Junkers Ju 252

infobox Aircraft
name =Ju 252
type =Transport
manufacturer =Junkers


caption =
designer =
first flight =October 1941
introduction =
retired =
status =
primary user =Luftwaffe
more users =
produced =
number built =15
unit cost =
developed from =
variants with their own articles =Junkers Ju 352

The Junkers Ju 252 was a cargo aircraft that made its first flight in late October 1941. The aircraft was planned as a replacement for the Junkers Ju 52/3m in commercial airline service, but only a small number were built as cargo aircraft for the Luftwaffe.

The original Ju 252 came about after talks between Junkers and Lufthansa in December 1938. Lufthansa requested a new design that would replace the Ju 52, but offer much greater loads, seating, range and performance. Junkers responded with the EF.77 design with a pressurized fuselage with seating for up to 35, making it one of the larger airliners in the world at that time. It was powered by three Junkers Jumo 211F engines, in nacelles almost identical in appearance, each complete with annular radiator, to those on Jumo 211-powered versions of the Junkers Ju 88, replacing the BMW 132 of the Ju 52, which dramatically improved performance. Compared to the Ju 52, the Ju 252 was twice as heavy (13,100 kg vs. 5,600), over 100 km/h faster (440 km/h vs. 305) and had dramatically improved range (3980 km vs. 1300) when fully loaded.

By the time the prototype was ready to fly in October 1941, the war was already in progress and the Luftwaffe took over development. Like earlier taildragger designs, the Ju 252 would normally be difficult to load when parked due to the sloping floor. Junkers developed a unique solution to this problem, the 'Trapoklappe", a hydraulically powered ventral loading ramp that lifted the plane off its tailwheel, leveling the floor and allowing oversized cargo to be loaded.

Although the Ju 252 was a vast improvement over the Junkers Ju 52/3m, the situation at that time did not permit any disruption of the existing production lines, and the Reich Air Ministry (RLM) was of the opinion that any replacement for the Junkers Ju 52/3m must make minimum demands on supplies of strategic materials and use powerplants not required by combat aircraft. Junkers was then instructed to investigate the possibility of redesigning the Ju 252 in order that a considerable portion of wood could be included in its structure, simultaneously replacing the Junkers Jumo 211F engine with the BMW Bramo 323R engine of which surplus stocks existed. The result was the Junkers Ju 352. Production of the Ju 252 was restricted to already completed prototypes plus those for which major assemblies had already been semi-completed, thus only 15 transports of this type were completed before production was switched to the Junkers Ju 352.

pecifications (Ju 252A)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=Fact|date=April 2008
crew=3-4
capacity=
payload main=
payload alt=
length main=25.10 m
length alt=82 ft 4¼ in
span main=34.08 m
span alt=111 ft 10⅛ in
height main=5.74 m
height alt=18 ft 10⅓ in
area main=122.63 m²
area alt=1,320 ft²
airfoil=
empty weight main=13,100 kg
empty weight alt=28,880 lb
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main=24,000 kg
max takeoff weight alt=52,910 lb
more general=
engine (prop)=Junkers Jumo 211F
type of prop=12-cylinder inverted-vee engine
number of props=3
power main=1,006 kW
power alt=1,350 hp
power original=
max speed main=437 km/h
max speed alt=272 mph
max speed more=at 5,800 m (19,030 ft)
cruise speed main=334 km/h
cruise speed alt=208 mph
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main=3,980 km
range alt=2,473 miles
ceiling main=6,300 m
ceiling alt=20,670 ft
climb rate main=228 m/min
climb rate alt=748 ft/min
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
guns=
** 1 x 13 mm MG 131 machine gun in dorsal turret
** 2 x 7.92 mm MG 15 machine gun in side windows
avionics=

References