By Joe Hertzler
A funny thing happened to me the other day at an FAA office that will remain unnamed. I was there for the initial meeting as part of the indoctrination process normal for a new entrant to the Air Carrier certification process. We were in the process of obtaining an Air Carrier certificate for an owner/operator of a Learjet Model 35. The Learjet Model 35 fits into the category under Part 135 of "9 or less," meaning the aircraft has a seating configuration excluding any pilot seat for nine passengers or less (ref 14 CFR Part 135.411).
As you might imagine, many things are discussed in those meetings, but the part of the discussion that left me scratching my head in disbelief is what we will be discussing this month.
I will start by saying this: It is critical that those who operate aircraft under Part 135 with a seating configuration of "9 or less" understand the implications of using an Approved Aircraft Inspection Program (AAIP) which is optional under 14 CFR Part 135.419.
What are the inspection requirements for a "9 or less" aircraft operating under Part 135?
Let's look through the line of regulations that defines exactly what is required.
135.411 (a)(1) specifically states that the aircraft shall be maintained under parts 91 and 43 as well as the other rules listed. The other rules listed are all "reporting" rules - rules that require the certificate holder to report to the FAA certain events, with the exception of the reference to Part 135.421. Additionally, the rule states that "An approved aircraft inspection program may be used under §135.419," but does not mandate such.
Following the direction of this rule we turn to 14 CFR Part 91. Because we are specifically interested in inspections and, in our case, "multi-turbine powered" aircraft inspections, we arrive at 14 CFR Part 91.409 (e) which applies to large and multi-turbine powered aircraft.
This rule points out that we must inspect the aircraft to a different standard than an "annual" inspection required for smaller less complex aircraft (ref 14 CFR Part 91.409 (a)). With the multi-turbine powered aircraft we must comply with the replacement times for life-limited parts (duplicated from 91.403 (c)) and select a program listed under 91.409 (f) that will cover inspection of the airframe and the engines, propellers, rotors, appliances, etc.
This then takes us to 91.409 (f). Now, it's important to understand what's here. There are four options for the aircraft owner/operator. Reading them can be confusing so I will attempt to simplify them here.
1. If you know of an air carrier operating under 121 or 135 who is using a continuous airworthiness inspection program for an identical make and model as yours you can use it too. If you choose to you would select option 1. Or,
2. If you know of an air carrier operating under 135 who is using an approved aircraft inspection program for an identical make and model as yours you can use it too. If you choose to you would select option 2. Or,
3. You can use the inspection program recommended by the manufacturer. Or,
4. You can create your own program and submit that program to the FAA for approval. If you choose to create your own program you must also meet the requirements of 91.409 (g) and 91.415.
So, at this point we know that to operate a "9 or less" aircraft under Part 135 we must maintain the aircraft in accordance with Part 91 and Part 43. Part 91 tells us we must choose one of the inspection program options contained in Part 91.409 (f).
The most common choice under 91.409 (f) is option (3), the manufacturer's inspection program. Unlike some of the piston-powered aircraft manufacturer inspection programs, for multi-turbine powered aircraft, manufacturers are clear and detailed as to what needs to be inspected, how often, and they are constantly revising their program.
There have been many misconceptions as to what makes up the "manufacturer's inspection program" over the years. Therefore, another important reference document to insert here is a section from the FAA Safety Inspector Handbook 8300.10 Volume 3, Chapter 26, Page 3 which provides clarification about the engines, propellers, rotors, appliances, etc.
To be in compliance we must be sure that we cover all of the inspection requirements from the engine, prop, appliance, and equipment manufacturers as well as the aircraft manufacturer. The inspection requirements for a multi-turbine aircraft operating under Part 91 are very complete.
Inclusion of the engines, props and appliances, and equipment is simply reiterated by 135.421 for "9 or less" aircraft operated under Part 135.
Additional maintenance requirements
The inspection program recommended by the manufacturer for multi-turbine powered aircraft is complete and the regulations mandate those inspections even for aircraft operating under Part 91. Under Part 135, aircraft with a seating configuration of nine or less passengers "shall" also use that program with one possible exception. The last statement in Part 135.411 provides one other option, "An Approved Aircraft Inspection Program (AAIP) may be used under §135.419."
The rule says that the FAA may find the manufacturer's inspection program inadequate and require an AAIP or the certificate holder may choose to create and submit an AAIP. If as a certificate holder, you choose to create and submit an AAIP, you are required to maintain it to the manufacturer's current revision.
Back to the beginning
In the meeting I referred to at the beginning of this article, the FAA took the position that in order to operate that Learjet Model 35 under 14 CFR Part 135, the applicant must submit an AAIP for approval.
For safety purposes and in the interest of good business practices our desire was to continue with the manufacturer's inspection program for this aircraft. The manufacturer is constantly receiving input from owners and modifying the inspection program to better serve those aircraft. It seems obviously safer to use the manufacturer's inspection program for the core of the inspection requirements and supplement it with additional requirements if necessary. In doing this we will always use the most current information from the manufacturer for inspections and when it comes time to sell the aircraft, the compliance with the manufacturer's program is current and complete.
We explained our position and our approach was to ask the FAA Flight Standards District Office to outline the elements of the Learjet Model 35 manufacturer's inspection program that they found to be inadequate. Their response was one that left us assured we were just wasting our time. They said, "The purpose of this meeting is to let you know what we must see in order to move forward with this certification. Without an AAIP we will not be able to continue with the certification."
It is important to point out that this is not the normal position of the FAA in most parts of the United States. Please take the time to clearly understand the regulations we have discussed here and consider the following points if you are thinking of placing your aircraft on an Air Carrier certificate:
- For multi-turbine powered aircraft the manufacturer's inspection program is the most current information to inspect to and is therefore the safest option.
- Supplementing the inspection program with additional requirements such as avionics checks and emergency equipment checks is very simple and easy to maintain.
- The FAA is not consistent in its interpretation. Keep asking the question until you get an answer that makes sense.
Until next month.
Joe Hertzler is the president of AVTRAK, Inc., an Aurora, Colorado-based company. Joe is an Airframe and Powerplant Mechanic with Inspection Authorization and also a Private Pilot.