DeHavlland DH-4 (U.S. Use) Designations

[Mark Nankivil]

Good Day All -

Came across this March 1925 Tech Order that calls out the various "special" DH-4 types and giving them specific designations. Quite the variety!

Enjoy the Day! Mark

 

[Apophenia]

I thought that Mark's USAAS DH-4 designation list was worthy of transcribing (for 'searchability').

DH-4B ----- Standard Liberty 12 installation - 88 gallon, plain, main gas tank - 96 gallon total fuel capacity
DH-4B1 ---- Standard Liberty 12 installation - 110 gallon, plain, main gas tank - 118 gallon total fuel capacity
DH-4B2 ---- Standard Liberty 12 installation - 76 gallon, leak-proof, main gas tank - 83 gallon total fuel capacity
DH-4B3 ---- Standard Liberty 12 installation - 135 gallon main gas tank - 143 gallon total fuel capacity
DH-4B4 ---- Airways airplane with Liberty 12 installation prepared in accordance with drawing No. 010400 -
110 gallon main gas tank - 118 gallon total fuel capacity
DH-4BD ---- Duster airplane, standard DH-4B equipped with duster apparatus
DH-4BG ---- Gas Barrage airplane, standard DH-4B equipped with smoke screen apparatus
DH-4BM ---- Standard DH-4B airplane modified with rear seat and rear baggage compartment only
DH-4BM1 --- Transport type airplane, built in accordance to specifications from Office, Chief of Air Service -
118 gallon total fuel capacity
DH-4BM2 --- Transport type airplane, built in accordance to specifications from Office, Chief of Air Service -
135 gallon main gas tank = 143 gallon total fuel capacity
DH-4BK ----- Standard DH-4B airplane equipped for night flying
DH-4BP1 ---- Photographic airplane, Liberty 12 installation, adapted to vertical mapping, oblique and motion picture photography in accordance with drawing No. X-39241
DH-4BP3 ---- Photographic airplane, Liberty 12 installation, adapted to vertical mapping, oblique and motion picture photography in accordance with drawing No. X-47746, 110 gallon main gasoline tank - 188 gallon total fuel capacity
DH-4BT ----- Training airplane, standard DH-4B modified for dual control including instruments and rear seat
DH-4M1 ---- Liberty 12 installation, metal fuselage in accordance with A.S. Specification 1560 or A.S. Specification 1561-B - 76 gallon main gas tank - 83 gallon total fuel capacity
DH-4M2 ---- Liberty 12 installation, metal fuselage in accordance with A.S. Specification 1567 - 110 gallon main gas tank - 118 gallon total fuel capacity
DH-4M2P --- Photographic airplane, Liberty 12 installation, metal fuselage in accordance with A.S. Specification 1568 - 110 gallon main gas tank - 118 gallon total fuel capacity
DH-4M2S --- Supercharged airplane, Liberty 12 installation, metal fuselage in accordance with A.S. Specification 1568 - 88 gallon main gas tank - 96 gallon total fuel capacity
XDH-4BP --- Experimental photographic airplane, Liberty 12 installation, cameras mounted in front cockpit
XDH-4BP2 -- Experimental photographic airplane, Liberty 12 installation, 135 gallon main gas tank - 143 gallon total fuel capacity[,] USD-9A wing
XDH-4BS --- Experimental airplane, Liberty 12 engine equipped with supercharger in accordance with A.S. Specification No. X-38250 - 88 gallon main gas tank - 96 gallon total fuel capacity
XDH-4L ----- Experimental airplane, Liberty 12 installation, 185 gallon main gas tank, 9 hour plane
XDH-4B5 --- Experimental airways airplane built in accordance with Engineering Division's drawings for carrying passengers or freight

 

[Apophenia]

At least one official US Army Air Service sub-type designation can be added to the list above - the DH-4C.

DH-4C - 1921 DH-4B modified by Packard for its 1A-1237 V-12
- DH-4C: Atlantic Aircraft (Fokker)-built DH-4B conversion; x 1
- DH-4C: Needed new engine mounts, cowling & radiator shell
-- Wing position shifted to allow for c/g change; new cabanes

A few of the surviving DH-4s also received later USAAS role-letter designations when modified. Some examples are the two types listing in the X-CO (Experimental - Corps Observation) category:

CO-7 - Boeing modernization of de Havilland DH-4 2-seater, x 3
- X-CO-7s: DH-4M-1* fuselages; new main u/c & tapered wings**
- X-CO-7 : 1924; USAAS serial A.S.24453 (c/n 520, ex-A.S.22884)
-- XCO-7 airframe delivered without engine fitted; static testing
- X-CO-7A: 1924; A.S.24453 (c/n 519, ex-A.S.23109 as DH-4M-1)
- X-CO-7A: As XCO-7A except delivered with standard Liberty 12
- X-CO-7B: 1925 A.S.24454 (c/n 521, ex-A.S.31216 as DH-4M-1)
- X-CO-7B: Fitted with inverted Liberty 12-A; balanced elevators
-- https://1000aircraftphotos.com/Contributions/GeorgeNelson/5192.htm
-- * DH-4M-1 was Model 16 within Boeing's designation system
-- * However, X-CO-7B was assigned internal Boeing Model 42
-- ** 2-bay panels with tapered planform outboard of first bay
-- CO-7 changes gauged "very poor" by USAAS observation board

CO-8 - Atlantic-built DH-4M-2 fitted with Loening CAO-1 wings, x 1
- X-CO-8: 1 x 420 hp Liberty 12A engine, 2-bay wing span 13.72 m
- X-CO-8: Atlantic built DH-4M-2 A.S.23163 (Wright Field's P-369)*
-- * Wing-swap seems intended to extend service life of DH-4Ms**
-- ** As opposed to testing for Loeing; if so, failed in its objective

An X DH-4M-1 of 1923 is also mentioned but doesn't fit the USAAS designation style. This is a bit of puzzle. As a Boeing-assembled airframe, X DH-4M-1 might have been an internal, corporate designation. But Boeing normally assigned its own model numbers - eg: Boeing Model 16 for the DH-4M and DH-4M-1.

There were also a range of DH-4s modified for trials purposes which seem to have had no designation changes at all. Some examples are:

DH-4s fitted, as per X-CO-8, with Loeing wings panels (x 20) for airmail service

Engineering Division ambulance: DH-4 mod.; 2 x litters + doctor & pilot
-- Wikipedia lists as 'DH-4Amb' [[i[sic[/i]]; I highly doubt this to be official

DH-4B modified as carrier for Engineering Division GL-1 target glider
-- DH-4B upper wing mods/various cradle types for launching of GL-1
-- https://www.secretprojects.co.uk/threads/aeromarine-projects-and-prototypes.18424/page-3#post-266851

Doubtless there are heaps more ...