SE-HGZ was constructed as a military H-19(D-4) back in 1958 by Sikorsky Aircraft Division in Stratford, USA. It left the factory in November the same year. It was initially operated by the US Air Force as 57-5981, but was transferred to the Italian Air Force in May of 1960. The Italians had longed for a search and rescue aircraft since 1953, but couldn't afford one. However, thanks to the Mutual Defense Assistance Act (MDAP) they could finally take delivery of six aircraft, of which this helicopter was one.
The helicopter was damaged when it hit power lines during a flood rescue operation in San Rocco di Gianico in September of 1960. Fortunately the damage was minor enough for the aircraft to be repaired on site rapidly in order to get it out of the flooding area before getting drenched by the water.

The machine was returned to the US Air Force at their Italian Livorno base in the summer of 1965.
It was later sold to Eisenhut Aviation and was transported by truck to the Swiss company Heliswiss at Bern-Belp in March of 1972. It was soon transferred to Pilatus in Stans, where it underwent a 4000 man hour massive conversion into a T-model. It was equipped with a new 800 hp Garrett-AiResearch TSE-331 turboshaft engine, which was de-rated to 650 hp. The conversion lowered the empty weight of the S-55 by approx 410 kgs. The aircraft made its maiden flight as N62540 in March of 1975 and was offered for sale.

The owner of the Swedish company AB Norrlandsflyg, Knut "Knutte" Hedström, was searching for a large and practical helicopter in the size of a Bell 205, but with a more reasonable price. He decided to go for the S-55T and purchased the recently modified aircraft in Switzerland. It was flown to Norrlandsflyg’s facilities in Gällivare, Sweden, in March of 1975, and was registered SE-HGZ a few weeks later (11th of April). Norrlandsflyg fitted the helicopter with extra cabin windows, new cockpit details and a stabilization plate behind the cabin, below the tail boom. SE-HGZ was the first S-55 of two in the Norrlandsflyg fleet. The second one (SE-HHY) was delivered in 1977.

The S-55 was very well suited for passenger- and cargo transports since the pilot sits separated from his load. You could practically fill the cabin from floor to ceiling but still fly away unaffected. Another advantage was the safety aspect: the high mounted main- and tail rotors made the aircraft very safe on the ground. The risk of getting skis or fishing gears in the main rotor is very low. The passenger seats could easily be removed if needed, offering a square formed cabin floor without any aerodynamic airframe design in the way. At the most the helicopter could carry up to 10 passengers and 2 pilots.

SE-HGZ "Igor" was mostly used for passenger transports in the mountainous areas in northern Sweden, but also it did some inter-hospital transports and sling load operations in the early stages of operation as well. The helicopter was very unique in Sweden. Only four S-55's have ever been registered here, and this one is the single one remaining in the country.

In late 2003 Norrlandsflyg made the crucial decision to concentrate its activities into the Air Rescue and Ambulance segment, and consequently offered the rest of the helicopters (including SE-HGZ) for sale. Piteå based Kallax Flyg AB purchased the helicopter on 2nd of February 2004, together with three other Norrlandsflyg helicopters. Kallax Flyg had the intention to use the S-55 for much of the same kind of activities it had been used for earlier, including a shuttle between Nikkaloukta and Kebnekaise in the summers. However, Kallax Flyg eventually purchased a Eurocopter EC 130 B4 (SE-JOX) to cope with the passenger capacity, and the S-55 came to be stored in a non-flying condition in Kiruna until mid-2011. The aircraft was reportedly moved to Arvidsjaur in December 2011 (photo above). It has not been air worthy since June of 2004.

In December 2013 SE-HGZ showed up on a Norwegian classified ads site, where it was offered for sale without an engine for roughly 250.000 NOK (~30.000 EUR). The helicopter was reportedly located in Norway at that time.