1 - FMV S 21/CFM S 25 (1926-1932)
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1921, the Army Aviation Company’s Workshops (FMV) at Malmen/Malmslätt
got an preliminary order of
ten reconnaissance aircraft of Henry Kjellson’s design. The aircraft
got the designation S 21 (S =
”Spaning” = ”Reconnaissance” - 21 = 1921, the year of the
design). The aircraft had a crew of two - pilot and observer. In these
days, aircraft engines was an article in short supply in Sweden. When 22
airship (!) engines type Maybach IVA (260 hp) eventually were obtained
from Germany, Kjellson, the chief engineer of FMV, had to design an
airframe which suited this engine.
first S 21 was delivered in 1922. During the trials, several
shortcomings were discovered. After some amendments, the other nine
airframes were built in 1923-1924. Notwithstanding a long tail, the
aircraft was nose-heavy. In the end of 1924, three of the ten aircraft
were written off due to crashes. When the Air Force was established in
July,1926, the six remaining S 21s were taken over under the new
designation S 1.
1924, FMV still had 25 Maybach-engines at its disposal. Therefore, a new
batch of ten airframes was ordered by the Army Aviation Company. But as
some modifications compared to the original design was made, the new
aircraft was named S 25. The
main alterations were a larger tailplane and a larger fin and side
rudder. As the delivery took in the end of 1926 and in 1927, the new ten
aircraft were delivered to the
Air Force. The S 25s also got the
Aircraft on floats were designated S 1H. The
workshops at Malmen had
incorporated in the organization of the new fighting service. The name
was changed to "Centrala Flygverkstaden i Malmslätt" (CFM).
The workshops at Malmen had been incorporated in the organization of the new fighting service. The name was changed to "Centrala Flygverkstaden i Malmslätt" (CFM).
1925, S 21 #4214 had been based at Boden in the north of Sweden for
ambulance transports from remote areas. S 25 #45 got a canopy over the
aft cockpit, which was used as room for a stretcher, and became spare
ambulance for the Junkers F13 which was stationed at Boden in 1928.
Finally, S 25 # 6220 got a heated stretcher space with a high canopy
provided with windows (”the Flying Allotment Cottage”). The exhaust
pipe was lengthened past the stretcher space. This aircraft was used as
a flying ambulace at F 4 at Östersund 1927-1932.
In spite of its shortcomings, S 1 made a good service as a reconnaissance aircraft until the beginning of the thirties, when it was replaced by the Fokker S 6 with its much more powerful engine.
The ordinary S 1s were armed with one fixed and one moveable 8 mm machine-gun m/22.
Top - S 1 CVM S 25, probably # 3228, at Malmen.
Below - S 1 CVM S 25 # 3228 at Malmen, built in the same place 1927.
S 1 with wheel gear: Length: 8,6 m. Span: 15,1 m. MTOW: 1.815 kg. Max. speed: 168 km/h.
© Lars Henriksson