Recently, a Pakistan International Airlines 777 en route from Lahore to Toronto was forced to turn back to Lahore following a hydraulic system issue.

The Incident

On July 3rd, Pakistan International Airlines flight PK-797 departed Lahore just before 4:40 a.m. local time for its 13-hour journey across to Toronto, running about 50 minutes late. The aircraft operating was a Boeing 777-200LR registered AP-BGZ.

About five hours into the flight, a technical issue with the plane's hydraulic system was detected as the aircraft was crossing from Kazakh to Russian airspace.

As a result, the crew of the 777 opted to turn the aircraft around and divert back to Lahore. After nine hours in the air, the flight landed right back where it started around 1:30 p.m. local time.

PIA said that flight 797's passengers would be accommodated on another aircraft to take them to Toronto. However, this has taken some time since the next flight from Lahore to Toronto did not operate until three days later on July 6th.
 

Nightmare Averted

When the hydraulic fault was detected, PK-797 was near the Russian city of Ufa, whose airport has a 12,000-foot runway and sees regular widebody service. Other nearby airports included Yekaterinburg, Kazan, and Nizhny Novgorod, all of which can handle widebody jets like a Boeing 777.

Given the delicate political situation involving Russia at the moment, the crew of PK-797 deemed it safer to divert back to Pakistan rather than opt for a diversion to a nearby Russian airport. 

Had the crew chosen to divert to Russia, the aircraft involved could have risked being stranded for an indefinite amount of time. This is due to sanctions placed on Russia by the United States, meaning flying spare parts into the country to fix the American-built Boeing 777 would have proven challenging.

A similar, albeit more serious, situation befell an Air India 777-200LR in early June. This aircraft was en route from Delhi to San Francisco when it experienced an engine issue above Russia. The plane diverted to Magadan (GDX) and its passengers were stranded there for nearly 36 hours before a replacement 777 was sent in to take them to San Francisco.

The afflicted Air India 777, to much relief, was repaired sooner than expected and ferried to Mumbai four days after its emergency landing. 

Shifting our attention back to the PIA 777, it seemed much more sensible for the betterment of the passengers and aircraft that the flight divert back to Lahore rather than risk any problems in Russia, even if it involved enduring five more hours back to the origin airport.

Background

PK-797 is one of PIA's two weekly services connecting Lahore, Pakistan's second-largest city, with Toronto, Canada's largest city.

PIA also serves Toronto twice per week from Karachi and once a week from Islamabad. The airline's fleet of two Boeing 777-200LRs is almost exclusively used for these flights.

AP-BGZ, the 777 involved, is an 18-year-old 777-240LR originally built in 2005. This aircraft, prior to joining PIA in 2006, is famous for being Boeing's "Worldliner" demonstrator aircraft registered N6066Z.

In fact, on November 10th, 2005, this very aircraft set the world record for the longest nonstop flight on record. The jet flew for nearly 23 hours nonstop from Hong Kong to London in an eastbound direction. It covered 11,664 nautical miles or 21,601 km, a record that remains unbroken to this day.

PIA's other 777-200LR, AP-BGY, was Boeing's 777-200LR prototype prior to joining the Pakistani flag carrier in 2006.