rate climb and suddenly realize that the vertical speed indicator is indicating a 700-foot-per-minute descent. It can happen.

• Use a cruise descent when approaching the destination airport. This requires descent planning, and if done properly, I regain most if not all of the time I lost while climbing to cruise altitude.

Forget the calculator, rules of thumb work quite well. The cruise descent rate is 500 feet per minute, which is considered maximum when flying unpressurized airplanes with passengers who are not accustomed to flying. Aerotitis (ear blockage) can be painful.

Remember these rules: If ground speed is 60 knots--one nautical mile per minute (npm)--you will travel two nm for every 1,000 feet of descent. If ground speed is 120 knots--two npm--you will travel four nm for every 1,000 feet of descent, and if 180 knots--three npm--you will require six nm for every 1,000 feet of descent.

That descent must terminate not at the destination airport, but four or five miles from it. This allows you to slow down before entering the traffic pattern and to observe local traffic against a sky background. Spotting traffic can be extremely difficult when you are looking down at a surface background, particularly in an urban area.

Here's a cruise descent in a typical fixed-gear, fixed-pitch-propeller airplane: I'm cruising at 7,500 feet, traffic pattern altitude at my destination is 1,200 feet, and my groundspeed is 110 knots. I estimate my groundspeed during the descent to be at least 130 to 140 knots, and I must lose about 6,000 feet. If I was doing 120 knots--two npm--my descent would require 24 miles. I want to be at pattern altitude four or five miles from the airport, and I'll be a little faster than 120 knots, so I'll start the descent when about 32 miles out.

At that point, I decrease pitch attitude, but as airspeed increases so does engine rpm, so I reduce power slightly to maintain cruise power. If necessary, I make an additional power reduction to keep from exceeding V_NO, the top of the green arc; an additional power reduction to keep from exceeding V_A, maneuvering speed, during moderate to severe turbulence; and further yet to provide the smoothest ride for my passengers whenever turbulence exists. At pattern altitude, I set slow cruise power--about 2,000 rpm--and decelerate before entering the traffic pattern.

• If number one for landing, I descend from pattern altitude when abeam my touchdown point on the runway, not when I'm at what's called the key point, the point where you have completed the turn onto the base leg. That wastes time.

On the ground, I check my flight time and fuel consumption. Very good! It's close to what I would have computed had I planned the entire flight at cruise speed.

Ralph Butcher, a retired United Airlines captain, is the chief flight instructor at a California flight school. He has been flying since 1959 and has 25,000 hours in fixed- and rotary-wing aircraft. Visit his Web site.