<!-- This article is a part of Wikipedia:WikiProject Aircraft. Please see Wikipedia:WikiProject Aircraft/page content for recommended layout. --> {{Infobox aircraft | name = HL.2 | logo = | logo_size = | image = LambachHLII.jpg | alt = | caption = HL.II replica, bearing the original's PH-APZ registration | long_caption = | other_names = | aircraft_type = Single seat aerobatic aircraft | aim = | outcome = | related = | national_origin = Netherlands | manufacturer = Lambach Aircraft | design_group = | designer = | builder = | issuer = | status = | owners = | primary_user = | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = 2 (1 original, 1 replica) | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = | first_flight = 4 May 1937 | initiated = | in_service = | last_flight = | expected = | developed_from = | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}

The '''Lambach HL.II''' was a single seat aerobatic biplane designed and built in the Netherlands to provide Dutch pilots in a local, annual competition with their own machine. It proved no match for contemporary Germany aircraft.

==Design and development== There were no Dutch aircraft competing in the North Dutch Flying Club's first international aerobatics competition held in Eelde in the spring of 1936; from a field of German and Dutch pilots, the best placed Dutchman came second, flying a British Tiger Moth. Hugo Lambach, who had already designed and helped build the Lambach HL.I at the Delft Student Aeroclub, was asked to produce an indigenous competitor. In January 1937 he set up a factory trading as Lambach Aircraft at Voorburg and by May the HL.II was designed and built, making its first flight on 4 May flown by Hein Schmidt Crans, the pilot who had come second in 1936.<ref name=DNV/><ref>{{Cite web |title=Koolhoven F.K.57 |url=https://www.airhistory.net/photo/294383/PH-KOK |access-date= |website=AirHistory |language=en}}</ref>

The HL.II is a conventionally laid out biplane with single bay wings of constant chord and rounded tips. These are mounted without stagger or sweep, braced with N-form interplane struts and a pair of similar form cabane struts. There are ailerons on both planes, externally connected. The fin and rudder are rounded, the latter extending to the keel. The tailplane is mounted on top of the fuselage and the elevators have a cut-out for rudder movement.<ref name=DNV/>

The HL.II is powered by a 130&nbsp;hp (97&nbsp;kW) de Havilland Gipsy four cylinder inverted inline engine driving a two blade propeller. Its lower fuselage is flat sided, the upper with rounded decking. Its cockpit, with a faired headrest, is placed just behind the trailing edge, where there is a round cut-out for enhanced visibility. The HL.II has a fixed conventional undercarriage, with mainwheels on crossed axles supported by V-struts and with a tailwheel.<ref name=DNV/>

==Operational history== There was little time to practice for the 1937 aerobatic event and Hein Schmidt Crans in the HL.II, faced with superior German aircraft, could only manage third place. Things went even worse in 1938, with the Dutch machine in last place, overwhelmed by the Germans. With war approaching, there was no competition in 1939 and on 10 May 1940 the sole HL.II was destroyed at Ypenburg by German bombs.<ref name=DNV/>

Lambach Aircraft had an even shorter life; it closed within the year, as other aircraft manufacturers focused on military production.<ref name=DNV/>

A replica built by students of the Technical University of Delft flew in 1995 but was soon grounded by fatigue cracks in the wing roots.<ref name=Mphotos/> It is now (2017) at the Aviodrome, Lelystad Airport,<ref name=Ogden/> being restored to flying condition.<ref name=FP/>

==Specifications== {{Aircraft specs |ref=De Lambach HL II<ref name=LHL2/> |prime units?=met <!-- General characteristics --> |genhide=

|crew=One |capacity= |length m=6.70 |length note= |span m= |span note= |upper span m=8.00 |upper span ft= |upper span in= |upper span note= |lower span m=7.00 |lower span ft= |lower span in= |lower span note= |height m=2.40 |height ft= |height in= |height note= |wing area sqm=16.7 |wing area sqft= |wing area note= |aspect ratio=<!-- give where relevant eg sailplanes --> |airfoil= |empty weight kg=468 |empty weight lb= |empty weight note= |gross weight kg= |gross weight note= |max takeoff weight kg=620 |max takeoff weight lb= |max takeoff weight note= |fuel capacity= |lift note= |more general= <!-- Powerplant --> |eng1 number=1 |eng1 name=de Havilland Gipsy Major |eng1 type=4-cylinder inverted air-cooled inline engine |eng1 hp=130 |eng1 note= |power original= |more power=

|prop blade number=2 |prop name= |prop dia m=<!-- propeller aircraft --> |prop dia ft=<!-- propeller aircraft --> |prop dia in=<!-- propeller aircraft --> |prop dia note=

<!-- Performance --> |perfhide=

|max speed kmh=215 |max speed note= |cruise speed kmh=185 |cruise speed mph= |cruise speed kts= |cruise speed note= |stall speed kmh=<!-- aerobatic --> |stall speed mph=<!-- aerobatic --> |stall speed kts= |stall speed note= |never exceed speed kmh=250 |never exceed speed mph= |never exceed speed kts= |never exceed speed note= |minimum control speed kmh= |minimum control speed mph= |minimum control speed kts= |minimum control speed note= |range km= |range miles= |range nmi= |range note= |endurance=<!-- if range unknown --> |ceiling m= |ceiling ft= |ceiling note= |g limits=+6, -3 |roll rate=<!-- aerobatic --> |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude= |wing loading kg/m2= |wing loading lb/sqft= |wing loading note= |power/mass= |more performance=

}}

<!-- ==See also== --> {{aircontent <!-- include as many lines are appropriate. additional lines/entries with carriage return. --> |see also= |related=<!-- related developments --> |similar aircraft=<!-- similar or comparable aircraft --> |lists=<!-- related lists --> }} <!--==Notes==-->

== References == {{Commons category|Lambach HL.II}} <references>

<ref name=DNV>{{cite book |title= De Nederlandse vliegtuigen |last1=Wesselink|first1=Theo|last2= Postma|first2=Thijs|year=1982|publisher=Romem |location=Haarlem |isbn=90-228-3792-0|page=108}}</ref>

<ref name=Ogden>{{cite book |title=Aviation Museums and Collections of Mainland Europe |last= Ogden |first=Bob|year=2009|publisher= Air Britain (Historians) Ltd|page=366|isbn=978-0-85130-418-2}}</ref>

<ref name=Mphotos>{{cite web |url=http://1000aircraftphotos.com/Contributions/Braas/10061.htm|title= Lambach HL.II|accessdate=11 March 2013}}</ref>

<ref name=LHL2>{{cite book |title=De Lambach HL II|last1=Nijenhuis|first1=W.A.S.|last2=Spek|first2=F.C.|last3=Moeleker|first3=P.J.J.|year=1996|publisher=Barjesteh, Meeuwes|isbn=90-5613-016-1}}</ref>

<ref name=FP>{{cite journal |date=November 2017 |title=briefings|journal= Fly Past|pages=8 }}</ref>

</references> <!-- ==Further reading== --> <!-- ==External links== -->

Category:1930s Dutch sport aircraft Category:Biplanes Category:Single-engined tractor aircraft Category:Aircraft first flown in 1937