Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-04-06
PILOT MUST Think
OF THREE MOTIONS
Rocking Boat" Declared
Best Way to Break Peril
GUS Craft "Spin."

Problems of balance, stability and
control Of airplanes are intricate when
the SO possible combinations Of motion
are considered, but, fortunately for the
pilot, he need only think of three, DR..
Hugh L. Dryden, chief of the aero
dynamics section, Bureau of Standards,
told members of the Standards Flying
Club at its regular meeting during the
past week.
These three principal forms of mo-
ton are freedom of the airplane to
move about any one of three axes or
combinations Of them; the pilot may
"roll' his plane about the longitudinal
axis, pitch" it like ship hobs up and
down on water about the lateral axis.
or he may "yaw" it by steering to the
left or right about the vertical axis.
DR.. Dryden discussed specially the
"spin." He stated that the skidding
effect usually begins just as the plane
is about to stall, forcing the outside
wing to travel faster than the inside
less ef1lcient angle. the outside wing
having a greater lift under these con-
ditionS.
Pilot Loses Control
This sets up a revolution, sometimes
called auto or Self-revolution, because
the pilot has lost control, forcing the
plane to spin at the rate Of about ona
turn in every three or four seconds
about its fore-and-aft axis, until 1t
reaches the earth, unless the pilot re-
gains his control. When plane spins 1t
loses from 200 to 500 feet in altitude
per revolution, and since two or three
revolutions occur before control Is re-
gained, the pilot should be at Q mini
mum altitude Of 500 to $500 feet.
DR.. Dryden suggested that the remedy
to get out of difficult spin is to rock
the boat" that Is, to get the plane
with the control stick, break through
the stable motion Of the spin. An
other good way is to get the aircraft
oscillating by rolling it with the con-
trolls and at the same time accelerating
and sharply turning the engine on and
of, he said.
Glider Activity Predicted.
DR.. George w. Lewis, director Of
aeronautical research Of the national
advisory committee for aeronautics, pre-
dicted great activity In the use OF
Sliders during the coming Summer and
said he looked forward to considerable
competition between the different clubs
that have been formed here recently:
Victor L. Lowe, secretary OF the
Standards Flying Club, announced that
the newly organized glider section OF
the club had collected all but about 500
| of the Sass needed to purchase its GID
err and that the lists for the present
unit would shortly be closed after the
receipt of few more applications FOR
membership. The order will then be
placed with the manufacturer.
Mr.. Lowe urged that members OF the
| glider section attend regularly the edu-
| cational and theoretical lectures being
| given before the club each Tuesday
| evening, inasmuch as gliding Is prAc-
tical preparation for powered flying,
| and the study of theory OF flight and
| allied subjects covered by these lee
| lures should not be omitted because OF
| glider activity.
.ss = Italian Flyer TO Join.
Among those present at last weeks
| lecture was Comdr Paolo Sbenardori.
newly arrived air attache OF the royal
| Italian embassy, replacing Comdr.
| Scaroni, who has been recalled to Italy.
| Comdr. Sbernadori has flown since
>l9l5 and hopes to have q plane sent
| to him from Italy soon. He expects to
join the glider section Of the Standards
| Flying Club.
DR.. Dryden will give the fifth and
| final lecture Of his series on aerody-
namics before the club in the east
building of the Bureau Of Standards
| at 8 pm, Tuesday on the subject Of
| propellers. The public Is invited,