As per the definitions of Type Approval and Type Certificate, Type Approval is more related to design approval or certificate of conformity.

A type certificate (TC) is issued to signify the airworthiness of the approved design or "type" of an aircraft to be manufactured.

Type approval or certificate of conformity is granted to a product that meets a minimum set of regulatory, technical and safety requirements

I have no idea why the very generic word "Type" is used to denote something totally unrelated to its meaning. What is the origin of this usage?

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    $\begingroup$ A manufacturer comes out with a new type of aircraft ("type" = "kind" = "model"), and it needs to be approved or certified. $\endgroup$ Feb 1 at 13:07
  • $\begingroup$ I don't think the word type is a misnomer since one definition is, "a category of people or things having common characteristics". We say types of vegetables, types of animals, etc. (in common language not biology). A four-engine 707 is a different type of airplane than a three-engine 727 with T-tail. Although In the case of aviation it seems to be more about commonality in flying characteristics. A 737 with larger engines that changes the handling is a different type, unless as in the case of 737 MAX software is used to remove the difference in handling, then it is considered the same type. $\endgroup$ Feb 1 at 15:10
  • $\begingroup$ @JohnK, but approval is a verb, certificate is a noun. The certificate just documents approval, right? $\endgroup$ Feb 1 at 15:22
  • $\begingroup$ @MichaelHall Actually I think I'm a little out of date. Canada has adopted "certificate" now. Mods in Canada used to be called STAs, A for Approval, but now when I look it up it says "Certificate". I've been out of the loop for a while. There was a harmonization project some years back to better align CARs and FARs. $\endgroup$
    – John K
    Feb 1 at 19:49

1 Answer 1


The word "type" has more than definition.

For example, it can also mean what you did on your keyboard to post this question...

However, in this context it is defined differently and in a manner that is entirely consistent with other uses of the word.

14 CFR defines type in Chapter 1, Subchapter A, Part 1:

(1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a specific make and basic model of aircraft, including modifications thereto that do not change its handling or flight characteristics. Examples include: DC–7, 1049, and F–27; and

(2) As used with respect to the certification of aircraft, means those aircraft which are similar in design. Examples include: DC–7 and DC–7C; 1049G and 1049H; and F–27 and F–27F.

(3) As used with respect to the certification of aircraft engines means those engines which are similar in design. For example, JT8D and JT8D–7 are engines of the same type, and JT9D–3A and JT9D–7 are engines of the same type.


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