Reformed from the split of HS50 as HS423 in the anti-submarine role with CH-124 Sea Kings. On 30 Jan 1995, the unit was redesignated MH423 to reflect its increasing contribution in maritime patrol activities. 
423 Maritime Helicopter Squadron conducts its final flight with CH-124 Sea King over Halifax Harbour on January 26, 2018. The squadron will transition to the CH-148 Cyclone. Sea King operations on the east coast will be carried out by 443 Maritime Helicopter Squadron, which belongs to 12 Wing Shearwater, Nova Scotia, but is based at Patricia Bay, British Columbia, until the Sea Kings retire at the end of 2018.
News of 423 Squadron | |
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Locations | |
| Years | Location | ICAO/FAA |
| 1974/ | CFB Shearwater | CYAW |
Models | Login to Edit | |
| Years | Models | |
| 2018/ | CH-148 Cyclone | |
| 1974/18 | CH-124 Sea King | |
In this unit |  | |
| Dates | |||
| 2011-apr-17 | 2011-apr | HMCS Athabaskan(DDG 282) | Visited Liverpool, with MH423 CH-124 12435 embarked. |
| 2010-may-28 | 2010-may | HMCS Athabaskan(DDG 282) | Visited Hudson River New York, with MH423 CH-124 12417 embarked. |
423MHS List of helicopters | Help Us | |
| C/N | Version | Built | In this Org | In other Org | |
 | 61-207 | ch-124 | 1963 | 12405 : 1992 423Sqn |  4005 : Royal Canadian Navy CHSS-2 d/d 1963 as 4005 Oct68 reser CH-124A 12405 |
| 61-253 | ch-124 | 1964 | 12412 : 21Jun86 as 423Sqn./412 embarked HMCS Algonquin (DDH 283) participated with+ | 4012 : Sikorsky S-61B, c/n 61-253, del Royal Canadian Navy as CHSS-2, 4012, 1964;+ |
| 61-345 | ch-124 | 1966 | 12435 435 : Ranged on deck aboard HMCS Athabaskan during visit to Liverpool Pier Head + | 4035 : Sikorsky S-61B, c/n 61-345, del Royal Canadian Navy as CHSS-2, 4035, 1966;+ | |
| 92-5005 | ch-148 | 2010 | 148805 : Longer time at Deelen |  : Sikorsky CH-148 CAF 148805 |
Operations | |
| Dates | Operation | |
| sep-17 | oct-17 |  Hurricanes Irma, Jose and Maria Relief Operations |
| 21-jun-86 | 22-jun-86 |  Fleet days 1986 |