- #How to install a sleeve stop and thimble set manual#
- #How to install a sleeve stop and thimble set full#
A fabricator or mechanic is encouraged to use a better method, technique, or practice, assuming he can produce supporting data acceptable to the Administrator. Per the signature page, AC43 may only be used in the absence of other, more up-to-date information, notably manufacturer’s data and established military and industry standards. A change requires regulatory due process, thus older data tends to remain as the minimum standard unless clearly proven unsafe. However, updating AC43 is not as easy as one might think. Kim explained that FAA managers realize industry techniques and practices change and improve with time.
#How to install a sleeve stop and thimble set manual#
…each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer’s maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, or practices acceptable to the Administrator…. The legal basis is found in FAR 43.13(a), also quoted on the title page: This advisory circular (AC) contains methods, techniques, and practices acceptable to the Administrator for the inspection and repair of nonpressurized areas of civil aircraft, only when there are no manufacturer repair or maintenance instructions. Kim began by noting how few users read the very first line on AC43’s signature page. FAA specialist Kim Barnette was kind enough to return my call. AFS-300 is the office responsible for AC43.13. To get answers, I started by going to the source, FAA AFS-300 in Washington, DC. Last, what about other manufacturers? Table 7-6 only lists Nicopress part numbers. Zinc-plated sleeves on stainless cable has been an obsolete recommendation for more than 40 years. However, the listed 28-series Nicopress part numbers are zinc-plated sleeves.
Note the asterisk next to the word “plated.” It means (per the note at the bottom of the table) that a plated sleeve is to be used on corrosion-resistant (stainless) cable. (Oddly enough, the correct values, 20 pounds respectively, are found in Table 7-3 in the same chapter.) AC43.13’s Table 7-6 is both out-of-date and incorrect.įor example, the “Tested Strength” values listed in Table 7-6 are too high for design and do not reflect the notable strength difference between carbon steel cable and stainless steel cable.
Although often cited by mechanics as their reference source, much of the information is outdated or incorrect.įig. Like much of AC43.13, the entire Nicopress section is old-so old it may have come directly from a CAM document when AC43 was first created. Information specific to Nicopress-brand oval sleeves is found in Chapter 7 and Table 7-6 (Fig. Most mechanics and builders are familiar with Advisory Circular AC43.13-1B/2B, Acceptable Methods, Techniques, and Practices, Aircraft Inspection and Repair. A cursory review of NTSB reports suggests swaged sleeve failures are about evenly divided between certificated aircraft and E/A-B and UL, with each group further divided between manufacturer and field fabrication error.ĪC43.13, MS51844E, and Manufacturer’s Data Experimental and ultralight kit producers are certainly not immune, nor are builders working alone at home. Maule Aircraft found itself in a similar situation following the failure of a rudder-cable swage. Subsequently AD required inspections of every aircraft built by American Champion between 19, as well as every aileron cable assembly purchased from American Champion and installed on previous production. The pilot of a 7KCAB Citabria suffered loss of aileron control due to a slipped oval sleeve. Improper crimping is not just a problem with mechanics in the field. Inspection of the operator’s fleet resulted in the replacement of 36 swages and 41 cable assemblies on 27 towplanes. Investigation found the banner operator’s mechanics had been using the wrong groove in the crimp tool and subsequently failed to gauge the crimps as required. The thimble eye in the end of an elevator cable had slipped in its oval-sleeve swage fitting, disconnecting the cable. It eventually impacted a rough field beyond the pickup area. He reduced power and the aircraft settled into a gentle descent.
#How to install a sleeve stop and thimble set full#
The pickup was routine until suddenly, during the pitch up, the pilot felt and heard a “pop” from the elevator cable and the stick moved full aft with no resistance. The pilot pushed the J5A into a gentle dive, aiming for the sweet spot above the poles. It was just another day in the banner-tow business.
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