P.Grosz, G.Haddow, P.Shiemer Austro-Hungarian Army Aircraft of World War One (Flying Machines)

Lohner 10.01 to 10.03

  After the Pfeilflieger Type C accident (see Lohner B.II series 12), the LA thoroughly tested each new design before approving production. Consequently, for static testing and flight trials, three prototypes of the improved Lohner Type E Pfeilflieger (AD 810 - AD 812) were ordered on 30 October 1914. Powered by the 100 hp Daimler engine, the first two aircraft, E-01 and E-02, were delivered on 10 December 1914 and E-03 on 21 January 1915. The designations were changed to 10.01-10.03 in February 1915. After passing military tests, the Type E was produced by Lohner as the B.III series 14 and by UFAG as the B.III (U) series 14.5.
  Serving as trainers, the Lohner E-01 (10.01) was written-off in October 1916 and the E-02 (10.02), the static load test airframe, later was flown by Fleks 2 and 4 through mid-1915 at least. From the outset the Lohner E-03 (10.03) prototype was modified, being equipped with a simplified wing cellule incorporating a thicker "Knoller profile." Later the complex Lohner undercarriage was redesigned with sprung axles replacing the shock-cord assembly. The E-03 (10.03) was flown as a trainer by Flek 4 until May 1915, when at the direction of Major von Umlauff, Lohner rebuilt the 10.03 by modifying the wings and installing a 100 hp Mercedes engine. As such the 10.03 became the prototype for the Lohner Type G and was assigned the designation B.IV 15.01 (see Lohner B.IV series 15 chapter).
  
Lohner 10.01 (AD 810) Specifications
Engine: 100 hp Daimler
Wing: Span Upper 13.60 m (44.62 ft)
Span Lower 9.10 m (29.86 ft)
Total Wing Area 31.9 sq m (343 sq ft)
General: Length 8.43 m (27.66 ft)
Height 3.48 m (11.42 ft)
Empty Weight 625 kg (1378 lb)
Loaded Weight 920 kg (2029 lb)
Climb: 1000m (3,281 ft) in 11 min


Lohner 10.07

  In April 1913, Lohner began the construction of a Gebirgsflieger (mountain flyer - AD 350), powered by a 80 hp Gnome rotary engine, designed to climb faster and operate at higher altitude than heavier aircraft with water-cooled engines. On 20 August 1913, shortly after completion, Uzelac test flew the machine which was delivered to the LA on 30 August 1913 under the designation "experimental machine G-1." Used as a trainer, it was based at Flugpark 3 in Gorz in February 1914. There is no record of wartime service.
  A second, private-venture Gebirgsflieger (AD 490) powered by a 100 hp Gnome, begun on 27 October 1913, was built in response to the success of the French rotary-engined aircraft at the Second International Flugmeeting. Because Lohner did not employ a full-time company acceptance pilot, it was not unusual for military pilots to carry out this task. On 27 February 1914, Oberleutnant Eugen Elsner performed the maiden flight which, according to a witness, demonstrated the plane's precise maneuverability, a rapid rate of climb, and high speed. Although built at the express wish of the LA, a subsequent lack of interest caused bitter recriminations. The machine did not participate in the two 1914 competitions. When purchased by the LA on 15 August 1914, it was designated LG-490 and entered training service with Flek 1 and later Flek 6. Numbered 10.07 in February 1915, the trainer was badly damaged on 2 December 1915 and written-off.

Lohner 10.07 (AD 490) Specifications
Engine: 100 hp Gnome
Wing: Span Upper 12.00 m (39.37 ft)
Span Lower 8.60 m (28.21 ft)
Chord Upper 1.56 m (5.12 ft)
Chord Lower 1.50 m (4.92 ft)
Total Wing Area 26.7 sq m (287 sq ft)
General: Length 7.80 m (25.59 ft)
Height 3.50 m (11.48 ft)
Empty Weight 460 kg (1014 lb)
Loaded Weight 780 kg (1720 lb)
Climb: 1000m (3,281 ft) in 8 min


Lohner 10.12

  Buoyed by the success of the Type B biplane, the LA requested Lohner to develop a lighter version with improved climbing ability for operation in mountainous terrain. A lighter engine was chosen, namely the four-cylinder 85 hp Hiero. Construction of the prototype known as the Gebirgsflieger Type C (mountain flyer - AD 353) was begun as a private venture on 4 April 1913. The prototype appeared at the Second International Flugmeeting at Aspern on 14 June 1913 for viewing only and was delivered to the LA in August. On 24 August 1913, crewed by Leutnant Hans Mandl and Oberleutnant Nikolaus Wagner Edler von Florheim, it became the second aircraft to fly over the Semmering, and the first carrying a passenger. While testing the engine the next day, the carburetor caught fire, destroying the top wing in the process.
  The LA purchased the Type C prototype (AD 353) on 10 September 1913 under the military designation C-01. Before committing the type for production, C-01 was flight tested in concert with a second prototype, designated C-02 (see Lohner 10.13). In February 1914 C-01 was stationed at Flugpark 3 in Gorz. The designation was changed to 10.12 in February 1915.


Lohner 10.13

  Lohner built a second Gebirgsflieger Type C prototype (AD 406) for factory flight test and evaluation. The completion date was prior to 10 September 1913. In view of the imminent delivery of Type C production machines, Uzelac requested the purchase of this company-owned aircraft for use as a transition trainer. Designated C-02, the Pfeilflieger was turned over to the LA on 13 December 1913 and formally purchased on 29 January 1914. Lohner C-02 was stationed at Flugpark 1 in February 1914 and redesignated 10.13 in February 1915. It was last reported based at Flek 7 in May 1915.


Lohner B.II Series 12

  For operation in mountainous terrain, the LA ordered the Type C Gebirgsflieger (mountain flyer), a lighter Type B that was powered by the new 85 hp Hiero four-cylinder engine which weighed 51 kg (112 lb) less than the six-cylinder, 90 hp Daimler. The Type C was a new design featuring a vertical fuselage sternpost as compared to the Type B's horizontal sternpost. To serve as an engine and structural-test machine, Cyklon (AC 957 - a lightened Type B) was purchased on 27 November 1912 and delivered to the LA in December. After Cyklon failed the load test, chief engineer Paulal blamed "the less-robust construction and worn airframe" and assured the LA that the production Type C would have a safety factor of at least 5 (3.5 was specified) which may explain why a production airframe was not subjected to load tests.
  The Type C prototype, designated C-01 (later 10.12), was delivered to the LA in August 1913. The second prototype remained the property of Lohner until purchased by the LA as C-02 (10.13) in January 1914. On 10 December 1913, the LA ordered 24 Type C Gebirgsflieger which were designated C-1 to C-24 (AD 500-523). Another Gebirgsflieger, designated C-25 and given a reinforced engine mount and longer fuselage, was delivered in July 1914. As their first production order, UFAG received a contract for 18 Type C, designated C-41 to C-58, on 9 January 1914.
  The first production aircraft, designated C-1, was accepted on 4 February 1914 and five machines followed in short order. Lohner flight testing was performed by company pilots Viktor Wittmann, Edmund Sparmann and Ferdinand Konschel with Lili Steinschneider, the first Hungarian woman pilot, often in the observer's seat. After a demonstration by Karl Illner, Uzelac who positively enjoyed flying new aircraft, took the Type C aloft. He reported vibrations of such intensity that his hands were "electrified," forcing him to wrap his arms around the wheel to maintain control. Being flown without a passenger, the aircraft was extremely nose heavy and only by pulling the control column hard against his chest was Uzelac able to land safely. Lohner blamed the vibrations on the Hiero engine, but Uzelac said such vibrations were absent from the Hiero-engined Etrich Taubes. On the plus side, the Type C with a passenger aboard showed good performance and flight characteristics.
  Oberleutnant Eugen Elsner, an experienced pilot assigned to the Versuchsflik (test section) and responsible for aircraft acceptance, was one of the officers who performed the customary "sign-off" flight. In reply to Elsner's inquiry whether tight turns and dives were safe, Paulal avowed that "there was absolutely nothing to fear." On 9 March 1914, a black day for the LA, Elsner and his passenger, Zugsfuhrer Philipp Srna, were killed when the left wing of aircraft C-2 collapsed in flight. Eye witnesses reported that the accident occurred in level flight, but Lohner claimed that Elsner was pulling out of a "full-throttle dive." All Type C aircraft were grounded, Lohner and UFAG production stopped, and an order for an additional 18 aircraft deferred pending the outcome of the crash committee findings.
  When airframe C-5 was tested on 14 March 1914, the wings failed much like Elsner's crash at a load factor of 2.4. Lohner then reinforced the wing cellule but it was not enough. On the third test, performed 20 March 1914, a new wing with heavier fittings, stronger struts, and additional wire bracing achieved satisfactory results. It was recommended that the existing wings be reinforced in the same manner, but the LA countermanded the crash commission on grounds that the profusion of additional wire rigging would make it difficult, if not impossible, to properly align the wings. Nor would the resulting performance meet the contractual specifications. In April 1914, the LA ordered Lohner to deliver new wings at the company's expense, but later provided funds to speed replacement in view of the deteriorating political situation. Professor Richard Knoller designed the new Type C wing employing a stronger spar and thicker rib section that "Paulal had so steadfastly refused to consider in the past."
  At the time of mobilization the Type C aircraft were grounded, but notwithstanding their poor condition six aircraft were provisionally reinforced and ready for assignment on 1 August 1914. Lohner was scheduled to complete the remaining modification by 31 October 1914. The Type C served with Fliks 4 and 6 in the Balkans and Fliks 8, 10, and 15 on the Russian Front. The first reports from the Front were hardly encouraging. On 25 August 1914, the commander of Flik 10 reported:
  The squadron's six aircraft have such strong vibrations induced by the unbalanced Hiero engine that in spite of great care taken during flight and landing, rigging wires snap and metal fittings, fuel and water lines break. Because of the vibrations, the instruments are unreadable.
  On the other hand, five Type C biplanes were flown by Flik 6 at Igalo from October-December 1914 with moderate success. Armed with an observer's machine gun mounted on the port side, Lohner C-11 supported infantry attacks at Grab (9 November 1914) and Trebinje (28 December 1914), thought to be among, if not the first, "infantry contact patrols" of the war. Another first occurred on 30 November 1914, when Oberleutnants Bela Losonczy von Losoncz and Johann Wierzejski of Flik 15, flying a Lohner Type C Pfeilflieger, shot down a Russian aircraft with a repeating rifle. At the Front, the Type C was flown only because no other aircraft were available, and it was quickly withdrawn as soon as German replacement aircraft arrived.
  In February 1915, the Type C was re-designated Lohner B.II 12.01 to 12.25 (ex C-1 to C-25). The Type C was withdrawn from the Front in May 1915 and seven dispatched to Fischamend for installation of new wings and other modifications. From early 1916 through March 1917, the Flugzeugwerk Fischamend built 45 Type C trainers, designated Lohner B.II (Fd) series 74. In June 1917, the last original Lohner B.II (12.17) was retired from service and placed into the aircraft collection at Fischamend.
Lohner B.II Series 12 Specifications
Engine: 85 hp Hiero
Wing: Span Upper 13.00 m (42.65 ft)
Span Lower 9.20 tn (30.18 ft)
Chord Upper 1.50 m (4.92 ft)
Chord Lower 1.49 m (4.89 ft)
Gap 1.85 m (6.07 ft)
Stagger 0.95 m (3.12 ft)
Total Wing Area 30.4 sq m (327 sq ft)
General: Length 8.30 m (27.23 ft)
Height 3.20 m (10.50 ft)
Empty Weight 560 kg (1235 lb)
Loaded Weight 920 kg (2029 lb)
Maximum Speed: 125 km/hr (78 mph)
Climb: 1000m (3,281 ft) in 7 min


Lohner B.III Series 14

  To restore confidence in Lohner aircraft after the Pfeilflieger wing failures, Professor Knoller was chosen to redesign the wing structure. First appearing in the Lohner Type E, Knoller's design had fewer wing ribs, a thicker rib section, reduced wire bracing, and wing tips supported by V-struts. The Knoller wing, approved by the LA in November 1914, was specified for 24 Type E Pfeilfliegers, of which 16 were ordered from Lohner and 8 from UFAG. The aircraft built by Lohner (AD 813-828), initially numbered E-1 to E-16, were re-designated B.III 14.01 to 14.16 in February 1915. The UFAG-built aircraft were numbered E-20 to E-27; then changed to E-51 to E-58 before being re-designated B.III (U) 14.51 to 14.58. When the contract was signed on 4 January 1915, Type E assembly was already underway. Deliveries were scheduled to end in early February; however, most of the aircraft were not accepted until April 1915.
  The Type E was issued singly to Fliks 2 (Serbian Front), 12 (Isonzo Front), and 16 (Karnten). Fitted with a 100 hp Daimler engine, the aircraft were reported so badly underpowered as to be virtually useless. Soon after the start of hostilities with Italy, Army Group Rohr wrote:
  Flik 12 is equipped with Type E Pfeilfliegers that are unable to carry machine gun or bomb armament. Owing to the poor rate of climb and radius of action, the aircraft are barely equal to the difficult mountainous terrain (Karnten region). To direct the heavy artillery, we urgently request aircraft with more powerful engines.
  As a result, many of the B.III series 14 aircraft were dispatched directly from the factory to training units (Fleks 1-5 and 7) and were soon joined by those from the Front. By October 1915, five B.IIIs remained in training inventory, and plans to modify these for dual controls were dropped. As late as July 1917, four B.III trainers were still active.

Lohner B.III Series 14 Specifications
Engine: 100 hp Daimler
Wing: Span Upper 13.60 m (44.62 ft)
Span Lower 9.14 m (29.99 ft)
Chord Upper 1.65 m (5.41 ft)
Chord Lower 1.55 m (5.09 ft)
Sweepback Upper 12 deg
Gap 1.90 m (6.23 ft)
Stagger 0.71 m (2.33 ft)
Total Wing Area 31.9 sqm (343 sq ft)
General: Length 8.43 m (27.66 ft)
Height 3.15 m (10.33 ft)
Empty Weight 685 kg (1510 lb)
Loaded Weight 1000 kg (2205 lb)
Maximum Speed: 115km/hr(71 mph|
Climb: 1000m (3,281 ft) in 11 min 20 sec


Lohner B.IV Series 15

  In May 1915, under the direction of Major von Umlauff Lohner rebuilt the Lohner 10.03 (Type E) prototype with new wings, a simplified undercarriage, and a 100 hp Mercedes engine. The rebuilt Pfeilflieger was designated Type G and upon delivery on 21 June 1915, received the military designation B.IV 15.01. It was the sole Type G built by Lohner, although UFAG delivered a batch of eight aircraft designated B.IV(U) series 15.5. Aircraft 15.01 was written-off in August 1915.

Lohner B.IV Series 15 Specifications
Engine: 100 hp Mercedes
Wing: Span Upper 13.60 m (44.62 ft)
Span Lower 9.10 m (29.86 ft)
Total Wing Area 31.9 sq m (343 sq ft)
General: Length 8.43 m (27.66 ft)
Empty Weight 725 kg (1599 lb)
Loaded Weight 1000 kg (2205 lb)
Maximum Speed: 115 km/hr(71 mph)
Climb: 1000m (3,281 ft) in 11 min


Lohner B.II(U) Series 12.4

  The first production contract UFAG received, signed on 9 January 1914, called for 18 Lohner Type C biplanes powered by the 85 hp Hiero engine. The original aircraft designation, C 41 to C 58, was changed to Lohner B.II(U) 12.41 to 12.58 in February 1915. The UFAG factory began production on 1 March 1914 and the first aircraft were rolled out in early June, only to be returned for "reconstruction" because serious structural deficiencies had been discovered in the Lohner-built Type C biplanes. Acceptance of the strengthened Type C began in August and ended in November 1914. The UFAG-built B.II was assigned to Fliks 4, 8, 9, 15 and 16. The most notable accomplishment occurred when six aircraft of Flik 9, carrying bombs in place of the observers, attacked the Serbian arsenal at Kragujevac on 24 November 1914. Flik 9 reported the undercarriages were so fragile that most of the aircraft suffered structural damage. Beginning in May 1915, the remaining biplanes were sent to Fleks 1-5 and 7 to serve as trainers until 15 November 1915, at which time those damaged aircraft requiring extensive repairs were to be written-off. However, a few UFAG-built B.II biplanes remained in training inventory until May 1916.


Lohner B.III(U) Series 14.5

  UFAG signed a production contract on 18 January 1915 for eight Lohner Type E biplanes powered by the 100 hp Daimler engine. As assembly work was already underway, the aircraft were scheduled for delivery between 1 and 25 February 1915. To avoid conflict with Lohner, the designation numbers E-20 to E-27 were changed to E-51 to E-58 and remained in force until February 1915, when the aircraft were redesignated Lohner B.III(U) 14.51 to 14.58. The biplanes, accepted during April-May 1915, served with Fleks 1, 2, 3, 5, 7, and 9 as trainers. Aircraft 14.58 was attached to Flik 16 as a trainer on the Italian Front in May-June 1916. Two aircraft remained active as secondary school machines until 1918.


Lohner B.IV(U) Series 15.5

  On 15 May 1915, UFAG received an order for eight Lohner B.IV(U) biplanes, numbered 15.51 to 15.58 and based on the Lohner Type G prototype (15.01). The airframe was identical to the Lohner B.III(U) series 14.5 except that a 100 hp Mercedes engine and a new undercarriage were fitted. Of the eight aircraft, accepted between May and July 1915, four were intended for Flik 12 on the Isonzo Front but they saw little operational service because of their poor performance. In mid-1916 all eight biplanes were attached to Fleks 1-5 and 7 and as of July 1917, three B.IV(U) series 15.5 trainers were still in service.


Lohner B.II(Fd) Series 74

  The rationale for building a patently obsolete pre-war aircraft when modern trainers were available appears hardly justifiable, even if the design was stable and easy to fly. Yet in early 1916, the Flugzeugwerk began production of 46 new Lohner B.II(Fd) series 74 trainers, the last of which was delivered in March 1917! Another seven were modified from original Lohner-built airframes. The series that numbered 74.01 to 74.53 was powered by a 85 hp Hiero engine. In the course of its training duties, the B.II(Fd) was often repaired and modified. It was flown as an advanced trainer at Fleks 1-7, 12, and 13 and Schulkompagnie 1. Forty-five B.II(Fd) biplanes were in the training command inventory as of 1 July 1917, and at least 15 were still active in mid-1918.

Lohner B.II(Fd) Series 74
Engine: 85 hp Hiero
Wing: Span Upper 13.50 m (44.29 ft)
Sweepback Upper 13 deg
Gap 1.80 m (5.91 ft)
Total Wing Area 32.0 sq m (344 sq ft)
General: Length 8.30 m (27.23 ft)
Track 1.90 m (6.23 ft)
Empty Weight 530 kg (1169 lb)
Loaded Weight 776 kg (1711 lb)
Climb: 1000m (3,281 ft) in 8 min 10 sec

E.Hauke, W.Schroeder, B.Totschinger Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918

10. Flugzeuge der Fabrik Jacob Löhner & Co. Wien, Floridsdorf
10.01 Löhner DD E-01 Dm 100
10.02 Löhner DD E-02 Bruchprobe Dm 100
10.03 Löhner DD E-03 Merc 100
10.07 Löhner ED Type Lohner-Gnöme, WNr. 490 Gn 80
10.12 Löhner DD Gebirgstype C-01, WNr. 353 H 85
10.13 Löhner DD Gebirgstype C-02, WNr. 406 H 85
12.01 — 12.40 Löhner B.II (Type C) H 85
12.41 — 12.58 Löhner B.II (U) H 85
14.01 — 14.16 Löhner B.III (Type E) Dm 100
14.51 — 14.58 Löhner B.III (U) Dm 100
15.01 Löhner B.IV (Umbau 10.03) Merc 100
15.51 — 15.58 Löhner B.IV (U) Merc 100

70. Flugzeuge der Flugzeugfabrik Fischamend, k.u.k. Fliegerarsenal
74.01 — 74.47 Löhner B.II (Fd) Umbau 12.01 — 12.47 H 85
74.48 — 74.53 Löhner B.II (Fd) Neubau H 85