![]()
PA-12 fractured rudders, grey rudder is from accident plane, from NTSBThe FAA has extended the comment period for an Airworthiness Directive for replacing the rudder equipment on Piper aircraft. The Notice of Proposed Rulemaking was published on Oct. 6, requiring the replacement of any rudder post made from 1025 carbon steel with a rudder equipped with a rudder post made from 4130N low-alloy steel. The comment period, slated to end on Nov. 20, was extended to Feb. 20, 2024.
The AD was issued as a result of two accidents involving Piper airplanes caused by broken rudder posts which structurally failed above the upper hinge in flight. Both of the crashes occurred in Anchorage, Alaska with the first on June 8, 2020 in a Piper PA-12 Super Cruiser and the second on July 23, 2021 in a Piper PA-14 Family Cruiser. Both of the planes sustained serious damage when the rudder structurally failed and after examination, it was determined that the rudder posts fractured above the upper hinge, with the top portion of the rudder folded over the upper tail brace wires and the carbon steel rudder posts had fractured due to fatigue. If these issues go unchecked, it could result in a broken rudder and reduce the flight crew's ability to maintain a safe flight and landing.Aft view of PA-12 accident plane and the plane's fractured rudder post, from NTSB docket
The AD required the replacement of 1025 carbon steel rudder posts which is expected to cost about $3,000 per aircraft, including the parts and labor. The notice applies to various Piper and FS2003 Corp. aircraft manufactured before 1974 when the steel carbon steel was replaced with a 4130N low-allow steel. Commentators had qualms with some of the planes included in the AD, like the inclusion of lower horsepower aircraft. Others questioned the inclusion of aircraft like the Piper J-3 Cub, which has flown without issue since the 1930s. Both accidents involved planes made under type certificates held by FS2003 Corp., (previously held by Piper). The FAA estimates the AD, if adopted as proposed, would affect 30,002 planes on the U.S. registry. The estimated labor cost for eight hours at roughly $85 per hour would come out to $680, the parts would come to $2,320, the cost per product $3,000 and the cost on U.S. operators $92,976,000.
After it issued the NPRM in October, aviation groups like the AOPA and Short Wing Piper Club urged the FAA to extend the comment period. The groups said that the NPRM is controversial, which could drive substantial costs. More time was also needed to prepare informed and meaningful comments with coordinated consensus among its members, asking for a 90-day extension to the comment period. The FAA agreed, stating that extending the comment period by 90 days would not compromise the safety of the affected airplanes.NTSB images of cracked rudder from PA-14 accident plane, from NTSB Docket
The applicable airplane models include PA-12 Super Cruiser, PA-14 Family Cruiser, Piper J4 Cub Coupe and PA-18 Super Cub. The AD categorizes the applicable aircraft into categories, specifying whether the compliance time is within two years, three years or five years after the effective date of the AD. Category I aircraft have both a rudder post mounted beacon light and a 150 or greater horsepower engine installed. Category II planes have either a rudder post mounted beacon light or a 150 or greater HP engine installed. The Category III planes include all other planes not in the first two categories without a rudder post mounted beacon light and with an engine less than 150 HP installed.
Some of the current posted comments relay concerns of the applicable aircraft, the scale of the AD and the possible inaccuracy of the estimated cost for replacement. Many of the comments recommended removing the lower HP aircraft from the list and focusing on higher-powered aircraft. The AOPA said it is preparing comments for the AD and encourages affected members to provide their own feedback.
See the proposed AD and find out how to submit a comment before the extended deadline"The FAA asks commenters to provide substantive recommendations for thorough inspection methods of the rudder posts which could be used in lieu of the mandatory replacement, as the proposed rule requires," AOPA VP of Regulatory Affairs Murray Huling said. "The comments should also include any make/model corrections to remove any aircraft which does not contain the subject part number."