Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-03-17
|F1ANDLEY PAGE WING SLOTS, SAFER FLYING AIDS,
CHECK STALLS AND SPINS OF u. S. NAVY PLANE
IN DEMONSTRATIONS ANACOSTIA AIR STATION
Lieut.. Carl B. Harper Tests
Device on Regular
Vought CorSair.
SHIP FLIES AT LOW SPEED
Craft ThrottIed Down to 80
Miles in. Climb, but
Kept Level.
SHIP FLIES AT LOW SPEE[

Handley Page wing slots, those p,Ir-
ported aids to safer flying which are so
widely used and enthusiastically ac-
claimed in England, but which still are
under a somewhat suspicious surveil-
lance In this country, were demonstrat-
ed on Navy Vought Corsair at the
Anacostia Naval Air Station last week
by Lieut.. Carl B. Harper, the Nays
expert on slotted wings, Lieut.. Harper
expects to fly this ship to Wright Field,
Dayton. Ohio the Army Air Corps ma
terrell base, within few days to DEM
onstrate it to the Arnly's aeronautlcal
technicianS.
The Corsair is the first military plane
in the United States to be equipped With
the slots. though other types soon are
to be ready for testing with similar
equipment. Lieut.. Harper has achieved
remarkable results with the slot-wlnged
Corsair In this city and at the Naval
Air Station. Philadelphia.
Slots Check Spins.
Stalls and SPINS which with an or
binary plane probably would prove DIS
astrous. have been checked promptly by
the opening of the slots. In flight at
the Naval Air Station last week with
the writer as a passenger, Lieut.. Har-
per deliberately stalled the plane,
throttling it down in climbing posi-
ton to an indicated air speed OF 56
miles per hour. AS the plane approached
stalling speed. the slots opened auto
matically in an almost uncanny fashion
and maintained the ship in fight at q
speed which under ordinary circurn-
stances would render the wings useless.
The method In which the slots oper-
ate involves complicated aerodynamics,
but in general their effect is explained
by the statement that they restore the
flow of air over airplane wings at times
when the normal flow is broken by lack
of speed Airplane wings depend upon
the flow of air around them for their
support. The air is forced up by the
leading edge of the wing in an arc above
the wing surface to create a vacuum,
and the sucking up Of the wing to fill
this vacuum is what creates the major
portion of the wings lifting power.
Pressure of the wind on the lower sur
face Is q minor lifting factor.
Air Stream Forces Slot.
The slot" is formed by long. mar
row, wing shaped structure which nor
maIly fits into the wing and forms its
| leading edge. When the stalling angle
Is reached the change In the direction
| Of the air stream automatically forces
the small wing away from the parent
wing and It is driven out on rocker
arms to q position in which 1t forces
the air stream back over the main
wing. so as partially to restore its lift.
| The slot also is great aid In break
ing up certain types Of spins IN which
the plane passes entirely out OF control.
though the experience of Navy pilots
with the Corsair shows that II Is not a
sure cure" for spins under certain con-
6itions.
| The British, however, have great con-
fidence In the efficacy Of slots. G. G..
Grey, q leading British authority on