Lambach HL II

The original HL II

Lambach HL II op YpenburgThe story of the Lambach HL II starts at the annual Pinkstervliegfeesten (Whitsuntide Flying Festival) at Eelde in the year 1936. Because of the supremacy of the Germans, several leading Dutch industrials and prominent sport pilots got the funds for a Dutch aerobatics airplane. At the same time the young Delft engineer Hugo Lambach had made some sketches for such an airplane, and with this assignment he could realize his dream. To continue the design and build Lambach Aircraft was founded in January 1937. With five and a half months to go to design and build the biplane. It consisted of a steel tube airframe covered with linen, on which the wooden wings with a span of 8 meters were attached. The airplane was powered by a de Havilland Gipsy Major Mk. 1 engine, an inverted 4-cylinder producing 130 hp. After her maiden flight on May 2, the test pilot Schmidt Crans praised the excellent flight characteristics. At the 1937 Pinkstervliegfeesten the Lambach became third after two Germans. This was a better achievement than it looks, since the festival was only two weeks after her maiden flight. Afterwards the airplane served as an advanced trainer at the Nationale Luchtvaartschool (National Aviation School). In the morning of May 10 1940, at the start of World War II, the aircraft was destroyed during German bombing raids at Ypenburg airfield, near The Hague. Only a set of drawings survived.

 

The replica

Lambach HL-II PH-APZ Engine Running

In the spring of 1989 the Society of Aerospace Students ‘Leonardo da Vinci’ was looking for an activity for its 9th lustrum. After some research the decision was made to rebuild the HL II. The complete set of drawings was copied by hand because of the poor quality of the originals. Soon the component production was started. This was shortly followed by the production of the wooden wings and the welding of the steel tube airframe. The Military Aviation Museum in Soesterberg made the engine at our disposal, which had to be completely overhauled. Supported by the many advices of Mr. De Koo, the former chief-engineer, the building was completed after 5 years of hard labour. The students attended to all aspects of aircraft manufacturing. For example, they have designed several modifications to the design to fulfil the modern airworthiness requirements. Also the certification of the building to guarantee the quality of the aircraft has been done by the students themselves.

At the first nice spring-day, 24th April 1995, the aeroplane was presented to the public and named "Lambach HL II". To those present, more than 600 people, the sound of the running Gipsy Major was a great experience. At the same day the builders heard that the HL II project had won the Phoenix group prize awarded by the Federation Aeronautique Internationale (FAI). This world-wide prize expresses that the Dutch really build airplanes of world-class.

 

Current location

The Lambach is currently stationed in the T2 hangar of the Aviodrome Aviation museum at Lelystad airport (EHLE).

 

Technical details

Lambach HL II Aanzichten

Registration PH-APZ
Year and place of fabrication: 1989-1995, Delft


Type: Lambach HL II
Serial number: 20002


Wing span: 8.00 meter
Length: 6.70 meter
Height: 2.40 meter
Empty weight: 4590 N (468 kg)
Maximum take-off weight: 6080 N (620 kg)


Stall speed: 43 KIAS (80 km/h)
Cruise speed (VA): 110 KIAS (204 km/h)
Maximum speed (VNE): 145 KIAS (269 km/h)
Maximum G-load: -2.9 / +5.8
Operating ceiling: 6000 ft MSL
Minimum take-off distance: 200 meter
Minimum landing distance: 300 meter


Engine: Gipsy Major Mk. 1
Builder: De Havilland Engine Co. Ltd.
Serial number: 95121 A 444646
Fuel: AVGAS / MOGAS
Oil: Aeroshell W100


Propeller Builder: Poncelet
Type: Two-bladed, wooden propeller with fixed pitch
Serial number: Poncelet - 90106 D 663 P458
Delft University of Technology