• Version
• 98 Downloads
• 841.09 KB File Size
• 1 File Count
• April 20, 2017 Create Date
• April 20, 2017 Last Updated

National Advisory Committee for Aeronautics, Research Memorandum - Stick-Fixed Stability and Control Characteristics of the Consolidated Vultke Model 240 Airplane as Estimated from Tests of a 0.092 Scale Powered Model

The Consolidated Yultee model 21m airplane is a twin—engine
low-fling transport of conventional design. It'h'as partial—span
Fowler—type flaps and a fully retractable tricycle landing gear.

A three—view drawing of the airplane'is shown in figure 1, and mam:
dimensions are given in tables I,’ II, and III.’ Drawings showing the
wing and empennage geometry are presented in figures 2, 3, and ll».
The elevators and rudder have straight—sided contour with'pl'ain
sharp-nose balance. The ailerons are true contour and have an
unsealed symmetrical meditmr-nose balance. All the control eta-faces
are equipped with spring tabs. The tab dimensions and spring
constants are given in table 111. The elevator trim tab is also
interconnected with the flap operating mechanism to reduce trim
changes due to flap operation and reduce control forces in lending.
The linkage is such that operation of the flaps produces a trim-tab
motion which moves the elevator in a direction tending to held
constant speed. lending forces are reduced by using the trim tab
as a differential servo tab which operates only with relative large
up-elevator deflections (51; = 12° down at 59 a: 25° up).

The paragraph numbering system .of reference 3 is retained in
the following discussion of the flying qualities of the Consolidated
Vultee model 2&0 airplane to facilitate cross reference to the Army
requirements.

E116 stick-fixed stability and control characteristics only are
presented. because hinge—moment data for control surfaces comer-able
to those of the Consolidated Vultee model 2&0 were not available.
It was not considered Justifiable to present in this report the
results .of control—force computations 'based on section. data, since
such computations would only be comparable to a preliminary design
estimate. me value of such an. estimate would be further lessened
by the uncertainties introduced by the complex tab arrangements on
the airplane.