The United States Navy acquired its first aircraft in 1911, a Curtiss Triad pusher floatplane.
Originally, the US Navy assigned serial numbers to its airplanes sequentially by manufacturer, a
separate sequence of numbers for each manufacturer.
The serial number had two parts. The first part was a letter which designated the manufacturer--
A for Curtiss, B for Wright, etc. The letter was followed by a number to show the
sequence of procurement from each manufacturer. For example, the first Curtiss-built Navy
airplane was serialed A-1, the second A-2, etc.
The system had to be quickly adapted to
accommodate different types of airplanes obtained from the same manufacturer--Curtiss had to be
given another letter, C, to distinguish its flying boats from its pontoon seaplanes,
the letter D was assigned to Burgess and Curtis (no relation), and E was assigned to Curtiss
amphibians.
In March of 1914, this manufacturer-based designation system was abandoned and was
replaced by a two-letter type and subtype classification scheme. The first letter was
the type or class--A stood for
Heavier Than Air, B for Free Balloon, C for Dirigible, and D for Kite Balloon. A second
letter was used to designate the subtype--for example AH was a hydro airplane, AB was a
flying boat, and AX was an amphibian. All of the surviving aircraft acquired under the
original scheme were redesignated and reserialed. A separate sequence of
serials was assigned to each type/subtype classification.
In May of 1917, at the time of US entry into WW 1, this was changed to a
sequential numerical list, irrespective of type. For some reason, the number 51
was taken as a convenient starting point. The old prefix letters were
retained for a short time, but no longer had any relationship to the serial numbers.
On May 19, 1917, the prefix letters were officially abandoned and replaced by the
single letter A for Aeroplane. These numbers were initially termed "building numbers", but
were later termed "designating numbers". In later years, they came to
be known as Bureau Numbers (BuNos), since they were assigned by the Navy's Bureau
of Aeronautics after that organization was established in 1921. The A-prefix was
deleted from the numbers at the end of Fiscal Year 1930 (after OJ2, A-9204).
The original sequence reached 9999 in 1935, and rather than expand the serial
number to five digits, a new sequence of numbers was started at 0001. This is the
so-called second series of Bureau Numbers.
In 1940, so many aircraft were being ordered as a result of President Franklin Roosevelt's
rearmament program that it was found necessary to terminate the second series at 7303 in order
to avoid confusion with aircraft having late numbers in the original series that were still in
service. A third (and final) series of Bureau Numbers was started with 00001 (using 5 digits from
the beginning). When the third series reached 99999 in 1945, it was allowed to continue into
six digits. This series of numbers continues in the present day. It has now reached over 165000.
Marine Corps aircraft are procured by the Navy, so they use Navy Bureau Numbers, but
the Coast Guard is a part of the US Department of Homeland Security (during peacetime) and
uses its own serial number sequence.
A Bureau Number is assigned to an aircraft when it is initially ordered, not when it is
actually delivered to the Navy. The total number of serial numbers assigned (by
now over 165000) does not reflect the actual number of aircraft delivered, because of large-scale
contract cancellations at the end of World War II and other program changes in recent years.
Not every assigned bureau number necessarily indicates an actual aircraft in Navy service, because
program cancellations often took place before actual delivery. In the pre-war years, assigned
bureau numbers that were cancelled before delivery were not reassigned, although this was quite
often done with late World War II numbers. There are occasional situations in which a bureau
number batch was successively allocated to two or even three separate aircraft orders, only to have
them all cancelled before delivery.
The US Air Force has an entirely different
serial numbering scheme, based on aircraft procurements within each fiscal year.
Occasionally, aircraft are transferred from the USAF to the Navy.
If the transfer is anticipated to be permanent, it is usually the case that
the transferred aircraft are given brand new Navy bureau numbers.
However, if the transfer is anticipated to be only temporary, the original USAF
serial numbers are often retained in Navy service, but sometimes it happens that aircraft loaned
to the Navy are assigned brand-new bureau numbers. Unfortunately,
the system is not always consistent.
There are several major exceptions in the assignment of numbers in the six digit numbering system.
In the 1960s, there were a block of six-digit numbers beginning with 00 that were assigned to an antisubmarine
drone helicopter known as QH-50C and QH-50D. The reason for this odd system seems to have been lost in history.
Another major exception is a set of non-sequential numbers beginning with 198003 and ranging
up to 999794. These numbers were usually assigned to aircraft that came to the Navy from the Air Force,
the Army, or even from foreign organizations. There doesn't seem to be any rhyme or reason to these
assignments--in many cases they were derived by modifying the Air Force aircraft numbering system. In other cases,
they were constructed out of manufacturer's construction numbers. For example, the Marine Corps
F-21As that were leased from Israel in 1987 for dissimilar air combat training were given bureau numbers
derived from the aircraft's three-digit construction number prefixed by 999.
In the immediate postwar years, like the USAF, the US Navy/Marine Corps often used a production block system
to keep track of minor production line changes that were not deemed sufficiently drastic as to call
for a new aircraft configuration sequence number. This system continued after the adoption
of the unified designation system in 1962. Just like the Air Force, the Navy/Marine Corps
did not use production block designations for all of their aircraft, and there was considerable
variation in the systems used from one aircraft type to another.
Block Numbers normally progressed in increments of 5 starting with -1, then -5, -10 and so on.
Intermediate numbers were reserved to denote field modifications carried out after the aircraft's delivery,
although the use of these seems to be exclusive to the USAF, and there is no known record of any
USN aircraft having such intermediate numbers. Exceptions to the 'plus 5' rule of progression were
fairly frequent, the prime examples being the McDonnell Banshee, Demon, and Phantom and the LTV
Corsair II, whose Block Numbers
progressed in single increments -1. -2, -3 and so on.
In addition to Block Numbers. the Navy also often used Block Letters to denote different production standards. although these
don't seem to be related to any USAF-style designation. . There were various
letter styles and combination of letters that were used. The differing styles appear to have no
particular significance and probably
existed because of the lack of any firm USN directive on the subject. Sometimes the sequence started
with the letter 'A' or 'a",
with the first change in production standard being denoted by 'B', then 'C', etc, until 'Z' was
reached. If letters beyond 'Z'
were required, it sometimes happened that the letters are started over from 'A', but on other
occasions the next change was denoted by 'AA'
to 'ZZ' . In order to avoid confusion with the number zero, the letter 'O' is skipped.
In the Navy, these Block Letters or Numbers were affixed to the
Bureau Number rather than being attached to the official designation
as was the practice in the USAF. However, unlike in the USAF, the Block Letter or Number was
most often used strictly on official records and was very
rarely painted on the aircraft itself.
When the Block Letters or Numbers do appear on the aircraft, they usually appear as a suffix
to the the full six-figure BuNo that appears either on the rear fuselage or fin, with the
letter or number appearing in smaller characters than the BuNo itself.
In the immediate postwar years, a scheme was adopted in which the designation and the
BuNo of the aircraft were painted in very small letters on the rear fuselage. Since
this number is seldom readily visible at any distance on most
Navy and Marine Corps aircraft, the last four numbers of the BuNo were often painted in
large characters on the fuselage sides or on the vertical tail, but there were
occasions in which the entire BuNo was replicated. This number became known as the modex.
There is some controversy as to the origin of the name "modex".
One possibility seems to be as follows.
When naval aircraft fly in their own controlled areas, they are identified by
their "Call Sign" -Nutgrass 122, Tigertail 012, Black Eagle 601, Lima Whiskey
05, etc. However, in civilian-controlled airspace these call signs mean little and don't
meet Air Traffic Control Standards. So, instead, these naval aircraft
are identified by NAVY (or MARINE) and the last four digits of the BuNo. Also
the transponder identifies (or "Squawks) the aircraft on the Radar screen the
same way. Since there are various "Modes" that the Air Traffic Control System
uses, we get the name MODEX, plus the last four digits of the BuNo.
In addition, most Navy and Marine Corps
aircraft are identified in squadron service and for maintenance purposes by something known
as a side number or side letter. The
side number is painted on the nose of each aircraft. I am not sure how the side numbers
are derived--I have seen one-digit, two-digit, and three-digit displays, but never more than three.
The side number sometimes consists of the last three digits of the BuNo, but on other
occasions it has
nothing to do with the BuNo--each Wing seems to have its own set of numbers and numbering
schemes, and their is considerable variation in side number format from one aircraft type to another.
In addition, there is a color coding scheme associated with the numbers.
According to one of my
sources, the digits in the side numbers beyond the first one
are in octal format (the digits going from 1 to 7,
then from 10 to 17, 20 to 27, etc), with digits 8 or 9 never being
used. This was supposedly done because maintenance actions were originally
recorded on punched cards and had to be processed through IBM electronic accounting machines and computers which could only handle octal numbers.
Curiously, the side numbers remain in octal format to this day
even though computer systems
have since been upgraded many times. However, I have seen side numbers beyond the first digit that do
indeed have an 8 or a 9, so
this restriction must not have been universal.
Another possible explanation for the origin of the octal side-number system is the nature of the early
IFF (Identification Friend or
Foe) systems. With the arrival of the Navy's E-2A airborne early warning aircraft, the side numbers changed from base-10 to base-8 numbering (e.g
500, 501, 502,..., 507, 510, 511, etc). The E-2As automatic tracking system required such a change, since its computers could only deal with
base-8 numbrs. IFF is used by controllers for 'positive control'. There are several modes:
two entered by the pilot at the direction of the controller, one for
squawking altitude, and one reserved for military use. Early transponders were set by
positioning toggle swithces ON or OFF, with there being four columns of 3 switches for a
4096 code or two columns of three for a 64-code. 4096 is the number of different four-digit numbers
that can be created without using an 8 or a 9 and including 0000 which should never be used
by airplane transponders. In such a scheme, there are 12 binary swiches. IFF can only handle three binary places,
thus 8's and 9's are not used. IFF systems at that time (and I
think they still do) used the octal system and the highest "squawk" in mode 2 was 7777, mode 1 and 3 was 77.
Hence the appearance of octal numbering system on aircraft. There are no doubt a few reasons
why octal rather than decimal is used, for one
thing it accurately reflects the underlying "bit-oriented" nature of the codes.
If decimals were used then for mode "A" (civilian, "3" military) only numbers
ranging from 0 through 4096 would be useable, probably harder to understand than
the ability to use any 4-digit number (0000-7777). Also, a previous military
mode (mode "1") only allowed 6 bit codes (00-77), upward compatilbility is
simplified if considered to be a doubling of the number of digits than if it
were a case of suddenly being allowed to use numbers in the range 64 to
4096. The latest addition to radar technology, Mode-S, expands the squawk codes
from 12 bits to 24 bits thus making it possible to permanently assign codes to
individual aircraft without duplication. However, despite being a recent
invention these codes are still represented using octal (as 8 digits) or hex (as
6 digits/letters).
The following is the side number scheme for carrier air wings. Generally, the first digit
identifies the type of aircraft, and the remaining 2 digits represent the individual aircraft
within a particular wing.
Carrier-based fighter squadrons typically have three-digit side numbers 1XX or 2XX (both sets of numbers
are used if there are two fighter squadrons
in the carrier wing). Numbers beginning
with 1 are colored red and those beginning with 2 are colored yellow. Usually, the squadron CO's plane is numbered
101 or 201, the executive officer's plane 102 or 202, and subsequent planes numbered in order of pilot seniority.
Sometimes, 100 or 200 is used to represent the CAG's (Commander of Air Group) plane, if there is one. I even have heard of a side
number of 000, which was supposedly
applied to the Admiral's plane. Light attack aircraft have
numbers begin with 3 (light green) or 4 (medium blue). Heavy attack aircraft have numbers beginning with 5
which are colored dark green. Fixed wing aircraft belonging to VAW squadrons have numbers 60X that are painted
maroon, although they are fairly rarely used. VAQ squadrons used numbers 61X which were painted dark blue
in color, but this was changed a few years ago to 5XX, usually starting at 500. The color is usually
black, with the exception of CAG aircraft which can be almost any color. VS squadrons use numbers 62X and 63X, with a light blue or dark red color, but S-3
squadrons also used side numbers 70X or 71X with a solid black color. Helicopter squadrons
use numbers 70X or 71X, with a green color. Some sources say that 3xx, 8xx, and 9xx are reserved for Fleet Replenishment Groups
(RAGs), but this seems not always to have been the case, since at least one A-7 light attach squadron used 3xx. One of my sources
has seen a picture of an F-4 with modex 3xx, A-4 with modex 2xx, F-14 with modex 4xx and F-model Super Hornet (which is usually
brings the 1xx or 2xx modex) with modex 4xx. Another source said that those numbers are describing the first, second, third, fourth
etc unit assigned to an air wing. It may very well be that the side number assignments are not always consiste.t
For example, all F-14 squadron carried either
1XX (and also 2XX if there are 2 F-14 squadrons in one air wing).
The XX begins at 01 and increases from there. In some cases, the last 2 digits of
this number are also
painted on the tail and wings of each aircraft, as well as on the upper trailing edges of the
flaps. This helps flight deck personnel on aircraft
carriers in identifying different planes on the deck, especially when they are
packed close together.
Marine aircraft normally use two-digit side numbers unless they are assigned to a carrier, in which case they adopt
a three-digit code as listed above. However, when they are assigned to amphibious assault
ships they still use a two-digit scheme.
Land-based Navy aircraft also use side numbers, but these are usually the last three digits of the BuNo.
Less predictable were the side numbers assigned
to Test Center, Air Station, and ship aircraft. However, ship aircraft usually have side numbers that are the ship's hull number. For example,
when the carrier USS John F. Kennedy (CV-67) had a C-1 assigned to it, the aircraft had "67" as the
side number.
I would appreciate hearing from anyone who has any additions or corrections to these modex and side numbers.
The ultimate end for many Navy and Marine Corps aircraft and helicopters once they leave active service
is the boneyards in Arizona. The dry climate and the alkali soil of the region makes it
ideal for open storage and preservation of aircraft. At the end of World War 2, many surplus Navy aircraft
were stored at NAS Litchfield Park, about 30 miles west of Phoenix, Arizona. After 1967,
this facility was closed and the Navy shifted the operation to Davis-Monthan AFB near
Tucson, Arizona. Excess DoD and Coast Guard aircraft are stored there after they are
removed from service. Sometimes the aircraft are actually returned to active service,
either as remotely-controlled drones or sold to friendly foreign governments, but most
often they are scavenged for spare parts to keep other aircraft flying or are scrapped.
Initially known as the Military Aircraft Storage and Disposal Center (MASDC), the name
was changed in October of 1985 to the Aerospace Maintenance and Regeneration Center
(AMARC). AMARC was officially redesignated on May 2, 2007 as the 309th Aerospace Maintenance and
Regeneration Group (AMARG), but it still uses the title AMARC for worldwide recognition and
legacy reasons. If I know of the date at which an aircraft was transferred to MASDC/AMARC, I
list it here.
When an aircraft entered AMARG, it was assigned a code number (known as a Production Control Number, or PCN) consisting of
four letters, followed by a three-digit number. The first two letters
specified the service (AA for Air Force, AN for Navy, AC for Coast Guard, AX for government agency aircraft, AY for foreign
allied aircraft). The second pair of letters specified the type of aircraft (e.g 3A for
the A-4 Skyhawk), and the three digit number specifies the order in which the particular plane of
that type was entered into AMARG. For example, the first A-4 admitted to AMARC would be numbered AN3A001, with
two zeros being added to pad out number of digits to 3. So the PCN was useful in telling at a glance who owned the
aircraft, what type of aircraft it was, and the order in which it arrived
at AMARG.
Prior to Oct 1994 the number in the PCN code had three digits, but AMARC realised that they were soon
going to have more than 1000 F-4s on inventory, and the decision was made that it was necessary to expand the number format
to four digits in order to accommodate new Phantom arrivals. I imagine that once AMARC had altered their database field to
use 6 characters, they then decided to use that style
for ALL new arrivals from Oct '94, and a zero was prefixed when the order number was less than 1000. Ref: eLaReF, Jun 17, 2012.
To add to the confusion, the same aircraft could have multiple PCNs. For example, if an aircraft in storage at AMARG is
returned to service, it will get a new PCN when it is returned
to AMARG for storage a second time. An aircraft can also be assigned a different PCN if it is administratively
tranferred to a different service while it is sitting in the boneyards. For example - AMARG currently stores
a C-131 that originally arrived as a Navy asset (and was assigned a Navy PCN). The Navy transferred the aircraft
to the Air Force (so the Navy PCN was removed and replaced by
an Air Force PCN). Then USAF transferred it to another government agency, so the USAF PCN was removed and replaced
by a U.S. Gov't agency PCN beginning with the prefix "AX." Same plane, three different PCNs. (Ref: Robert D. Raine, Jun 27, 2013)
In addition to aircraft that are transferred between services, an aircraft could receive multiple PCNs if it came back to the
facility multiple times - for example - an aircraft might
have come in to AMARG for service life extension (it would have been given a PCN for the duration of its refit). Then
it would have been returned to the operational fleet. During its service, if the "operators" determine that all aircraft of
this type need something else to be checked, the aircraft would return to 309 AMARG for that check as part of some minor repair work.
On arrival it would have received a new (2nd) PCN. On completion of the minor repairs, the aircraft would return again to the operators.
Eventually when the operators determine that the aircraft is no longer needed and retire it to storage, a third
PCN would have been assigned. (Ref: Robert D. Raine, Jun 27, 2013)
Recently, AMARG introduced a new computer system and decided to stop assigning a PCN when an aircraft arrives at the facility.
Everything is now done by serial number, since no two aircraft have exactly the same serial number. PCNs were not
removed from older aircraft, but new PCNs are no longer assigned to aircraft when they arrive. (Ref: Robert D. Raine, Jun 27, 2013)
A list of military aircraft transferred to MASDC/AMARC is available at www.amarcexperience.com.
Manufacturer's Serial Numbers
When an aircraft is constructed, the company which built it assigns it a manufacturer's serial number. This number is usually displayed
on a plate mounted somewhere inside the aircraft.
When the aircraft is sold to the Navy or the Marine Corps, it is issued a bureau number (it's military serial number) by the Defense Department. These two numbers bear no
relationship with each other, but they are often confused with each other. When I know the manufacturer's serial number of a particular military
aircraft, I list it. If a military aircraft ultimately ends up in civilian hands, it is issued a civil registration number by the owner's national
civilian aviation authority. In the USA, these numbers are issued by the FAA, and are known as N-numbers in the USA, since they all begin
with the letter N. Typically, the FAA uses the aircraft's manufacturer serial number
to track these aircraft. For example, a lot of R4D military transport aircraft ended up in civilian hands after their military service ended, and they are
tracked by using their manufacturer's serial numbers.
History of a Particular Aircraft
There are a lot of people who want to know about the operational history or ultimate disposition of a particular Navy or Marine Corps aircraft
referred to in this database,
but about which I have little or no information. If you have a specific question
about the history of a particular Navy aircraft, you might try the
Naval Historical Center
which is located in Washington, DC. They have cards on virtually every aircraft
ever owned or operated by the Navy, and they might be able to answer your question
fairly quickly. However, their collection of Aircraft History Cards covering 1911 to 1987 has been transferred to the
National Naval Aviation Museum at Pensacola, FL. Another source is the Aircraft History Card file maintained by
the National Air and Space Museum Archives Division, which
maintains microfilm copies of aircraft records created by the US Navy. They also may be able to help you. You could
also try the National Naval Aviation Museum, located at Pensacola, FL. Another
source might be the US Naval Safety center, located in Norfolk VA. However, you are
always welcome to e-mail me in any case
and I will see if I can dig up something.
The following is a list of serial numbers and bureau numbers for US Navy and US Marine Corps aircraft from 1917 onward. It is incomplete, with numerous gaps.
If I know the disposition of a particular aircraft, or if the aircraft has some special historical significance, this information is listed
here too. Enjoy yourself browsing through these lists--there are lots of
neat historical interludes provided here. I would appreciate hearing from anyone who has additions or corrections to these lists.
Search Engine
If you want to search this site for a serial number or for a particular aircraft
type, go to Jeremy Kuris's search engine:
Search Engine For This
Site
Send e-mail with comments and/or suggestions to 
First Alphanumeric Series (1911-1914)
Second Alphanumeric Series (1914-1917)
