Frayed Flap Extend Cables - Cessna


REFERENCE : SAIB: CE-13-27  Date: April 5, 2013

           The FAA recently received a report of a failed flap extend cable. The failure occurred on approach when the flaps were deployed to 45 degrees. The sudden retraction of the right flap caused the airplane to roll about 80 degrees to the right. The pilot was unable to retract the left flap, but was able to maintain control with the assistance of a passenger, divert to another airport, and land safely by utilizing almost full left aileron control. The report stated the cable was original (over 4,800 flight hours), and the most recent 100-hour inspection had been completed approximately 10 flight hours prior to cable failure.
             A search of the FAA’s service difficulty report (SDR) system revealed numerous events of a similar nature over a 20 year period. Most reports of fraying occurred near pulleys, and some included comments such as “failure occurred behind a pulley and is not easily inspected without the use of a mirror.” If the cable is not properly inspected, it can appear to be acceptable when it really is not. This SAIB focuses on the condition of the flap extend cables as they route around pulleys on all Cessna 401, 401A, 401B, 402, 402A, 402B, 402C, 411, 411A, 414, 414A, 421, 421A, 421B, 421C, and 425 airplanes. However, it also applies to the entire flight control system on any airplane model with cable driven flight controls. Inadequate inspection of the flight control cables may result in undetected wear and/or corrosion that could lead to cable failure.
                                                Recommendations
The FAA recommends the following:
            1. Follow the existing maintenance manual instructions and inspection intervals. For the Cessna airplanes listed above, this typically is a visual inspection of each flight control cable every 200 hours or 12 months, and an expanded inspection of each flight control cable every 600 hours. These intervals may vary slightly depending on model and use of the airplane, so please reference the appropriate airplane maintenance manual.
           2. For both the visual and expanded inspections, operate the flight controls through their full travel so that all portions of the cable are exposed for inspection. This may require one person



Comments

Post a Comment

Popular posts from this blog

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
Read more

Brake System Cessna 172

                             BRAKE SYSTEM -MAINTENANCE PRACTICES              1. Description and Operation A. The hydraulic brake system is comprised of two master cylinders, located immediately forward of the  pilot’s rudder pedals, brake lines and hoses, and single-disc, floating cylinder brake assemblies located at  each main landing gear wheel. B. The parking brake system is comprised of a pull-type handle and mechanical connections which are  linked to the rudder pedal assembly. Pulling aft on the brake handle applies mechanical pressure to the  rudder pedals, activating the brakes and locks the handle in place. Turning the handle 90 degrees will  release the parking brake and allow for normal operation through the rudder pedals. C. Brake operation is accomplished by pushing on the upper part of each rudder pedal. This motion is  mechanically transmitted to the respective brake master cylinder, and through fluid-carrying lines out to  the brake assembly where fluid pressure
Read more

McCauley Propeller Installation fixed pitch

Image
Propeller Installation for all fixed pitch propellers (except 1A162 model propellers).                   WARNING: MAKE SURE THE MAGNETO IS GROUNDED BEFORE INSTALLING  THE PROPELLER OR CONNECTING EXTERNAL POWER.                NOTE: McCauley recommends that propeller mounting nuts (if applicable) be replaced at each  propeller installation, whenever possible. However, nuts may be reused providing the threads are in good condition and the locking material prevents turning of the nut on the  stud by hand. Propeller mounting bolts must be magnetic particle inspected in accordance  with ASTM E-1444 or replaced whenever the propeller is removed from the engine.                NOTE: The aircraft maintenance manual or STC installation instructions should always be  consulted for any specialized procedures applicable to a specific aircraft. Various spinner arrangements not manufactured by McCauley may be used which require additional procedures. (1) Make sure the mating surfaces of t
Read more