Drawing: Cobra Drawing: Cobra

Aircraft Systems and Components

Airspeed and Directional Sensor (AADS): The AADS is mounted on a boom to the right side of the airframe between the pilot and gunner stations. The purpose is to measure local airflow pitot and static pressure, the angle of the airflow relative to the helicopter, and the air temperature. The probe can swivel 360 degrees in pitch and 60 degrees plus or minus in yaw, accurately senses impact and static pressure up to 250 knots forward, 50 knots aft, 50 knots left and 50 knots right. The probe information is also used for rocket and automatic gun operations. A 115 VAC heater is contained within the probe which can be activated by the pilot during inclement weather. Thumbnail: ADS
AADS

Landing gear:

  1. Consists of two aluminum cross tubes and skids
  2. The skid have steel skid shoes to minimize skid wear
  3. Fiberglass fairings can be attached to the crosstubes for aerodynamic purposes (these are rarely used).
  4. Skid width - 7 feet

Landing light: Their are two types of landing lights incorporated on the AH-1. The first is a skid landing light which is shown in the picture and the other is a retractable pilot controlled searchlight.

    Skid landing light

  1. Normally attached to left forward crosstube.
  2. ON-OFF switch located on pilot's window sill.
  3. Elevation adjustment must be made from the ground.

    Searchlight

  1. 3-position switch (ON-OFF-STOW).
  2. Control switch ("Chinese hat") extends, retracts, and moves light left or right.
  3. May have either a white or IR light depending on the mission requirement.

Rain removal system:

  1. Shutoff valve - switch to control valve on ECS panel. 28-VDC nonessential bus.
  2. Jet nozzle - located below and forward at gunner's window to direct high-velocity air to gunner's windshield.
  3. Thermoswitch - located in windshield and controls air mixing valve to maintain temperature on windshield of 100 5F (38 3C) to 125 5F (52 3C).
  4. Air mixing/clearing valve - electronically/thermally controlled and pneumatically operated to maintain proper temperature of air to prevent windshield damage.
  5. Duct - screened inlet on left side of nose for ambient air entrance to air mixing/clearing valve.
  6. Drain valve - low point in system to drain condensation when system is off. Operates automatically.

Synchronized Elevator
The synchronized elevator is located near the aft end of the tailboom and is connected by control tubes, idlers, and bellcranks to the fore and aft cyclic system. The control linkage is attached to the aft horn of the swashplate which causes the angle of attack of the elevator to change as it moves in conjunction with fore and aft cyclic stick movement only.

Because of the peculiar operation of the overcenter bellcrank in the system, the elevator's angle of attack is changed in an unconventional manner, dependent upon the position of the cyclic stick in the cockpit. The elevator is at maximum nose down when the cyclic stick is centered or in the normal flight position. By being in the maximum nose down position during forward flight the elevator tends to keep the nose of the helicopter up, thereby, increasing the CG range and improving the controllability

Tailboom:

  1. Tapered semi-monoque structure employing aluminum skins, honeycomb panels, longerons and stingers.
  2. Attached to fuselage by four large bolts.
  3. Supports the tail rotor, fin, and synchronized elevators.
  4. Houses tail rotor driveshaft and some electrical equipment, with forced air ventilation provided by the TOW blower.

Tail Rotor:
The tail rotor is a two-bladed, semirigid rotor system that is underslung and delta hinged with a flex beam employing 1 degree preconing. The purpose of the tail rotor is to provide thrust for antitorque control of the helicopter.

  1. Blade span - 47 inches
  2. Blade chord - 11.5 inches
  3. Tail rotor diameter - 8 feet, 6 inches
  4. asymmetrical airfoil with a swept tip

Tail Skid:
A tubular steel tail skid is installed on the aft end of the tailboom. The skid act as a warning to the pilot upon an inadvertent tail-low landing and aids to prevent tail rotor from damage.

Telescopic Sight Unit (TSU):
The TOW system has a stabilized telescopic sight with low (2-power) magnification and (13-power ) magnification positions. The gunner can select either power by moving the MAG switch on the left handgrip of the TSU.

Drawing: TSU sight - low power
When the gunner selects the LO position, he has a 28-degree field of view (FOV). By applying pressure to the sight control, the gunner can move the TSU. The bucket containing the optics can be moved in azimuth 110 degrees to the left and right of the helicopter centerline, 30 degrees in elevation, and 60 degrees in depression. The sight slews at a rate of 73 degrees per second in azimuth and 45 degrees per second in elevation for low magnification; it slews at a rate of 4.4 degrees per second in azimuth and 3 degrees per second in elevation in high magnification. When the sight is operating in the LO position, a circle is displayed on the sight reticle. This circle represents the field of view for high magnification. With it the gunner determines when he can move to high magnification without losing contact with the target. He also uses it to see in which direction and how far he must search to acquire the target after switching to the HI position.

Drawing: TSU sight- Hi power

When the sight is operating in the HI position, the gunner has a 4.6-degree FOV. The reticle image displayed in the TSU consists of an outer circle with a vertical and a horizontal cross hair. Vertical marks that aid the gunner in estimating range to the target are positioned along the horizontal cross hair on high magnification only. The distance between the outer vertical marks is 10 mils; the inner marks, 2 mils. At the center of the sight reticle is an opening that is 0.4 mils wide. This area displace a 54-inch square at the maximum range (3,750 meters) of the missile. This is the aiming point for the gunner when he is sighting on targets.

 

Wings

  1. Provide additional lifting surface and support wing stores pylon.
  2. Have a span of 10 feet 9 inches (widest part of aircraft).
  3. Each wing has two pylons. The inboard pylons are fixed and the outboard pylons are articulated by hydraulic actuators.
  4. Each pylon will support 670 lbs. of weight.
  5. Attached by five bolts.

Wire Strike Protection System:

Drawing: Wire strike protection system

The wire strike protection system consists of three cutter assemblies, a windshield channel and a nose deflector. An upper cutter assembly is mounted on top of the pilot station, forward of the ADF loop antenna. A chin cutter assembly is mounted under the nose, just forward of the gunner station. A lower cutter assembly is mounted on the forward fuselage, under the ammunition compartment. The wire strike protection system is designed to protect the helicopter from wire obstructions at low levels of flight.


Back to the main page Your Free E-Mai Log In Pagel

Google
 
Updated: 12 January 2008
AVIATION TOP 100 - www.avitop.com Avitop.com
Born on 25 September 1998