Lab
Library
Journal
Shop
Sign in
to keep
Share image
1
165
The Aeroplane Speaks. Fifth Edition
·
H. Barber
84
Now,
we
will
suppose
that
a
gust
or
eddy
throws
the
machine
into
the
lower
position.
It
no
longer
travels
in
the
direction
of
T,
since
the
momentum
in
the
old
direction
pulls
it
off
that
course.
M
is
now
the
resultant
of
the
Thrust
and
the
Momentum,
and
you
will
note
that
this
results
in
a
decrease
in
the
angle
our
old
friend
the
neutral
lift
line
makes
with
M,
i.e.,
a
decrease
in
the
angle
of
incidence
and
therefore
a
decrease
in
lift.
We
will
suppose
that
this
decrease
is
2°.
Such
decrease
applies
to
both
main
surface
and
stabilizer,
since
both
are
fixed
rigidly
to
the
aeroplane.
The
main
surface,
which
had
12°
angle,
has
now
only
10°,
i.e.,
a
loss
of
one-sixth.
The
stabilizer,
which
had
4°
angle,
has
now
only
2°,
i.e.,
a
loss
of
one-half.
The
latter
has
therefore
lost
a
greater
proportion
of
its
angle
of
incidence,
and
consequently
its
lift,
than
has
the
main
surface.
It
must
then
fall
relative
to
the
main
surface.
The
tail
falling,
the
aeroplane
then
assumes
its
first
position,
though
at
a
slightly
less
altitude.
Should
a
gust
throw
the
nose
of
the
aeroplane
up,
then
the
reverse
happens.
Both
main
surface
and
stabilizer
increase
their
angles
of
incidence
in
the
same
amount,
but
the
angle,
and
therefore
the
lift,
of
the
stabilizer
increases
in
greater
proportion
than
does
the
angle
and
lift
of
the
main
surface,
with
the
result
that
it
lifts
the
tail.
The
aeroplane
then
assumes
its
first
position,
though
at
a
slightly
greater
altitude.
Marker
Marker
Fine marker
White-out
Fine white-out
Circle
Paint
Unmarker
Hand
Scalpel
Dice
Sieve
Purify
Undo
Redo
Start over
