The Airbus Helicopters EC135 / H135 is a lightweight five/seven seat twin-turbine-engine multi-role helicopter with a radius of 720 km.
The EC135 is offered with either Safran Helicopter Engines (former: Turbomeca) Arrius 2B2 or Pratt & Whitney PW206B2 engines.
Development of the Eurocopter EC135 started in the 80s as the MBB Bo.108 Advanced Technology Helicopter. The prototype BO108 with
conventional tail rotor flew first on 15 October 1988. When the helicopter divisions of MBB from Germany and Aérospatiale from
France merged in January 1992 to form the Eurocopter Group, the Bo108 program was transferred as well. An advanced low noise ducted
10-blade Fenestron tail rotor was, next to other modifications, incorporated into the design and the name of the helicopter was
changed into Eurocopter EC135. The prototype of the EC135 (D-HBOX s/n S-01) flew first on 15 February 1994 and went in series
production in 1996 at Donauwörth. On 14 June 1996, the German certification was granted by the LBA and the first customer delivery
followed on 31 July that year. Next to the EC135 a special military version was developed designated the Eurocopter EC635. The
EC635 has a structural reinforcement of cabin structure and can be equipped with wire-guided, laser-guided, autonomous missiles. Over
1300 EC135 / H135 / H135M airframes have been delivered since the helicopter entered service in 1996. In March 2015, Airbus Helicopters
renamed its entire product line to better reflect its closer allignment with ist parent company and simplify the naming convention for
the portfolio. Therefore, the EC135 T3/P3 were renamed as “H135” as stated in revison No.EASA.R.009 Issue: 07 of the Type Certificate
Data Sheet for EC135 dated 18 March 2015. “H135M” is used as marketing designation for the military EC635 P3(CPDS); EC635 P3H; EC635 T3(CPDS)
and EC635 T3H helicopters. The ICAO Aircraft Type Designator for the EC135 / H135 helicopters is EC35.
As a result of the merger between the Eurocopter parents Aérospatiale-Matra; DaimlerChrysler Aerospace (DASA)
and Construcciones Aeronàuticas Sociedad Anonima (CASA) in July 2000, the Eurocopter group became a division of the new formed
EADS (European Aeronautic Defence and Space company). Taking off into 2014, EADS was rebranded as "Airbus Group". Uniting
all its activities under a single brand, its helicopter division Eurocopter was rebranded as Airbus Helicopters on 8 January 2014.
On 5 December 2003, Eurocopter EC135 P2 s/n 0315 was exported to the USA for final assembly at the American Eurocopter (AEC),
EADS North America, Columbus, Mississippi facility. On 7 January 2004, the Eurocopter EC135 P2 was registered with the American
Eurocopter test-registration N591AE, with 12 January 2004 as Airworthiness Date. On 30 January 2004, registration N319MS was
reserved for this helicopter by Metro Aviation Inc., and on 17 May 2004, the EC135 P2 was registered N319MS with Metro Aviation,
Inc. On 28 July 2004, the EC135 P2 N319MS was registered with INHS Leasing Co LLC, Spokane, Washington. As before the 2003-built
EC135 P2 N319MS was operated by Metro Aviation in the State of Washington as Northwest MedStar, a critical care transport service
service of Inland Northwest Health Services. On 27 October 2004, the EC135 P2 N319MS was involved in a strange incident: after
departing a referral facility the helicopter experienced smoke in the cockpit and cabin area. The pilot had to made a precautionary
landing and the patient was transferred via ground ambulance. After a thorough inspection of the aircraft and circumstances,
maintenance determined that this occurrence may have been a result of an inspection conducted earlier that day. During this
inspection both engines were washed internally as well as the exterior of the helicopter with soap and clear rinse water.
Following the incident, maintenance instituted a new procedure after washing engines: the heating and demisting system has to be
run down during ground run up checks and after heavy washing of the helicopter and the aircraft has to be flown for drying purposes.
After the incident, the aircraft returned to service with no reoccurrence of the smoke. On 1 April 2016, the critical care transport
service of Inland Northwest Health Services flown by Northwest MedStar was acquired by Life Flight Network. On 4 October 2016, Life
Flight Network LLC reserved registration N846LF for the EC135 P2 N319MS. On 31 August 2017, EC135 P2 N319MS was re-registered N846LF
with INHS Leasing Co LLC as owner and Life Flight Network as operator. On 10 September 2017, EC135 P2 N846LF was seen in service
with Life Flight Network at the Columbia Gorge Regional Airport, also known as The Dalles Airport, Washington, US.