Special inspections

Throughout this document when a word is emphasised, (Different Color) it indicates a link to the required document.

As stated before, the majority of projects require only two inspections, but there are other ways to build/acquire a homebuilt aircraft.


A major Portion, (51%) inspection resumes itself to counting the number parts built/assembled by the builder and the number of parts built/assembled obtained from another source. The builder must build/assemble more than half of the parts utilised to build the aircraft.

It is required when:
1. The kit is not published on the Revised listing of amateur-built aircraft kits.
2. The project is based on an existing model and / or using recycled parts.

It is not required when:
3. The kit is published on the Revised listing of amateur-built aircraft kits.
4. The aircraft is built strictly from plans and materials.

A homebuilt can be built using parts coming from a previous aircraft. Most of the time, these projects originate from previously certified aircraft. Specific regulations govern this method of building a homebuilt aircraft. The details of the regulation are contained in the Si 549-001 Conversion of Commercially-Produced Aircraft and Use of Commercially-Produced Parts in Amateur Aircraft Projects. The builder is well advised to read the regulation concerning this approach to building an amateur-built aircraft.

As defined in the regulation the constructor must build and/or assemble the major portion of the project. The easiest way to proceed is for the prospective builder to acquire the 51% Amateur Determination Checklist C22E procedure and perform a 51% evaluation. If the project seems to meet the requirement of the regulation and of the major portion, the builder can start his project by filling a Letter of Intent and an Inspection Requestrequesting a 51% inspection and send it with the appropriate Fee to MD-RA Inspection Services. The builder must prepare all the parts for the inspector. Note that all the structural parts making this project must be available to the inspector during the inspection. The inspector will calculate the percentage in favour of the builder and decide if the project is or not acceptable.

If the project as inspected does not meet the major portion requirements, the builder will be asked to modify the project to built/assemble more parts until it meets the requirements, otherwise the project will not be eligible for registration as an amateur built aircraft.  

When the project is found to meet the major portion requirements, the inspector will sign and date the procedure form. The builder will also sign the procedure form signifying that he now has a specific project to build. The inspector will then fill, sign and date an Amateur Built Aircraft Inspection Report, C21 confirming that the project meets the requirements. The 51% evaluation report will be sent to the MD-RA Regional Representative for review. The builder will then be formally informed of the results and authorized to proceed to the PRE-COVER inspection, via the white copy of the Amateur Built Aircraft Inspection Report, C21 document.

NOTE: It is very difficult to convert an already approved/certified aircraft to another category (such as Advanced Ultra Light, Certified aircraft and Maintenance by Owner aircraft) because of the 51% rule which applies in all these cases. No points are given for repairing and/or opening and closing a structure as these actions are not considered building. Such project is always considered on an individual basis and must be approved by Transport Canada.

Wooden and composite aircraft have components that must be inspected before they are closed. Wooden aircraft usually have boxed spars. A boxed spar has a top and bottom flange and two sides holding the flanges apart. These spars must be inspected before the last side is glued. Some aircraft have numerous boxed spars; the wing main spar and rear spar, the elevator and stabilizator spars and the fin and rudder spars. Composite structures also have specific to type inspections. Check with MD-RA to determine what type of inspection is required. Once these parts are inspected the builder will be allowed to continue his project up to the pre-cover inspection.

An inspector may require a SUPPLEMENTARY inspection to correct specifics problems.

It is permissible to import a completed foreign amateur built aircraft. The regulations defining the rules and the procedure are contained in the MSI 2008-11-26, Inspection and Flight Certification of Imported Amateur-Built Aircraft. The rules and procedures are simple but must be adhered to successfully import an amateur built aircraft. First the rules:

  1. The aircraft must be certified as an amateur built aircraft in the country of origin.

  2. The aircraft was constructed in accordance with standards of the State of construction, and the Minister finds them to be equivalent to Canadian standards.

  3. The aircraft was issued a permanent Flight Authority pursuant to the regulations of the State of construction, and has subsequently completed not less than 100 hours air time.

  4. Once imported, the aircraft is considered to be a new Canadian amateur built aircraft project, and therefore must undergo a complete final inspection for compliance with Canadian standards, by a Minister's Delegate - Recreational Aviation (MD-RA).

Second, the procedure:

Once an amateur built aircraft has been selected, the importer must perform the following tasks.

  1. The importer files a Letter of Intent and an Inspection Request, (Import) and submits the required documents to MDRA for review to establish, whether or not, the aircraft is eligible for import. The MDRA reviewer will advise the importer as to the results of the review.

  2. The aircraft is flown/transported into Canada.

  3. The aircraft is modified and repaired, (as necessary), to bring it up to Canadian standards as per Exemption from Section 549.01 of the Canadian Aviation Regulations and Chapter 549 of the Airworthiness Manual-Airworthiness Standards-Amateur Built Aircraft. All imported amateur built aircraft, including helicopters; which have an enclosed engine compartment must have a firewall installed between the cabin and the engine compartment. The firewall must be made of fireproof material. Composite aircraft must show proof of compliance to Canadian STD 523.853, (f) Passenger and Crew Compartment Interiors. Must have a gascolator located at the lowest point in the fuel system. The word EXPERIMENTAL in 2” letters must be removed.

  4. An annual inspection must be performed as per CAR’s 625 App. B& C.

  5. The aircraft must be registered as a Canadian amateur built aircraft.

  6. The importer files an Inspection Request for a final, (Import) inspection. Upon receipt of payment, MDRA will send out the required documentation, to the importer and to the assigned inspector, to initiate the process.

  7. The final inspection is done when the aircraft is fully completed, fuelled, and in all respects ready for flight except that all cowlings, covers, inspection opening, fairings,...etc. have been removed for inspection. The inspection must be performed at the declared base of operations for the aircraft. For more details refer to paragraph 3.2 Final Inspection, of this document.

  8. At the end the importer is issued a Special Certificate of Airworthiness and Operating Conditions appropriate to an imported amateur built aircraft.