[WWII] Bucker Bu 131 Jungmann

[Phaelen Bleux]

Biplane of the Month Club: March

Bucker Bu 131 Jungmann
After working for SAAB, Carl Bucker returned to Germany with designer Anders Andersson to set up his own aircraft company. The first plane they manufactured was the Bu 131, a light trainer biplane intended for both the civilian and military market. It was built very extensively for the Luftwaffe (although exact numbers are unknown), and exported to Czechoslovakia (400 planes), Hungary (100 planes) and Romania (150 planes). It was license-built in Spain (as the CASA 1.131), Sweden (75 planes), as well as Japan (1,037 planes, designated the Type 4 Primary Trainer or Nippon Ki-86a, Allied reporting name "Cypress"). It continued to be built in Czechoslovakia after the war as the Aero C-104 and was used in Spain as a trainer until 1968.
Although generally unarmed, some Bu 131s were equipped to carry 2.2-lb. and 4.4-lb. bombs under the wings, and were used for night harassment over the Soviet lines. Earlier "armed" versions simply allowed the rear occupant space to toss out light fragmentation bombs.
The Bu 131 has a crew of two: pilot and instructor. It burns 4 gallons of gasoline per hour at routine usage. It had a historical range of 404 miles.

Bucker Bu 131B Jungmann
Subassemblies: Recon Fighter chassis +2; Recon Fighter wings +2; 2 fixed wheels +0.
Powertrain: 78-kW HP gasoline engine with 78-kW prop and 13.2-gallon fuel tank [Body].
Occ.: 2 XCS Body
Cargo: 7.5 Body

Armor F RL B T U
Body: 2/2 2/2C 2/2C 2/2C 2/2C
Wings: 2/2C 2/2C 2/2C 2/2C 2/2C
Wheels: 2/3 2/3 2/3 2/3 2/3

Statistics:
Size: 22'x24'x7' Payload: 0.32 tons Lwt.: 0.75 tons
Volume: 96 Maint.: 135 hours Cost: $2,193

HT: 7. HPs: 15 Body, 50 each Wing, 3 each Wheel.

aSpeed: 114 aAccel: 3 aDecel: 48 aMR: 12 aSR: 1
Stall Speed: 44 mph. Take-Off Run: 242 yards. Landing Run: 194 yards.
gSpeed: 163 gAccel: 8 gDecel: 10 gMR: 0.5 gSR: 2
Ground Pressure: High. 1/6 Off-Road Speed.

Design Notes:
Historical wing area was 145 sf. Although the plane is obviously a biplane, monoplane wings were purchased for the design due to the small historical wing area, but then had weight, cost and HP doubled to increase design weight. Design weight was further increased 5%* to the historical. Armor is purchased as cloth, although the engine cowling was actually light sheet metal. Design payload was 486 lbs; the historical value has been substituted. Design aSpeed was 108 mph. Performance calculations were based on historical values for wing area and loaded weight.
*This 76 lbs. of "unaccounted for" design weight could be translated into a bomb payload of up to 16 4.4-lb. bombs (as no historical loadout was available).

Variants:
The -A (1932) featured a 60-kW engine.
The -C was a single plane with a 68-kW engine.
Modern licensed replicas continue to be built as the BP 131.