• Version
• 57 Downloads
• 6.99 MB File Size
• 1 File Count
• April 20, 2017 Create Date
• April 20, 2017 Last Updated

National Advisory Committee for Aeronautics, Research Memorandum - Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099) - Lateral and Directional Stability and Control Characteristics

This report contains the flight—test results of the lateral-
and directional—stability and control phase (including tests with
winghtip tanks) of a general flying—qualities investigation of the
Leckheed P—8OA airplane Gummy No. hh—85099). These tests were
conducted at indicated airspeeds up to h9h miles per hour (0. 691 Mach
number) at low altitude and up to 378 miles per hour (0. 816 Mach
number) at high altitude.

These tests showed that the flying qualities of the airplane
were for the most part in accordance with the requirements of the
Army Air Forces Stability and Control Specifications.. The only
major deficiency noted was the negative lateral stability with the
Wing-tip tanks installed.

Flight tests on a Lockheed P—BOA airplane Ghnmy No. 4h—85099)
were conducted at the request of the Air Materiel Command, Army Air
Forces, to obtain quantitative measurements of the flying qualities.
This report presents the data obtained during the lateral~ and
directional—stability and control tests. The longitudinal—stability
and control characteristics have been reported in reference 1.

A three—view drawing of the airplane is presented in figure 1
and photographs of the airplane as instrumented for flight tests are
given in figures 2 and 3. The basic dimensions of the airplane are
given in tables I and II.

The ailerons are piano hinged on the upper wing surface and
have no aerodynamic balance. The aileron control forces are lessened
by the use of a hydraulic boost system employing a boost ratio of
15 to l. The friction of the aileron control as measured on the
ground during a slow lateral movement of the stick (no load on the
surfaces, aileron boost operating} was 4.5 pounds through the neutral
position. This value is greater than the 2-pound allowable friction
value specified in reference 2. Figure h presents the variation of
total aileron angle with stick position as measured on the ground
with no load applied to the aileron surfaces. The rudder—control
friction was :8 pounds when measured at the point where the pilot
normally applies pressure. The maximum allowable friction force
specified in reference 2 is 7 pounds.