9th AF Patch

416th Bombardment Group (L)






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Aircraft Identifiers

Military Aircraft were identified in numerous ways.
Below is some information on the primary Aircraft Identifiers found on 416th Bomb Group Aircraft during WWII.

Aircraft Designation

"Every USAAS/USAAC/USAAF/USAF aircraft, since 1924, has been assigned a unique identifier that spells out the planeís intended purpose, model, series within the model and any special purpose.

This designation system contains between three and six parts:, some optional, some required, and are described in detail below. As an example, we will work with a B-29 assigned to a USAAF school as a trainer. The designation of our example is TB-29A-60-BN. Itís serial number is 44-62094, manufacturerís construction number 11570.

Breaking the designation down into its component parts we have:

 T   B  -29  A  -60 -BN
(1) (2) (3) (4) (5) (6)

Definitions of the component parts on the designation are:
(1) Status or special purpose prefix. Optional.
(2) Type symbol. Required.
(3) Model Number. Required.
(4) Series Letter. Required for the second and later aircraft in the series.
(5) Block number. Optional.
(6) Manufacturer Identification. Required.
" (Mann, p. 8)

The 416th Bomb Group flew A-20 Havoc and A-26 Invader aircraft in combat.

The Type symbol "A" signifies these were classified as "Attack" aircraft.

"-20" and "-26" were Model Numbers, which identifies the number of different models that have been ordered procured under the specific Type symbol designation. Identity of the manufacturer has no impact on the model number, thus the A-20 was the 20th and A-26 the 26th "Attack" design ordered by the USAAF.

Series Letters were applied as a suffix to the Model number to indicate that there have been modifications to the original Model. The 416th BG flew A-20's with the Series Letters "B and "G" which were configured with Solid noses to operate as "Gun Ships", and Series Letters "C", "J" and "K" which had Plexiglas noses to allow for a Bombardier/Navigator and to operate as Flight lead aircraft. For the A-26 aircraft flown by the 416th BG, Series Letter "B" was the Solid nose "Gun Ship" variation and "C" had the Plexiglas nose. Even though a given aircraft was originally manufactured as a certain Series Letter, the nose configuration could be switched from solid to Plexiglas or vice-versa, thereby causing the Series Letter to change.

Block Numbers identified a group of airplanes with the same modifications and with interchangeable parts for maintenance and service.

Most of the A-20 aircraft flown by the 416th Bomb Group were manufactured at Douglas Santa Monica, California (Manufacturer Identification = DO), a few at Douglas Long Beach, California (DL). The A-26's were manufactured at either Douglas Long Beach, California (DL) or Douglas Tulsa, Oklahoma (DT).

Technical Data Block on Fuselage below cockpit canopy
USAAF S/N: 41-39264
Aircraft Designation: A-26B-20-DL

Type "A" - Attack type
Model Number "-26" - 26th Model of Attack type
Series Letter "B" - Second ("B") Series of A-26
Block Number "-20" - Block 20
Manufacturer Identification "-DL" - Manufactured at Douglas Long Beach, California

98 A-26B-20-DL where manufactured, USAAF S/Ns 41-39201 to 41-39299

Military Aircraft Serial Number (USAAF S/N)

The name of the current United States Air Force changed through time as follows:

     USASC -  1-Aug-1907 to 14-May-1918 - United States Army Signal Corps
     USAAS - 14-May-1918 to  2-Jul-1926 - United States Army Air Service
     USAAC -  2-Jul-1926 to 20-Jun-1941 - United States Army Air Corps
     USAAF - 20-Jun-1941 to 18-Sep-1947 - United States Army Air Force
     USAF  - 18-Sep-1947 to Present     - United States Air Force

During the period of the 416th Bomb Group WWII service, the branch of service was known as the United States Army Air Force (USAAF), so this page will reference this identifier as "USAAF Serial Number" or "USAAF S/N".

"Starting on July 1, 1921 (the beginning of Fiscal Year (FY) 1922) a new serial number system was adopted based on procurement within each Fiscal Year. Each serial number now consisted of a "base number" corresponding to the last two digits of the FY in which money was allocated to manufacture the aircraft, and a "sequence number" indicating the sequential order in which the particular aircraft was ordered within that particular FY. For example, airplane 22-1 was the first aircraft ordered in FY 1922, 23-1 was the first example ordered in FY 1923, etc. This system is still in use today.

It is important to recognize that the serial number reflects the Fiscal Year in which the order for the aircraft is placed, NOT the year in which it is delivered. Nowadays, the difference between the time the order is placed and the time the aircraft is actually delivered can be as much as several years.

Following the passage of the Lend-Lease Act in 1941, USAAF serial numbers were allocated to US-built aircraft intended for service with Allied air forces during the Second World War. This was done strictly for administrative purposes, even though these aircraft were never intended for USAAF service. Later, during the Cold War, aircraft supplied to US allies under the Mutual Aid Program or the Mutual Defense Assistance Program were assigned USAF serial numbers for record-keeping purposes, even though they never actually served with the USAF.

Not all the aircraft which served with the US Army Air Force were issued USAAF serial numbers. The best-known examples are those aircraft acquired abroad by the US Army during the Second World War. In most cases, they operated under their foreign designations and serials. For example, the Spitfires acquired in the UK under "Reverse Lend-Lease" were operated under their British designations and their British serial numbers. In addition, some US-built aircraft that were ordered by Britain prior to Lend-Lease but later impressed into USAAF service still retained their Royal Air Force serials." (Baugher-usafserials.html)

Three examples of aircraft originally slated for Britain but retained by the USAAF and used by the 416th Bomg Group are Douglas RDB-7B / Boston III aircraft having RAF Serial Numbers AL-377, AL-866 and AL-878, all of which were involved in training accidents prior to the Group's overseas transfer.

A USAAF Serial Number provides the most unique means of identifying an aircraft and rarely changed throughout the life of the airplane.

Technical Data Block on Fuselage below cockpit canopy
USAAF S/N: 43-9380

Individual Aircraft Record Card
USAAF S/N: 41-39238

Radio Call Number (Tail Number)

"The lack of a readily-visible serial number on Army aircraft began to be a serious problem, and on October 28, 1941, shortly after the USAAF had been formed, an order was given that numbers of no less than 4 digits would be painted on the tail fin of all Army aircraft (where feasible) in a size large enough to be seen from at least 150 yards away. This was officially called the radio call number, but was almost universally known as the tail number. Since military aircraft were at that time not expected to last more than ten years, the first digit of the fiscal year number was omitted in the tail number as was the AC prefix and the hyphen. For example, Curtiss P-40B serial number 41-5205 had the tail number 15205 painted on its tail fin, Curtiss P-40K serial number 42-11125 had the tail number 211125 painted on the fin, and P-51B 42-106559 had 2106559 painted on the tail. Since the Army (later Air Force) used the last four digits of the tail number as a radio call sign, for short serial numbers (those less than 100), the tail number was expanded out to four digits by adding zeros in front of the sequence number. For example, 41-38 would have the tail number written as 1038.

Consequently, in most situations for a World War II-era aircraft where the tail number is visible, you can deduce the serial number simply by putting a dash after the first digit, prefixing a 4, and you automatically have the serial number. Unfortunately, there were many deviations from these rules--there are examples in which only the last 4 or 5 digits were painted on the tail, which makes identification of the aircraft particularly difficult." (Baugher-usafserials.html)

Tail Numbers
Left: Tail Number: "39450" = USAAF S/N: 43-9450 (A-20)
Right: Tail Number: "139274" = USAAF S/N: 41-39274 (A-26)

Note The A-26 USAAF S/N: 41-39274 is an example of an Aircraft which was
Ordered in 1941 (thus the "41" S/N), but was not actually built until 1944.

416th Bomb Group Combat Mission Loading Lists often identified Aircraft
by only the last three digits of the Tail Number/Serial Number.

In this Loading List example:
Position 1 - "914" is USAAF S/N "43-9914" 
Position 2 - "129" is USAAF S/N "43-10129"
Position 3 - "225" is USAAF S/N "43-9225" 
Position 4 - "393" is USAAF S/N "43-9393" 
Position 5 - "711" is USAAF S/N "43-9711" 
Position 6 - "221" is USAAF S/N "43-9221" 

Manufacturer Serial Number (MSN)
also called Manufacturer Construction Number (c/n)

"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 Air Force, it is issued a 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." (Baugher-usafserials.html)

"All military aircraft built during the Second World War had a manufacturer's construction number and a corresponding serial number applied by the AAF (a bureau number in the case of the Navy) and stenciled on the aircraft on the production line. The first digit of the serial number [Tail Number] signified the year in which the aircraft was ordered (not built): for example, the [Tail] number '212345' on the aircraft meant that the aircraft was ordered in 1942 - (4)2-12345." (Bowman, p. 142-143)

While the Manufacturer's Serial or Construction Number was an important identifier during construction of the aircraft, it was seldom referenced after the aircraft was placed into service.

Technical Data Block (TDB)

"The three-line fuselage data block was reduced in size to one-inch characters in 1932 and placed on the left hand side of the fuselage near the cockpit. This is known as the Technical Data Block (TDB). The data block not only displayed the full serial number, but also the exact model type and sometimes the aircraft's home base or the branch of the military with which it served. The TDB eventually became the only place on the aircraft where the serial number was actually displayed. It was often true that the only other sort of identification shown was a unit and base identification code displayed on both sides of the fuselage or on the fin. This made it difficult to identify the actual serial number of the aircraft, leading to a lot of confusion." (Baugher-usafserials.html)

"In 1932, the Model designation and serial number were transferred to the port side of the forward fuselage. This, with other details, became what is currently known as the Technical Data Block, or TDB. [An example of] The approved format of the TBD would read as follows:

A.A.F SERIAL NO. 44-62094

REFERENCE T.O. 1234-5-67
" (Mann, p. 11)

Technical Data Block on Fuselage below cockpit canopy
U.S. ARMY - A-20G-25-DO
A.F. 43-9363

Project Number

"With airplanes starting to flow off the production lines, some method of determining which unit got which planes had to be established. This was accomplished by use of the Project designation. Every plane was allocated to a Project, which in turn were prioritized by USAAF staff.

The Project number was a five digit code, found in the header data of most IARCís [Individual Aircraft Record Cards]. It is a five character numeric for allocation of the plane to, for example, a Group being outfitted for initial deployment. Planes allocated to replacement usage to an existing organization carried a "R" suffix to the Project number. An occasional "S" suffix identified a plane being specially modified with unique equipment." (Mann, p. 11)

Technical Data Block on Fuselage below cockpit canopy
Project Number: 92692-R
USAAF S/N: 43-21764

Individual Aircraft Record Card
Project Number: 92851-N
USAAF S/N: 41-39284

Bomb Group Marking

Aircraft were also typically marked to identify their Bomb Group. For the 9th Air Force Light (A-20/A-26) Bomb Groups, these markings were:

  • 409th Bomb Group - Solid Yellow vertical stripe along the trailing edge of the tail rudder

  • 410th Bomb Group - Alternating White and Black vertical stripe along the trailing edge of the tail rudder

  • 416th Bomb Group - Solid White (A-20's) or Solid Black (A-26's) vertical stripe along the trailing edge of the tail rudder

Examples of 9th Air Force Light Bomb Group A-26 Tail Rudder markings
L-R: 409th BG, 410th BG, 416th BG
(Copied from A-26 Invader Units of World War 2, by permission of the Author, Jim Roeder)

Fuselage Code (Squadron Code and Call Letter)

Aircraft were marked with letters/numbers on both sides of the Fuselage to identify the Bomb Squadron (2 character Squadron Code, positioned closer to the front of the Aircraft) and individual aircraft Call Letter within that Squadron (single letter A thru Z, positioned closer to the Aircraft tail.).

Squadron Codes for the 416th Bomb Group Squadrons were:

  • 5H - 668th Bomb Squadron
  • 2A - 669th Bomb Squadron
  • F6 - 670th Bomb Squadron
  • 5C - 671st Bomb Squadron

Fuselage Codes were unique at any given point in time. However, the same Fuselage Code was often used for more than one Aircraft over the course of time, and occasionally a given Aircraft was assigned different Fuselage Codes at different times.

For example, when the 416th Bomb Group changed from A-20 to A-26 type aircraft, the same Fuselage Codes formerly used for the A-20's were re-assigned to the newer A-26s. Also, there were times when aircraft were damaged and removed from service, so the Fuselage Code was re-assigned to the replacement aircraft.

If a damaged aircraft returned to service, it may receive a new Fuselage Code either because the prior Fuselage Code was now in use on another aircraft, or when the aircraft was re-assigned to a different Bomb Squadron.

Examples of Fuselage Codes from each of the 416th BG Squadrons

416th Bomb Group Combat Mission Loading Lists often identified Aircraft
by the only the individual aircraft letter, presuming the Squadron is known.

In this Loading List example from the 671st Bomb Squadron,
Position 1 - "X" is "5C-X"
Position 2 - "I" is "5C-I"
Position 3 - "G" is "5C-G"
Position 4 - "K" is "5C-K"
Position 5 - "M" is "5C-M"
Position 6 - "F" is "5C-F"

Aircraft Nose Art

While certainly not official, many aircraft were given names such as "Desperate Ambrose", "Heavenly Body", "Sugar Baby", etc. by their flight and/or maintenance crew. Names and Art work were typically painted on the nose, with additional names occasionally painted on engine cowlings.

671st Bomb Squadron A-26C "Reida Rae", including "Bootie" painted on engine cowling
USAAF S/N: 43-22499
This Aircraft has been completely restored and is the centerpiece for the 416th Bomb Group display at the New England Air Museum.
(see Memorial Exhibit)

Several example photos of Aircraft Nose Art are available on Captain Francis J. Cachat's 416th Photo Collection, Plane Nose Art page.

Douglas Fuselage Number

Many photographs of Douglas A-26 Invader Aircraft display a two or three digit number positioned on one or both sides of the aircraft. I refer to these numbers as a "Douglas Fuselage Number".

While both the Manufacturer Serial Number and Douglas Fuselage Number were assigned by Douglas Aircraft Company, these two numbers are not related and are not the same.

Douglas Fuselage Number: 70 (above and to the right of "Eva Mae")
USAAF Serial Number: 43-22321, Manufacturer Serial Number: 18468
A-26B-15-DT, "Eva Mae", 416th BG, 668th BS, 5H-T
Early, 1945 Laon, France
L-to-R: Lt. Lumir J. "Lou" Prucha, SSgt. Leland "Lee" Ferguson

See the Aircraft Identifiers - Douglas Fuselage Number webpage for more details and photos.

Civil Registration Number

"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 C-47 Skytrain aircraft ended up in civilian hands after their military service ended, and they are tracked by using their manufacturer's serial numbers." (Baugher-usafserials.html)

Civil Registration Number: N86481
USAAF S/N: 43-22499 "Reida Rae"
Flew 39 Combat Missions in the 671st Bomb Squadron
Had 10 different Civilian owners between 1958 and 1971


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