LIPNUR Sikumbang

__NOTOC__

{{Infobox aircraft

|name=LIPNUR Sikumbang

|image=NU-200-Si-Kumbang (cropped).jpg

|image_size=300

|caption=NU-200 prototype on display at the Dirgantara Mandala Museum in Yogyakarta

|type=Counter-insurgency aircraft

|manufacturer=Angkatan Udara Republik Indonesia, Depot Penjelidikan, Pertjobaan dan Pembuatan/LIPNUR

|designer=Nurtanio Pringgoadisuryo (id)

|first_flight=1 August 1954

|introduction=

|retired=1967

|status=

|primary_user=Indonesian Air Force

|more_users=

|produced=

|number_built=2

|variants=

}}

The LIPNUR Sikumbang ({{langx|id|Beetle}}) was a low-wing monoplane of mixed construction built in Indonesia in 1954 as a COIN and anti-guerrilla-warfare aircraft. Of conventional configuration, it had fixed tricycle undercarriage and seated the pilot under a bubble canopy. A single example was built under the designation NU-200 in 1954, and another as the NU-225 in 1957. The latter machine was grounded in 1967.

Design and development

=NU-200=

Due to various internal rebellions that happened across Indonesia in the early 1950s, Major Nurtanio Pringgoadisuryo, head of Indonesian Air Force’s Research, Development, and Production Depot, was inspired to design and build a light counter-insurgency aircraft to meet the demands of the Air Force.{{sfn|Stroud|2017|pages=112}} Nurtanio, together with two technicians, Second Lieutenant Achmad and Second Lieutenant Tosin, built the aircraft in their spare time with limited funds from the Air Force and tooling, spare parts and materials available at the depot's facility in Andir airfield, Bandung.{{cite web|url=https://aviahistoria.com/2024/08/01/penerbangan-perdana-sikumbang/ |title=Penerbangan Perdana Sikumbang |website=aviahistoria.com|date=1 August 2024 |access-date=31 October 2024|lang=id}}

The aircraft was powered by a single 200 hp de Havilland Gipsy Six air-cooled inverted inline piston engine with two-bladed fixed-pitch propeller. The fuselage was made from welded 4130 steel (chromoly) with metal skins, while the wings and tail surfaces were all-wood material. It has cantilevered low wing with NACA 23012 airfoil, with the wing consisted of one-piece two-spar wooden construction with plywood covering, fitted with electric split-type flaps and statically balanced ailerons. The tail surfaces were made of wood with plywood skins, with trim-tab fitted to the port elevator and rudder. The aircraft has a fixed tricycle landing gear with cantilever oleo shock struts and non-steerable nose wheel.{{sfn|Stroud|2017|pages=112}}

The first prototype was dubbed NU-200 Sikumbang. The "NU" stands for Nurtanio, while "200" refers to the power of its Gipsy Six engine. The NU-200 first flew on 1 August 1954 piloted by Captain Powers, an American flight instructor and test pilot hired by the Indonesian Air Force.{{sfn|Stroud|2017|pages=112}} Originally, Nurtanio was supposed to flew the first flight, however Marshal Soerjadi Soerjadarma, the Air Force chief of staff, ordered him not to do so. The NU-200 flew for 15 minutes. Captain Powers praised the aircraft's flight control, although there's an issue with the engine cooling system, which forced him to reduce the power.

The NU-200 was flown to Kemayoran Airport in February 1955 for an exhibition. Nurtanio also planned to flew the aircraft over the {{convert|2900|m|ft|abbr=on}} summit of Mount Merapi in central Java. Marshal Soerjadarma, on recommendation from Nurtanio's friend Jacob Salatun, again disapproved the idea and ordered him to cancel the flight.{{sfn|Stroud|2017|pages=112}} Instead, Nurtanio flew the aircraft over Bandung and as he landed it, the engine was having a trouble and "spluttering to a halt".{{sfn|Stroud|2017|pages=112}}

Variants

NU-200: First prototype, powered by a 200 hp de Havilland Gipsy Six engine with two-bladed fixed-pitch wooden propeller and fixed tricycle landing gear.
NU-225: Improved pre-production variant, powered by a 225 hp Continental O-470-A engine with Hartzell metal propeller and retractable tricycle landing gear.{{sfn|Stroud|2017|pages=113}}
NU-260 Kumbang: Four-seat liaison aircraft variant of the NU-225, also planned for the civilian market. A single prototype was under construction before the project was cancelled.{{sfn|Stroud|2017|pages=113}}

Specifications (NU-200)

{{Aircraft specs

|ref=Jane's All The World's Aircraft 1955–56Bridgman 1955, p. 165.

|prime units?=met

|genhide=

|crew=1

|capacity=

|length m=8.16

|length ft=

|length in=

|span m=10.61

|span ft=

|span in=

|aspect ratio=6.6:1

|airfoil=NACA 23015 at root, NACA 23009 at tip

|height m=3.35

|height ft=

|height in=

|wing area sqm=16.9

|wing area sqft=

|empty weight kg=795

|empty weight lb=

|gross weight kg=1090

|gross weight lb=

|fuel capacity={{convert|205|L|USgal impgal|abbr=on}}

|eng1 number=1

|eng1 name=de Havilland Gipsy Six

|eng1 type=air-cooled inverted six-cylinder inline engine

|eng1 kw=

|eng1 hp=200

|prop blade number=2

|prop name=fixed pitch

|prop dia m=

|prop dia ft=

|prop dia in=

|perfhide=

|max speed kmh=256

|max speed mph=

|max speed kts=

|cruise speed kmh=224

|cruise speed mph=

|cruise speed kts=

|range km=960

|range miles=

|range nmi=

|ceiling m=5030

|ceiling ft=

|climb rate ms=

|climb rate ftmin=1000

|more performance=

|avionics=

}}

References

{{cite book|last=Bridgman|first=Leonard|title=Jane's All The World's Aircraft 1955–56|year=1955|publisher=The McGraw-Hill Book Company|location=New York}}
{{cite journal |last1=Stroud |first1=Nick |date=15 October 2017 |title=Indonesia's Fledgling Insects |journal=The Aviation Historian |volume=21 |pages=110–117 |issn=2051-1930}}
{{cite book |last= Taylor |first= Michael J. H. |title=Jane's Encyclopedia of Aviation |year=1989 |publisher=Studio Editions |location=London |pages=61 }}
[https://web.archive.org/web/20090829085051/http://www.indonesian-aerospace.com/book/d27.htm Harapan dan Tanggapan Pemerhati dan Mitra]

Category:1950s Indonesian attack aircraft

Category:Counter-insurgency aircraft

Category:Single-engined tractor aircraft

Category:Low-wing aircraft

Category:Aircraft first flown in 1954

Category:Single-engined piston aircraft

Category:Aircraft with fixed tricycle landing gear