time for each thousand feet above pattern altitude. For
a typical light aircraft cruising at 120 knots (two miles
per minute), that translates to 4 miles of distance for
every thousand feet of descent. So if our cruise altitude
is 5,000 feet above pattern altitude, we should start our
descent at least 20 miles from the airport.
Manage Power for Efficiency
Power management is another key to efficient flying.
The first step is to lean the engine according to the
manufacturer’s recommendations. Improper leaning
can easily cost a gallon per hour in extra fuel burn for
a light aircraft. Remember that every time we change
altitude or power setting, it’s time to recheck the
One mistake pilots make is to not plan
an efficient descent profile.
Choosing the proper power setting is also critical to
efficiency, and we can often improve performance by
selecting an appropriate power setting. In general, we
do well to keep our power settings high when struggling
against a head wind. However, when the wind is light or
comes around to the tail, it’s time to reduce power. On a
250 nautical mile trip in a C-172, we can save 3 gallons
of fuel by reducing the power setting from 75 percent
to 55 percent, and it costs us just an extra 18 minutes
of flight time. Unless we’re renting the aircraft by the
hour, the time added to the flight plan might easily be
worth the fuel savings.
Another strategy to improve efficiency is to gain all
possible aerodynamic advantages. The first step is to
make certain the aircraft is properly rigged. To check
the rigging, trim the aircraft for cruise flight, and
then hold the ailerons level and take your feet off the
rudder pedals. If the craft is rigged correctly, the turn
coordinator ball should center, indicating coordinated
flight. If not, we may be wasting energy in the form of
drag as we slip or skid through the air.
If the aircraft has a rudder trim control, we can
adjust it ourselves to maintain coordinated flight. If
not, consider having a mechanic look at it. Oftentimes,
correcting an out-of-rig situation is a simple matter of
adjusting a bendable trim tab on the rudder.
Aircraft owners may want to consider some
aftermarket modifications to improve efficiency. One
angle that pilots of aircraft with fixed-pitch props take
is to replace a “climb prop” with a “cruise prop” that
has a greater pitch. While this provides the advantage
of a higher cruise speed, keep in mind that it increases
takeoff distance and reduces climb performance. Any
such change must be accompanied by the requisite
changes to the performance section of the pilot’s
Perhaps a more economical strategy is to look at
aftermarket accessories such as gap seals to improve
the aerodynamic efficiency. Gap seals prevent airflow
between the front of the ailerons or flaps and the wing.
They are relatively inexpensive and can improve cruise
speed for some light aircraft by 3 percent or more. Other
technologies such as vortex generators can also improve
performance significantly. When considering airframe
modifications, be sure to examine the cost-benefit
picture before making a decision.
The Sharp Corners of Safety
One place we don’t want to cut corners is in the
maintenance department. Too many pilots who have
attempted to cut costs by skimping on maintenance
have paid dearly for that decision. Even an unplanned
diversion to deal with a maintenance issue can be
significantly more expensive than dealing with the
issue in advance.
Whatever our strategy for improving performance,
we need to make certain it makes sense from a weather
standpoint. Shaving a few miles or minutes off a flight
might not make sense in the grand scheme of things if
it means upping the risk by flying in marginal weather
conditions. Likewise, we should think long and hard
before committing to a long over-water flight to reduce
the length of a trip.
Finally, never cut corners on safety procedures in
the name of improved efficiency. While it might be
tempting to fly a straight-in approach to the runway
to save a minute or two, following proper pattern
procedures greatly reduces the risk of a midair collision.
In addition, intersection departures may seem like
a good way to save a few minutes of operating time,
but the disadvantage of reduced runway length in an
emergency can more than overshadow any potential
In these challenging economic times, keeping costs
in line is an important consideration for most pilots. By
applying a few simple strategies, we can minimize the
costs without compromising safety.
Robert N. Rossier has been flying for more than 30 years.
A former aerospace engineer and flight school manager
in Colorado, he spent 12 years flying for a small airline/
charter service in the Northeast, serving as chief pilot
and check airman. He has been writing for the aviation
industry for nearly 20 years and was the recipient of a
2001 Aerospace Journalist of the Year Award.