Junkers A 48  and K 47

The Junkers K 47 designed by Dipl-Ing Karl Plauth and Hermann Pohlmann was intended primarily as a two-seat fighter monoplane, but following the standard Junkers practice of the period, an ostensibly civil counterpart was evolved in parallel as the A 48. Work on the K 47 was begun in 1927, and in order to overcome the restrictions imposed on the development of combat aircraft in Germany appertaining at that time, the prototype was assembled in Sweden by the Junkers subsidiary, A.B Flygindustri at Limhamn-Malmo, although on 1 November 1927, shortly before flight testing of the K 47 began, Plauth lost his life in a flying accident.

Registered S-AABW (and later reregistered SE-ABW), the K 47 began flight trials from Bulltofta airfield early in 1928. It was an exceptionally sturdy and, for its time, an aerodynamically clean all-metal monoplane of low-mid configuration employing a typical Junkers tubular structure with corrugated duralumin skinning. Possessing a performance comparable with most and superior to some contemporary single-seat fighters, it carried a fixed forward-firing armament of two 7,9-mm Madsen machine guns in the upper decking of the forward fuselage, and a similar weapon mounted on a Knauth "rocking carriage" in the rear cockpit. This "carriage" was essentially a balancing beam, one end of which served as a seat for the gunner and the other as a support for the gun, offering an 18 deg movement on each side of the centreline and from 0 to 90 deg in the vertical plane. The two crew members were seated back-to-back in tandem open cockpits, and all fuel was housed by two tanks in the wing roots.

The K 47 prototype differed in a number of respects from both the production two-seat fighter and the essentially similar A 48 civil model. Whereas the prototype had trailing-edge taper from half-span, inset ailerons, rounded wingtips, and bracing wires above and below the wing which had no dihedral, the production model introduced marked wing dihedral, trailing-edge taper from the root, ailerons extending to blunt wingtips, and sloping bracing struts from the undercarriage to half-span replacing the upper and lower wire bracing. This was later made on the first prototype.The prototype K 47 was powered by a Bristol Jupiter VII with an international rating of 420 hp, but the first Swedish-built production model was powered by a Pratt & Whitney Wasp rated at 550 hp, and the aircraft was offered with either Madsen guns and Madsen mechanical synchronising equipment or Vickers guns and Vickers Constantinesco oil synchronising equipment).

Further development of the K 47 was largely confined to the installation of alternative power plants, these including the Mercury IV S2 supercharged radial of 540 lip and the Pratt & Whitney Hornet of 580 hp.. However, the Chinese government elected to purchase the Hornet-powered K 47, and 10 two-seat fighters of this type were shipped by A.B Flygindustri to China.

Production was undertaken by Junkers at Dessau under the designation A 48, totally 23 built.AB Flygindustri was assembled and/or modified 17 of these.Demonsration tour were made with several of the planes. Swedish registrations were used. The A 48 was granted a Certificate of Airworthiness by the DVL in Germany on 5 March 1929, and variants included the A 48b with a Bristol Jupiter VII, the A 48ba with the BMW-built Hornet of 550 lip (this power plant also being installed in theA48da), the A 48dy with a 540 lip Siemens Sh 20, and the A 48fi which, with a Siemens-built Jupiter VI, differed from other variants lin having a single fin-and-rudder assembly in place of the standard twin assembly. Only one exemple of the A 48dy was produced, this (D-2012) being evaluated in June 1931 at the Adlershof research establishment, but several examples of the Jupiter- and Hornet-powered A 48 were completed at Dessau. Fitted with racks for two 25-kg bombs attached to the wing bracing struts, these aircraft participated in shallow dive-bombing and close-support trials at Boblingen and elsewhere, eventually being transferred to the para-military NSFK (Nationalsozialistisches Fliegerkorps) as trainers, one or two remaining in service into the ‘forties.

Source: AB Flygindistri i Limhamn 1925-1935      (L. Andersson)
                Flying Review International Sept. 1970
                Die Deutsche Luftrüstung (Nowarra)
Type WerkNr Registration History
K47 3351 S-80 "Plauth", S-AABW, SE-ABW, D-IGER Built in Dessau and flown for the first time on 29th September 1928. Transported to Limhamn, Sweden and got swedish registration. Used for demonstration tours. Modified in 1930 with struts instead of wires between fuselage and wings.Sent to Germany 9th of March 1934,used by the DVS as a trainer. Crashed in August 1935.
K47b 3352   To Sovietunion in 1929. used by the NII VVS, the development center.
K47b 3353   To Sovietunion in 1929. used by the NII VVS, the development center.
  3354    
K47b 3355 SE-ACF, D-2284, TE+HR ? Delivered to Limhamn, registrade 18/12 1929. Sent to Turkey for demonstrations. Also to Rumania and Portugal. Took part in the ILIS exhibition in May 1931 (Stockholm). Used for dive bombing trials 1933-34. Crashed 1934 but was repaired
K47 3356 SE-ADL Delivered to Sweden after testing in Dessau. Used for dive bombing trials. Delivered finally to China, named T'ien Ch'u
K47 3357 P-1 Delivered to China
K47 3358 P-2 Delivered to China
K47 3359 P-3 Delivered to China
K47 3360 P-4 Delivered to China
K47 3361   Delivered to the Reichswehr in May 1930. Used at Lipetsk Crashed 20th of August 1931
K47,A48fi 3362 D-1057 Delivered to the Reichswehr in May 1930. Used at Lipetsk. Modified to single fin in Dessau in June 1931.sent back to Lipetsk. Back to Germany after closing of Lipetsk
K47 3363 D-2532, D-IPOS Delivered to the Reichswehr in May 1930. Used at Lipetsk. Used by the DVS ?
K47 3364 P-5 Delivered to China
  3365 D-2012 ?  
K-47 3366 P-6 Delivered to China
K47 3367 P-7 Delivered to China
  3368    
  3369    
  3370    
K47f, K47fi 3371 SE-ACT, D-2185, D-IKEF Delivered to Erprobungsstelle Travemünde in Sept 1931
  3372 D-2248 ? Delivered to Erprobungsstelle Travemünde in Jan 1932.Crashed just after delivery before it got its registration
  3373   Delivered to Erprobungsstelle Travemünde
Designation Engine
A 48 / K 47 1 Bristol Jupiter VII
A 48 / K 47b 1 Bristol Jupiter VII
A 48 / K 47ba 1 BMW Hornet Series III
A 48 / K 47bi 1 Gnôme-Rhône Jupiter VI 9Af
A 48 / K 47da 1 BMW Hornet A-2 Series III
A 48 / K 47fi 1 Siemens-Halske Jupiter VI
K 47bo 1 Pratt & Whitney Wasp (proposal)
K-47ce 1 Armstrong Siddeley Jaguar (tested in Dessau, proposal)
K 47 1 Bristol Mercury (proposal)
K 47 1 Salmson AB 18 (proposal)
K 47 1 Lorraine Dietrich
Type K 47 K 47 K 47fi
Engine Bristol Jupiter VII 420 - 450 hp Pratt & Whitney or BMW Hornet Siemens Jupiter VI
Dimensions Span 12.40 m, length 8.55 m, height 2.60 m, wingarea 22.8 m2 Span 12.40 m, length 8.55 m, height 2.60 m, wingarea 23.5 m2 Span 12.40 m, length 9.08 m, height 2.70 m, wingarea 23.5 m2
Weights Empty 1085 kg, flying weight 1635 kg, wingloading 72.5 kg/m2, powerloading 3.9 kg/hp Empty 1060 - 1130 kg, flying weight 1650 - 1700 kg Empty 1125 kg, flying weight 1700 kg
Performance Max. speed 245 km/h at sea level, 290 km/h at 3500 m, cruising speed 245 km/h, landing speed 100 km/h, climb to 1000 m 2.2 min, to 3000 m 6.3 min, to 5000 m 11.7 min, service ceiling 8100 m , max. altitude 8500 m, required startlength 175 m Max. speed at 900 m 277 km/h, cruising speed 240 km/h, landing speed 105 km/h, climb to 1000 m 2 min, to 3000 m 6.5 min, to 4000 m 9.5 min, service ceiling 8000 m, max. altitude 8600 m, required startlength 175 m. landing 225 m  
Production
Ju K47 S-80 Plauth
First prototype
Ju A 48da TE+HR
One of the last surviving planes