OEMs & the TC Holder

By Norm Chalmers — August 02, 2013

I am providing this preamble to clarify my usage of abbreviations, etc. These abbreviations are all commonly used in the aviation industry and you may come upon them in your day-to-day work.

Preamble and Acronyms
(Italicized type denotes a quotation.) AD: Airworthiness Directive;  CAR: Canadian Aviation Regulation, which is a law of Canada; CofA: Certificate of Airworthiness; EASA: European Aviation Safety Agency; FAA: Federal Aviation Administration; FAR: Federal Aviation Regulation (USA); ICA: Instructions for Continued Airworthiness (including maintenance manuals et al); STC: Supplemental Type Certificate; STD: TC-approved standard; TATC: Transportation Appeal Tribunal of Canada; TSB: Transportation Safety Board of Canada; TC or minister or “tower of darkness” or “the Tower” indicates Transport Canada headquarters in Ottawa; TC Data Sheet: Type Certificate Data Sheet; TC Holder: Type Certificate Holder/Owner; USA: United States of America.

One term that is not included in my preamble above is “OEM”, which is the initialism for the phrase Original Equipment Manufacturer. OEM is an abbreviation that is used extensively, but it is also often used incorrectly, even in official publications emanating from the Tower. That is to be expected from TC, because they allow official publications to quote from the Merriam-Webster Collegiate Dictionary. Please note that the Gage Canadian Dictionary is the official Government of Canada English dictionary, but very few TC offices have a copy on hand. Most inspectors and managers do not have access to one because book stores charge for current copies. They are also hard to find on Kijiji or Craigslist for cheap.

Back to my topic, the term that OEM is most often confused with is “TC Holder” which is the same TC as in the term “TC Data Sheet”. Understanding the difference between these terms will also help you to understand the official basis for numerous documents.

First, we examine “TC holder” or “type certificate holder”. This is the entity that is named on the type certificate document and in the TC data sheet, both of which I have explained in previous AMU issues. This entity has the rights to all of the type certification data and is held responsible for the design and continued airworthiness support of the aircraft or other aeronautical product. This support includes the maintenance manuals, parts manuals, wiring diagrams, service bulletins and all of the other data that you, as the owner or maintainer, receive in support of your aircraft. The TC holder is the entity that the responsible CAA communicates with on design matters such as ADs.

Next, we examine the OEM. For most aircraft or aircraft parts, the OEM is also the TC holder. In many cases, the TC holder has moved onto new designs and no longer wants to make and sell parts for an ageing aircraft. They may enter into an agreement with another organization that wants to take over the manufacturing and sale of the parts. In that situation, the TC holder licences the right to make and sell the product. Usually this is limited to only parts and not complete aircraft. For some old designs of small single engine aircraft, the actual manufacturing has passed through numerous companies making the picture confusing. To help you determine which of these organizations made your aircraft, look at the original factory (OEM) aircraft data plate, or part number if it is still there, for the manufacturer identification.

One example that may help me explain this is the venerable DHC2 Beaver. The original TC holder and manufacturer was the de Havilland company based near Toronto. To get out of making that aircraft and move on to their newer and more lucrative models, de Havilland licensed manufacturing rights to Viking Air on Vancouver Island, British Columbia, over 4,000 kilometers away. Viking received the rusty jigs and took over the business of making Beaver parts. One of the requirements that Viking was also responsible for was to identify parts they made with a discriminating mark such as a “V” adjacent to the part number. If your part has the “V”, it was made by Viking. If it doesn’t, hopefully it was made by de Havilland. Both are OEM parts, but of different OEMs.

The problem for de Havilland was that they were still being held responsible for the design and continued airworthiness of the Beaver. The problem for Viking was that they didn’t have direct on-site access to all the historical design documentation or the ability to make changes. The solution for both organizations was to transfer the type certificate from de Havilland to Viking, and that was done.

This leads us to another related topic. Who actually made the part? That OEM part you’re holding in your hand may not have been made or fabricated by the OEM. That OEM may have contracted out the fabrication of that part, or some special process, to another company. Once again, we get onto the topic of making money. Often, aviation companies want to do this. The key factor is scale of production. In many cases, smaller companies are more able to produce small numbers of parts at a profit. The OEM can become an assembler of parts that have been fabricated or processed by smaller companies. In this situation, the OEM is still the only entity that can certify the parts. Just to add clarity, you may buy parts for your de Havilland Beaver made in Ontario from the aircraft part OEM (specifically, Viking Air) residing in Sidney, BC, when parts are also fabricated down the street and around the corner from you in Campbell River.

Now for something completely bromidic; we will examine the TC form 24-0019 Letter of Notification. This is the document that TC Airworthiness inspectors use to notify aircraft operators of particular conditions that the inspectors have observed and believe may be airworthiness defects of concern. Notice that I use the term “may be”. When inspectors inspect aircraft, they use their experience – however shallow or deep that may be – to judge whether a defect is an airworthiness issue. The 24-0019 is their notice to you of those concerns, and is fair warning that you may have a problem that compromises the effectivity of your CofA. The form states “Pursuant to section 8.7(1) of the Aeronautics Act, the aircraft described above has been inspected and the following defects or deficiencies have been noted:”

Blank lines are provided so that notes regarding observations can be written.
“In accordance with the Canadian Aviation Regulations, entries relating to these defects and deficiencies shall be made in the aircraft technical records and, where appropriate, corrective actions have to be taken before further flight of the aircraft.”

This only applies if the defects written on the form are valid. At that time, you have become aware of the defects and you need to note them in the journey log and get them fixed, as per the form, before flight. If the inspector is wrong and the observations noted are not defects, then you don’t need to do anything. As a courtesy, and to keep the TC office from wasting time chasing the aircraft down with the intention of grounding it, you should return the 24-0019A reply form to the TC office with your explanation of the mistaken assumptions. It’s easier to keep your aircraft flying than it is to get it back in the air.

Finally, here is a parting comment on the abdication of their safety responsibilities by the royalty “working” in TC headquarters in Ottawa. The minister recently issued Civil Aviation Safety Alert CASA 2013-01 hot on the heels of CASA 2011-03 back in 2011. Once again, the minister avoided being saddled with safety responsibilities. These two documents are the minister’s way of saying “Be careful, boys and girls. Play nicely, but don’t hurt anyone,” or “We don’t want to appear heavy-handed or move toward regulation by directive”. If they try to convince the families of crash victims, I’d be doubtful of their success. Better to keep their crowns in the sand with their heads in them.

Note that I know some of the individuals working in the Tower who daily battle to address safety concerns but are overruled by the policy mandarins. My sympathies are for aviation victims and their families and then for all the TC employees who labour away daily wearing bureaucratic straitjackets and gags. Nuff said.

Please be aware that I am not a lawyer or legal expert. What I write in my column is not legal advice or legal opinion. If you face a legal issue, you must get specific legal advice from a lawyer and preferably one with experience in the aviation matters in your own country.

About The Author

Norm Chalmers

NORM CHALMERS worked with Transport Canada as an Airworthiness Inspector for 25 years. Before this, from 1967 to 1983, he worked in the aircraft maintenance industry in and around Western Canada and in the Arctic. His industry experience includes the operational maintenance of normal and commuter category aircraft and smaller transport category aircraft in the corporate sector as well as several years working in major repairs in the helicopter sector. As an Airworthiness Inspector, he has been responsible for most duties related to the position, including the approval of all aspects of maintenance, manufacturing, training, and responsibilities related to distribution organizations. Norm now operates Pacific Airworthiness Consulting; www.pacificairworthiness.ca

View all articles by Norm Chalmers.