# Why is the C-xx aircraft series used by multiple manufacturers?

Lockheed Martin C-130J Super Hercules

Boeing C-17 Globemaster III

Cessna C172

Unlike A and B, why is C used by various manufacturers? Are there any copyrights for such alphabets used in aircraft model name?

• Unlike A and B: if you think all Bs are done by Boeing, I would take a look at the B-2. And for As, a quick look at A-6 and A-10. – Federico Aug 29 '15 at 6:50
• As for B, you are forgetting all Beechcrafts. – Martin Argerami Aug 29 '15 at 16:37
• I'm wondering if you're confusing the military designations (A10, B2) with commercial model numbers (A300, A380) and atc abbreviations (B737, B777). – TomMcW Aug 29 '15 at 20:04
• @TomMcW yes I am (was) ..!! – anshabhi Aug 30 '15 at 11:16

Trademark law is a tricky thing: Two companies can use the same mark (name) as long as they are in different areas of business - like Apple (the computer company) & Apple (the record label that published The Beatles) (which got incredibly complicated when iTunes happened and the computer company entered the music business).
Even within the same business area commonly-used names can overlap. A good example of this is the Cessna 140 and Piper's Cherokee 140: they're both referred to as "a 140" in their respective pilot communities, but their manufacturer model numbers are different (Cessna's model number is 140/140A, Piper's is PA-28 140).

None of that applies in this case though, because the names you're looking at don't come from the manufacturer:

The C in US military aircraft models (C-130, C-17, C-5, etc.) specifies it as a Cargo aircraft (Similarly F is used for fighters, A for attack aircraft, and B for bombers). Combined designations also exist (e.g. the AC-130 Spectre, a Lockheed C-130, which is subsequently converted to a weapons platform by Boeing).

The aircraft designations in these cases are assigned by the military, not the manufacturer, and they may not match the manufacturer's designation (though for aircraft designed exclusively for military service they may).
Several manufacturers produce aircraft in each category (e.g. the F-14 was a Grumman aircraft, while the F-16 is made by Lockheed/General Dynamics), and many manufacturers produce aircraft in multiple categories (Lockheed for example).

The US Military Trainer version of the Cessna 172 is designated as the T-41 Mescalero, but it is clearly recognizable as a (mostly-standard) Cessna 172.

The use of C172 for the Cessna 172 is also not the manufacturer's model designation: It is the ATC aircraft type code and is used as a matter of convenience when talking about a generic aircraft (e.g. "Your typical Cessna 172"). Cessna light aircraft models are generally designated by the family number (150, 152, 162, 172, 182...) and a variant letter or letters (172S, 172RG, etc.), which indicate a specific set of aircraft within the general 172 family that share some common characteristics.

• Don't all the C172s share a type certificate? – rbp Aug 29 '15 at 15:32
• Also Apple and Apple fought it out in court, especially since Apple Computer is now in the Music Business. en.m.wikipedia.org/wiki/Apple_Corps_v_Apple_Computer – rbp Aug 29 '15 at 15:34

The reason 'C' is in the names of C-17 Globemaster III and C-130J Super Hercules is because US DoD follws the 1962 United States Tri-Service aircraft designation system.

As per this system, all aircrafts are assigned a Basic mission code, here 'C' for Cargo(Transport). This is given by the DoD and bears no resemblance to the civil aircraft (Company) name.

For example, the USAF and US Army operate a variant of Cessna 172, which is called T-41 Mescalero.

The Cessna 172 may be called C172 by some users, thought there is no 'official' name as such for the Cessna 172 Skyhawk.