Gross weight also has an effect on takeoff distance. Proper consideration of this item must be made in predicting the powered parachute’s takeoff distance. Increased gross weight can be considered to produce a threefold effect on takeoff performance:

If the gross weight increases, a greater speed is required to produce the greater lift necessary to get the powered parachute airborne at the takeoff lift coefficient. As an example of the effect of a change in gross weight for a typical PPC, a 21 percent increase in takeoff weight will require a 10 percent increase in lift-off speed to support the greater weight.

A change in gross weight will change the net accelerating force and the mass that is being accelerated.

The takeoff distance will vary at least as the square of the gross weight. Adding a 200-pound passenger to a machine that already weighs 400 pounds, with a pilot weighing 200 pounds, will increase the gross weight by 33 percent. That increase of one passenger will degrade the performance of the powered parachute dramatically. The 33 percent increase in takeoff gross weight would cause:

For the powered parachute with a high thrust-to-weight ratio, the increase in takeoff distance might be approximately 76 percent, but for the powered parachute with a relatively low thrust-to-weight ratio, the increase in takeoff distance would be more. Such a powerful effect requires proper consideration of gross weight in predicting takeoff distance.

The effect of pressure altitude and ambient temperature is to define primarily the density altitude and its effect on takeoff performance. While subsequent corrections are appropriate for the effect of temperature on certain items of powerplant performance, density altitude defines specific effects on takeoff performance. An increase in density altitude can produce a fourfold effect on takeoff performance:

If a powered parachute of given weight and configuration is operated at greater heights above standard sea level, it will still require the same dynamic pressure to become airborne. Thus, the powered parachute at altitude will take off at the same indicated airspeed as at sea level, but because of the reduced air density, the true airspeed will be greater.

Proper accounting of pressure altitude (field elevation is a poor substitute) and temperature is mandatory for accurate calculation of takeoff roll distance.

The most critical conditions of takeoff performance are the result of some combination of high gross weight, altitude, temperature, and unfavorable wind. In all cases, the pilot must make an accurate calculation of takeoff distance from the performance data of the AFM/POH, regardless of the runway available, and strive for a polished, professional takeoff procedure. In the calculation of takeoff distance from the AFM/POH data, the following primary considerations must be given:

Aircraft noise problems have become a major concern at many airports throughout the country. Many local communities have pressured airports into developing specific procedures that will help limit aircraft noise while operating over nearby areas. For years now, the FAA, airport managers, aircraft operators, pilots, and special interest groups have been working together to minimize aircraft noise for nearby sensitive areas. As a result, noise abatement procedures have been developed for many of these airports that include standardized profiles and procedures to achieve these lower noise goals.

Standard noise abatement procedures don’t necessarily apply to powered parachutes, but similar issues exist. Powered parachutes fly at lower altitudes, fly tighter patterns, and tend to fly early in the morning and late in the evening when the winds are lightest. Powered parachute pilots should actively work with airport management to determine takeoff areas, patterns, and procedures that emphasize both safety and good neighborhood relations.

Specific noise abatement flight procedures are found in the A/FD where runway surface, slope and elevation can be found for flight planning.