CAUTION

Do not operate slats with wings folded as
structural damage will occur to the slats and
outer wing.

LANDING GEAR SYSTEM

The aircraft is equipped with fully retractable, tricycle
landing gear. The gear is electrically controlled and
hydraulically actuated by the utility hydraulic system.
Accidental retraction of the landing gear when the
aircraft is on the ground is prevented by safety switches on
the main gear. Ground safety locks may also be installed
to further secure the gear against inadvertent retraction.
The following systems have circuits that are wired
through the landing gear control handle or landing gear
scissors switches: landing gear control, landing gear
position indicator, auxiliary air door, anti-skid, landing
gear warning light, landing lights, angle of attack system,
fuel pressurization and vent system, nose gear steering
system, and the external stores emergency release.

- CAUTION

A malfunction of the landing gear scissors switch
may disable the nose gear steering and also cause
the anti-skid system to cut out without warning.
This will result in loss of brakes and, ultimately,
directional control. The primary method of
regaining brakes and, therefore, directional
control is by disengaging the anti-skid system.
See Wheel Brake Failure, section III.

MAIN GEAR

Each main gear is hydraulically retracted and extended.
When the gear handle is UP and the weight is off the gear,
the gear will retract. As the main gear retracts, the wheels
are automatically braked to a stop by the anti-spin system
and the struts are mechanically compressed. When the
gear is up and locked, pressure is automatically released
from the anti-spin system. The struts automatically
return to their normally extended position during gear
extension. The gear is locked down by an internal finger
type latch in each side brace actuator. The main gear
retracts inboard and is enclosed by fairing doors that
protrude slightly from the underside of the wing. The gear
is locked up by a hydraulically actuated overcenter
uplatch mechanism. All main gear doors remain open
when the gear is extended.

NOSE GEAR

The nose gear is hydraulically retracted and extended.
The gear is locked in the down position by an internal
finger latch within the gear actuating cylinder. A
hydraulically actuated overcenter mechanism locks the
gear in the up position. The nose gear retracts aft into the
fuselage and is covered by mechanically operated doors
that close flush with the underside of the fuselage. The

TO 1F-4E-1

forward door is attached to the nose gear strut, and closes
with strut retraction; the aft door is operated and latched
closed by the gear uplatch mechanism. The nose gear is
equipped with twin nose wheels and a combination
shimmy damper steering actuator. A self-centering cam is
incorporated in the nose gear strut to position it for
retraction. The aircraft can be steered by differential
braking of the main gear wheels in the event nose gear
steering is not utilized. In this event, the steering-damper
unit acts as a shimmy damper.

LANDING GEAR CONTROL HANDLE

Operation of the landing gear is controlled by a handle at
the left side of the front cockpit instrument panel. The
handle has a wheel shaped knob for ease of identification.
Placing the handle in the UP or DOWN position energizes
a solenoid valve to connect utility system hydraulic
pressure to properly position the landing gear. A red
warning light is in the landing gear control handle. This
light illuminates whenever the control handle is
positioned to retract or extend and remains illuminated
until the gear is locked in place.

Landing Gear Emergency Extension Handles

Two 100 cubic inch air bottles, charged to 3000 psi, provide
sufficient compressed air to extend the landing gear in the
event of a utility hydraulic system failure. The front
cockpit control is incorporated into the landing gear
control handle. Pulling the landing gear control handle
full aft, when it is in any position, operates an air valve
which directs 3000 psi compressed air to open all gear
doors, release the gear up-locks and extend the gear. The
rear cockpit control is on the rear cockpit left subpanel
and is labeled EMERG LDG GEAR. A spring loaded
locking plunger locks the rear handle in the emergency
position when it is pulled full aft. The front and rear
cockpit emergency landing gear control handles are
connected to the same air source.

Landing Gear Warning Light

The landing gear warning light, marked WHEELS, is on
the upper left corner of the front cockpit instrument
panel. The WHEELS light will flash when the airspeed
drops below flap blow-up (approximately 230 knots), and
the landing gear has not been lowered. The landing gear
handle light illuminates when the gear is unlocked or
when the gear is out of phase with the gear handle.

Landing Gear Position Indicators

The landing gear position indicators are on the left
subpanel front cockpit and the left subpanel rear cockpit.
The position of the landing gear wheels is indicated by
drum dials viewed through cutouts in the panel. With gear
up, the word UP will appear on the three indicators; gear
in transient will be indicated by a barber pole; and with
gear down, a picture of a wheel will be seen in each
indicator.

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