Can someone describe the numbering system used by the military and how it has changed over the years? I know that there are fighter aircraft such as the F-15, F-16, F-22, etc but why are there aircraft numbered like the F-117? and why is the B-2 a B-2 when we have had B-17s in the past?


1 Answer 1


At present, all US military aircraft follow the 1962 United States Tri-Service aircraft designation system. The first letter ('F' or 'B') denotes the mission of the aircraft, while the number denotes the design number. The designation system produces a Mission-Design-Series (MDS) designation. From Designating and Naming Military Aerospace Vehicles:

4.1. Designator Definition:

4.1.1.The MDS designator is an official DoD recognized alpha-numeric symbol designation of a military defense aerospace vehicle. .... The designator describes the aerospace vehicle in two components where the components are separated by a hash.The first component, comprised only of alpha characters, describes the mission of the vehicle.The second component, comprised of both alpha-numeric characters, describes the design number and design series of the vehicle.

4.1.2. Standard aircraft MDS designators are comprised of the following: status prefix(optional), modified mission(optional), basic mission(required), design number (required), design series (required).

The document also gives some examples of this implemenatation:

Tri Service designation

Tri service designation- examples

Both tables from Designating and Naming Military Aerospace Vehicles

The 1962 system replaced the earlier system, where each service had their own systems in place for naming of aircraft.

More details about the aircraft designation can be found in this page.

Basically, the counters were reset while the 1962 sytem was adopted, leading to unrelated sets of aircraft numbering. As for individual aircraft numbering, there has been a number of cases where the system was not followed, like the F-117 Nighthawk.

Adherence to this system has been patchy at best. So, you have B-1 Lancer and B-2 Spirit after B-52 Stratofortress (this was due to the counters being reset), while the next bomber has been named B-21 Raider.

  • $\begingroup$ And what are the usual missions of the vehicle that gives the first component, comprised only of alpha characters? F for fighter? B for Bomber? W for weather? $\endgroup$ Commented Oct 11, 2016 at 8:55
  • 1
    $\begingroup$ @Marine1 Yes. A for attack, B for Bomber, C for transport etc. It's in attachment 3 of the linked document. $\endgroup$
    – aeroalias
    Commented Oct 11, 2016 at 9:01

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