Country of origin:

United States of America

Description:

Single-seat medium-lift helicopter

Power Plant:

One 1,343 kw (1,800 shp) Honeywell T53-17A-1 turboshaft

Specifications:

History:

The K-Max was designed and built by Kaman Aerospace as an affordable, medium-lift helicopter able to perform vertical lifts, suited for emergency response missions ranging from firefighting and disaster relief to search-and-rescue, power line work, and timber harvesting. The prototype was first flown in March 1992, Canadian certification being received in 1994.

A variant developed was the Firemax, a heli-tanker model with a 2,649 litre (583 Imp gal / 700 US gal) fixed tank system developed by Kawak Aviation Technologies. Rainer Heli Lift and Isolair Inc developed a carbon fibre tank for firefighting, this being tested on N699RH for the first time on 16 November 2006.

The K-Max, which has also been known as the K-1200, had intermeshing rotors and was optimised to carry external loads. Its rotors followed the principles developed in Germany by Flettner during World War II, Anton Flettner joining the Kaman organisation after the cessation of hostilities. Known as the “synchropter”, the design has counter-rotating, intermeshing blades which provided not only the lift but also counter torque, thus the design did not require a tail rotor. Control was by use of servo-flaps mounted on the trailing-edge of each rotor. Accommodation was provided for a pilot only, but two passengers could be attached externally to the sides of the machine forward of the main legs.

Sometimes known as the ‘aerial truck’, the K-Max was designed to be certified for repetitive external lift operations. It had a narrow, wedge-shaped profile which permitted good visibility for the pilot during operations, especially when precision was required to place suspended loads.

Examples have been operated in Austria, Canada, Colombia, Japan, South Korea, Liechtenstein, Switzerland and the United States. A total of 38 examples was completed, and about 26 were still in operation in late 2008, production taking place over a period of ten years.

Two were delivered in August 2008 to Lockheed Martin Systems for use in testing and development of a manned / unmanned helicopter program. A contract to demonstrate vertical replenishment to the United States Navy was awarded in August 1995 and during a two-month period two machines (c/ns 0010 and 0013) lifted 453,592 kg. In May 1996 a follow-on contract involved a total of 142 hours being flown when 2,449,400 kg was lifted. These two machines were then deployed to the Arabian Gulf on board the ‘USS Niagara Falls’.

In August 1988 the prototype was involved in trials for Magic Lantern mine detection systems. In November 2001 it was involved in testing at the US Naval Undersea Warfare Center at Newport on Rhode Island where it recovered torpedoes used in exercises.

Power plant was the Textron-Lycoming T53-127A-1 turboshaft, a commercial variant of the 1,343 kw (1,800-shp) T-53-L-703 military engine, the engine being de-rated to 1,119 kw (1,500 shp) to make it compatible with the transmission and to ensure longer engine life.

For some years in the late 1990s and into the 21st century a number of examples have been imported to Sydney, NSW during the summer season and operated out of Bankstown, NSW on firebombing operations.

One owned by Superior Helicopters of Oregon (N312KA – c/n A94-0024 – ‘Jumpin Jack Flash’) was imported to New Zealand and operated on logging operations in the Rotorua area, this machine being able to lift 2,722 kg (6,000 lb) from sea level up to 2,438 m (8,000 ft).

In December 2008 another K-max arrived in New Zealand. This machine had previously been registered as N358KA, then operated with the Colombian Army as EJC-500 before becoming N358KA again. It became ZK-HEE (c/n A94-0029) registered to Skywork Helicopters / K-Max of Warkworth. Registered as a K-1000, it was flown and operated in Western Australia in 2009.

In January 2011 the machine was flown from its base at Albion Park, NSW to Karara, QLD where it lifted six sections of a 36.05 m (120 ft) electrical power transmission into place. In June that year it was cancelled from the NZ Civil Aircraft Register as sold abroad. In September 2011 it operated in the Proserpine, QLD area.

This machine was in fact registered to Skywork Helicopters of Figtree, NSW on 9 June 2013 and became VH-IUU. In October 2013 it was noted in the Blue Mountains west of Sydney, NSW operating as ‘Helitack 217’ but was later exported on 30 January 2015 as N43HX.

Examples have been operated in Australia for the firebombing seasons on the eastern seaboard and inland, including N162KA, N242KA and N267KA. One, N134WC (c/n A94-0006) of Woody Contracting Inc of Oregon, passed 20,000 flight hours on 8 May 2007 and another, N202WM (c/n A94-0011) of HeliQwest of Colorado, reached 10,000 flight hours on 15 July 2007.

Production of the series ceased in 2003 after 38 examples had been delivered. In 2015 Kaman announced it was re-launching the machine after receiving orders from existing operators, including Rotex Helicopter of Switzerland, which used the type for heli-logging, and Helicopter Express of Atlanta, Georgia, USA, which used the type for firefighting and heavy lifting. Production was due to recommence in 2017 with a production rate of 10 machines per year.