The Complacent Frogs -Field Approvals, Then and Now
I serve on various committees that focus on the regulatory arena and impending FAA guidance materials under review. I was asked recently to look at a draft FAA Order titled “8300.x Major Repair and Alteration Data Approval.” As I read through the document, I couldn’t believe some of what I was reading. A great analogy for the situation we find ourselves in, as it pertains to FAA field approvals, is one many of you will be familiar with.
The story goes like this: when you place a frog in a pot of boiling water, it will jump out to escape the heat. However, if you were to place the frog in the water and slowly turn up the heat, the frog would simply lie in the water and boil to death when the temperature of the water gets too hot to survive. The frog becomes relaxed and complacent and doesn’t notice the temperature change.
So it is with the field approval process as it has evolved during the past 20 years. Although none of the regulations related to the use of FAA form 337 and who is responsible to complete and disposition the form have changed much over the past years, the guidance material and policy within the FAA has changed significantly. To be clear, much of the guidance is a great improvement and helpful in setting standards for determining the difference between a major repair and a minor repair and between a major alteration and a minor alteration. What I have a big problem with is the FAA’s campaign, stealthily hidden within the new guidance material, to remove the authority from the repair station and the technician with inspection authorization to make that major/minor determination. Unfortunately, this is one area where the FAA can effectively regulate through policy and intimidation.
In this article, I will take us all through the history of FAA form 337, its use, the need for STC and the need for field approval, as well as provide my observation as to what has occurred (the heat slowly being turned up) during the past 20 years to make many of us believe that the situation we find ourselves in is the way it should be. I, for one, do not share that opinion. I believe the evolution of the field approval and STC process has a result that is completely counter to the intent of the regulations themselves, conceived and codified in 1958.
Lets start out by reviewing a few relevant regulations:
1.1 General definitions.
Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications—
(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
(2) That is not done according to accepted practices or cannot be done by elementary operations.
Major repair means a repair:
(1) That, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
(2) That is not done according to accepted practices or cannot be done by elementary operations.
43.7 Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or component parts for return to service after maintenance, preventive maintenance, rebuilding, or alteration.
(b) The holder of a mechanic certificate or an inspection authorization may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in Part 65 of this chapter.
(c) The holder of a repair station certificate may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in Part 145 of this chapter.
43.9 Content, form and disposition of maintenance, preventive maintenance, rebuilding, and alteration records…
(d) In addition to the entry required by paragraph (a) of this section, major repairs and major alterations shall be entered on a form, and the form disposed of, in the manner prescribed in appendix B, by the person performing the work.
Appendix B to Part 43 — Recording of Major Repairs and Major Alterations
(a) Except as provided in paragraphs (b), (c), and (d) of this appendix, each person performing a major repair or major alteration shall—
(1) Execute FAA Form 337 at least in duplicate;
(2) Give a signed copy of that form to the aircraft owner; and
(3) Forward a copy of that form to the FAA Aircraft Registration Branch in Oklahoma City, Oklahoma, within 48 hours after the aircraft, airframe, aircraft engine, propeller, or appliance is approved for return to service.
65.95 Inspection authorization: Privileges and limitations.
(a) The holder of an inspection authorization may —
(1) Inspect and approve for return to service any aircraft or related part or appliance (except any aircraft maintained in accordance with a continuous airworthiness program under Part 121 of this chapter) after a major repair or major alteration to it in accordance with Part 43 [New] of this chapter, if the work was done in accordance with technical data approved by the Administrator; and
145.201 Privileges and limitations of certificate.
(a) A certificated repair station may —
(1) Perform maintenance, preventive maintenance, or alterations in accordance with Part 43 on any article for which it is rated and within the limitations in its operations specifications … 3)Approve for return to service any article for which it is rated after it has performed maintenance, preventive maintenance, or an alteration in accordance with Part 43 … (c) A certificated repair station may not approve for return to service’
(1) Any article unless the maintenance, preventive maintenance, or alteration was performed in accordance with the applicable approved technical data or data acceptable to the FAA.
(2) Any article after a major repair or major alteration unless the major repair or major alteration was performed in accordance with applicable approved technical data
This is how the maintenance rules tie together with respect to major alterations and major repairs, content form and disposition of maintenance records of such, and those persons authorized to approve for return to service following such work.
Part 43 clearly places the responsibility of the identification of a major alteration or major repair on the “person performing the work.” In the case of a certificated repair station, the person is indeed the repair station. So, as the person performing the work, if I determine that the work to be performed is a major alteration or a major repair, then the work performed “shall be entered on a form, and the form disposed of, in the manner prescribed in appendix B” (of Part 43). Appendix B clearly states that the form referenced in Part 43.9 (d) is FAA form 337. Next, the FAA Form 337 Approval block can be signed by, among other authorities, a certificated repair station and a person holding an inspection authorization. Part 65.95 provides the person holding inspection authorization with the authority to approve for return to service following major alteration or major repair, and Part 145.201 provides a certificated repair station with the authority to approve for return to service following major alteration or major repair. Both Part 65 and Part 145 clearly state that the major alteration or major repair must have been performed in accordance “with technical data approved by the Administrator.”
Okay, that’s the basic flow of the regulation. There are a couple basic questions. Where is the line between a major and minor alteration and a major and minor repair? FAR Part 1 provides basic definitions, and in both cases, major repair and major alteration, the language includes “appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics.” This is important for one key reason. I want to now call your attention to the language contained in Part 21 related to major change in type design.
21.93 Classification of changes in type design.
(a) In addition to changes in type design specified in paragraph (b) of this section, changes in type design are classified as minor and major. A “minor change” is one that has no appreciable affect on the weight, balance, structural strength, reliability, operational characteristics, or other characteristics affecting the airworthiness of the product. All other changes are “major changes.”
It is clear, at least to me, that the definition of a major alteration and a major repair was certainly derived from the definition of a major change in type design. Current and proposed guidance material from the FAA ignores the regulatory correlation between a major alteration or major repair and a major change in type design. In fact, they clearly state that there is a difference. I disagree. What are some examples of major alteration and major repairs? I won’t include all of the descriptions found in Part 43 Appendix A, but if you look there, you will see examples that the FAA provided during the recodification of the federal aviation regulations in 1958. Therein lies the problem. They haven’t been revised substantially since then. Instead, the FAA and industry have been in tug of war of sorts through guidance material.
Think back to 1958. (Okay, I wasn’t even born then. Many of you weren’t either.) Has much changed since 1958? Need I say more? However, I remember how things were before we got wrapped around the axle with field approvals about 15 years ago.
There has always been a clear division within the FAA between aircraft certification and flight standards. Aircraft certification is all about the engineering of and manufacturing of aircraft and parts of aircraft. Flight standards is all about the operation and ongoing maintenance of in-service aircraft. The division between these two FAA entities is a natural human factor, if you will. For example, FAA personnel working in aircraft certification are primarily engineering people. Personnel working within the flight standards organization are primarily maintenance and operations people. They are different types of people with different focuses and purposes and they literally think and process things differently by design.
The way things worked when I started in this business, a 337 form was issued in three different ways. First, it was used as a form where the data used to perform the work was already FAA approved data and the person approving the work upon its completion simply signed the form and dispositioned it properly. Second, it was used as a form where the data used to perform the work was not completely approved, (some may have been but not all data was FAA approved) and the form was taken to the FSDO for a field approval prior to the work being completed and then ultimately approved for return to service, again by the person authorized to sign the approval for return to service. Third, it was used similarly to the first case in that the data was already approved, but it was in the form of an STC, which in that day was primarily used when the alteration was to be accomplished on multiple aircraft. STCs were used to create repeatable packages and field approvals were primarily used for single-case alterations. However, there was a clause, and it was used often when the alteration was not complex and the installer knew they would be performing the modification on like aircraft again in the future, allowing the FSDO to approve for duplication by endorsing block three during a field approval of the 337 form.
AC 43-9 E “Instructions for completion of FAA form 337, Major Repair and Alteration” CANCELLED
5, c, (3) Approval by examination of data only - duplication on identical aircraft -“The alteration identified herein complies with the applicable airworthiness requirements and is approved for duplication on identical - aircraft make, model, and altered configuration by the original modifier.”
Note: This clause has been removed in the current revision to AC 43-9 (now F).
Back then, the STC process was much like it is today. The application and approval process was the one place where we, within the flight standards world, crossed over into the aircraft certification world in order to obtain an STC.
There came a time when the alterations simply got to be more complicated than the flight standards inspectors were able to keep up with. Likely, created by the other age-old problem where FAA inspectors in one region, and even at the FSDO level had a completely different standard or knowledge level and within the FAA, there came a deep concern on field approvals. It seems that FAA inspectors in one region would review the work of an inspector in another region and occasionally bring it into question. Likely there was reason for concern and a problem did indeed exist. In my mind, this is where the failure took place. This is when the leadership within the FAA had a choice. They could have decided to train the flight standards inspectors and standardize the field approval process within the flight standards group — raise the knowledge level of the field inspectors, give them the tools they needed to continue to do field approvals, but with standards across regions. Again, the rules had not changed significantly.
Instead, the decision was made to involve the aircraft certification division. I can just imagine how it went. A FSDO inspector called the ACO and said, “Hey, I’m looking at this 337 for the purpose of a field approval, could you take a look at it for me and help me determine if the data is adequate?” Now, if I’m that ACO engineer, I only know one method for approving major alterations, and that’s an STC. An STC is my reality and there is a structured process for obtaining an STC. I’m an engineer and I know there is really only one right way to do things. The ultimate result of getting the ACO involved in the evaluation of the data submitted for a field approval is a “one-time” STC, not a field approval. I know I wasn’t really there to witness how this all happened exactly, but the result is pretty clear and I believe it paints the picture itself. This is how the aircraft certification division helped the flight standards division. They took over. Flight standards just allowed the aircraft certification division to have more influence and inappropriate control over the area of the industry that aircraft certification simply shouldn’t control: in-service airworthiness. This is when the temperature began to get turned up and ultimately cooked the frog.
I specifically remember hearing that the Dallas FSDO had made the decision to never provide a field approval again. As I recall, that was the first major change in direction for flight standards. As a maintenance industry, we were faced with quite a struggle. We had to figure out how to maneuver this new terrain. It caused a lot of extra expense and aircraft downtime, not to mention even more problems as FSDO policies became even more disjointed between offices.
Here we are today, and as I read through the guidance material already issued in the form of advisory circulars and the proposed FAA orders, I see that the frog is cooked. We are in a completely new world today, but only in the form of guidance material. I stress to you that the regulations that I laid out in the beginning of this article are the current regulations. The only thing that has changed is the guidance material and the policies of the FAA.
Until next time …
For more information, please take the time to read through the following guidance documents provided by the FAA and available through www.faa.gov.
• Draft Order 8300.X, titled “Major Repair and Alteration Data Approval”
• “Major Repair and Alteration Data Approval Job Aid” (Associated with Draft Order 8300.x)
• AC 43.9-1, “Instructions for Completion of FAA Form 337”
• AC 43-210, “Standardized Procedures for Requesting Field Approval of Data, Major Alterations and Repairs”
• AC 21-40, “Guide for Obtaining a Supplemental Type Certificate”
• AC 21-47, “Submittal of Data to an ACO, a DER or an ODA for a Major Repair or a Major Alteration”
Joe Hertzler has more than 25 years of experience in business aviation. He has earned a reputation as an efficiency expert when it comes to aircraft maintenance and is well known for his in-depth understanding of maintenance regulations and how they affect aircraft compliance. He has helped many in dealing with critical and urgent FAA interactions and often speaks on the topic of aircraft maintenance and compliance at industry events, such as the NBAA Maintenance Managers Conference, PAMA meetings and IA renewal seminars. Hertzler also serves on the National Air Transportation Association’s (NATA) Maintenance and Systems Technology committee. Contact him at JoeHertzler@gmail.com.