Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-03-15
AVIATION
BY JOSEPH s. EDGERTON.
-$HIS business of handling airplane
traffic at busy airports is be-
coming a problem calculated to
wrinkle the hroWS of strong men

QUPCL1ll4 VI aubJ4llbD4lC u dA4AS ny o3GAAeSA
lights around Washington's sculpture
bearing circles is a cause of anguish for
directors and directed alike, it may be
realized that the task of guiding the
flow Of traffic above and around an air.
port is no puny undertaking.
Around Washington's circles traffic
directing is comparatively simple. Traf-
fic approaches on one level and from
only six or, at most, eight definitely
established and fixed directions. Air
port traffic may approach from an inf
mite variety of directions and a. an I'M
limited variation of altitude.
Moreover, an automobile can stand
still while waiting for the red light to
give way to green. If an airplane stands
still in the air close to the ground for
any reason at all it's time for tie angels
to begin twanging their golden harps
and singing "Halleluiah!" over the ar
rival Of one or more sinners at the ulti-
mate port of call
And so, though fixed traffic light
may be entirely justified for auto
mobiles which may stand and stand
awaiting the flicker of green which
beckons them to clash their gears and
dash into another red light, a fixed
airport traffic light wouldn't do at all.
Fixed red and green lights might be
so arranged as to be visible to airplanes
at any altitude or direction from the
airport, but when the airport traffic
director wanted to signal to one airplane
that the way was clear for him to come
IN to land it might be exceedingly diff
cult for him to make another pilot, also
waiting to land, understand that the
green was not meant for him, too.
How to Signal?
The problem Of directing airport traf-
fle, including the taking off and land
ing of airplanes and their movements
on the ground, has been the subject of
long study, still in progress, by a
special committee created by the De-
partment of Commerce. This commit
tee, composed of Federal aviation Off
Gals and representatives of the aero
nautical industry, has found an amaz-
ing variety of methods of handling air.
plane traffic.
At some airports flags are used. diff
1erent colorS meaning different things.
AT others, traffic directors stand in the
runways and signal directly to the pilots
to come in or take off. Some airports
have used ground panels of cloth. MANY
combinations Of lights have been tried,
including separate sets for each run
way on fields where surfaced runways
are used. The employment of radio has
been suggested. Sirens audible to pilots
above the roar of the airplane motors
also have been tried without great
deal of success.
Neutrality-suspicious. Airport, which is
coming to rank as one of the country's
business airports, has found the matter
OF trattc direction one Of considerable
Importance. Washington has been the
scene OF the country's heaviest sight
seeing hopping" since the beginning of
commercial aviation. and this activity
now IS concentrated entirely on one
airport Charles Augustus MacAtee the
1fTHOrtfe %Yo F5r n
own right, who has been mistaken for
Charles Augustus Lindbergh, has been
forced to flag as many as 800 landings
and take-offs during the main flying
period on busy days, the rate reaching
40 to so take-offs and landings an hour
during rush hours.
Though the flag system has been
working fairly we'll neither MacAtee
nor Jack Rabbit, manager OF the air
port. was satisfied with the system
When there were several pilots watch
ing for signals at once. as was very
often the case, there were likely to be
complications which. with airplanes
moving at flying speeds, could not be |
tolerated. The flags we're virtually use |
less after dark. even in the glare of the /
airport flocdlights.
Here's One Method.
And SO Rabbit and MacAtee went
into the huddle and evolved a piece of
equipment. They took heavy iron base
like that which supports a traffic DO
1iceman's umbrella in the good old
Summer time. Upon this they erected
3-foot length Of pipe, free to rotate
The pipe supported across its top a
crosspiec9 formed Of another pipe about
4 feet long.
On each end of the crosspiece they
placed l,oo0--watt projection light, re-
sembling a glorified automobile spot
light and free to turn in all directions
as are the smaller spotlights In front
OF each protector is a 2-foot length of
pipe, painted black inside, through
which the light beams are directed. In
one tube is red glass; in the other
green. On top Of each pipe is a small
sighting tube, through which the oper-
ator may look to aim the beam with
great accuracy, even in the brightest
sunlight when he cannot SEE the rays.
Because Of the large pipes in front Of
the projectors the lights may be seen
only from directly ahead, and they may
be seen wildly in the most glazing sun
light. Each Of the lights is controlled
BY a switch on the crossarm BY means
Of the sliding tube the lights may be
turned, singly or together, on the cock
pit Of an airplane anywhere on the air
port or above. No pilot other than
the one on whom the light is turned
can see the beam, so there is no posi-
bility of confusion. So bright is the
light that the pilot for whom it is in
tended cannot very well avoid sesing
the signal.
The lights may b. used to direct the
taxying Of planes about the airport, to
signal for take-ofIs or to direct land
ings. They may be used to flag a pilot
back to the loading platforms for addi- /
tional passengers or messages.
Lights to Go skyward.
For experimental purposes the lights
have been mounted on the observation
pl- torn Of the airport administration
building beside the control tower. They
have been used Sc FIR only for ground
operations, but viii be used later for
handling traffic in the air Is well When
this is done they viii be mounted on
top Of the control tower so there will
be no distractions in any direction.
Operation Of the lights is simple. Sup
pose there are two airplanes on the field,
enc ready to take of, the other about to
taxi 10 the t7ke-Cn position. MacAtce
turns the red light on the pilot Of the
plane waiting to taxi across the field
so as to hold him in place. The green
light is sighted on the pilot waiting %
take of, and MacAtee, making certain
the way is clear. switches on the green
light signaling the pilot ID go.
If he wants the pilot at the take-of
point to return to the loading platform,
he gives him both red and green lights,
and then the green light alone to show
him the way is clear for him to move
back 70 the loading point. He may use
the red light to hold any other plane
which may threaten the safety OF the
trip across the field
II two planes are waiting to take of
one may be- given the green light and
the other the red to hold him until the
first plane is clear