FARs vs. Consensus Standards

Last month I provided further information in the development of maintenance practices under the Light Sport ASTM Consensus Standards vs. the FARs in response to inquiries after publication of my article in the July 2012 issue of Aircraft Maintenance Technology magazine, “Opportunity With Light Sport Aircraft Maintenance Under the ASTM Consensus Standards,” a primer on the ASTM LSA Consensus Standards system. In this part I’ll look closer into the who, when, and how of S-LSA maintenance as well as some tips for AMTs working on S-LSA aircraft.

AMT Authority: Who?

FAR 43.1 makes it clear that Part 43 applies to maintenance, preventive maintenance, rebuilding, and alteration of any aircraft having a U.S. airworthiness certificate, except as noted (such as certain experimental aircraft). Subsection (d) explicitly includes S-LSA in the governing provisions of Part 43, except for certain Standard Category requirements, like filing a Form 337 for major alterations.

The familiar provisions of FAR 43.3 grant authority to certificated AMTs to perform maintenance, preventive maintenance, and alterations as provided in Part 65. The equally familiar FAR 43.7 gives authority to AMTs to approve aircraft for return to service, after undergoing maintenance, repair or alteration, also as set out in Part 65. Let’s take a look at this part next.

FAR 65.81 permits a certificated mechanic or repairman to perform or supervise maintenance, repair, or alteration of aircraft for which the mechanic is rated. However, the AMT may not perform the task unless he or she has satisfactorily performed it at an earlier date, or until the mechanic has demonstrated the ability to perform the task satisfactorily under the direct supervision of another AMT who has previous experience with the task. The AMT must also understand the task, and have the current manufacturer’s instructions and manuals available to complete the task pursuant to these instructions. FAR 65.107 contains similar provisions for Light Sport Repairman with Maintenance Ratings (LSRM) working on Special Light Sport Aircraft.

Given the legal authority conferred by these FARs, so the argument goes, neither the ASTM consensus standards, nor the manufacturers’ manuals or other service instructions, have the right to curtail the AMT’s activities. Definitions found in F2626, the maintenance manual content requirements specified F2843, and the requirements often found in S-LSA maintenance manuals addressing such things as “task-specific training requirements,” “level of certification requirements,” and limitations on overhaul activities to manufacturers or their appointed facilities, are all void as without legal basis and in conflict with the FARs. Got that?

This issue was the focus of the FAA OLC letter mentioned earlier. The AMT rejected the Rotax requirement, brought forward by the S-LSA manufacturer in its maintenance manual, that the AMT have Rotax factory training. He argued instead that as long as he was operating within the authority of his A&P certificate and ratings, and according to Rotax maintenance instructions and procedures, he was on legally solid ground, even without the Rotax factory training certificate. The FAA lawyers agreed.

A final note about who. Whereas the ASTM Consensus Standards purport to limit the authority of AMTs via maintenance manuals and other service and inspection instructions, they arguably expand the authority of certificated pilots. Although FAR 43.3(g) allows pilots to perform certain prescribed preventive maintenance tasks, no authority is granted to make required inspections. Some S-LSA maintenance manuals detail inspections that can be performed by pilots. A good argument can be made that there is no legal authority for this, and pilots should refrain from making such inspections. (We are not talking about pre-flight inspections here.) Let’s move on.


Although there is less legal conflict between the ASTM Consensus Standards and the FARs as to when prescribed maintenance and inspections must be undertaken, some S-LSA manufacturers have muddied the waters with regard to inspections, at least, by publishing manuals that contain annual condition inspection and 100-hour inspection checklists that are not the same. This creates legal problems for AMTs and safety concerns as well. Here’s why.

FAR 91.327 imposes operating limitations on S-LSA aircraft. One of these requires that the aircraft be inspected according to procedures developed by the manufacturer. The regulation goes on to prescribe two circumstances in which inspections must be accomplished: the annual condition inspection and, for S-LSA used for compensation or hire, the 100-hour inspection. Although F2626 defines the 100-inspection to be the same as the annual condition inspection except for the required inspection intervals, some manufacturers’ 100-hour inspection checklists are an incomplete subset of inspection tasks contained in the annual condition inspection checklists. This makes the “time in service” inspection less than complete than the annual inspection, contrary to both the ASTM definitions and the FARs.

Many S-LSA owner/operators, and many AMTs working on these aircraft, understandably take the manufacturers’ inspection checklists as gospel and follow them, thereby creating potential safety as well as legal problems for themselves. Although the scope and detail requirements of Appendix D of Part 43 do not apply to the inspections of S-LSA aircraft, a complete inspection of the aircraft is required at each prescribed inspection interval.

There is one instance in which manufacturers can say when. That is in issuing instructions for continued safe operation of the aircraft in the context of Safety Directives, as authorized implicitly by both the ASTM standards and FAR 91.327.


Finally we come to the topic upon which everyone is agreed: the how of S-LSA maintenance. The manufacturers are entitled, in fact legally required, to develop and make available maintenance manuals, instructions, Safety Directives, and other such guidance to owner/operators and maintenance personnel to enable their products to be continued in a condition for safe flight. These requirements are found in FAR 91.327 as well as in the ASTM Consensus Standards themselves. Thanks for this area of agreement at least!

In doing so, however, so the FAA lawyers say, S-LSA manufacturers are not permitted to impose training, experience, or certification requirements beyond the requirements of the FARs, as already discussed.

What’s an AMT to do?

First, don’t panic and decide to stay clear of S-LSA aircraft and the world of the ASTM Consensus Standards. Embrace the opportunity presented by this new segment of the aviation maintenance industry, as encouraged in my original article. Follow developments as the controversy surrounding these issues is resolved by future developments. And follow these additional guidelines:

1. Make sure you have the current manufacturers’ maintenance materials and follow them, and have the task-specific experience required by Part 65, just as you would with Standard Category aircraft maintenance.

2. Perform all required condition inspections (whether on an annual requirement of when or 100-hour requirement of when) with the same scope and detail contained in the manufacturer’s condition inspection checklist, even if the published 100-hour checklist is abbreviated, and be sure that you are always conducting a complete inspection, sufficient for you to confidently return the aircraft to service in a condition for safe operation.

3. Comply with the manufacturers’ training and experience requirements, even if different from or more extensive than that required by the FARs, if economically and practically feasible. Make sure you always follow the current manufacturer’s maintenance instructions, including utilizing the required tools and equipment (or their equivalent). Ref FAR 43.13.

4. Pay particular attention to continued safety information such as Safety Directives, as well as the Airworthiness Directives and published Airworthiness Limitations for all FAA-approved components incorporated into the aircraft.

Stay tuned!

This article is intended as an overview of the areas of conflict and dispute about the interplay between the ASTM Consensus Standards and the Federal Aviation Regulations. Future articles may dig deeper and focus in on specific trouble spots as they arise. Meanwhile, particular questions may be directed to Doug Hereford and me. We will try to answer them. AMT


Ed Leineweber is an aviation and business attorney practicing in Madison, WI. He is a CFII and holds the LSRM certificate. A retired Wisconsin Circuit Court Judge, he previously operated two FBOs and managed both airports. He is an incurable Bowers Fly Baby aficionado; currently completing a Fly Baby project and restoring a nearly 50-year-old Fly Baby. Ed regularly writes a SP/LSA column for the Midwest Flyer Magazine. He can be reached at eleineweber@bmrlawyers.com and (608) 604-6515.