An evaluation of climb performance data reduction methods

Author

Scott W. Sowles

Date of Award

12-1999

Degree Type

Thesis

Degree Name

Master of Science

Major

Aviation Systems

Major Professor

Ralph D. Kimberlin

Committee Members

Frank Collins, Fred Stellar

Abstract

Climb performance of aircraft is an extremely important aspect to the aviation community. Flight test engineers evaluate climb performance using many different data reduction techniques. This thesis presents a climb performance flight test of two single engine aircraft and an evaluation of three different climb performance data reduction techniques used for single-engine general aviation aircraft. A total of two different techniques are used to determine climb performance of aircraft. The two techniques used for climb performance are steady climb and level acceleration. The thesis incorporates the steady climb method on a Cessna 150M Commuter and a PiperSaratoga PA32-301. The three different data reduction techniques used in the flight tests are PfW (standardized power) versus CIW (standardized rate of climb) method,density altitude method, and equivalent altitude method.In order to evaluate the three different data reduction techniques, a total of two flight tests were conducted. The first flight test incorporated a steady climb techniquePiper Saratoga (N1 lUT), and the second flight test incorporated a steady climb technique on a Cessna 150 Commuter (N66525). The flight tests were performed atTullahoma airport located in Tullahoma, Tennessee, during daylight hours and in visual meteorological conditions on two different test days.All three methods are accurate when compared to one another in close to standard temperature conditions. The major differences between the methods are the aircraft efficiency and propeller efficiency estimations used in the equivalent altitude and density altitude data reduction methods. Aircraft efficiency is estimated in the equivalent altitude method and does not change the results significantly when the estimated value is increased or decreased. Aircraft efficiency and propeller efficiency values are estimated in the density altitude method. The results for the aircraft tested change in a range of eighty feet when the estimated values are increased and decreased.Results show that an exact value of aircraft and propeller efficiency needs to be calculated in order to determine the accuracy of the density altitude method.The results also show inaccurate results for the density altitude climb performance data reduction method where a non standard temperature lapse rate or temperature inversion is encountered. The PIW versus CIW method shows a minimum change from the temperature inversion and the standard lapse rate encounters. Other Results include the fact that the PIW versus CIW and the equivalent altitude methods are easy to use and simple to follow. The density altitude method is difficult to use and hard to follow.

Recommended Citation

Sowles, Scott W., "An evaluation of climb performance data reduction methods. " Master's Thesis, University of Tennessee, 1999.
https://trace.tennessee.edu/utk_gradthes/10015