Helikopter Service Flight 165

{{short description|Crash of a Sikorsky S-61 helicopter into the North Sea}}

{{Use dmy dates|date=September 2019}}

{{Infobox Airliner accident

| name = Helikopter Service Flight 165

| occurrence_type = Accident

| image = Ocean Traveler - SAS2009-10-2055.jpg

| image_size =

| alt =

| caption = A Helikopter Service Sikorsky S-61 similar to the accident aircraft

| date = 26 June 1978

| type = Structural failure

| site = North Sea, Norway

| coordinates = {{coord|61|01|N|002|48|E|display=inline,title}}

| aircraft_type = Sikorsky S-61

| aircraft_name =

| operator = Helikopter Service

| tail_number = LN-OQS

| origin = Bergen Airport, Flesland, Bergen, Norway

| destination = Statfjord A, North Sea, Norway

| passengers = 16

| crew = 2

| injuries =

| fatalities = 18

| survivors = 0

}}

Helikopter Service Flight 165 was a crash of a Sikorsky S-61 helicopter into the North Sea, {{convert|78|NM}} northwest of Bergen, Norway, on 26 June 1978. The aircraft was en route from Bergen Airport, Flesland to Statfjord A, an offshore oil platform. The accident was caused by a fatigue crack in a knuckle joint, causing one of the rotor blades to loosen. All eighteen people on board were killed in the crash.{{cite web |url=http://www.aibn.no/ln-oqs-pdf?pid=Native-ContentFile-File&attach=1 |title=Rapport om luftfartsulykke i Nordsjøen den 26. juni 1978 ca. kl. 1115 med helikopter S-61 LN-OQS, tilhørende K/S Helikopter Service A/S |publisher=Accident Investigation Board Norway |language=Norwegian |date=17 January 1980 |accessdate=19 September 2012 |archivedate=26 August 2014 |archiveurl=https://web.archive.org/web/20140826103126/http://www.aibn.no/ln-oqs-pdf?pid=Native-ContentFile-File&attach=1 |url-status=live |df=dmy-all }}