October 4, 2019

Incident at 45NM QUÉBEC / JEAN LESAGE INTL QC (CYQB)

A Government of Canada, Department of National Defence Lockheed C-130 (CFC2540) on a flight from Trenton, ON (CYTR) to St. Johns, NL (CYYT) indicated they had a cracked windshield and needed to descend from FL290 to FL200. CFC2540 requested a diversion to Trenton, ON (CYTR). No emergency declared. No impact.

July 10, 2019

Incident at 50NM GASPÉ QC VOR/DME (YGP)

A Boeing KC-135R (ROMA65) from Bangor, ME (KBGR) to Salt Lake City, UT (KSLC) had an engine malfunction indication, requested to dump fuel and return to KBGR. The fuel dump occurred from 0850Z to 0910Z at FL290. No emergency declared. No impact on operations. Affected agencies notified.

July 11, 2019

Incident at 52NM MANIWAKI QC NDB (YMW)

After having received and correctly read back clearance to descend to FL290, an Air Canada Airbus A320-214 (C-FXCD/ACA396) from Calgary, AB (CYYC) to Montreal/Trudeau, QC (CYUL) was seen passing FL280 in descent. No impact on operations.

June 16, 2019

Incident at 10NM S QUÉBEC / JEAN LESAGE INTL QC (CYQB)

An Air Transat aircraft, make and model unknown (TSC267+), origin and destination unknown, was given and read back FL290 by the LE sector. TSC267+ checked in with the GR sector while descending to FL270. No impact on operations, aircraft was still at FL360 during the check-in.

July 30, 2019

Incident at 20NM PORT HARDY BC VOR/DME (YZT)

A Philippine Airlines Boeing 777-300 (RPC7782/PAL116) from Manila, Philippines (RPLL) to Vancouver, BC (CYVR) was at FL350 and started descending without clearance. Controller noticed and then cleared the aircraft to FL290. No impact to operations.

July 17, 2019

Incident at 5024N / 12627W

A China Eastern Airlines Airbus A330-243 (B5952/CES597) from Shanghai Pudong, China (ZSPD) to Vancouver, BC (CYVR) started to descend to FL290 without clearance. No impact to operations.

April 13, 2019

Incident at AGNOB intersection

An Alitatlia Airbus A330-200 (AZA65F) from Toronto/Pearson, ON (CYYZ) to Rome, Italy (LIRF) climbing to FL290 received a traffic alert and collision avoidance system (TCAS) resolution advisory (RA) from crossing traffic at FL300. They had the traffic visually and there was no operational impact.
UPDATE: AOR-249508-V2: Traffic was not passed. AZA65F had the traffic visually and there was no operational impact.

January 27, 2019

Incident at 92NM ESE PITTSBURGH INTL / PITTSBURGH, PA (KPIT)

TSB Report #A19F0024: C-FTVF, a Boeing 737-800 aircraft operated by Air Transat, was conducting flight TSC447 from Holguin/Frank País Intl (MUHG), Cuba to Toronto/Lester B. Pearson Intl (CYYZ), ON with 6 crew members and 183 passengers on board. During cruise flight at FL290, approximately 90 nm east-southeast of Pittsburgh Intl (KPIT), PA, the flight encountered severe turbulence for approximately 30 seconds. Altitude and pitch variations were minor. Speed variations were +/- 10 kts, and the aircraft experienced rolls of approximately 30° that were managed by the auto-pilot. The flight crew requested and was authorized to FL270, and the aircraft continued to destination without further incident. There were no injuries. The operator’s maintenance inspected the aircraft in accordance with the Aircraft Maintenance Manual (AMM). No defects were found, and the aircraft was returned to service.

August 29, 2019

Incident at 4905N / 09534W

A Federal Express Corporation Airbus A310-324 (N811FD/FDX134) on a flight from Memphis Intl, TN (KMEM) to Winnipeg/James Armstrong Richardson Intl, MB (CYWG) was northwest bound descending from FL380 to FL290 and advised responding to a traffic alert and collision avoidance system (TCAS) resolution advisory (RA). The traffic was a southeast bound Air China Cargo Company Boeing 777-200 (B2094/CAO1053) on a flight from Anchorage Intl, AK (PANC) to Chicago/OHare Intl, IL (KORD) at FL330 which passed 5.1NM south of FDX134. No other impact to operations.
Update TSB Report #A19C0107: N811FD, a Airbus A310-324 aircraft operated by FedEx, was conducting cargo flight FDX134 from Memphis Intl (KMEM), USA to Winnipeg/James Armstrong Richardson Intl (CYWG), MB. At approximately 100 nm SE of CYWG, FDX134 requested a descent from flight level 380 and was cleared to flight level 290 by Winnipeg Centre Area Control Centre (ACC). FDX134 subsequently started the descent. ACC then cleared B-2094, a Boeing 777-FFT operated by Air China Cargo as flight CAO1054 at flight 330, to turn right 10 degrees to provide separation with FDX134. As FDX134 was descending through flight level 340, the crew of FDX134 asked ACC about traffic ahead of them. During the radio transmission regarding the traffic, FDX134 received a TCAS TA/RA to climb. FDX134 complied with the TA/RA, notified ACC of the manoeuvre and advised once clear from the traffic. FDX134 continued for an uneventful landing at CYWG. Review of the available radar information indicates that the nearest distance between the two aircraft was 5.1 miles laterally and 600 feet vertically. Minimum separation requirements are 5 miles or 1000 feet.

August 17, 2019

Incident at 6010N / 13730W

The pilot of a United States Air Force Boeing CC-177 Globemaster III (COKE141) from Eielson Air Force Base, AK (PAEI) to Tacoma/Joint Base Lewis–McChord, WA (KTCM) communicated they were receiving door warning indications and requested descent to FL240. Pilot did not declare an emergency at this time and said they would have a better assessment once level at FL240. Aircraft was handed off to Anchorage while still in descent and leaving FL290, approximately. Anchorage controller was made aware of the issues reported by the pilot prior to the hand off. No impact to operations.

February 7, 2019

Incident at 130NM WINNIPEG MB VORTAC (YWG)

After establishing contact with the Winnipeg Area Control Centre (ACC), a SkyWest Airlines Bombardier CL-600-2D24 (Series 900) (SKW4559) from Minneapolis/St. Paul International, MN (KMSP) to Winnipeg/Richardson International, MB (CYWG) was cleared to continue on the NORAK TWO arrival into CYWG, and was subsequently observed beginning their descent out of FL360 without a descent clearance. After a query from the controller, the aircraft was cleared to FL290. No operational impact.

September 28, 2019

Incident at 5700N / 03130W

A WestJet Boeing 737-7CT (C-FWSK/WJA31) on a flight from Glasgow, Scotland (EGPF) to Halifax/Stanfield Intl, NS (CYHZ) declared a medical emergency with North Atlantic Traffic Services (NATS), and requested a diversion to Reykjavik, Iceland (BIKF) as it exited NATS airspace and entered Canadian airspace. Air traffic services (ATS) were unable to provide the requested clearance due to traffic, and the aircraft was advised that there was negative traffic at FL290. The aircraft descended to FL290 using contingency procedures, at which point a clearance direct to BIKF was issued by Gander Area Control Centre (ACC). The aircraft landed safely at 1214Z. No impact to operations.

August 3, 2019

Incident at 5630N / 05920W

An American, corporately registered Boeing 737-300 (N604SW) from Portland Intl Jetport, ME (KPWM) to Keflavik, Iceland (BIKF) was cleared from FL370 to FL350 due to traffic. After initially levelling off at FL350, the aircraft descended from FL350 without clearance, and contacted air traffic control (ATC) to indicate that they were descending to their expected oceanic flight level. Aircraft was re-cleared to FL290. No traffic. No impact to operations.

July 15, 2019

Incident at 4440N / 06550W

A WestJet Boeing 737-7CT (C-GWJF/WJA882) from Toronto/Pearson, ON (CYYZ) to Halifax/Stanfield, NS (CYHZ) was cleared to FL290 and the pilot read back that they were descending to FL290. The aircraft checked in with the low sector and reported descending to FL280. Controller asked the pilot to confirm their cleared level and they confirmed FL280. No impact on operations, safety was not jeopardized, no separation issues.

May 30, 2019

Incident at 4244N / 06444W

An Emirates Boeing 777 300 series (A6EGF/UAE210) from Newark, NJ (KEWR) to Athens, Greece (LGAV) reported continuous moderate to severe turbulence. The aircraft descended from FL330 to FL290.

Incident at 4256N / 06443W

A Delta Air Lines Boeing 777-233LR (N860DA/DAL84) from Atlanta, GA (KATL) to Paris, France (LFPG) reported continuous moderate to severe turbulence. The aircraft descended from FL310 to FL290.

May 21, 2019

Incident at 40NM GREENWOOD NS TACAN (UZX)

A Jazz Bombardier CL-600-2D24 (series 900) (C-GDJZ/JZA8630) from Ottawa/MacDonald-Cartier, ON (CYOW) to Halifax/Stanfield, NS (CYHZ) cleared to descend to FL290, was observed descending to FL280 without air traffic control (ATC) clearance. No loss of separation.

November 15, 2018

Incident at MONTRÉAL / PIERRE ELLIOTT TRUDEAU INTL QC (CYUL)

A Bombardier CL-600-2B19 (100 series) operated by Jazz (C-GJZZ/JZA8033), flying from Philadelphia (KPHL), PA, to Montreal/Pierre-Elliott-Trudeau (CYUL), QC, declared an emergency. It reported mechanical issues with the right engine and requested emergency vehicle response. The aircraft landed without incident at 0003Z. No operational impact.
UPDATE from Airworthiness: A Civil Aviation Safety Inspector (CASI) looked into this occurrence. Flight Crew conducted an in-flight shut down during descent due to a low oil pressure on the right engine. During maintenance troubleshooting, it was noted that the preformed packing for the air turbine starter (ATS) carbon seal assembly (assy) outer body was missing. A packing was installed, an oil leak check performed, and the aircraft released to service. An Safety Management System (SMS) report was submitted and the event investigated by the Company.
Update TSB #A18F0268: C-GJZZ, a Bombardier CL-600-2B19 (CRJ200) aircraft operated by Jazz Aviation LP, was conducting flight JZA8033 from Philadelphia Intl (KPHL), PA to Montreal/Pierre Elliott Trudeau Intl (CYUL), QC with 3 crew members and 41 passengers on board. Approximately 25 minutes after the departure during cruise flight at FL290, the flight crew received a fluctuating oil pressure indication on the number 2 engine. Passing through 15 000 feet during the descent to CYUL, the flight crew elected to shut the number 2 engine (General Electric CF34-3B1) down since the oil pressure was decreasing and the oil pressure warning activated. The flight crew declared a PAN PAN, briefed the passengers, and completed a successful landing at CYUL without further incident. The operator’s maintenance found that the O-ring behind the number 2 starter seal was missing. A new seal with the O-ring was installed as per GE’s maintenance manual 72-61-00. The number 2 engine oil tank was serviced, engine runs were performed, and no leaks were found. The aircraft was returned to service.

July 11, 2018

Incident at 50NM NW MONTREAL QC VOR/DME (YUL)

An Air Canada Boeing 787-8 (C-GHPQ/ACA005) from Montreal/Pierre Elliott Trudeau Intl, QC (CYUL) to Narita Intl, Japan (RJAA) reported that it was climbing to FL290 during initial contact with the PO sector, even though it had received and read back clearance from sector LA to climb to FL280. No impact on operations.

February 25, 2018

Incident at 4813N / 06909W

An Etihad Airways Boeing 777-300 (ETD76T) on a flight from Chicago/O'Hare Int'l, IL (KORD) to Abu Dhabi, UAE (OMAA) reported severe turbulence at FL310. The aircraft requested and was cleared to FL290.

September 18, 2018

Incident at 34 NM SE THUNDER BAY ON (CYQT) (ATS operating irregularity)

A Skyservice Aviation Learjet 45 (C-GEJD) from Thunder Bay, ON (CYQT) to Toronto/Lester B. Pearson, ON (CYYZ) was cleared to FL280. The pilot's incorrect read back of FL300 was not caught by the controller. When checking in with the next sector, the controller stopped C-GEJD at FL290 due to traffic.

Incident at LONDON ON VOR/DME (YXU) (ELT)

Multiple aircraft at FL260 to FL290 reported a strong emergency locator transmitter (ELT) signal in the vicinity of London, ON (CYXU). Trenton Joint Rescue Coordination Centre (JRCC) was advised.

August 16, 2018

Incident at yow 156 / 33

An Air Canada Rouge Airbus A319-114 (C-GBHR/ROU1704) from Toronto/Lester B. Pearson Int'l, ON (CYYZ) to Deer Lake, NL (CYDF) at FL330 declared a pressurization issue and requested to descend to FL290. At 1940Z, when reaching FL290, the aircraft advised that the pressurization was now stable and continued towards its destination without declaring an emergency. No operational impact.

June 20, 2018

Incident at 25NM TRENTON ON (CYTR)

An Air Canada Rouge Boeing 767-375 (C-FXCA/ROU1914) from Toronto/Pearson International, ON (CYYZ) to Barcelona/El Prat, Spain (LEBL) was climbing from FL290 to FL310 in the vicinity of Trenton, ON (CYTR) when the aircraft reported being struck by a laser 5 to 6 times. ROU1914 provided the controller with coordinates. Trenton, ON (CYTR) aerodrome officials were notified and the military police were called out.

May 2, 2018

Incident at 4909N / 09211W

A Jetport Inc. Bombardier BD-700-1A10 (C-FLGZ) from Sault Ste Marie, ON (CYAM) to Kenora, ON (CYQK) was instructed to descend to FL290 on heading 280 and correctly read back the clearance. C-FLGZ subsequently contacted the East Low Controller in descent through FL389, reported descending to FL280, and was issued further descent. No operational impact.

April 2, 2018

Incident at PETERBOROUGH ON (CYPQ) (ELT)

An Air Canada Airbus A320 (ACA413) en route from Montreal/Pierre Elliott Trudeau Int'l, QC (CYUL) to Toronto/Lester B. Pearson Int'l, ON (CYYZ) reported a strong emergency locator transmitter (ELT) signal descending through FL290-FL270 over Peterborough, ON (CYPQ). No other reports. No operational impact.

October 20, 2018

Incident at 25NM NW Albany (KALB)

TSB #A18F0241: C-FEJD, an EMB170-200 was being operated by Sky Regional Airlines as flight SKV7672 from Lester B. Pearson Intl - Toronto (CYYZ) to General Edward Lawrence Logan Intl - Boston (KBOS). During the climb through FL300 for FL310 the crew noticed the cabin altitude was at 8000 feet and in the amber caution range. A descent was requested and at FL290 the cabin altitude continued to rise with a Cabin Altitude High message. A full emergency descent was completed with a descent to 10000 feet. An emergency was declared by the crew with a request to divert to Albany International Airport (KALB). The aircraft landed on RWY28 KALB uneventfully with ARFF on standby. The aircraft was inspected and ferried to CYYZ for further maintenance.

October 7, 2018

Incident at 4702N / 08636W

An Air Bravo Corp. Pilatus PC-12 (AB237) from Hamilton, ON (CYHM) to Thunder Bay, ON (CYQT) was level at FL290 on the hand off from the Minneapolis (MSP) Area Control Centre when the Canadian Automated Air Traffic System (CAATS) estimate received by the Winnipeg Area Control Centre (WG ACC) indicated that AB237 was at FL280. No operational impact. No loss of surveillance separation.

October 3, 2018

Incident at 80NM Annette Island, AK VORTAC (ANN)

An Alaska Airlines Inc. Boeing 737 700 (N625AS/ASA7004) from Seattle-Tacoma Int'l Airport (Sea-Tac), WA (KSEA) to Ketchikan Int'l Airport, AK (PAKT) was observed on surveillance descending below FL290 without authorization. No operational impact.

December 27, 2018

Incident at 30NM SWIFT CURRENT SK (YYN) VOR/DME

The Winnipeg area control centre (ACC) controller instructed an Airsprint Inc. Cessna 525A (C-FIAS/ASP511) from Swift Current, SK (CYYN) to Calgary Intl, AB (CYYC) to climb to FL340 without coordination with the sector responsible for FL290 and above. No other aircraft in the vicinity and no impact to operations.

January 30, 2018

Incident at 5130N / 11139W

An Air Canada Embraer ERJ 190-100 IGW (ACA355) on a flight from Ottawa/MacDonald-Cartier, ON (CYOW) to Calgary, AB (CYYC) was cleared to descend to FL290 and read back the clearance limit. On contact with the next sector, the aircraft indicated they were cleared to FL240. The controller corrected the clearance limit prior to descent below cleared altitude.

December 22, 2018

Incident at 5613N / 04408W

At 1324Z an Aeroflot-Russian Airlines Boeing 777-M0ER (VQ-BQB/AFL100) from Sheremetyevo Intl Airport, Russia (UUEE) to New York/John F. Kennedy Intl Airport, NY (KJFK) descended from FL300 to FL280 without clearance. Opposite direction traffic of a Federal Express Corporation McDonnell Douglas MD-11F (N613FE/FDX9001) from Memphis Intl Airport, TN (KMEM) to Cologne Bonn Airport, Germany (EDDK) at FL290. AFL100 requested FL280 after it was asked to confirm flight level (FL).
Update TSB Report #A18A0098: VQ-BQB, a Boeing 777-300 aircraft operated by Aeroflot Russian Airlines, was conducting flight AFL100 from Moscow/Sheremetyevo Intl (UUEE), Russia to New York/John F. Kennedy Intl (KJFK), NY. N613FE, a McDonnell Douglas MD-11F aircraft operated by Federal Express, was conducting flight FDX9001 from Memphis Intl (KMEM), TN to Cologne-Bonn/Konrad Adenauer (EDDK), Germany. At approximate position 56°13 N / 044°08 W, AFL100 descended from FL300 to FL280 without a clearance. Opposing traffic was FDX9001 at FL290. Since the 2 aircraft did not establish the required vertical separation for 15 minutes before and after crossing tracks, a loss of separation occurred.

December 11, 2018

Incident at 4334N / 05925W

An Air India Boeing 777-300 (VTALM/AIC144) from Newark International, NJ (KEWR) to Chhatrapati Shivaji Maharaj International, India (VABB) reported severe turbulence at FL310, and descended to FL290. No injuries were reported and there was no impact to operations.

November 14, 2018

Incident at 4827N / 05802W

A United Airlines Boeing 777-200 (UAL82) from Newark International, NJ (KEWR) to Indira Gandhi International, India (VIDP) reported severe turbulence. The aircraft descended from FL290 to FL270. No issues were reported by the crew. No impact to operations.

November 3, 2018

Incident at GANDER CENTRE / ACC DE GANDER

At 1341Z, a Lan Cargo Boeing 767 300 (LCO1501) from Miami Intl, FL (KMIA) to Amsterdam, Netherlands (EHAM) descended from F330 to FL290. A descent clearance was not issued. No other traffic affected.

October 17, 2018

Incident at In the vicinity of: GANDER INTL NL (CYQX)

A United Airlines, Inc. Boeing 777 222 (N226UA/UAL932) from Washington-Dulles International Airport (KIAD) to Frankfurt, Germany (EDDF) declared a medical emergency at 0511Z, descended to FL290, and was then issued a clearance to divert to Gander, NL (CYQX).

October 13, 2018

Incident at 4557N / 05926W

A Swiss International Air Lines Ltd. Airbus A330-300 (SWR15X) from New York/John F. Kennedy International, NY (KJFK) to Zurich, Switzerland (LSZH) and a Transportes Aereos Portugueses, S.A. Airbus A330-200 (TAP214) from Newark International, NJ (KEWR) to Francisco Sá Carneiro, Portugal (LPPR) reported experiencing moderate to severe turbulence. SWR15X was at FL370 and climbed to FL390. TAP214 was at FL350 and descended to FL290. The Halifax Flight Information Centre (HZ FIC) was notified.

June 7, 2018

Incident at 5030N / 00403W

A WestJet Boeing 737 MAX 8 (WJA24) from St. John's, NL (CYYT) to London, UK (EGKK) declared a medical emergency approaching 40W and requested to return to CYYT. WJA24 was recleared to CYYT direct upon reaching FL290.

October 15, 2017

Incident at 40NM CHIBOUGAMAU / CHAPAIS QC (CYMT)

En route to Beijing, China (ZBAA), a Boeing 777-300 (CCA880), from Montreal/Pierre-Elliott-Trudeau, QC (CYUL) to Beijing, China (ZBAA) descended from FL290 to FL260 due to severe turbulence. No impact on operations.

June 24, 2017

Incident at 50NM SEPT-ÎLES QC (CYZV)

Severe turbulence reported by a China Southern Airlines Company Boeing 777-300 (CSN600) on a flight from New York/John F. Kennedy, NY (KJFK) to Guangzhou, China (ZGGG) at FL290. The aircraft climbed to FL300 as a result. Halifax (HZ) flight information centre (FIC) was advised.

June 20, 2017

Incident at MENBO intersection

A Horizon Air Industries Embraer ERJ 170-200 LR (QXE2620) on a flight from Seattle/Tacoma, WA (KSEA) to Calgary, AB (CYYC) reported in with the Edmonton Centre crossing MENBO and descending through FL260. The coordinated altitude with Vancouver, BC (VR) area control centre (ACC) was FL290. No impact to operations.

November 17, 2017

Incident at 5400N / 08335W

An Air Canada Boeing 777-300 (ACA005) on a flight from Toronto/Lester B. Pearson, ON (CYYZ) to Tokyo, Japan (RJTT) requested descent to FL280 due to moderate turbulence. The controller cleared the aircraft to maintain FL290 until lower could be coordinated. The aircraft descended to FL280. No impact to operations.

November 16, 2017

Incident at 50NM SUDBURY ON (CYSB)

A Delta Air Lines Boeing 747-400 (DAL159) on a flight from Detroit Metro/Wayne County, MI (KDTW) to Seoul, South Korea (RKSI) reported an engine issue and requested to return to KDTW and dump fuel. Fuel dump commenced at 50W Sudbury, ON (CYSB) at 1830Z to 1845Z at FL290. The aircraft was re-routed to KDTW with no emergency. No operational impact.

July 17, 2017

Incident at OTTAWA / MACDONALD-CARTIER INTL ON (CYOW)

A Sander Geophysics Limited Cessna 404's (C-GBWE) on a local flight from Ottawa/MacDonald-Cartier, ON (CYOW) emergency locator transmitter (ELT) was accidentally set off around 1725Z. Numerous aircraft in the vicinity of CYOW between FL250 and FL290 reported the signal. The Trenton joint rescue coordination centre (JRCC) was advised. No impact to operations.
Correction: The aircraft was on the ground undergoing maintenance when the ELT was accidentally set off.

January 11, 2017

Incident at 60NM NW SAULT STE. MARIE ON (CYAM)

TSB Report#A17O0008: C-FCAE, a Boeing 767-300 aircraft operated by Air Canada, was conducting flight ACA146 from Calgary Intl, AB (CYYC) to Toronto/Lester B. Pearson Intl, ON (CYYZ). While cruising at FL370 approximately 60 nautical miles North West of Sault Ste. Marie, ON (CYAM), the right hand air data computer failed. The flight crew completed the Airspeed Unreliable QRH procedure, declared a PAN PAN and initiated a descent to FL290. Aircraft systems returned to normal after selecting the right hand air data switch to alternate mode and the flight continued to destination. The operator?s maintenance replaced the right hand air data computer in accordance with the aircraft maintenance manual section 34-12-01.

June 15, 2017

Incident at 61NM LETHBRIDGE AB (YQL) VOR/DME

An Air Canada Airbus A320-200 (ACA342) on a flight from Vancouver, BC (CYVR) to Ottawa/MacDonald-Cartier, ON (CYOW), level at FL310, reported moderate turbulence coincident with a climb to FL313. The flight was cleared to FL290. No operational impact.

April 26, 2017

Incident at 60NM W CALGARY INTL AB (CYYC) (Communication navigation surveillance/air traffic system)

At 0347Z, a WestJet Boeing 737-800 (WJA2315) from Cancun, Mexico (MMUN) inbound to Calgary, AB (CYYC) was cleared to descend to FL290 when ready. A WestJet Boeing 737-800 (WJA513) en route from Calgary, AB (CYYC) to Kelowna, BC (CYLW) at FL360 read back the clearance. Fifteen seconds later WJA2315 read back the same clearance. At 0349Z, WJA513 checked in with Vancouver Centre still at FL360 but thinking they had clearance to FL290. No separation loss and no other impact to operations.

April 5, 2017

Incident at 80NM S MARY RIVER NU (CMR2)

A Nolinor Aviation Boeing 737-200 (NRL793) from Resolute Bay, NU (CYRB) to Iqaluit, NU (CYFB) executed a missed approach at Mary River, NU (CMR2) due to weather and was cleared to FL350. The aircraft then requested to level off at FL330 due to an equipment issue. The flight then declared PAN PAN and requested descent to FL230 due to a pressurization issue. Descending through FL290, the flight requested to maintain FL280 and was cleared to FL280. There was no traffic in the area, and no further assistance was required. The flight continued to destination CYFB.
UPDATE: TSB REPORT#A17W0059: C-GNLW, a Nolinor Airlines Boeing 737-200, was operating as flight NRL793 from Resolute Bay, NU (CYRB) to Mary River, NU (CMR2). NRL793 conducted a missed approach at CMR2 due to weather and the flight was heading to the alternate airport at Iqaluit, NU (CYFB). During the en route climb toward FL350 at approximately FL334, the cabin altitude warning light illuminated with a cabin altitude of 10 500 feet and rising at a rate of 1000 feet per minute. The flight crew stopped the climb and declared PAN PAN with a request to descend in order to manage the cabin pressure. During the descent the flight crew actioned the QRH. At FL280 the cabin pressurization was able to be controlled and stabilized at 8000 feet cabin altitude. NRL793 continued toward CYFB at FL280 and landed without further incident. There were no injuries. Company maintenance found the outflow valve heated gasket inoperative.

October 6, 2017

Incident at HOIST intersection

An Isle of Man Registered British Aerospace BAE 125 1000A on a flight from Boston, MA (KBOS) to Reykjavík, Iceland (BIKF). At 1159Z, the aircraft advised it was leaving FL370 descending to FL290 (Oceanic Level) without clearance from the radar controller.

Incident at JOOPY intersection

At approximately 1033Z, a United States Air Force Boeing CC-177 (RCH347) on a flight from Bangor, ME (KBGR) to Ramstein Air Base, Germany (ETAR) advised they were leaving FL330 descending to FL290 (their Oceanic Level) without clearance from the radar controller. No other traffic.

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