The Lambach HL.1 was a one-off, simple
tandem
Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction.
The original use of the term in English was in ''tandem harness'', which is used for two ...
two seat
trainer designed and built by members and ex-members of the
Delft Student Aeroclub (DSA) in the
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
in the mid-1930s.
Design and development
When in the early 1930s members of the DSA were trying to bring down the costs of tuition they decided that in the absence of public finance they would build their own aircraft. J.W.H. (Hugo) Lambach, a former DSA member, was asked to design a machine which would be cheap to produce and operate. A group of about twenty-five students set about its construction; some members of
Pander Aircraft
Pander may refer to:
People
* Arne Pander (1931–2015), Danish international speedway rider
* Christian Pander (born 1983), a German footballer
* Heinz Christian Pander (1794-1865), Russian biologist and embryologist
* Pier Pander (1864–1919) ...
, including their chief designer Theo Lock, also assisted from time to time. Work began in the spring of 1934 and the Lambach HL.I made its first flight on 5 July 1935, piloted by Dick Asjes.
[
The HL.I was a ]cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cant ...
low-wing monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...
with wings of constant chord
Chord may refer to:
* Chord (music), an aggregate of musical pitches sounded simultaneously
** Guitar chord a chord played on a guitar, which has a particular tuning
* Chord (geometry), a line segment joining two points on a curve
* Chord ( ...
and rounded tips. Its tail was conventional, with a braced straight-tapered horizontal tail mounted on top of the fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
and a largely rounded vertical tail with a rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adverse yaw a ...
which extended below the tailplane, moving within an elevator
An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They ar ...
cut-out.[
Its fuselage was round in section and tapered a little both forward and aft of the wings. The front open cockpit was just ahead of the wing leading edge and the rear cockpit, from which the HL.I was flown solo and which had a short, faired headrest, was at about two-thirds wing ]chord
Chord may refer to:
* Chord (music), an aggregate of musical pitches sounded simultaneously
** Guitar chord a chord played on a guitar, which has a particular tuning
* Chord (geometry), a line segment joining two points on a curve
* Chord ( ...
. During early testing the HL.1 was configured as a single-seater; it was also initially powered by a 34 kW (45 hp) Szekely SR-3
Szekely aircraft engines were three-cylinder radial engines built in Holland, Michigan in the 1920s and 30s. They were used to power small aircraft such as the Rearwin Junior, Taylor H-2 and American Eagle Eaglet. Often criticized for reliab ...
three- cylinder radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...
installed with its cylinder head
In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinder (engine), cylinders and forms the roof of the combustion chamber.
In sidevalve engines, the head is a simple sheet of metal; whereas ...
s exposed for air cooling, but this proved unreliable and was replaced by a 67 kW (90 hp) Pobjoy Niagara
The Pobjoy Niagara is a British seven-cylinder, air-cooled, radial, aero-engine first produced in 1934. The design ran at higher speeds than conventional engines, and used reduction gearing to lower the speed of the propeller. This led to a not ...
seven-cylinder radial, also with cylinders exposed. Both engines drove two-blade propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
s. The HL.1 had a fixed, conventional undercarriage
Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Ter ...
with its mainwheels on tall, vertical, largely faired legs braced laterally by an inverted V pair of strut
A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension.
Human anatomy
Part of the functionality o ...
s and longitudinally by trailing struts; there was also a tailskid.[
]
Operational history
The HL.I was appropriately registered as ''PH-DSA'' on 1 January 1936. In March the DSA transferred it to the Nationale Luchtvaartschool (National Flying School) at Ypenburg Airport
Ypenburg Airport (Dutch: Vliegveld Ypenburg), which later became Ypenburg Air Base was an airport in the Netherlands in Leidschenveen-Ypenburg near the city of The Hague. The ICAO code was EHYB.
History
The airfield was established in 1936, initia ...
where it served until the Germans
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, region2 =
, pop2 = 534,000
, region3 =
, pop3 = 157,000
3,322,405
, region4 =
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invaded the Netherlands on 10 May 1940. The HL.1 avoided destruction by bombing which took many Dutch aircraft that day. The aircraft began to degrade after being moved out of its hangar
A hangar is a building or structure designed to hold aircraft or spacecraft. Hangars are built of metal, wood, or concrete. The word ''hangar'' comes from Middle French ''hanghart'' ("enclosure near a house"), of Germanic origin, from Frankish ...
by German forces and it was eventually handed back to the Technical University of Delft for instructional purposes, where it was dismantled.[
]
Specifications (Pobjoy engine)
References
{{reflist, refs=
[{{cite book , title= De Nederlandse vliegtuigen , last=Wesselink, first=Theo, last2= Postma, first2=Thijs, year=1982, publisher=Romem , location=Haarlem , isbn=90 228 3792 0, page=95]
1930s Dutch sport aircraft
Low-wing aircraft
Aircraft first flown in 1935