A weather mystery solved!
I asked for some help earlier this month to solve the mystery of where the photos below of a hail-damaged aircraft came from. Thanks to email replies I received from Chris Trott, Patty Jones, Ennien Ashbrook, and the pilot, Richard Barrieau, the mystery has been solved! The airplane was a Boeing 727-200 jet flown by Capital Cargo International Airlines (aircraft registration N708A). It took off from Calgary, Canada, and was enroute to Minneapolis the night of August 10, 2006, when it encountered large hail as it climbed from 30,000 feet to 35,000 feet in a thunderstorm over Alberta. An upper-level disturbance, in concert with a warm, moist air mass, combined to produce a large area of severe thunderstorms, including the one that damaged the unfortunate airplane. The hail damaged the airplane's windshield, nose cone, cowling on the two engines, leading edge of the right wing, lenses, and right side lights. An in-flight emergency was declared, and the the aircraft returned safely to Calgary International Airport. The landing was routine, as the pilot's windshield was undamaged and the weather was clear in Calgary. In an email I received from the pilot, he ruefully informed me that August 10 was his birthday. I think next year he should ask for the day off!
According to some of the mechanics that worked on the aircraft, the damage was mostly cosmetic. Replacement of the nose cone, windshield, cowling on the two engines and the leading edge of the right wing, plus the damaged lenses and lights only took a few days, and the plane has been back in service since September. Some erroneous information on the Internet stated that the airplane was a total loss, and that two crew members quit after they walked off the airplane; that was not the case.
The size of the hailstones the airplane hit is impossible to judge, as none of the stones penetrated the windshield and gave themselves up for examination! As the First Officer commented in a blog entry, "there was no way to measure the size of the hail much less compare it to sporting equipment." So, we'll never know if the plane hit golf ball, tennis ball, softball, or beachball sized hail.
We do know that at the ground, the thunderstorm produced at least golf ball sized hail. According to an email I received from Ennien Ashbrook, "the storm caused record damage to several communities between Red Deer and Calgary. In a couple of heavily-hit rural communities, the entire west walls of houses were completely destroyed, not even the interior drywall left standing. Damage-causing hailstorms are common here, but this one was a real record-breaker."
Hail damage to commercial passenger aircraft is rare, as modern aircraft radar and air traffic control procedures are adept at helping aircraft avoid hail-producing thunderstorms. If anyone has photos or accounts of damaging hail that has affected a commercial jet aircraft, I'd be interested to try to discover the most severe hail damage ever suffered by a commercial aircraft. Send suggestions via email or in the comments section of the blog.
One such incident occurred when hail damaged a Brazilian Airbus jet in March of this year (see photos posted by the MetSul Meteorologia Weather Center). This website also mentions two other cases of hail damage to commercial aircraft--a hailstorm over Germany that left a hole the size of a football in an Airbus plane which had more than 200 passengers on board enroute to England, and an Easyjet 737 that had an emergency landing in Geneva in 2003 after hail did extensive damage to the nose and wings of the plane.
Tropical Storm Durian
In the Western Pacific, residents of the Philippine Islands are anxiously watching Tropical Storm Durian, which is on track to hit the main island of Luzon later this week. The storm is currently suffering from reduced outflow aloft thanks to the influence of a trough to the northwest. However, the influence of this trough is expected to wane over the next 24 hours, and Durian is expected to intensify into a major typhoon. If it hits the Philippines as a major typhoon, it would be the fourth such storm to hit the islands in the past two months.