Unit Specific 201

201.1.1 Fuselage 

1. Forward section- includes the flight station.

2. Mid body section- the midsection of the aircraft.

3. Aft fuselage section- includes the tail cone. 
 

201.1.2 Wings

1. Center- built as an integral part of the fuselage. It consists of a box-type beam, which is an assembly of the front and rear spar, top and bottom skin panel, and ribs. The spar is130 inches form BL56L to BL56R. After the structure assembly is completed, the box beam is sealed to form auxiliary fuel tanks.

2. Left wing outer panel - outer wing consists of wings flaps, leading and trailing edge, wingtips, ailerons, and engine nacelles.

3. Right wing outer panel - Outer wing consists of wing flaps, leading and trailing edge, wingtips, ailerons, and engine nacelles. 
 

201.1.3 Tail 

1. Horizontal stabilizer- (Longitudinal Stability) Provides stability of the aircraft about the lateral axis. This is the base in which the elevators are attached. 

2. Vertical stability- (Directional stability) maintains the stability of the aircraft about its vertical axis. Serves as a base to which the rudder is attached. 
 

201.1.4 Flight Controls/ Surfaces:

1. Flaps- Powered by the combined No.1 and No. 2 hydraulic systems, the wings are of a high- lift fowler type. This type of flap uses a combination of aft movement to increase the wing area, and a drooping (downward) movement to change the airfoil section.  

2. Ailerons- Operated by a lateral side to side movement of the control stick or a turning motion of the wheel on the yoke. The ailerons are interconnected in the control system and work simultaneously, but in opposite directions to one another. As one aileron moves downward to increase lift on its side of the fuselage, the ailerons on the opposite side of the fuselage move upward to decrease lift. This opposing action allows more lift to be produced by the wing on one side of the fuselage than on the other side. This result in a controlled movement a roll because of unequal forces on the wings. 

3. Rudder- Used to move the aircraft about the vertical axis. If the pilot moves the rudder to the right, the aircraft turns to the right; if the rudder is moved to the left, the aircraft turns to the left. The pilot moves the rudder to the right by pushing the right rudder pedal, and to the left by pushing the left rudder pedal. 

4. Elevators- The elevator control system is initiated when the control stick is moved fore and aft. Raising the elevators causes the aircraft to climb. Lowering the elevators causes it to dive or descend. 

5. Trim Tabs- small airfoils recessed in the trailing edge of a primary control surface. Trim tabs enable the pilot to neutralize any unbalanced condition that might exist during flight, without exerting any pressure on the control stick or rudder pedals. Each trim tab is hinged to its parent control surface, but is operated independently by a separate control. 
 

201.1.5 Landing Gear- comprises of two main gears and the nose ear. Each gear consists of dual wheels and forward-retracting struts. The gear is designed so that the weight of the aircraft on the gear keeps it down and locked. 

1. Struts- Absorbs the shock that otherwise would be sustained by the aircraft structure during takeoff and taxiing, and landing.  

2. Brakes- Four multiple-disc brake assemblies, one for each main gear wheel, are mounted on the struts side of each main gear axle. Brake clearance is adjusted automatically. 

3. Wheels- Equipped with 36 ply tires, the wheels are made from either aluminum or magnesium alloy. Each P-3 consists of a dual wheels and forward retracting struts. 
 

201.1.6 Hydraulics- Two independent 3,000-psi hydraulic power systems operate the hydraulic equipment on the aircraft. (Designated system No. 1 and No. 2)  

1.Pumps- Three electrically driven pumps with variable displacement. Each pump has a maximum usable output of 8 gpm, 2 gpm are tapped off the pump and used for motor cooling. At 1,800 psi, a low-pressure warning is initiated. 

2. Reservoirs- System no. 1 is powered by tow AC motor pumps, each which is capable of operating all of the hydraulic units in the aircraft. With a maximum of 5.6 U.S. gallons with an empty brake accumulator or 5 gallons with a fully charged accumulator; the reservoir serviced if the level falls 0.8 gallons. System No. 2 is powered by one AC motor pump, and fluid is supplied from a 1-gallon reservoir. Hydraulic pressure from this pump is used to assist in operation of the wing flaps, bomb bay doors, ailerons, rudder, and elevators booster units, all of which receive pressure from both systems. This system must be refilled if it falls below one quart. 

3. Booster Assemblies-The booster system is designed so that the pilot has a normal feel of control forces when hydraulic pressure is available to the booster cylinders. Hydraulic flight control boosters operated by both hydraulic systems are incorporated in each of the three surface control system. 

4. Actuators- The actuators unit transforms hydraulic fluid pressure into mechanical force, which performs work. 
 

201.1.7 Airframe Components 

1.Forward Radome-Concical shaped fiberglass structure weighing 150 pounds. The shell is riveted to a channel shaped former, which provides structural rigidity and serves as a support for the hinges, latches, and aligning pin receptacles. This structure houses the forward radar antenna, ESM components, IFF components, and two sensors for the missile warning system.  

2. Aft Radome- a fiberglass structure used to house the aft radar antenna, the MAD equipment, and two sensors for the missile warning system.  

3. Bomb By-The bomb bay is located under the belly of the aircraft aft of the nose gear. It is used to transport weapons and cargo.

* Warning* Operations of the bomb bay doors when personnel or equipment are in the vicinity of the doors can cause death or injury to personnel and damage to equipment.

*The bomb bay switch shall be placed in the DOOR position before further action is taken. Failure of the switch to match the door position may result in unexpected operation of the bomb bay doors.

*Flight station personnel shall retain hands in view and bomb bay operator shall take no action while the outside observer is out of sight**

*Note* anytime the bomb bay doors are open and hydraulic power is required, an outside observer shall be posted to ensure that the bomb bay area remains clear.** 

 

201.1.8 Cabin Pressurization System 

1. Engine Driver Compressors (EDC)- The normal mode of operation of the air conditioning and pressurization system employs two engine driven compressors mounted on engine No.2 and 3. Heated, compressed air from the EDCis ducted through two-air cycle cooling units in the nose wheel well and then into the flight station and cabin. Air is drawn through the aircraft by the cabin exhaust fan and ducted overboard through the outflow valve, which controls pressurization. 

2. Cabin Exhaust Fan- Used to draw cabin air through the electronics compartment. Cabin exhaust fans must be operating to allow power applications to the SASP (single advanced signal processor) system.  

3. Out Valve- Used to draw in air, and duct it overboard to control pressurization. 
 

201.1.10 High Rate of Discharge (HRD) Bottles 

1. Fire Extinguishing System -Equipped with two independent, electrically controlled, high rate of discharge fire extinguishing systems, one for each side of the aircraft (engines 1 and 3 and engines 2 and 4) When activated, bromotrifluoromethane, a fire extinguishing chemical, is discharged into all three zones of the engine selected. Each system includes two fire extinguishing agent container bottles located forward of the firewall in the inboard engine nacelles. Each bottle is equipped with two discharge valves, a charging valve, a charging valve and safety disc, and a pressure temperature gauge. The bottle is filled with 10.5 pounds of bromotrifluoromenthane and is charged to approx. 600 psi with nitrogen. Two dischargers are available for one engine on one side, or one discharge for each engine on one side, from two associated bottles. 

2. Auxiliary Power Unit (APU)-Discharged from the flight station by the manual release switch located adjacent to the APU fire detection indicator lights on the right side of the glare shield panel. At a temperature of 400 degrees (F), the warning light will glow, flights station and cabin warning horns sound and the APU shuts down. When the exhaust doors close, the fire-extinguishing agent automatically discharges. 
 

201.1.11 discuss the two types of oxygen bottles: 

1. Walk Around- (7) seven portable oxygen bottle are stowed at the tactical stations except stations 9 & 10, whose bottles are located at the aft end of the sonobuoy storage bins. With the regulator set at 100% oxygen and with user experiencing little or no physical exertion, approx. 22 minutes of oxygen is available. For the same person performing moderate work, consequently breathing at a faster rate, approx. 5-10 minutes of oxygen is available per bottle. 

2. Main- Oxygen systems designed to supply an active flight crew of three with approx. 3.5 hours at an altitude of 25,000 feet. Supplied from three high-pressure 1,800-psi bottles through three regulators, one for each flight crewmember. 
 

201.1.12 State the purpose of the aircraft foul weather system:

Ice control systems on the P-3 enable the aircraft to perform its missions under various weather conditions and return home safely. Engine bleed air from the 14th stage of the compressor (diffuser assembly) is used to de-ice the wings and anti-ice the engine air scoop, compressor inlet, and torque meter shroud assembly. Electrical heating circuits anti-ice and/or de-ice the propellers, empennage, instrument probes, windshield and side windows. The term anti-ice refers to a system that prevents ice formation. De-icing refers to a system that removes ice build-up.  

201.1.13 describe the following foul weather systems: 

1.Ice Detectors-Probe mounted on the lower starboard side of the fuselage, just aft of the nose radome. Provides an indication in the flight station that structural icing conditions exist. The probe contains a pressure switch that is actuated by ice formation and completes a circuit that illuminates the ICING light on the flight station vertical enunciator panel. The pressure switch also completes a probe heating circuit that then melts the accumulated ice. When the ice melts, the pressure switch opens, de-energizing the signal light and probe heater circuitry. New ice accumulation repeats the cycle causing the ICING light to blink on and off. The frequency of icing light flashes is proportional to the severity of icing conditions. 

2. Angle of attack (AOA) Heat- a thermostatically controlled probe heater prevents ice formation on the fuselage mounted AOA probe. 

3. Engine Ice control- the engine anti-ice systems uses the 14th stage bleed air to prevent ice formation on the engine air scoop, torque meter shroud, and compressor inlet assembly. 

4. Propeller Ice control (Prop De-ice)- Electric heating elements are used to anti-ice and de-ice the propellers. Continuous heat anti-icing is applied to the front spinners of all four propellers when the system is turned on. The propeller blades cuff, aft spinner, and islands are cyclically heated (de-iced), one propeller at a time, cycling through all four propellers in sequence 1 to 4. The cycle repeats as long as the system is operating and stops on the propeller being de-iced when the switch is turned off. 

5. Wing De-ice- 14th stage bleed air is used to remove ice from the wings leading edge. Engine bleed air passes through a motor driven bleed air valve to a manifold that runs parallel to the wing leading edge. The bleed air then enters one of six ejector assemblies (also called piccolo tubes) that run lengthwise inside each leading edge section. A pneumatically operated modulating valve controls airflow to each ejector assembly. From the ejector assemblies, bleed air enters a passage formed by the two layers of the wing leading edge skin. A series of jet action nozzles mounted on each ejector assembly causes the bleed air to mix with air from the plenum area as it enters the leading edges. This warm air mixture circulates aft through the leading edge upper and lower passages and is discharged back into the plenum. As plenum air is displaced by incoming air, it is exhausted overboard through louvers in the aft end of the nacelles. 

6. Empennage Ice Control (EMP De-ice)- Portions of the horizontal and vertical stabilizer leading edges are electrically heated in a system that simultaneously anti-ices a series of parting strips while momentary heating power is applied sequentially to deice 20 cycling strips. A two-speed timer motor controls the sequencing of power to the cycling strips. A thermal sensor relay automatically turns the system off if an overheat condition is detected. 

7.Windshield Heating-The three forward windshield panels are electrically heated to prevent icing. The heating consists of separate pilots and co-pilots systems. Both systems are essentially the same, except that the pilots system heats only the port forward panel, while the co-pilots system heats the center and starboard panels. The heating circuit is cycled off when the temperature reaches a preset maximum (regardless of High or Low selection) and comes on when the temperature drops to a preset minimum. 

8. Windshield Wipers- provides two -speed selection and is controlled individually by the pilot and co-pilot. 

9. Pitot Heat- two pitot tubes are mounted symmetrically on either side of the lower fuselage, just aft of the nose radome. Each Pitot tube is anti-iced by an integral heating element. 
 

201.2.1 how do the following components work together to achieve the system's functions: 

1 Structures- the fuselage of the aircraft is of a semimonoque construction consisting of sheet skin panels, circumferential bulkhead rings and continuous longitudinal stringers. The fuselage is divided into 3 major components: Forward, Center and the aft section. 

2. Flight Control/Surfaces- the primary flight controls are operated from the flight station through conventional cable systems. 

3. Hydraulics- hydraulically operated booster's assemblies for all three primary control surfaces are utilized and are operated from independent 3,000-psi hydraulic systems No. 1 and No. 2. 
 

201.2.2 Define the following terms: 

1. Anti- Icing refers to a system that prevents ice formation. 

2. De-icing refers to a system that removes ice build up. 
 

201.2.3 discuss the three methods that generate air conditioning: 

1. EDC's
2. Ambient Air
3. Air multiplier

201.2.4 what type of aviator's breathing oxygen is used on P-3 aircraft: 

Aviator's breathing oxygen (MIL-o-2721 OD) is supplied in two types I and type II. Type I is gaseous oxygen and type II is liquid oxygen. Oxygen procured under this specification is required to be 99.5% pure. The water vapor content must not be more than 0.02 milligram per liter when tested at 21.1 degrees Celsius (70 degrees Fahrenheit) and at sea level pressure. 
 

201.3.1 what is the normal operating pressure of the hydraulic system: 

3,000 psi 
 

201.5.1 what are the safety precautions pertaining to opening the forward and aft radomes: 

Caution: The forward and aft radomes shall not be opened when winds are gusting or when wind velocities exceed 20 knots. 

201.5.2 what effect does HRD extinguishing agents exposure have on personnel: 

Trifluorobromomethane is fluorinated hydrocarbon. It is most common extinguishing agent used in aircraft fire extinguishing systems. It is a more efficient extinguishing agent than CO2, and under normal atmospheric pressure and temperature, it is a colorless, odorless, and tasteless gas. It exists in a liquid only when contained under pressure. 
 

Trifluorobromomethane is very volatile. It is a non-toxic but dangers to suffocation exist because, like carbon dioxide, it replaces oxygen when breathed.