New-York tribune., 1918-12-16
More Than 100000
Parts in Makeup
OF Flying Boat
Each Must Be Perfect, and
Naval Aircraft Factory
Has l25 Inspectors to
See No Mistakes Are Made

PHILADELPHIA, Dec. 15.-There are
more than 100000 parts in one large
seaplane, built at the Naval Aircraft
factory. The absence of any one of
these parts may hold up the assembly
of an entire boat. Every part must be
perfect. 1t must be inspected, not once
but many times. An imperfection may
mean that boat costing thousands of
dollars is worse than valueless
The responsibility for the quality of
parts and for the quality of the out
put is placed III the Inspection Section,
Engineering Department, which has a
corps of l25 inspectors. each passing
on the quality of somo part at one
stage in productions Every one Of the
$4,000 screws is inspected after it has
been sunk in the wood Each wood
part is inspected many times to detect
the presence of pitch pockets, knots,
spiral grain or any one of many de-
fects that may reduce strength
Ordinoarily only little more than 5
per cent of the wood in tree is good
enough to become q part of sea-
plane. Take for example, a longeron
longitudinal beam of the hulN. The
boat of a seaplane depends for shape
and strength upon it's keel and lon
gerons. On each side of the keel or
backbone OF the boat are two lon
gerons. These lengthwise strips of
wood correspond to gunwales, and
therefore must be strong, tough.
ight-grained and easily bent in
shape.
Second Growth Ash
Ash has been found most suitable for
this purpose and from the forests of
New York and Northwestern Pennsyl-
vania come the ash used for this pur-
pose. Government inspectors visit the
lumber yards in these states and select
the best white ash, rejecting most of
that which is offered.
That selected is known as "second-
growth" or wood which has grown
rapidly and has therefore wide rings,
such as one finds in young thrifty
timber with plenty of room for de
to obtain suitable ash in ffty-foot
lengths, so the longerons must be made
up of several sections spliced together.
After reaching the navy yard the
ash is inspected as it is unloaded. AS
needed the lumber is brought to the
factory, and sawmill men rough it to
size. 1t is then placed in the hands
of skilled cabinetmakers and furn-
ture factorymen. These men run it
through moulds to obtain the shape
needed. An inspection of each indi-
vidual piece follows.
II flaws have been uncovered by pre-
vious operations the inspector must
determine what use other than the one
originally specified can be made of the
material. Approximate lengths are cut
off with allowance for bending and the
ends are then tapered. A careful in
spectlon is made to determine the cor
i roctnpSS nd tn
material not in exact accordance with
. the specifications All pieces to be
used are treated tc coat of wood
4: filler.
Steamed Until Pliable
Sections of 7he pieces to be shaped
] are steamed until soft and pliable
then clamped to a form and remain
until dry. When removed they are
again inspected for any possible COM
preston failure or buckling of the
fibre Those that are found satisfac-
tory are fitted together with scarf
JOINTS, which are white loaded, riveted
and reinforced With wrapping.
Again the forward end of the lonp-
eron is steamed, and while still plia-
Bile the longeron is fitted into place
and given the necessary curve at the
DOW The final inspection does not
occur until the longerons are in place
and dry.
Similar care is exercised with every
other wood part and with every metal
part. AS further example, take the
care IN the preparation of one metal
lifting. Across the top of the sea
planes boat is a sidewalk. A Liberty
motor rests on each end of this side
walk and below hangs the outer sec
tlon of a wing. But the agent which
must connect these three principal
parts of the seaplane is a fitting which
easily might be placed in a box 9x61a x8
inches - 40
Nowhere else in seaplane construc
tlon IS the need for maximum strength
and minimum weight so great. There
lore the little fitting must be made up
OF several sections sixteen in all
ana or different gauges of steel. Three