Reversed break lines found to be major factor
A TSB report is in on an incident that occurred in August 2012 at St. John’s International Airport involving a very large and relatively new cargo plane.
An Ilyushin 76 cargo aircraft overshot the end of the runway at St. John’s International airport on Aug. 13, 2012. There were 10 crew members aboard the plane and no one was injured. The main runway at the airport remained closed while the incident was investigated. — File photo by Keith Gosse/The Telegram
On Aug. 13, a Volga Dnepr Airlines cargo aircraft was on a flight from Prestwick, Scotland to St. John’s International Airport when it overshot the runaway in
St. John’s by approximately 640 feet.
Ten crew members were on board and an instrument landing system approach was carried out as the aircraft landed a little after 4 p.m. The plane had only 175 flying hours on it and had made 45 previous landings without incident.
There was reportedly no standing water on the runaway, though it was said to be wet.
“There were no injuries and aircraft damage was limited to cuts and localized rubber melting on the main tires,” the report says.
However, there were major questions about why a new four-engine heavy cargo transport aircraft being flown by a seasoned crew in daylight hours and fine weather would miss the runaway by so much.
There were several disconcerting factors — including a heavier-than-detected tailwind — but the most disturbing reasons involved the quality of the 16 tires on the plane and the brake lines which were actually found to be reversed.
Here’s what happened.
As the plane approached, it experienced a heavier than anticipated tailwind, one that actually exceeded the aircraft manufacturer’s limitations.
The aircraft then did not touchdown in the recommended touchdown area but overshot it. Then it experienced some hydroplaning.
During a hydroplaning incident, the brake lines are supposed to work by releasing pressure on the tire that’s skidding.
In this incident, pressure was maintained on the skidding tires and taken off the ones that weren’t. Making matters worse, all 16 of the main tires were worn in excess of 80 per cent reducing wet runway traction and increasing the chances of hydroplaning.
That, of course, means overshooting the runaway is also more likely.
There were no injuries.