Kaman K-MAX

https://en.wikipedia.org/wiki/Kaman_K-MAX

The Kaman K-MAX (company designation K-1200) is an American helicopter with
intermeshing rotors (synchropter) by Kaman Aircraft. It is optimized for
external cargo load operations, and is able to lift a payload of over 6,000
pounds (2,722 kg), which is more than the helicopter's empty weight. An unmanned
aerial vehicle version with optional remote control has been developed and
evaluated in extended practical service in the war in Afghanistan.

After being out of production for more than a decade, in June 2015 Kaman
announced it was restarting production of the K-MAX due to it receiving ten
commercial orders. The first flight of a K-MAX from the restarted production
took place in May 2017 and the first new-build since 2003 was delivered on July
13, 2017 for firefighting in China.

The K-MAX series is the latest in a long line of Kaman synchropters, the most
famous of which is the HH-43 Huskie. The first turbine-powered helicopter was
also a Kaman synchropter.

The K-1200 K-MAX "aerial truck" is the world's first helicopter specifically
designed, tested, and certified for repetitive external lift operations and
vertical reference flight (Kaman received IFR Certification in 1999), an
important feature for external load work. Other rotorcraft used for these tasks
are adapted from general-purpose helicopters, or those intended to primarily
carry passengers or internal cargo. The K-MAX can lift almost twice as much as
the Bell 205 using a different version of the same engine. The aircraft's
narrow, wedge-shaped profile and bulging side windows give the pilot a good view
of the load looking out from either side of the aircraft.

The transmission has a reduction ratio of 24:1 in three stages, and is designed
for unlimited life. The rotor blades (which turn in opposite directions) are
built with a wooden spar and fiberglass trailing edge sections. Wood was chosen
for its damage tolerance and fatigue resistance; and to take advantage of field
experience and qualification data amassed from a similar spar on the HH-43
Huskie helicopter, built for the U.S. Air Force in the 1950s and 1960s. The
pilot controls blade pitch with tubes running inside the mast and rotor blades
to move servo flaps that pitch the blades, reducing required force and avoiding
the added weight, cost and maintenance of hydraulic controls.

The K-MAX relies on two primary advantages of synchropters over conventional
helicopters: The increased efficiency compared to conventional rotor-lift
technology; and the synchropter's natural tendency to hover. This increases
stability, especially for precision work in placing suspended loads. At the same
time, the synchropter is more responsive to pilot control inputs, making it
possible to easily swing a load, or to scatter seed, chemicals, or water over a
larger area.

Thirty-eight K-1200 K-MAX helicopters had been built by 2015. As of January
2015, 11 of these were not airworthy or had been written off in accidents and
five were in storage at Kaman; and in March 2015 the number of operational
K-MAXs was 21. The production line was shut down in 2003.

Restart of production line

In February 2014, Kaman revisited resuming K-MAX production, having recently
received over 20 inquiries for firefighting, logging and industry transport
requirements as well as requests for the military unmanned version. Ten firm
orders convinced Kaman to put the design back into production again. As of 2014,
the K-MAX line had flown 300,000 hours and cost $1,200 per flight hour to
operate.

At Heli-Expo 2015 in Orlando, Kaman reported it continued toward reopening the
production line building 10 aircraft. Kaman received deposits and the assembly
line was restarted in January 2017. Kaman test flew the first K-MAX from
restarted production on May 12, 2017.

The first new-build since 2003 was delivered on July 13, 2017 to Kaman’s Chinese
sales agent Lectern Aviation, which will deliver it to Guangdong Juxiang General
Aviation, Guangdong Province for firefighting as the second is to be delivered
the following week. Due to production scheduling, Kaman needed to decide in 2017
whether to extend production beyond the first 10, and Kaman made the decision in
June 2017 to produce a further 10 aircraft, reaching into at least 2019.


Role
Medium lift helicopter

Manufacturer
Kaman Aircraft

First flight
December 23, 1991

Status
In production

Produced
1991–2003, 2015–present

The unmanned K-MAX competed with the Boeing H-6U Little Bird for the Marine
Corps unmanned lift/ISR capability. In April 2014, Marines at Quantico announced
they successfully landed an unmanned K-MAX, as well as a Little Bird,
autonomously using an iPad-like mini-tablet. The helicopters were equipped with
Autonomous Aerial Cargo/Utility System (AACUS) technology, which combines
advanced algorithms with LIDAR and electro-optical/infrared sensors to enable a
user to select a point to land the helicopter at an unprepared landing site. The
Office of Naval Research selected Aurora Flight Sciences and the Unmanned Little
Bird to complete development of the prototype AACUS system, but Lockheed
continued to promote the K-MAX and develop autonomous cargo delivery systems.

Both unmanned K-MAX helicopters in use by the Marine Corps returned to the U.S.
in May 2014, when the Corps determined that they were no longer needed to
support missions in Afghanistan. After deploying in December 2011, originally
planned for six months, they stayed for almost three years and lifted 2,250 tons
of cargo. The aircraft were sent to Lockheed's Owego facility in New York, while
the service contemplated the possibility of turning the unmanned K-MAX from a
proof-of-concept project into a program of record. Formal requirements for
unmanned aerial cargo delivery are being written to address expected future
threats, including electronic attack, cyber warfare, and effective hostile fire;
these were avoided in Afghanistan quickly and cheaply by flying at night at high
altitudes against an enemy with no signal degradation capabilities. Officials
assessed the K-MAX helicopter that crashed and planned to repair it in 2015. The
helicopters, ground control stations, and additional equipment are stored at
Lockheed's facility in Owego. The two unmanned K-MAXs, designated CQ-24A, were
to be moved to a Marine Corps base in Arizona by the end of September 2015 to
develop tactics and operations concepts to inform an official program of record
for a cargo UAV.

Lockheed Martin demonstrated a fire fighting version in November 2014, and again
in October 2015, when it delivered over 24,000 pounds (11,000 kg) water in one
hour. A casualty evacuation exercise was performed in March 2015 in coordination
with an unmanned ground vehicle and mission planning system. A medic launched
the UGV to evaluate the casualty, used a tablet to call in and automatically
land the K-MAX, then strapped a mannequin to a seat aboard the helicopter.

Specifications (K-MAX)

General characteristics
Crew: one
Capacity: 6,000 lb (2,700 kg) external load
Length: 51 ft 10 in (15.8 m)
Rotor diameter: 48 ft 3 in (14.71 m)
Height: 13 ft 7 in (4.14 m)
Empty weight: 5,145 lb (2,334 kg)
Useful load: 6,855 lb (3,109 kg)
Max. takeoff weight: 12,000 lb (5,400 kg)
Powerplant: 1 × Honeywell T53-17 turboshaft, 1,341 kW (1,800 shp), flat rated to
1,118 kW (1,500 shp) for take-off / 1,350 shp in flight)

Performance
Maximum speed: 100 knots (185 km/h, 115 mph)
Cruise speed: 80 knots (148 km/h, 92 mph)
Range: 267 nmi (495 km, 307 miles)
Service ceiling: 15,000 feet (4,600 m)
Fuel consumption: 85 gallons/hour




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