From 10 February 1908, when it purchased its first aircraft, to September 1919 the predecessors of the Air Force used no designation system for its aircraft.

The first such system was introduced in September 1919 and continued until May 1924. The details of this system are listed in Table 1.

A          Ambulance
AO       Artillery Observation
CO       Corps Observation
DB       Day Bombardment
GA       Ground Attack
IL         Infantery Liaison
M         Messenger
NBL     Night Bombardment‑Long Distance
NBS     Night Bombardment‑Short Distance
NO       Night Observation
PA        Pursuit‑Air Cooled
PG       Pursuit‑Ground Attack
PN        Pursuit‑Night
PS        Pursuit‑Special
PW       Pursuit‑Water Cooled
R          Racer
S          Seaplane
T          Transport
TA        Trainer‑Air Cooled
TP        Two Seat Pursuit
TW       Trainer‑Water Cooled

Table 1: Air Force Types 1919‑1924

The next system was in operation from May 1924 to 11 June 1948, when it evolved into a similar system which continued until September 1962.

An example of a designation is EC‑121C‑LO‑20 in which:

E          =          prefix (refer table 3)
C          =          type (refer table 2)
121       =          sequence number of type
C          =          major modification (A to Z, excl. I and O)
LO        =          manufacturer (refer table 4)
20         =          block number (from FY 1941)

A          Attack, Amphibian
AG       Assault Glider
AT        Advanced Trainer
B          Bomber
BC        Basic Combat
BG       Bomb Glider
BLR      Bombardment‑Long Range
BQ       Controllable Bomb
BT        Basic Trainer
C          Transport
CG       Transport Glider
CQ       Target Control
F          Reconnaissance, Fighter
FG        Fuel Glider
FM       Fighter‑Multi place
G          Autogyro, Glider
GL        Glider
H          Helicopter
HB        Heavy Bombardment
K          Tanker
L          Liaison (from April 1942)
LB        Light Bombardment
O          Observation
OA       Amphibian
OQ       Aerial Target‑Unmanned
P          Fighter
PB        Fighter‑Biplane
PG       Powered Glider
PQ       Aerial Target‑Manned
PT        Primary Trainer
Q          Target Drone
R          Helicopter, Reconnaissance
S          Sonic Test, Search‑and‑Rescue, Sailplane
T          Trainer
TG        Training Glider
U          Utility
UC        Utility Transport (until 26 July 1947)
V          Convertiplane
X          Research

Table 2: Air Force Types 1924‑1962

May 1924 ‑ June 1948

C          Cargo/Passenger
E          Exempt
F          Photo Reconnaissance
K          Ferret
R          Restricted (not for combat use)
S          Sea‑Air Rescue
T          Trainer
V          Staff Transport
W         Weather
X          Experimental
Y          Prototype
Y1        Prototype funded from ‘Fiscal 1’ funds
Z          Obsolete

June 1948 ‑ September 1962

A          Airways Beam Checking
B          Bomber
C          Cargo/Passenger
D          Drone Director
E          Exempt, Early Warning
G          Glider, Parasite Carrier
J          Special Tests
K          Tanker
L          Liaison
M         Missile, Medical
N          Special Tests
P          Passenger
Q          Drone (recoverable)
R          Reconnaissance
S          Sea‑Air Rescue
T          Trainer
V          Staff Transport
W         Weather
X          Experimental
Y          Prototype
Z          Obsolete

Table 3: Air Force Prefixes

AB        Army Ballistic Missile Agency
AD       Aero
AE        Aeronca
AG       Air Glider
AH        American Helicopter
AJ        Aerojet General
AL        Atlantic Research
BA        Bell (Atlanta)
BB        Babcock
BC        Bell Aerosystems
BD       Bridgeport
BE        Bell (Buffalo)
BF        Bell (Fort Worth)
BH        Beechcraft
BL        Bellanca
BN        Boeing (Renton)
BO       Boeing (Seattle)
BP        Bureau of Naval Weapons
BR        Briegled, Brantly
BS        Bowlus
BU        Budd
BV        Boeing‑Vertol
BW       Boeing (Wichita)
BX        Bendix (Detroit)
BY        Bendix (Michawaha)
CA        Chase (West Trenton)
CAN     Canadair
CCF      Canadian Car and Foundry
CC        Canadian Commercial
CE        Cessna
CF        Consolidated (Fort Worth)
CH        Christopher
CK        Curtiss Wright (Louisville)
CL        Culver
CM       Commonwealth, Chrysler/Missiles
CN        Chase (Willow Run), Chrysler/Space
CO       Convair (San Diego)
CP        Convair (Pomora)
CR        Cornelius
CS        Curtiss Wright (St.Louis)
CU        Curtiss
CV        Vought
DC       Douglas (Chicago)
DE       Douglas (El Segundo)
DH       De Havilland Canada
DK       Douglas (Oklahoma)
DL        Douglas (Long Beach)
DM       Doman
DO       Douglas (Santa Monica)
DT        Douglas (Tulsa)
FA        Fairchild (Hagarstown)
FB        Fairchild (Burlington)
FE        Fleet
FL        Fleetwings
FN        Ford Aeronutronic
FO        Ford
FR        Frankfort
FS        Firestone
FT        Fletcher
GA       G & A
GC       General Motors (Cleveland)
GE       General
GF        Globe
GK       General Motors (Kansas)
GM       General Motors (Detroit)
GN       Gibson
GO       Goodyear
GP       General Electric
GR       Grumman
GT        Grant Central
GY       Gyrodyne
HA        Hughes/Missiles
HE        Helio
HI         Higgins
HO       Howard
HP        Handley Page
HS        Hawker Siddeley
HU        Hughes
IN         Interstate
KA        Kaman
KE        Kellett
KM       Kaiser
LD        Lockheed/Missiles
LK        Laister‑Kauffman
LM        Lockheed (Marietta)
LO        Lockheed (Burbank)
MA       Martin (Baltimore)
MC       McDonnell (St. Louis)
MD       Martin (Denver)
MF       Martin (Orlando)
MG       Martin (Marietta)
MH       McCulloch
MM       McDonnell (Memphis)
MO       Martin (Omaha)
MP       Minneapolis‑Honeywell
MS       Motorola
MX       Maxson
NA        North American (Inglewood)
NC        North American (Kansas City)
ND       Noorduyn
NF        North American (Fresno)
NH        North American (Columbus)
NI         North American (Downey)
NK        Nash‑Kelvinator
NL        Norris Thremador
NO       Northrop
NT        North American (Dallas)
NV        Northrop (Ventura)
NW       Northwestern
OM       On Mark
PH        Piasecki
PI         Piper
PL        Platt‑le‑Page
PP        Philco
PR        Pratt Read
RA        Republic (Evansville)
RD       Read‑York
RE        Republic (Farmingdale)
RI         Ridgefield
RL        Raytheon (Lexington)
RO       Robertson
RP        Radioplane
RW       Raytheon (Waltham)
RY        Ryan
SA        Stroukoff
SC        Southern
SE        Seibel
SI         Sikorsky
ST        St. Louis
SP        Spartan
ST        Space Technology
SU        Sperry (Utah)
SW       Schweizer
TA        Taylorcraft
TE        Temco
TH        Thiokol
TI          Timm
TE        Texas Engineering
TX        Texas Instruments
UH        Hiller
UN        Universal Moulded Products
VE        Vega
VI         Vickers Canada
VL        Vertol
VN        Vultee/Convair (Nashville)
VO       Vought
VU        Vultee/Convair (Downey)
VW       Vultee/Stinson (Wayne)
WA       Ward
WE       Western Electric
WI        Wichita Engineering
WO       Waco

Table 4: Air Force Manufacturers


Before 1917 the serials of the US Navy aircraft included a designation code as part of this serial (refer table 5).


A          Curtiss (Land and Hydroplanes)
B          Wright (Land and Hydroplanes)
C          Curtiss (Flying Boats)
D          Burgess & Curtiss (Hydroplanes)
E          Curtiss (Amphibian)


AH        Hydro Aeroplane
AB        Flying Boat
AX        Amphibian

Table 5: US Navy 1911‑1916

No designation system was used between 1917 and 1922.

On 29 February 1922 a designation system was introduced that, apart from some modifications, such as the reversal of manufacturer and type code on 10 March 1923 and other on-going modifications, was used until 18 September 1962.

An example of a designation is XF8F‑2N in which:

X          =          prefix (refer table 7)
F          =          type (refer table 6)
8          =          sequence number of type for manufacturer
F          =          manufacturer (refer table 8)
N          =          suffix (refer table 7)


A          Ambulance, Attack
B          Bomber
BD       Assault Drone
BF        Bomber‑Fighter
BT        Bomber‑Torpedo
DS       Anti‑submarine Drone
F          Fighter
G          Single Engined Transport, Tanker
H          Hospital, Helicopter(*)
J          Transport, Utility
JR        Utility Transport
L          Glider(*)
M         Marine Expeditionary
N          Trainer
O          Observation
OS       Observation Scout
P          Pursuit, Patrol
PB        Patrol Bomber
PTB      Patrol Torpedo Bomber
R          Racer, Transport
RO       Rotorcycle
S          Scout, Anti‑submarine
SB        Scout Bomber
SN        Scout Trainer
SO       Scout Observation
T          Torpedo, Transport, Trainer
TB        Torpedo Bomber
TD        Traget Drone
TS        Torpedo Scout
U          Unpiloted Drone, Utility
W         Eelectronic Search
Z          Airship(*)
(*) these designations were followed by a further letter.

Table 6: Navy Types 1922‑1962

Note that the letters H, L, Z, as well as the letter V for winged aircraft which was never shown, were part of an identifcation system for types of Navy vessels, which included ships, such as C for Carriers.

A          miscellaneous modifications, armament fitted, arrester gear, ex Army, amphibious, land based version
B          miscellaneous modifications, special armament, British version
C          arrester gear, reinforced for catapulting, cannon armed
CP        trimetrogen camera
D          droptanks, drone control, special search or radar
E          electronic equipment
F          flagship conversion, special power plant
G          gun fitted, search and rescue
H          hospital
J          special weather equipment
K          drone conversion
L          winterised, searchlight equipment
M         missile launcher
N          night fighter, all weather
NA        night fighter modified for day attack
NL        night fighter winterised
P          photographic
Q          electronic counter measure
R          transport
S          anti‑submarine
T          trainer
U          utility
W         special search, early warning
X          experimental
Y          prototype
Z          administration
Note that in some cases an Army suffix was used.

Table 7: Navy Prefixes and Suffixes 1922‑1962

A          Aeromarine, Allied, Atlantic, Brewster, General, Noorduyn
B          Beechcraft, Boeing, Budd, Aerial
BS        Blackburn (*)
C          Cesnna, Convertawings, Culver, Curtiss, De Havilland Canada
CH        Caspar (*)
D          Douglas, McDonnell, Radioplane, Frankfort
DH       De Havilland (*)
DW       Dayton‑Wright
E          Bellanca, Edo, Elias, Gould, Hiller, Piper, Pratt‑Read
F          Fairchild (Canada), Fokker, Grumman
G          Gallaudet, Eberhart, Globe, Goodyear, Great Lakes, AGA
H          Hall‑Aluminium, Howard, Huff‑Daland, McDonnell, Stearman‑Hammond, Snead
HP        Handley Page (*)
J          Berliner Joyce, General, North American
JL         Junkers Larsen (*)
K          Fairchild (Kreidner Reisner), Kaiser, Kaman, Keystone, Kinner, J.V. Martin, Kreidner Reisner, Nash‑Kelvinator
L          Bell, Columbia, Loening, Langley, LWF
M         Martin, General Motors, McCullough
N          Gyrodyne, Naval Aircraft Factory
O          Lockheed, Piper, Viking
P          Piasecki, Piper, Pitcairn, Spartan, Vertol
PL        Parnall (*)
Q          Bristol, Fairchild, Stinson, Ward Hall
R          Aeronca, American, Brunswick‑Baltic‑Collender, Ford, Interstate, Maxson, Radioplane, Ryan
RO       Romeo (*)
S          Schweizer, Sikorsky, Stearman, Stout, Sperry, Supermarine
T          New Standard, Northrop, Taylorcraft, Temco, Timm, Thomas Morse
U          Vought
V          Lockheed, Vultee, Vickers (Canada)
VK        Vickers (UK) (*)
W         Waco, Wright, Willy’s Overland, Canadian Car & Foundry
X          Cox Klemin
Y          Consolidated (Convair)
Z          Pennsylvania Aircraft

Table 8: Navy Manufacturers 1922‑1962

(* = not effectively used)

The same designation system was also used for aircraft of the USMC and the USCG.

The Navy system did not have a classification for experimental aircraft. Instead these aircraft were designated by the manufacturer’s code followed by the manufacturer’s model number (eg Douglas D-558, Kaman K-225 and Vought V-173).

This treatment was formalised in BuAer Instruction 05030.4 (Model Designation of Naval Aircraft, Guided Missiles and KD Targets), dated 17 October 1957 which stated in paragraph 3.b.:

“Research Airplanes: Airplanes designed and constructed for research purposes are designated by the designer’s code letter (see 3.a.5.) followed by his design project number, for example:”D-652″ would designate a naval research aircraft designed by Douglas and would be the 652nd design project by Douglas.”


From 1956 to September 1962 the US Army used its own designation system.

An example of a designation is YAO‑1‑GR in which:

Y          =          classification (where appropriate) (refer table 9)
A          =          configuration of aircraft (refer table 9)
O          =          aircraft type (refer table 9)
1          =          sequence number of type/function
GR       =          manufacturer (refer table 10)


D          Drone
J          Special test, temporary
N          Special test
T          Training
X          Experimental
Y          Service trials

Configuration of Aircraft

A          Fixed Wing
H          Helicopter
V          V/STOL aircraft

Aircraft type

C          Transport
O          Observation
S          Staff transport
T          Training
U          Utility
Z          Experimental

Table 9: US Army Type

AP        Curtiss Wright (Aero Physics)
AV        Avro Canada
BF        Bell
BR        Brantley
BV        Boeing‑Vertol
CH        Chrysler
DA       Doak
DH       De Havilland Canada
DJ        Sud‑Ouest
FA        Fairchild
GI         Goodyear
GR       Grumman
HS        Hawker Siddeley
HU        Hughes
LO        Lockheed
PH        Piasecki
RY        Ryan
UH        Hiller
VL        Vertol
?          Mississippi State University
?          De Lackner

Table 10: US Army Manufacturer


Early attempts toward a unified designation system started in the early fifties and resulted, in particular, in the use of the T-28 designation for both the US Air Force and the US Navy as well as the T-34 designation. In addition some designations were ‘reserved for US Navy use’, such as some designations in the H = helicopter series which were re-used at a later date.

It was not until 18 September 1962 however, that the Department of Defense established a tri‑service designation which was based on the then existing Air Force system. The directive was issued on 6 July 1962.

This system also prescribed the two-letter code suffix to identify the manufacturing plant of an aircraft but they were dropped from the regulations in 1976 although, in some instances, they continued to be used informally after that date.

An example of a designation is XFV‑12A‑NR in which:

X          =          prefix (refer table 12)
F          =          prefix (refer table 12)
V          =          type (refer table 11)
12         =          sequence number of type
A          =          major version (A to Z, excl. I and O)
NR        =          manufacturer (refer table 4)

Sometimes a block number is added.

A          Attack
B          Bomber
C          Transport
E          Electronic
F          Fighter
G          Glider*
H          Helicopter*
K          Tanker
L          Laser
O          Observation
P          Patrol
Q          Drone (recoverable) (from 1997)
R          Reconnaissance
S          Anti‑submarine
T          Trainer
U          Utility
V          V/STOL*
X          Research
Z          Airship*
*preceded by a further type letter.

Table 11: Tri‑Service Type

A          Attack
C          Transport
D          Drone Director
E          Electronic Search
F          Fighter
G          Permanently Grounded (not normally referenced)
H          Search and Rescue
J          Special Tests (Temporary)
K          Tanker
L          Cold Weather Version
M         Missile Carrier, Special Missions
N          Special Tests (Permanent)
O          Observation
Q          Drone (recoverable)
R          Reconnaissance
S          Anti‑submarine
T          Trainer
U          Utility
V          Staff Transport
W         Weather
X          Experimental
Y          Prototype
Z          Design Study

Table 12: Tri‑Service Prefixes

Although in principle the tri‑service commenced each type designation with ‑1, in practice the H, T, U and X type designations continued the sequence of the preceding Air Force designations even though the H and T type designations commenced with ‑1 in 1962. In particular the T-designation has been confusing because both sequences have been used simultaneously whilst the tri-service sequence was ‘re-started’ at some point in time.

There are various non-standard designations; mostly these are ‘designations of convenience’, such as the KC-10A. There is also evidence of skipping of designations either to avoid confusion with other aircraft, the prime example being V-14/X-14, or simply to facilitate the request by the manufacturer, such as F-19/F-20.

Around 2000 a trend developed to assign designations which were significantly out of sequence. These were mainly ‘designations of convenience’ and in most cases the reason is obvious.

Prior to computer records a sequential designation system aided in filing and retrieving hard copy records of aircraft. These days, with computers, there is no need for a strict sequential sequential order. In addition aircraft manufacturers began to suggest a designation that had a commercial value.

Designations also include non-standard pre-fixes which, in some cases reflect the country that has purchased the aircraft, eg NF-5A for the Netherlands. It is likely that these are not formal Tri-service pre-fixes.

In addition, non-standard suffixes have been used extensively.

There are also a number of aircraft which do not have a designation at all. Some of these are confiscated aircraft, others seem to be used in operational situations.

Civil Air Patrol

Gippsland GA.8
of CAP (Source: CAP)

Aircraft operated by the Civil Air Patrol (CAP) do not carry designations or military serials. Instead they are included in the civilian register.

Allocation of Designations – Process

The current process of allocating a designation is explained in the following article:


By Andreas Parsch, 28 October 2002

Through FOIA requests to the USAF Nomenclature Office, I have gained a reasonably clear picture of how an official U.S. military aircraft or missile designation (called an “MDS”, for “Mission, Design, Series”) is allocated.

Because there have been a few misunderstandings about this subject, especially as to who decides what and when, I’ll explain in some detail the various steps taken when establishing an official MDS.

The central coordinating office in the process is the USAF Nomenclature Office (part of AFMC/LGIS at Battle Creek, MI). It is officially the DOD Control Point (DODCP) for aerospace nomenclature assignments. I will refer to this office as DODCP in this article.

Step 1

Before official (written) correspondence is started, sometimes (probably often, possibly almost always) someone from the Program Office (PO) of an aircraft/missile program phones or faxes the DODCP for some informal discussion on a new MDS for their vehicle. If an MDS is tentatively established, DODCP records this MDS and very sketchy data on the project (e.g. the department of the requester) either on a Nomenclature Record Form, or simply on an informal hand-written note. This record (form and/or note) is then stored in a ledger book, and the MDS is now regarded as “reserved” (at least that’s the term which continues to be used in the replies to my FOIAs). So if a new MDS in the same mission series is requested soon afterwards, the reserved MDS will be skipped.

[Step 1, while apparently frequently taken, is not strictly necessary. In principle, the PO can start with Step 2.]

Step 2

The PO sends a written request for assignment of a new MDS to the DODCP. For USAF POs this is done directly, while for Navy/Army/NASA/CG, this is done via that service’s DCP (Departmental Control Point), which handles and forwards all MDS requests for the respective service. The written request must include a reasonably detailed description of the program and the vehicle, so that DODCP can determine which new MDS (if any!) should be assigned. The request must include a proposal for an MDS. For a completely new design (as opposed to a modification of an exsting one), a proposal for a design number may or may not be included. E.g., the request can ask for allocation of “C-___A” if simply the next C-series number is desired. On the other hand, e.g. “C-42A” can also be requested when the requester particularly likes the number 42 and/or thinks it’s the next in sequence anyway.

[If Step 1 is never followed by Step 2, the result is a reserved MDS which is never officially requested, let alone assigned. This has e.g. happened for A-11, C-36, V-17/19/21 and X-39, and effectively results in a gap in the list of allocated designations. However, if a reservation is explicitly cancelled by the original requester before the next number is allocated, the number can effectively be reused (as has been the case for C-16)]

Step 3

DODCP checks for any inconsistencies between the proposed MDS and the regulations. In the end, DODCP comes up with a recommended designation, which may or may not be identical to the one proposed by the requester. Especially if Step 1 is omitted, discrepancies are not unlikely.

Step 4

DODCP sends a copy of the original request, together with its own recommendation, to the USAF Headquarters (HQ USAF) in the Pentagon, where the final decision for MDS allocation is made. DODCP (usually) includes a proposed brief data set for the MDS for inclusion in DOD’s official MDS listing (publication DOD 4120.15-L

Step 5

HQ USAF decides which of the proposed MDS (the originally requested one or – if different – the DODCP’s recommendation) is to be used. In theory, HQ USAF can also come up with an MDS of its own and have this allocated. In practice, however, in most cases the originally requested MDS is approved, even if DODCP recommends a different one. A classical example for this case is the F-35 designation. It can also happen that HQ USAF completely rejects MDS assignments, leaving the MDS effectively in the “reserved” state. This has happened, e.g., for “XAGM-153A”.

Step 6

HQ USAF sends its decision (usually, confirmation of the assigned MDS) back to DODCP. DODCP then stores all related correspondence away in its filing system, and creates a proper entry for the new MDS in its internal database system.

Step 7

DODCP notifies the PO (for USAF programs) or the responsible DCP (for non-USAF programs) of the result of the request (usually, the assignment of an official MDS).

Project Numbers

In the 1930’s aircraft which were tested were given a designation in a series commencing with 900, preceded by letters such as XP, XB etc. Some of these aircraft were later procured and given a proper designation, others were never procured.

Table 13 lists these aircraft.

Where the tests resulted in the procurement of aircraft with a standard designation, these test have been discussed with that designation. In those instances where the tests did not result in a procurement, the aircraft have been discussed as undesignated aircraft. Those aircraft for which no details have been found have been markes as * in the following list.


XP-900             Lockheed YP‑24
XB-901             Boeing YB‑9
XP-902             Boeing pursuit (*)
XP-903             Boeing pursuit (*)
XP-904             Curtiss XP-23 (?)
XB-906             Ford Trimotor Bomber
XB-907             Martin XB‑10
XP-908             Keystone or Curtiss
XC-909             Northrop YC-19
XC-910             Boeing Monomail (C-18)
XO-911             Curtiss observation (*)
XPT-912            Stearman YPT-9
XPT-913            Spartan C2-60 primary trainer
XPT-914            Verville YPT-10A
XPT-915            Stearman YBT-5
XB-917             American Airplane bomber (*)
XC-918             Douglas Y1C-21
XC-920             Sikorsky Y1C-28
XB-921             American Airplane Pilgrim 100B
XP-923             Command Aire pursuit
XO-924             Thos. Morse Y10‑42
XP-925             Boeing 218
XO-926             Vought observation (*)
XP-927             New Standard pursuit
XC-928             Fairchild (*)
XP-929             Northrop pursuit
XO-930             Great Lakes (*)
XPT-930            Inland Model T
XPT-931            New Standard D-32
XO-932             Thos. Morse Y1O‑41
XPT-933            Consolidated Y1PT‑11
XP-934             Curtiss XP‑31
XBT-935            Stearman (?)
XP-936             Boeing Y1P‑26
YBT-937            Consolidated Y1BT-7
XA-938             Lockheed Y1A‑9
XP-939             Lockheed (?)
XP-940             Boeing XP‑29
XC-941             Fairchild XC‑31
XC-942             Bellanca Y1C-27
XPT-943            Stearman PT‑13
XA-944             Seversky SEV-3 or Sikorsky Amphibian (as XC-944)
XPT-945            Stearman XPT-13
XP-948             Northrop 3A or Vought V-143
XB-950             Martin 123 (B-10)

Table 13: 900 series

Bureau of Aeronautics design numbers

The US Navy’s Bureau of Aeronautics (BuAer) was established on 10 August 1921. Its duties were defined as comprising “all that relates to designing, building, fitting out, and repairing Naval and Marine Corps aircraft”.

As part of the process of defining types of aircraft needed, the BuAer used its drafting rooms to make design studies, including three-view drawings, performance calculations and, sometimes, wind tunnel data. After basic decisions were made, BuAer began sending the drawings and data to industry as part of informal design competition. Thus, the companies could either propose their own designs or develop an airplane based on the BuAer design. After they responded, BuAer evaluated their proposals, usually selected one or more for development, and issued contracts for complete design data and prototype airplanes.

In the late 1930s, BuAer stopped putting three-view drawings in the design competition package. Losers had complained that they were not chosen because they had not slavishly followed the whims of BuAer’s designers. Eliminating the drawings not only freed BuAer from that charge, but also eliminated any tendency among company designers to copy a BuAer design rather than use it as guidance in thinking creatively about the Navy’s problems.

In the late 1920s and early 1930 a number of these specifications were identified as BuAer designs. Known numbers are listed, along with the designations of the contractors’ aircraft. It may be possible that other numbers were not all associated with aircraft.

BuAer 35           Boeing TB
BuAer 77           NAF T2N, Martin T5M
BuAer 86           Berliner Joyce OJ, Keystone OK
BuAer 96           Atlantic FA, Curtiss F9C, Berliner Joyce FJ
BuAer 106         Great Lakes SG, Loening S2L, Sikorsky SS
BuAer 107         Martin FM
BuAer 110         Great Lakes BG, Consolidated B2Y
BuAer 111         Two seat bi-plane fighter (F12C)
BuAer 113         Vought F3U, Douglas FD
BuAer 120         Berliner Joyce F3J, Loening FL, Grumman F2F
BuAer 124         ‘Hook-up’ fighter for airships, to replace F9C (not built)
BuAer 145         Replacement of Douglas TBD (not built)

Table 14: BuAer design numbers

Possible Design 124
(Source: R.C. Johnson)

There was also a series of Bureau of Aeronautics Design Research Division Study (ADR), with known numbers 42 and 45. It is likely that this series was used post-war.

The US Navy also used Outline Specification (OS) and Type Specification (TS) designations during design stages.

Materiel Command Design numbers

The Materiel Command Design (MCD) at Wright Field, Ohio) also had an in-house design staff, just as BuAer did, and they also produced design packages intended to suggest what might meet Service’s needs, or simply what might be technically feasible for a given requirement. It is known that MCD numbers were assigned but no registry of MCD number has surfaced.

 EPSON scanner image
392 (also associated with MX423) (Source: Wright Field Aircraft Lab.)

Other designations

In the late forties experimental projects were assigned a MX number whilst, commencing in the fifties new Weapons and Support Systems were identified by the letters WS and SS, followed by a number.

Examples of MX numbers are MX‑324 and MX‑334, both a Northrop design as discussed as an undesignated aircraft, MX‑653 (which evolved into the X‑1) and MX‑774 (which evolved into the SM‑65).

Aircraft Serials

Three distinct systems of numbering individual aircraft are used by resp. the Air Force, the Navy and the Coast Guard.

Air Force

Air Force aircraft between 1908 and 1917 were numbered sequentially.This sequence was continued from 1917 to 1921 but with the prefix AS. In mid-1918 a separate series for seaplane was commenced and which was discontinued in 1919.

A separate series, commencing with 94000, was used from 1919 for aircraft that were tested. This series continued until early 1920.

From 1 July 1921 Air Force aircraft were numbered by Fiscal Year (FY) commencing with 22‑001. Originally the aircraft displayed the second digit of the year followed by the sequence number in that year so that the 375th aircraft procured during the FY 1957 had serial 57‑375 in the records and displayed the number 7375 on the aircraft itself.

If after a period of 10 years the aircraft was still on strength and the number was likely to cause confusion with a later aircraft, eg 67‑375, the number displayed on the earlier aircraft was preceded by a ‘0’, eg. 0‑7375.

In 1923 the USAAC briefly used a separate serials sequence for gliders whilst there is an indication of separate serials for airships and balloons in the thirties.

At various times some missiles (but clearly not all) purchased in a FY were included in the same annual sequence of aircraft serials. There is also evidence of a separate series of serials for guided missiles incorporating the letters GM (from 1952 to 1954) and R (from 1955 to, at least, 1958) in the fiscal year part of the serial.

US Army

The US Army has always used serials within the USAF system. Initially these were intermixed within the same sequence but, beginning in 1967, the US Army began using serials beginning at 15000 for each FY. In 1971 the US Army started a new serial series, starting at 20000, but still linked to a FY indicator. This series has continued consecutively since then.


Since the 1990s the straight annual sequence has increasingly been interrupted through:

  • long range production programme where aircraft procured in different years have sequential serials irrespective of the FY;
  • serials made up of FY+construction number;
  • serials made up of FY+a digit to indicate the first unit that operated the aircraft (eg in the case of some C-130H/J aircraft).

In particular on combat aircraft, the serials can be shown truncated in such a manner that it does not readily reveal the FY and serial.

Like with designations, whilst originally serials were in a neat sequential order to enable filing of hardcopy cards, these days there is no need for such a sequential order.


Serials for the US Navy and USMC aircraft are issued by the Bureau of Aeronautics (BuA). The serials do not include missiles.

An alphanumeric was introduced in 1911 which was used to 1914. After that a revised alphanumeric system was introduced.

The first numeric series was commenced with A51 on 19 May 1917. It was used until 9999 was reached in 1933. The A prefix was dropped on 1 June 1931 from 9206 onwards.

In 1933 a second series was commenced with 0001. When this series reached 7303 in 1940, a third series was commenced with 00001. This series, now in six digits, remains in use.

Coast Guard

From 1927 to 1934 the US Coast Guard had a two digit serial system. From 1935 to 1936 a three digit serial was used in which the 100 series was for amphibians, 200 for flying boats, 300 for land planes and 400 for convertibles. On 13 October 1936 a V prefixed serial was issued, commencing with V101. This was applied to all aircraft ever owned by the USCG, including those no longer in service. The V was dropped in 1945 and in January 1951 a ‘1’ was placed before the serials.

From February 1969 a separate series, commencing with 1, was used for Executive aircraft.

There is currently evidence this system of serials has been abandoned in favour of a system in which the first two digits refer to a specific type.

In addition the US Coast Guard has used aircraft previously owned by the US Navy or USAF and used these with the original US Navy or USAF serial although truncated to four digits.

When aircraft transferred from one service to another, they usually retained their original serial which, however, may be modified in appearance.

Other serials

From 1917 to the late 1920’s individual aircraft which were tested at McCook Field, later Wright Field, were given a P‑serial. Some of these aircraft also carried normal serials. In the discussion of aircraft these have been referred to as Wright Field serials even though, in some instances, the serials were assigned whilst test were still performed at McCook Field.

P serial, no other US identification
(Source: H. Vossers archive)

Various identification schemes have been used for captured equipment, including TAIC‑#, S‑#, EB‑#, FE‑# and TC‑# with some aircraft receiving serials in multiple systems (in particular FE and TC). Some aircraft were given normal serials.

Messerschmitt Me-109
(Source: USAAF?)

Throughout the years there have been aircraft which were registered to the US military forces with civilian registrations. These included aircraft used at training facilities.

Aircraft Markings

Nationality Insignia

During the Mexican War (1915) aircraft of the Army carried a blue star on a white disk.

The American Expeditionary Force in France (1917‑1918) carried red‑blue‑white roundels.

On 21 April 1917 the US Navy adopted a white star with a red centre on a blue disc. The Army adopted a similar insignia on 1 January 1921.

On 18 August 1942 the red centre was deleted.

On 29 June 1943 two white bars were introduced to the star and the entire insignia was bordered in red.

On 17 September 1943 the red border was replaced by a blue one.


On 11 June 1948 a red line appeared in each of the white bars.

With the introduction of low‑visibility paint schemes, an insignia in an outline of black or grey was introduced.

Aeronca L-16 of New York CAP
(Source: CAP?)

The Civil Air Patrol aircraft carried an insignia showing a red three-bladed propeller in the Civil Defense white-triangle-in-blue-circle. The red markings were later deleted for aircraft in combat areas to prevent confusion with enemy insignia.

‘Buzz’ letters

During and after the second world war, certain Air Force aircraft carried call signs consisting of two so‑called ‘buzz’ letters followed by the last three digits of the serial. These ‘buzz’letters are listed in table 3.1 although in a number of cases the ‘buzz’ letters were never carried on the aircraft.

Attack Aircraft
AA = A‑24, AB = A‑25, AC = A‑26, AD = A‑31, AE = A‑41

Bomber Aircraft
BA = B‑17, B‑57, BB = B‑19, B‑66, BC = B‑24, B‑26, BD = B‑25, BE = B‑26, B‑45, BF = B‑29, BG = B‑32, B‑35, BH = B‑37, B‑45, BJ = B‑39, BK = B‑42, B‑50; BL = B‑44, BM = B‑36

Transport Aircraft
CA = CQ‑3, CB = C‑43, CC = C‑45, CD = C‑46, CE = C‑47, CF = C‑48, CG = C‑49, CH = C‑53, CJ = C‑54, CK = C‑60, CL = C‑64, CM = C‑69, CN = C‑74, CP = C‑78, CQ = C‑82, CR = C‑87, CS = C‑97, CT = C‑99, CU = C‑117, CV = C‑119

GA = PG‑2, GB = PG‑3, GC = CG‑4, GD = CG‑10, GE = CG‑13, GF = CG‑14, GG = CG‑15, GH = CG‑18

Photo Reconnaissance Aircraft
FA = F‑2, FB = F‑5, FC = F‑6, FD = F‑7, FE = F‑9, FF = F‑10, FG = F‑13, FH = F‑15

FA = F‑94, F‑5, FB = F‑101, FC = F‑102, FD = F‑103, FE = F‑106, FF = P‑51, FG = F‑104, FH = F‑105, FJ = F‑4, FK = F‑61, FN = F‑80, FP = F‑81, FQ = F‑82, FS = F‑84, FT = F‑80, FU = F‑86, FV = F‑89, FW = F‑100
PA = P‑38, PB = P‑39, PC = P‑40, PD = P‑42, PE = P‑47, PF = P‑51, PG = P‑55, PH = P‑58, PJ = P‑59, PK = P‑61, PL = P‑63, PM = P‑75, PN = P‑80, PP = P‑81, PQ = P‑82, PR = P‑83, PS = P‑84

Liaison Aircraft
LA = L‑2, L‑4, LB = L‑3, L‑5, LC = L‑4, L‑16, LD = L‑5, L‑17, LE = L‑6, L‑15, L‑18, LF = L‑14, L‑19, LG = L‑13, L‑20, LH = L‑16, L‑21, LJ = L‑17, LK = L‑26

Training Aircraft
TA = AT‑6, TB = AT‑7, TC = AT‑11, TF‑102, TD = AT‑21, T‑34, TE = BT‑12, T‑37, TF = PT‑13, T‑38, TG = PT‑17, T‑39, TH = PT‑19, TJ = PQ‑8, T‑41, TK = PQ‑14, TL = T‑28, TP = T‑29, TQ = T‑31, TR = T‑33

Table 15: ‘Buzz’ Letters

Other Markings

Over the years aircraft of all services have carried squadron and other unit insignia as well as individual markings. Included in these markings are letter codes indicating either the unit or the base to which the aircraft belongs.


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