Nederlandse Modelbouw en Luchtvaartsite

Dutch Modelling and Aviation

In Memoriam

Klaas Willem Jonker
† April 30, 2018

On Monday 30 April 2018, Wilko Jonker died after a long illness at the age of 58. He leaves behind a wife and two children. The Dutch military aviation and plastic modeling were his hobby and on this website he shared all the knowledge he has collected over the years. His hobby has been able to distract him from the persistent disease in his body until the last week of his life. The contacts with other hobbyists were a major support for him.

This website will be maintained by different people for as long as possible, so that other enthusiasts can continue to benefit from extensive content.

Sikorsky SH-34J/UH-34J


This model was developed based on specifications of the US Navy from 1952, drawn up for a larger successor to the Sikorsky H04S-3 (Sikorsky S.55). These had also to be suitable for anti-submarine warfare.
The contract for the construction of the prototype, equipped with a Wright R-1820 radial engine of 1137 kW was received in June 1952.
The first flight was made in March 1954 had and the new helicopter had received the designation XHSS-1.
The first production machine was its first flight on September 24, 1954.

The production version HSS-1 Seabat, equipped with "dunking sonar" and ASW equipment, first flew in August 1955 and was operational in August 1955.
The HSS-1N (SH-34J) was suited for night operations and for use in bad weather and was equipped with Doppler Navigation; automatic stabilization and ditto hoover possibility.

In January 1957, the only HSS-1F equipped with two General Electric T58 turbine engines, made its first flight.
HSS-1 / SH-34 and HSS-1N / SH-34J Seabats which were stripped of their ASW equipment were later designated as UH-34G, respectively UH-34J.

In 1962 the multiplicity of type definitions was standardized in the uniform DoD marking system.
The HSS-1 was designated as SH-34G. The HSS-1N received the designation SH-34J.

The United States Marine Corps in October 1954 placed an order for the HUS-1 Seahorse, which could carry 12 marines. This enter service in February 1957.
Four examples were adapted for use in the Arctic and were designated as HUS-1L (LH-34D)
Some HUS-1 aircraft were equipped with an inflatable float system and designated as HUS-1A.

The US Coast Guard also used a number of examples in use as HUS-1G.
After 1962 these were designated as UH-34D respectively UF-34E.

One HUS-1 was borrowed by the United States Army for evaluation purposes and in 1955 the United States Army ordered the utility transport version, H-34 Choctaw which could carry 16 men. 500 examples were delivered. From 1962 and on these were referred to as CH-34A and CH-34C and differed only in equipment.
In April 1955, the first of 437 new H-34A's entered service.
Later, another 21 HUS-1 were taken from the United States Marine Corps and these were designated H-34A.

The H-34A was the first helicopter safe enough for regular use by the US President.
  For this purpose the US Army established in 1957 the Executive Flight Detachment equipped with adapted Choctaws. These aircraft, designated VH-34A, were equipped with sound insulation, luxurious VIP interior design and modern communications equipment.

In 1960 followed a modification program for the H34A and B versions of the USAF and U.S. Army in order to standardize both types to H-34C.
Added were automatic flight stabilization and other improvements.
After 1962, about 190 H-34Cs and 179 H-34As were in use, these were designated as CH-34C and CH-34B. Some were later converted to VH-34C.

The H-34 was also built under license by Sud-Aviation which 110 units built for France plus another nine examples for Belgium.
Also Westland achieved the licensing rights in 1956 and developed the Wessex, a turbine version. Sikorsky continued to build the original version with radial engine.
Only in January 1970 Sikorsky announced conversion kits for retrofitting with the Pratt & Whitney PT6 Twin-Pac turbine engine. The first flight of the S-58T was on August 19, 1970.
The type certification was granted in April 1971.
Sikorsky built 153 conversion kits, until California Helicopter International bought the rights in 1981. Later also offered Orlando Helicopters conversions for the S-58.

The civilian S-58B and S-58D were passengers and freighter versions, and similar to their military counterparts. The S-58B could carry 12 passengers.
Until the end of production in January 1970 were 1820 examples built by Sikorsky in several versions.


XHSS-1 Seabat:
Three Sikorsky S-58s for evaluation by the  U.S. Navy, later designated as YHSS-1 and from 1962 as YSH-34G.
HSS-1 Seabat:
anti sub version for the U.S. Navy. From 1962 amd on designated as SH-34G; 215 examples built.
  • HSS-1F Seabat: One HSS-1 for research purposes equipped with two YT-58-GE; from 1962 and on designated as SH-34H.
HUS-1 Seahorse:
transport version of the HSS-1 for the U.S. Marine Corps, from 1962 and on designated as UH-34D, 462 examples built.
  • UH-34D: designation of HUS-1 after 1962; 54 examples new built.
  • HUS-1A Seahorse: 40 examples of HUS-1s equipped with floats, from 1962 and on designated as UH-34E.
  • HUS-1G Seahorse: Version of the HUS-1 for the  US Coast Guard, from 1962 and on designated as HH-34F; six examples built.
  • HUS-1L Seahorse: Four modified HUS-1s for used under polar conditions, from 1962 and on designated as LH-34D.
  • HUS-1Z Seahorse: Seven modified HUS-1s with VIP interior to be used by the  Executive Flight Detachment, from 1962 and on designated asVH-34D.
YHSS-1N Seabat:
Prototype of a modified HSS-1, from 1962 and on designated as YSH-34J.
HSS-1N Seabat:
Night- and bad weather version of the HSS-1 with improved avionics and autopilot, from 1962 and on designated as SH-34J, 167 examples built.
  • UH-34J: Stripped version of the SH-34J, al ASW equipment removed and used for training and transport .
  • HH-34J: Ex-USN UH-34Js used by the U.S. Air Force.
  • VH-34J: VIP version of the SH-34J.
U.S. Army version of the HSS-1 with a 1525 hp Wright R-1820-84, from 1962 and on designated as CH-34A; 359 examples built  plus 21 HUS-1 originating from U.S. Navy.
  • JH-34A: H-34A used for weapon tests.
  • VH-34A: VIP version of the H-34A.
H-34A conversion with minor changes; from 1962 and on designated as CH-34B.
version of H-34B with minor changes and converted H-34A; from 1962 and on designated as CH-34C.
  • JH-34C: CH-34C used for weapon tests.
  • VH-34C: VIP version of the CH-34C.
designation for aircraft with USAF serials, delivered under MAP and MDAP conditions to other countries.
commercial version of the basic transport version.
commercial version of the improved transport version.
Commercial passengers and transport version.
Commercial passengers and transport version
Commercial conversion with turbine engines: kits produced by Sikorsky, Orlando Helicopter and California Helicopter.


Technical information
Length with rotor 14,25 m Rotor diameter: 17,27 m
Height: 4,36 m Tail Rotor diameter: - m
Empty weight: 3754 kg Full weight: 5900 kg
Max. speed: 196 km/hr Cruising speed: 158 km/hr
Range: 400 km Service ceiling: 3500 m
Engine type: One Pratt & Whitney R-1830-43 Twin Wasp rated 1200 hp
Crew: Four

SH-34J: one torpedo

UH-34J: none


All examples, except the 134 and 135 were delivered under MDAP conditions. The H-registrations had been initially reserved for the aircraft, but (in the Netherlands) were never implemented, because the RNlNAS already had changed to a three-digit registration when the aircraft were delivered.

The 134, 135, 137,138, 142 and 144 had the anti-submarine warfare equipment removed in 1966 and were converted to UH-34J.
Initially, all S-58s were assigned to aircraft squadron no 8, but in August, 1967, the remaining Sikorskies (134, 137, 138, 142 and 144, were transferred to aircraft squadron 7.

Sikorsky SH-34J/UH-34J




Serial Constr. nr. Bu.No. Date in service Date out of service Notes
134  58-1721 150729 26-06-1963 04-05-1971 Not delivered under MDAP.
Is HUS-1 SeaHorse.
Modification to UH-34J in 1966.
Preserved for instructional purposes to Anthonie Fokkerschool, The Hague.
Later to Military Aviation Museum.
135 58-1611 149840 26-06-1963 08-06-1970 Not delivered under MDAP.
Written off an scrapped naval air station Valkenburg
136   149841 30-03-1962 17-08-1965 Written off.
137 58-1442 149842 30-03-1962 03-08-1971 Modification to UH-34J in 1966. Returned to MAAG and became N59333
138 58.1373 149131 04-09-1961 08-06-1970 Modification to UH-34J in 1966.
Returned to MAAG and became N59331
139   149132 04-09-1961 25-10-1961 Crashed in sea near Scotland.
Written off.
140   149133 04-09-1961 31-03-1963 Crashed in sea near Gibraltar.
Written off.
141   147632 05-01-1960 22-09-1965 ex 8-5; Crashed in sea near Scotland.
Written off.
142 58-1150 147633 05-01-1960 05-04-1972 ex 8-6; Modification to UH-34J in 1966.
Returned to MAAG and became N59329
143   147633 05-01-1960 02-04-1968 ex 8-7; Accident, written off and scrapped.
144 58-1158 147634 05-01-1960 08-06-1970 ex 8-8; Modification to UH-34J in 1966.
Returned to MAAG and became N59330.
145   147635 05-01-1960 31-01-1963 ex 8-9; Crashed in sea near Gibaltar.
Written off


All available models are basically the UH-version. For the SH-version, the ASW version, one had to add several things.
For example, a sonar system has to be installed, the sonar of a British Sea King can be used, as this was the same type.
The torpedo launcher one has to scratch built one and another, as no alternative is available, though Italeri has produced an Italian version of HSS-1N, which had the torpedo launchers added. The Dutch SH-34J's carried only one launcher on the left.

1/72nd Scale


  • Italeri
  • Revell
    • Set 04424: (in fact same as the Italeri kit) Sikorsky H-34G Heeresflieger
  • HobbyBoss
    • Set 87215: Sikorsky UH34A Chocktaw (Belgian AF, Aeronavale)
    • Set 87222: Sikorsky UH34D Chocktaw (US Marines)
Sikorsky SH 34J AKleijn
A model of a Sikorsky UH-34J, kit used it the Italeri/Revell kit, built by Adri Kleijn.


Building a model of the Sikorsky UH-34J, by Peter Banis.

Sikorsky SH34J PBanis 8 Sikorsky SH34J PBanis 7 Sikorsky SH34J PBanis 6 Sikorsky SH34J PBanis 4 Sikorsky SH34J PBanis 2 Sikorsky SH34J PBanis 11 Sikorsky SH34J PBanis 3 Sikorsky SH34J PBanis 9 Sikorsky SH34J PBanis 1 Sikorsky SH34J PBanis 10 Sikorsky SH34J PBanis 5 Sikorsky SH34J PBanis 13 Sikorsky SH34J PBanis 12


Modelling add-on

  • Cobra Company
    • Set 72002: Sikorsky H34 Choctaw Super Detail set (Revell/Italeri)
  • Eduard
    • Set E72-224: Detailset Sikorsky S58 (UH34)
  • Airwaves
    • Set EC72168: Detailset Sikorsky UH-34 'Sea Horse' (voor Italeri kits)
    • Set SC7245: Westland Wessex / Sikorsky H34
  • Part Etchings
    • Set S72-023: Sikorsky H34 Seahorse (Revell/Italeri) (exterior & cabin)
    • Set S72-024: Sikorsky H34G Seahorse (Revell) (Cockpit)
  • Whirlybits
    • Set A72116: Sikorsky H34 Floatation Gear
    • Set A72117: Sikorsky H34 V type front Undercarriage (Italeri/Revell)
    • Set A72121: Sikorsky H34 Auxiliary fuel tank and mount
    • Set A72114: Sikorsky H34 Under fuselage DF Loop
    • Set A72113: Sikorsky H34 / Wessex Doppler Radar Heads


  • Dutch Decal
    • Set 72034: Set decals for aircraft like Sikorsky S.51
    • Set Dutch museum planes 2: Decals for aircraft on display in Military Aviation Museum at Soesterberg.

1/48th Scale


  • Italeri
    • Kit 2712: H-34G/UH-34J.
  • Model Rectifier Co.
    • Kit 64101: Sikorsky H34D Chocktaw "US Marines""
    • Kit 64106: Sikorsky UH34D Seahorse "VX-6 Operation Deep Freeze, Antartica, VC-1, JMSDF)

Modelling add-on

  • Eduard
    • Set FE662: Detailset Sikorsky H34 Interior Self Adhesive (MRC)
    • Set E49-666: Detailset Sikorsky H34 Cargo Seatbelts (MRC)
    • Set E49-662: Detailset Sikorsky H34 Self Adhesive (MRC)


  • --
    • Set --: --



Scheme Colour name FS number BS number Humbrol XtraColor Vallejo ModelColor Vallejo ModelAir Hataka
Standard #1 Upper sides Extra Dark Sea Grey ~6099 BS:640 123 / 106 X005 / X376 70.866 71.110 ~140
Under sides Sky - BS:210 90 X004 / X130 - 71.302 ~026

Check for an extensive conversion table with lots of colour and paint systems.

Sikorsky HSS-1N B-leg.
Sikorsky S-34J V-leg.
Sikorsky UH-34J B-leg.
Sikorsky UH-34J V-leg.




Aircraft number 146: H-34 Choctaw in action   Pag. 13 - 19   Uitgever Squadron/Signal Publications Inc., Carrolton, Texas
Zestig jaar Marineluchtvaartdienst in Beeld. Hugo Hooftman pag. 113 - 115 1977 Uitgever Europese Bibliotheek, Zaltbommel
Dutch Military Aviation 1945-1978 Paul A. Jackson Pag. 109; 116 - 117 1978 Uitgever Midland Countries Publications, Leicester
Nederlandse Marinevliegtuigen Thijs Postma & Nico Geldhof pag. 64 1978 Uitgever Omniboek, 's Gravenhage
Modelbouw in Plastic jaargang 12, nummer 4: De S-58 van de MLD. Fred Bachofner pa. 129 - 130 1983 Uitgever I.P.M.S. Nederland, Nederland
70 Jaar Marine-LuchtvaartDienst Nico Geldhof pag. 134 1987 Uitgeverij Eisma b.v., Leeuwarden
Vliegen voor de Vloot: 70 jaar Marineluchtvaartdienst Harm J. Hazewinkel Pag. 62 1987 Uitgever Rebo Produkties, Sassenheim
Sikorsky H-34 G-1, II, III:: Flugzeuge der Bundeswehr Siegfried Wache   1987 Uitgever Flugzeug Publikations Gmbh., Illertissen
Camouflage en Kentekens J.Greuter e.a.   1997 Bonneville – Bergen (NH)
85 JAAR Marineluchtvaartdienst in beeld: Van Farman tot NH 90 Helikopter peter Korbee pag. 128 - 129 2002 Uitgever Korbee MLD Promotie, Valkenburg



Special thanks to M. Schönfeld who provided me with some information about the conversion of the UH-34J scale models.  Special thanks to  Lt. Kol. b.d. L.M.M. Baltussen for corrections of the serial overview