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Checking Your Six: Comanche Stabilator Maintenance

Checking Your Six: Comanche Stabilator Maintenance


Piper’s long-running preference for stabilators began with the PA-24 Comanche. A&P/IA KRISTIN WINTER discusses the stabilator system and its most common problems, as well as what you can do to keep your tailfeathers airworthy.

The Piper PA-24 Comanche was the first Piper production aircraft to use an all-moving stabilator instead of the more common horizontal stabilizer and elevator combination. Piper obviously liked the result, as they used stabilators in the Aztec and in all the Cherokees and their derivatives.

Piper stabilators have proven to be fairly robust, with only a few issues that can easily be addressed with heads-up maintenance. In this piece, we will look at the known issues with Comanche and Twin Comanche stabilators.

Torque tube horn cracking
(AD 2012-17-06)

The stabilator system had been reasonably AD-free until 2012, when the FAA issued AD 2012-17-06, which addresses cracking in the torque tube horn that attaches the counterbalance arm to the torque tube, to which in turn the stabilator halves are attached.

The cracks propagate from the inside, as all three of the cracked horns in the photo show (See photo below).

The cracks progress from there to the outside, and eventually, a secondary crack will propagate on the aft side, as cracks in the front have now progressed to the point there is relative movement inside the horn. Once this happens, complete failure of the horn is likely but a few flight hours away.

Wilco issues COVID-19 and Sun-n-Fun statement

Wilco issues COVID-19 and Sun-n-Fun statement

Wichita, KS – (March 18, 2019) – Wilco Vice President Mike Hattrup announced today that Wilco will offer all customers, both website and phone, a discount as a result of the postponed 2020 Sun-n-Fun Aerospace Expo.


Wilco’s Covid-19 Response and Sun-n-Fun 2020


Wilco Inc. does not anticipate being able to participate in the rescheduled SUN ‘n FUN Aerospace Expo in Lakeland FL this year.  We recognize the impact this will have on the aviation community and we will greatly miss seeing our friends and customers at the Expo.  However, we do not feel that those who have had their plans disrupted should be penalized because of it.  Therefore, we want to proceed as if SUN ‘n FUN is still happening in early April, however, we will do so virtually and from our office in Wichita.


Effective immediately and through April 30, 2020 Wilco Inc. will extend our show prices to all customers who order via our website, www.wilcoaircraftparts.com , as well as to all call-in customers, who use the coupon code SNF 2020.  Website orders will require you to enter the code SNF 2020 in the coupon code field.  For phone and email orders, simply mention the coupon code when ordering.   This discount will apply to all items and lines except 4130 Steel Sheet and Plate.   We will also cap freight charges for all orders (except batteries and windshields) at $10.00 per shipment if you let us select the carrier and method.  Air Freight or expedited shipments, as well as batteries and windshields, will be at your expense.


About Wilco:


Wilco is an after-market distributor of aircraft parts, including Concorde Batteries, Lamar Technologies, LP Aero Plastics, PM Research, Rapco and Rapco Fleet Support, and Whelen Lighting, in addition to maintaining over twenty thousand square feet of Piper Surplus inventory.  Wilco is also a distributor of 4130 Chromoly Steel Sheet and Plate in 16 different thicknesses and over 100 different sizes in both Annealed (AMS6350/6351) and Normalized (AMS6345) conditions


Wilco has been providing quality products, service and support since 1953.





Superior Air Parts is totally committed to the safety of its customers and is working closely with the FAA to determine the root cause and best course of action.

Coppell, TX (February 25, 2020)  — Representatives of Superior Air Parts, Inc., announced today that the company is aware of the FAA’s recent notice of proposed rulemaking (NRPM) concerning a proposed airworthiness directive (AD) for Superior Air Parts (SAP) model O-360, IO-360 reciprocating engines, and certain Lycoming Engines model AEIO-360, IO-360, and O-360-series reciprocating engines.

“Unfortunately, we were only informed of the proposed rule two-weeks ago. Since then, we have been in contact with the FAA regarding their findings to fully understand the issue and identify the most likely cause of the failures,” stated Scott Hayes, VP of sales and marketing Superior Air Parts, Inc. “Our engineering team is currently reviewing all of the available information, and once we have determined the actual cause, we can work with the FAA to determine the most logical course of action.”

Hayes said that the FAA estimates the AD would affect 115 crankshaft assemblies installed in U.S. registered certified aircraft. 

“All I can say for certain is that it is still just too early to form any type of conclusion about what caused these three crankshafts to fail the way they did,” stated Bill Ross, VP of product support, Superior Air Parts, Inc. “We want every one of our customers to know that we put safety ahead of everything and will do everything in our power to find the root cause as soon as possible.”

Hayes said that the affected crankshafts were all produced by a specific Superior Air Parts vendor between 2012 and 2014, with the following parts numbers: (P/N) SL36500-A20 or P/N SL36500-A31, with serial numbers 82976-01; 82976-02; SP12-0003 through AP12-0089, inclusive; SP13-0034 through SP13-0150, inclusive; or SP14-0151 through SP14-0202, inclusive.

The crankshaft assemblies were installed as original equipment on new Superior Air Parts Model O-360 and IO-360 engines, and as replacement parts under Parts Manufacturer Approval (PMA) on certain Lycoming Model AEIO-360, IO-360, and O-360 engines.

Link to FAA NPRM:


For more information, please contact:

Scott Hayes, VP Sales and Marketing: 972.215.6992

Bill Ross, VP Product Support: 214.395.9183

About Superior Air Parts, Inc.

Superior Air Parts, Inc., is a wholly-owned subsidiary of the Superior Aviation Group. Founded in 1967, Superior Air Parts is the leading manufacturer of FAA approved aftermarket PMA replacement parts for Lycoming and Continental Aerospace Technologies aircraft engines. In addition, the company manufactures the FAA certified Vantage Engine and the XP-Series Engine family for experimental and sport aircraft builders. For more information, visit:  www.superiorairparts.com

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