U.S. Naval Aviation Designations

By Lieutenant Colonel Ronald J. Brown

U.S. Marine Corps Reserve, Retired

During the Korean conflict, the Navy Bureau of Aeronautics used designation systems that conveyed a lot of information about its squadrons and aircraft in a concise manner.

Squadron Designations:

The Bureau recognized three aircraft squadron types: lighter than air (Z); heavier than air (V); and helicopter (H). In addition, Marine aircraft squadrons were identified by the insertion of the letter “M” between the aircraft type and the squadron function. In general, a three letter prefix followed by up to three numbers was used to identify individual Marine aircraft squadrons. The first letter (a “V” or “H”) identified the primary aircraft type used by the squadron, the second letter (“M”) identified it as a Marine aviation unit, and the third (“O” indicating observation and “R” for transportation) identified the squadron’s primary mission; the numbers in the suffix sometimes identified the squadron’s unit affiliation and always noted its precedence order.

Thus, VMO-6 was the sixth heavier-than-air Marine observation squadron formed. The single digit indicated that the squadron was not specifically affiliated with a particular aircraft wing (observation squadrons were attached to ground units). On the other hand, HMR-161 was the first Marine helicopter transport squadron assigned to the 1st Marine Aircraft Wing (the first “1” indicating initial assignment to the wing, numbers above “6” were used for non-fixed wing aircraft, and the last “1” signifying it was the first squadron formed).

Aircraft Designations:

Individual aircraft designations used a similar identification system. The Bureau of Aeronautics gave each naval aircraft a mixed letter and number designation. Except for experimental or prototype helicopters, the first letter was an “H” indicating rotary-wing status; the second letter indicated its primary purpose (“O” for observation, “R” for transport, or “T” for trainer); a number (except in the case of the first model) indicated the manufacturer’s sequence for producing that specific aircraft type; the next letter identified the manufacturer (“L” for Bell, “P” for Piasecki, or “S” for Sikorsky); and the number following a dash indicated a sequential modification of that aircraft model.

Thus, the HO3S-1 was Sikorsky Aircraft’s third model observation helicopter with one modification; the HRP was Piasecki’s first transport helicopter; the HTL-4 was the fourth modification to Bell Aircraft’s original trainer helicopter; the HO5S was Sikorsky’s fifth observation model; and the HRS-1 was Sikorsky’s first transport helicopter.

The Bureau’s system was a good one that remained in use for four decades, but there were a few problems. First, aircraft were often used for roles other than those assigned. For example, the HO3S-1 was actually a utility aircraft that during field service performed many tasks other than observation, a task that actually became a seldom-used secondary mission in Korea. Second, the proliferation of missions and manufacturers as time passed led to confusing duplication of letters (“T” was variously used to indicated torpedo, trainer, and transport aircraft). Third, lack of inter-Service consistency produced confusion (the Navy HO3S-1 was an H-5F to the Air Force and Army). The naval aircraft designation system was replaced by a joint aircraft designation system in 1962, but the Bureau’s squadron designation system remains in effect.


6 thoughts on “U.S. Naval Aviation Designations

  1. I have a question; why is the letter V used to designate a heavier than air aircraft? Using an “H” for helicopter makes sense but I don’t understand the reason for the “V” and the “Z.” I have puzzled over this for many years.

    I was a medical officer; maybe I am not supposed to know the answer?
    Thanx, CRL

  2. I’m a helicopter pilot and have wondered the same. Here’s the best answer I’ve found.

    Source: http://www.history.navy.mil/avh-1910/APP16.PDF

    “The use of the “V” designation with fix-wing heavier-than-air squadron designations has been a question of debate since the 1920s. However, no conclusive evidence has been found to identify why the letter “V” was chosen. It is generally believed the “V” was in reference to the French word volplane. As a verb, the word means to glide or soar. As a noun, it described an aeronauticaldevice sustained in the air by lifting surfaces (wings), as opposed to the bag of gas that the airships (denoted by “Z”) used. The same case may be made regarding
    the use of “Z”. It is generally believed the “Z” was used in deference to Count Ferdinand von Zeppelin, the German general and developer of the airship in 1900. However, documentation has not been located to verify this assumption.”

  3. Dear Dumb Doc, The “V” indicates “fixed wing” in the modern time, v.s. Helicopter: H. That is what I was told in flight training during the early ’60’s. I was a RF-4B Phantom II pilot and thereafter became a physician/flight surgeon in the Navy. Then a small-town doc. So, I know how dumb docs are!!!

    I had a great experience being a small-town doc for 23 years, but flying the Phantom II was “the best”.

    Yours. Lance

  4. I have made the contention for many years now that the USMC squadron designation system is not quite identical to the navy’s. For example, although several Marine units may have a single- or double-digit designation, the triple-digit ones are only used once. Huh? The single-digits are MAW units (MASS-2, Marine Air Support Squadron of 2nd MAW; H&HS-4 of 4th MAW) and the double-digit ones are MAG units, such H&MS-12/MALS-12 (1st MAW, 2nd group), whereas triple-digit units are of the wing/group/squadron order. Thus VMSB-232 eventually became VMFA-232. The point here is that the squadron type may change over time but that three-digit number stays the same in its history, so you can trace it back at least to July 1941. I say that the 231 means originally assigned as 2nd MAW, 3rd group, 1st squadron. The highest last two digits seem to be a 5 for fixed-wing units, as noted that the helo units have 6 or higher in the middle number, can go up to 9 in the squadron (last) position. A zero for the center digit (air group) is a training squadron, although not all training squadrons have a zero there.
    Navy squadron numbers may be used for several squadrons, i.e. VF-213, VA-213 VQ-213. Also, their old original numbers were attached to their carrier air groups, so CV-3 had Fighting Three (VF-3), Bombing Three (VB-3), Torpedo Three (VT-3), etc. It wasn’t long before this system was dropped due to the rapid and massive build-up of WW II.
    The VMO squadrons apparently were attached one per MAW. Although there were only 5 MAWs in WW II, apparently the Corps was working on more if you check the unit numbers (VMO-6 and others).
    Re helos, I don’t believe any fixed-wing group or squadron numbers went beyond 5, which was plenty for one MAW or MAG, so the rotaries took it from there, or rather, were assigned as such.
    I think also I have seen Marine squadrons designations in the 9xx series but have no idea why they are so high.
    I still am looking for any official reference to this system. There has to be one.

  5. Overlooked in this discussion is US Navy General Order No. 541 issued 17 July 1920 “In order to provide a standard nomenclature for types and classes of vessels comprised in the United States Navy”.

    “A” which now would make sense for Aeroplane, as they were referred to then, was actually assigned to “auxiliary ships” which contained a long list from colliers (AC) to lighter than aircraft tenders (AZ). Don’t let the Z in AZ fool you yet.

    It was the infant days of Naval Aviation, post World War I and after the Northern Bombing Group which is to say that Naval Aviation wasn’t even really a blip on the radar. (Pun intended)

    It has been mentioned that Z may have been issued for lighter than air in deference to Ferdinand von Zeppelin but I ask how much respect was due any German on the heels of The War to End All Wars?

    I think “Z” was assigned to lighter than air simply because it was last on the old sailor’s list, X wasn’t used because it would look like a target, Y had been assigned to “district craft” and V was simply there. I’ll leave readers to argue if U, V and W ever get confused. (U and W weren’t used in 1920 and I haven’t the will to find out if they’re used now)

    So yes, it’s simply a designation and with the demise of LTA and advent of helicopters it just made sense evolve the V to fixed wing even though we’ve had a few jets (F-14 and Crusaders) where the wings may have not been all that “fixed”.


  6. I’m looking for the Bureau number of a Sikorsky helicopter UH34D that flew in Vietnam designation YZ64 with HMM363 in 1966. I was a crew chief mechanic gunner and was shot down in this bird on September 15 1966. I’m looking for the planes location

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