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Showing posts from July, 2012

The SHEL Model

               “SHEL” model :  component are (Software, Hardware, Environment, Liveware) are depicted with a pictorial impression of the need for matching the components.            The following interpretations are suggested: liveware (human), hardware (machine), software (procedures, symbology, etc.) and environment (the conditions in which the L-H-S system must function).                    Liveware (the human) is at the centre of the model. Human is generally   considered t he most critical as well as the most flexible component in the system.  People are subject to considerable variations in performance and suffer many limitations, most of which are now predictable in general terms. The edges of this block are jagged, and so the other components of the system must be carefully matched with them if stress in the system and eventual breakdown are to be avoided. In order to achieve this matching, an understanding of the characteristics of this central component is essential. Ex

Cessna 152 Magneto Timing

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         The magneto is equipped with an impulse coupling.  Internal timing is fixed and the breaker points are not adjustable.          Timing marks are provided on the distributor gear and distributor block visible through the air vent holes.           For timing to the engine a timing hole is provided in the bottom of the magneto adjacent to the magneto flange.                                                                                                                                                                      A timing pin can be inserted through this timing hole into the mating hole in the magneto rotor shaft to lock the magneto approximately in the proper firing position.          Rotate the crankshaft in direction of normal rotation until No. 1 cylinder is on the compression stroke and continue rotating the crankshaft until the correct advance timing mark on the front of the starter ring gear is in exact alignment with the small drilled hole located at the t

Cessna 152 Magneto Check

MAGNETO CHECK. NEVER ADVANCE TIMING BEYOND SPECIFICATIONS IN ORDER TO REDUCE RPM DROP. Too much importance is being attached to RPM drop in single ignition. RPM drop on single ignition is a natural characteristic of dual ignition design. The purpose of the following magneto check is to determine that all cylinders are firing. If all cylinders are not firing, the engine will run extremely rough and cause for investigation will be quite apparent. The amount of RPM drop is not necessarily significant and will be influenced by ambient air temperature, humidity, airport altitude, etc. In fact, absence of RPM drop should be cause for suspicion that the magneto timing has been bumped up and is set in advance of the setting specified. Magneto checks should be performed on a comparative basis between individual right and left magneto performance. a. Start and run engine until the oil and cylinder head temperatures are in normal operating ranges. b. Advance engine speed to 1700 RPM. c. Tu

Cessna 152 Propeller replacement

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DESCRIPTION. An all-metal. fixed-pitch propeller, equipped with a spinner. REMOVAL a. Remove spinner  b. Remove safety wire from mounting bolt heads . c. Remove bolts and washers and remove forward bulkhead. NOTE The aft spinner bulkhead  is installed between propeller  and crankshaft flange and is removed as the  propeller is removed. INSTALLATION. a. Clean mating surfaces of propeller. crankshaft flange and spinner bulkheads. NOTE Ensure that nose cap is installed prior to completing  following steps. b. Position aft spinner bulkhead between propeller and crankshaft flange. c. Align propeller blade with t.c. mark on aft side of ring gear, and rotate propeller clockwise, as viewed from the front, to first bolt hole. d. Install forward spinner bulkhead and propeller bolts. e. Tighten bolts evenly, then torque to 300-320 lb.-in. or 25-26 lb-ft. f. Safety wire propeller mount bolts, ensuring that safety wire is around bolt heads not over top. g. Install spinner.

Cessna 152 Engine Controls.

The throttle, mixture and carburetor heat controls are of the push-pull type. The mixture control is equipped to lock in any position desired. To move the control, the spring-loaded button, located in the end of the control knob, must be depressed. When the button is released, the control is locked. The mixture control also has a vernier adjustment. Turning the knob in either direction will change the control setting. The vernier is primarily for precision control setting. The throttle control has neither a locking button nor a vernier advancement, but contains a knurled friction knob which is rotated for more or less friction as desired, The friction knob prevents vibration induced "creeping" of the control. The carburetor heat control has no locking device.   THROTTLE CONTROL. Before rigging throttle control ,check that staked connection between rigid conduit and flexible conduit is secure. If any indication of looseness or breakage is apparent, install new throttle

Cessna 172R Dimensions & Specification

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        AIRPLANE OVERALL            Length (Overall)             27’ - 2” Height (Maximum)          8’ - 11” Wing Span (Overall)       36’ - 0”  Tail Span                       11’ - 4”  L/G      Track Width       8’ - 4 1/2”         FUSELAGE DIMENSIONS Cabin Width (Max Sidewall to Sidewall)                          3’ - 3 1/2” Cabin Height (Floorboard to Headliner)                          4’ - 0” MAXIMUM WEIGHT                         Ramp - 2457 Pounds                        Takeoff -2450 Pounds                         Landing -2450 Pounds FUEL CAPACITY                                 Total 56.0 Gallons        Usable 53.0 Gallons ENGINE DATA-    Type Lycoming IO-360-L2A                                Oil Capacity 8.0 Quarts                                Oil Filter CH48110                                RPM (Maximum)- 2400 RPM                               Horsepower-172R 160 Hp PROPELLER-Type--McCauley 1C235/LFA7570 Diameter (Maximum to Minimum)-172R 75” -

Cessna 152 Instrument System

                         INSTRUMENT PANEL. The instrument panel assembly consists of a stationary panel and shock mounted panel. The stationary panel contains fuel and engine instruments which are NOT sensitive to vibration. The shock-mounted panel contains major flight instruments such as horizontal and directional gyros which ARE affected by vibration. Most of the instruments  are screw-mounted on the panel backs..                                      ENGINE INDICATORS. TACHOMETER. The tachometer is a mechanical indicator driven at half crankshaft speed by a flexible shaft Most tachometer difficulties will be found in the drive-shaft To function properly, the shaft housing must be free of kinks, dents and sharp bends. There should be no bend on a radius shorter than si inches and no bend within three inches of either terminal. If a tachometer is noisy or pointer oscillates, check cable housing for kinks, sharp bends and damage. Disconnect cable at tachometer and pull it out of ho

Cessna 152 Electrical System

Electrical Power Supply System.                                                                                                         Battery and External Power Supply System.                                                                                    Alternator Power System                                                                                                                   Aircraft Lighting System                                                                                                                          Pitot Heater.                                                                                                                                             Stall Warning,                                                                                                                                       ELECTRICAL POWER SUPPLY- SYSTEM.-  Electrical energy for the aircraft is supplied by a 28-volt, direct-current.single wire. negative ground electrical

Occurrence Reporting

       (a) The organisation shall report to DGCA, the state of registry and the organisation responsible for the design of the aircraft or component any condition of the aircraft or component identified by the organisation that has resulted or may result in an unsafe condition that hazards seriously the flight safety.       (b) The organisation shall establish an internal occurrence reporting system as detailed in the exposition to enable the collection and evaluation of such reports, including the assessment and extraction of those occurrences to be reported. This procedure shall identify adverse trends, corrective actions taken or to be taken by the organisation to address deficiencies and include evaluation of all known relevant information relating to such occurrences and a method to circulate the information as necessary.             (c) The organisation shall make such reports in a form and manners established by DGCA and ensure that they contain all pertinent information abo

Man hrs Planning

 P roduction means work completion of work such as  inspection, modification,               repair,    servicing      etc.  Man hrs planning is an important factor of production planning. 145. A.47 Production planning (a)  The organisation shall have a system appropriate to the amount and complexity of  work to plan the availability of all necessary personnel, tools, equipment, material, maintenance  data and facilities in order to ensure the safe completion of the maintenance work. ( b) The planning of maintenance tasks, and the organising of shifts, shall take into  account human performance limitations . AMC 145.A.47(a) Production planning 1. Depending on the amount and complexity of work generally performed by the  AMO, the planning system may range from a very simple procedure to a complex organisational set-up including a dedicated planning function in support of the production function. complementary elements: - scheduling the maintenance work ahead, to ensure t

Responsibilities of CAT

Responsibilities of commercial air transport operator CAR M. A. 201(h) In the case of commercial air transport the operator is responsible for the continuing airworthiness of the aircraft it operates and shall: 1. be approved, as part of the air operator certificate/permit, pursuant to M.A. Subpart G for the aircraft it operates; and 2. be approved in accordance with CAR-145 or contract such an organisation; and 3. ensure that paragraph (a) is satisfied. {M.A.201 Responsibilities (a) The owner is responsible for the continuing airworthiness of an aircraft and shall ensure that no flight takes place unless: 1. the aircraft is maintained in an airworthy condition, and; 2. any operational and emergency equipment fitted is correctly installed and serviceable or clearly identified as unserviceable, and; 3. the airworthiness certificate remains valid, and; 4. the maintenance of the aircraft is performed in accordance with the approved maintenance} AMC M.A.201 (h) Resp

ELT Periodic Maintenance

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 Artex ME 406 ELT Periodic Maintenance          Artex suggests testing of the ELT every 1 to 2 months. This provides an indication of the integrity of the ELT and antenna system. If performed at this rate, the accumulated operating time will not reduce the 6-year life rating of the battery pack.             Minimum maintenance requirements for ELTs are stated in CAR Sec 2 Series R Part III appendix A Para 4. Each emergency locator transmitter must be inspected within 12 calendar months after the last inspection for-- (1) Proper installation; (2) Battery corrosion; (3) Operation of the controls and crash sensor; and (4) The presence of a sufficient signal radiated from its antenna.                    To ensure continued reliability and airworthiness, your ELT must be inspected for damage and wear caused by age, exposed elements, vibration, etc. Inspections are also to take place annually per FAR Part 91.409. FAR 43, Appendix D(i) states in part that each person performing an

ELT transmitter Test

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             Whenever the ELT is switched from “ON” to “ARM” a 406 MHz signal is transmitted, however, it is specially coded as a “Self-Test” signal that is ignored by the COSPAS-SARSAT satellites                         Always perform the tests within the first 5 minutes of the hour. Notify any nearby control tower of your intentions.               Do not allow test duration to exceed 5 seconds. A false alarm may be generated.         Any time the ELT is activated, it is transmitting a 121.5 MHz distress signal. After approximately 50 seconds, a “live” 406 MHz distress signal is transmitted and is considered valid by the satellite system. Self-Test • Tune a receiver (usually the aircraft radio) to 121.5 MHz. Turn the ELT aircraft panel switch “ON” for about 1 second, then back to the “ARM” position. The receiver should voice about 3 audio sweeps. • At turn-off (back to ‘ARM’ state) the panel LED should present 1 pulse (buzzer will not sound for 1 pulse). If more are displa

Cessna 152 Landing gear

1. LANDING GEAR: The aircraft is equipped with a fixed tricycle landing gear, consisting of tubular spring-steel main gear struts, and an air/oil steerable nose gear shock strut. Two piece, die-cast aluminum wheels are installed on the main and nose landing gear. The wheels are equipped with tubes and disc-type brakes. The nose wheel is steerable with the rudder pedals up to a maximum pedal deflection, after which it becomes free-swiveling up to a maximum of 30 degrees, each side of center. Nose and main wheel fairings are available for installation. 2. MAIN LANDING GEAR: The tubular, spring-steel main landing gear struts are attached to the aircraft at inboard and outboard forgings, located in the belly of the aircraft. A bracket is bonded to each strut for attachment of a step. Hydraulic brake lines are routed down and clamped to each main gear strut. The axles, main wheels and brake assemblies are installed at the lower end of each strut. 3. NOSE GEAR: A steerable nose wheel, mo

Cessna 152 Fuselage TN

1. FUSELAGE. 2. WINDSHIELD AND WINDOWS: The windshield and windows are single-piece; acrylic panels set in sealing strips and held by formed retaining strips, secured to the fuselage with screws and rivets. Sealant used in conjunction with a felt seal is applied to all edges of windshield and windows with exception of the wing root area. The wing root fairing has a heavy felt strip which completes the windshield sealing 3. WINGS: Each all-metal wing is a semi cantilever, semimonocoque type, with two main spars and suitable ribs for the attachment of the skin. Skin panels are riveted to ribs. Spars and stringers complete the structure. An all-metal, piano-hinged aileron, flaps and a detachable wing tip are mounted on each wing assembly. A single metal fuel tank is mounted between the wing spars at the inboard end of each wing. Colored navigation lights are mounted at each wing tip 5. HORIZONTAL STABITIZER: The horizontal stabilizer is primarily of all-metal construction. Consisti