Maintenance and Certification

Maintenance and Certification Logo

Repair and Modification of
Amateur-built Aircraft

by Maurice Simoneau, Civil Aviation Safety Inspector, Aircraft Maintenance and Manufacturing, Standards, Civil Aviation, Transport Canada

Recreational aviation

Owners of recreational aircraft, including amateurbuilt aircraft, sometimes have the impression that their recreational aviation activities take place outside the mainstream of civil aviation, and therefore that certain requirements of the Canadian Aviation Regulations (CARs) do not apply, or have little application, to their aircraft.

In recent years, the regulatory burden applicable to recreational aviation has been made somewhat lighter and clarifications have been made where necessary. For example, with aircraft operating under a special certificate of airworthiness in the amateur-built classification, entries regarding the technical records for the airframe, engine and propeller may be kept in the journey log (see CAR 605.92(3)). In the case of airworthiness directives, a clarification was made about exemption from requirements for owners of aircraft in the amateur-built or owner-maintenance classification (see CAR 605.84(1)(b)).

Despite the above, unless the CARs say otherwise, amateur-built aircraft are subject to the same maintenance requirements as aircraft for which the Minister has issued a type certificate.

Maintenance

All maintenance tasks and all elementary work (see Appendix A of CAR standard 625) must be entered in the aircraft’s technical record. Aside from elementary work, a maintenance release for all maintenance tasks performed (see CAR 571.10) can be signed by the owner of the aircraft or by an aircraft maintenance engineer (AME) (see CAR 571.11).

This rule also applies to repairs and modifications to amateur-built aircraft, the subject of this article. CAR 571.06 describes the conditions applicable to repairs and modifications to an amateur-built aircraft. Paragraphs 571.06(1) and (2) are of the greatest interest in this case.

CAR 571.06

The first two paragraphs of CAR 571.06 address repairs and modifications. They stipulate the following:

(1) Except as provided in subsection (5) and in the case of aircraft that are operated under a special certificate of airworthiness in the owner-maintenance classification, a person who signs a maintenance release in respect of a major repair or major modification on an aeronautical product shall ensure that the major repair or major modification conforms to the requirements of the relevant technical data

(a) that have been approved or the use of which has been approved within the meaning of the term “approved data” in section 571.06 of the Airworthiness Manual; or

(b) that have been established within the meaning of the term “specified data” in section 571.06 of the Airworthiness Manual.

(2) Except as provided in subsection (5), a person who signs a maintenance release in respect of a repair or modification, other than a major repair or major modification, shall ensure that the repair or modification conforms to the requirements of the relevant technical data within the meaning of the term “acceptable data” in section 571.06 of the Airworthiness Manual.

Admittedly, CAR 571.06 is difficult to understand, and the somewhat convoluted wording does not help. To make it easier to understand, here is a simplified version of these two paragraphs:

a) all repairs and modifications must be performed in accordance with acceptable technical data, within the meaning of the term “acceptable data” in section 571.06 of the Airworthiness Manual;

b) all major repairs and major modifications on an aircraft for which a type certificate has been issued or accepted by the Minister for the purposes of issuing a certificate of airworthiness must be performed in accordance with either “approved” technical data, within the meaning of the term “approved data” in section 571.06 of the Airworthiness Manual, or “specified” technical data, within the meaning of the term “specified data” in section 571.06 of the Airworthiness Manual;

c) aircraft for which a special certificate of airworthiness in the owner-maintenance classification has been issued are exempt from the requirement to perform major repairs and major modifications in accordance with “approved data” or “specified data”, within the meaning of the terms “approved data” and “specified data” in section 571.06 of the Airworthiness Manual; major repairs and major modifications may be performed in accordance with “acceptable data”, i.e. acceptable to the Minister.

The above version makes it clear that only the general rule in a) applies to amateur-built aircraft. Versions b) and c) above are exceptions to the rule; b) is an exception to a), and c) is an exception to b).

General rule

The general rule, as stated in a) – “all repairs and modifications must be performed in accordance with acceptable technical data, within the meaning of the term “acceptable data” in section 571.06 of the Airworthiness Manual” – is applicable to all aircraft, whether certified or not, whether used under a certificate of airworthiness or a special certificate of airworthiness, and whether used for commercial or recreational purposes. The same rule applies to all aircraft, including amateur-built aircraft.

The general rule specifies that technical data must be “acceptable” in order to perform any repair or modification. The data include:

  1. drawings and methods recommended by the manufacturer of the aircraft, component, or appliance (manufacturer’s maintenance manual, structural repair manual, overhaul manual, service bulletins, technical instructions);

  2. Transport Canada advisory documents; and

  3. advisory documents issued by foreign airworthiness authorities with whom Canada has entered into airworthiness agreements or understandings such as current issues of Advisory Circular (AC) 43.13-1 and -2 issued by the U.S. Federal Aviation Administration (FAA), Civil Aviation Information Publications issued by the Civil Aviation Authority (CAA) of the United Kingdom, or Advisory Circulars - Joint (ACJs) issued by the Joint Aviation Authority (JAA), or Acceptable Means of Compliance issued by the European Aviation Safety Agency (EASA).

FAA Advisory Circulars 43.13-1B and 43.13-2B are recognized as the references for all amateur-built aircraft owners and manufacturers. Whether for repairing fabric coverings, refurbishing tubular members, replacing a wooden part or installing a doubler, AC 43.13 is the go-to source of information.

Methods and drawings set out in airworthiness directives may also serve as acceptable data for repairs or modifications. While amateur-built aircraft owners do not have to comply with airworthiness directives, it is highly recommended that they review applicable directives in order to decide whether to comply on a voluntary basis for the purpose of improving the safety of their aircraft.

However, it is possible that AC 43.13-1B and 43.13-2B do not have the answer for a particular repair or modification required. In such cases, aircraft owners could either develop their own data for a repair or modification, or they could show that their data complies with standards recognized in the aviation community or with generally accepted practices. This technical data does not need to be approved by Transport Canada. The owner must ensure that the data is appropriate to the repair or modification in question. It’s a matter of common sense!

The general rule that all repairs and modifications must be performed in accordance with “acceptable” technical data is the only rule that applies to amateur-built aircraft (and to aircraft in the owner-maintenance classification), which greatly simplifies things for the owner. However, it must not be forgotten that a modification may have an impact on structural strength, performance, operation of the power unit, or flight characteristics. A modification must not be taken lightly. It is important to think before acting.

Technical records

Details of the repair or modification must be entered in the journey log or in the technical record, and must be accompanied by the maintenance release. It is important to enter data references; without them, the data has little value. For example, the entry might read:

Figure 4.36. Welded patch repair

Lower right fuselage spar, 20 inches from the leading edge of the horizontal stabilizer: repaired by adding doubler, oxy-acetylene weld, repainted.
Reference: AC 43.13-1B, chapter 4, section 5, paragraph 4.94 and figure 4-36.

The described maintenance has been performed in accordance with the applicable airworthiness requirements.

[signed] Ty Wright       date

Maintenance release

After a repair or modification, owners must not forget the maintenance release, which includes the following statement or similar: “The described maintenance has been performed in accordance with the applicable airworthiness requirements.”

Conclusion

Every repair or modification must be performed in accordance with acceptable technical data. This data may include analyses, calculations, references, drawings, or sketches. Every repair or modification must be entered in the appropriate technical record and there must be a maintenance release for it.

If a job needs to be done, it should be done well.

As the owner of an amateur-built aircraft, don’t you deserve a job well done?

Fatigue Risk Management System for the Canadian Aviation Industry: Introduction to Fatigue Audit Tools (TP 14577E)

This is the sixth of a seven-part series highlighting the work of the Fatigue Risk Management System (FRMS) Working Group and the various components of the FRMS toolbox. This article briefly introduces TP 14577E—Introduction to Fatigue Audit Tools. Intended for managers, this document provides an overview of tools available to help determine whether scheduling provides employees with adequate opportunities to get sufficient sleep. The complete FRMS toolbox can be found at www.tc.gc.ca/eng/civilaviation/standards/sms-frms-menu-634.htm. —Ed.

Introduction

The purpose of this guide is to provide an overview of various tools and techniques to ensure that work schedules meet the requirements of a Fatigue Risk Management System (FRMS). An effective FRMS consists of several levels of fatigue hazard controls (see Developing and Implementing a Fatigue Risk Management System (TP 14575E) for a detailed discussion). One of the first things that companies need to examine is whether the schedule provides employees with an adequate opportunity to get enough sleep to be fit for work (Level 1 control).

Hazard-Control Model for Fatigue Risk Management

Chart - Hazard-Control Model for Fatigue Risk Management

Designing a work schedule

In the past, hours-of-service (HOS) rules have been used to ensure that a schedule provides adequate sleep opportunity between shifts and does not result in significant work-related fatigue. In principle, this appears to be a reasonable strategy. However, HOS regulations designed to be applied generically to an entire industry can be inflexible and ineffective for an individual organization. They may not guarantee sufficient sleep opportunity.

In designing an FRMS, it is important to understand that there is no such thing as a perfect schedule. Work schedules need to be structured around competing needs, such as operational safety and employee family and social life. For example, the “family friendliness” of a work schedule is likely to be determined by how much time off it provides during times of high social value (i.e., afternoons, evenings, and weekends). The “sleep friendliness” of a work schedule depends on the breaks it provides during times of high sleep value (i.e., nights between 9 p.m. and 9 a.m.). While sleep should be the primary concern, other factors such as the family and social life of employees should be considered, because they can have a direct effect on whether employees are able to use the time off to sleep. Consulting with employees during the early stages of implementing an FRMS can help find a balance between these competing needs.

Providing adequate sleep opportunity

To determine whether a given schedule may result in work-related fatigue, calculate the sleep opportunity that it provides. There are various ways to do this. This document outlines two methods of managing sleep opportunity:

  • Automated fatigue audit systems. Biomathematical modelling software has been developed that can predict how much sleep an employee is likely to get in a given schedule. The software is able to calculate a fatigue likelihood score for each employee at any given point in the schedule.

  • Manual fatigue audit systems. For organizations with relatively simple schedules or that may not want to invest in software, manual calculations can also be performed to generate scores that provide an indication of fatigue likelihood.

We conclude this introduction to TP 14577E by encouraging our readers to view the entire document at www.tc.gc.ca/ media/documents/ca-standards/FRMS_14577-eng.pdf.

TC AIM Snapshot: Shuttle Procedure

A shuttle procedure is defined as a manoeuvre involving a descent or climb in a pattern resembling a holding pattern. Shuttles are generally prescribed on instrument procedures located in mountainous areas. In the approach phase, it is normally prescribed where a descent of more than 2 000 feet is required during the initial or intermediate approach segments. It can also be required when flying a missed approach or departure procedure from certain airports. A shuttle procedure shall be executed in the pattern as published unless instructions contained in an ATC clearance direct otherwise.

To ensure that the aircraft does not exceed the obstacle clearance protected airspace during a shuttle descent or climb, the aircraft must not exceed 200 KTIAS while in the shuttle descent or climb, nor exceed one minute outbound still air time. Normal aircraft speed may be flown once the aircraft leaves the shuttle pattern.

(Ref: Transport Canada Aeronautical Information Manual (TC AIM), Section RAC 10.9)

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