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National Advisory Committee for Aeronautics, Research Memorandum - Low-Speed Wind-Tunnel Tests of a Pilotless Aircraft Having Horizontal and Vertical Wings and Cruciform Tail

Low Speed tests of a pilotless aircraft were conducted in the
Langley propeller—research tunnel to provide information for the
estimation of the longitudinal stability and control, to measure
the aileron effectiveness, and to calibrate the radome and the
Machmeter pitot—static orifices.

It was found that the model possessed a stable variation of
elevator angle required for trim throughout the speed range at the
design angle of attack; A comparison of the airplane with and without
JATO units and with an alternate rocket booster showed that a large
loss in longitudinal stability and control resulting from the addition
of the rocket booster to the aircraft was sufficient to make the
rocket—booster assembly unsatisfactory as an alternate for the JATO units.

Reversal of the aileron effectiveness was evident at positive
deflections of the vertical wing flap indicating that the roll—
stabilization system.would produce rolling moments in a tight right
turn contrary to its design-purpose.

verticalswing—flap deflections caused large errors in the static—
pressure reading obtained by the original static—tube installation.
A practical installation point on the fuselage was located which should
yield reliable measurement of the free-stream static pressure.

Low Speed Wind Tunnel tests of a pilotless aircraft having hori—
zontal and vertical wings and a cruciform tail were made at the
Langley propeller-research tunnel. These tests were made to provide
information for the estimation of the longitudinal stability and
control, to measure the aileron effectiveness, and to calibrate the
radome and the Machmeter pitot—static orifices.

The aircraft, powered by rockets located in the tail, is
designed so that a Machmeter regulates the rocket thrust to main—
tain the flight speed at a Mach hunter of approximately 0.85. The
airplane is intended to fly at zero angle EB attack relying on
pressure differentials set up at the radome orifices to effect
proper changes in the control surfaces.: The crucifornetail control
surfaces fulfill the function of both rudder and elevator. The
horizontal wing flaps are used to provide lift eontrol,whereas
the vertical wing flaps are utilized fer turns. Ailerons are also
provided for roll stabilization.