Chicago aviation officials are evaluating whether to stop using an epoxy material applied to potholes during airfield maintenance after a newly repaired patch of runway blew out while a jetliner was taking off at Midway Airport last week.
No injuries were reported in the incident Thursday morning on Midway's busiest runway, but a business-class plane that landed immediately after the pavement blowout sustained damage to a tire, officials said.
"The pilot saw some debris on the left side of the runway, moved the plane over but then hit this shallow pothole," said Tony Molinaro, a spokesman for the Federal Aviation Administration.
The epoxy material was applied to Midway's Runway 31 Center in April, said Gregg Cunningham, a spokesman for the Chicago Department of Aviation.
The airport immediately shut down Runway 31 Center Thursday and crews used asphalt to repair the damaged area, which measured about 4 feet by 4 feet and 4 inches deep, Cunningham said.
Crews also made asphalt repairs on two other sections of the runway "as a precaution," he said.
Runways must be free of defects and debris to ensure safe flight operations. Excellent pavement conditions are especially critical at Midway because the Southwest Side airport's relatively short runways give pilots little room to recover from an unexpected incident or emergency. City crews inspect Midway's runways at least three time a day, Cunningham said.
It was not known how the epoxy patch on Runway 31 Center became dislodged, but Molinaro said the FAA believes oil or moisture may have gotten underneath the patch, eventually weakening it.
Because the epoxy patch lasted only three months, the city is considering using alternative methods for pavement maintenance.
"We felt we needed to take a close look and investigate to make sure this epoxy is the best possible material we can be using," Cunningham said.
Thursday's incident was the second airfield pavement problem in less than a week at Midway.
On July 14, a jet blast from a Frontier Airlines plane departing Runway 22 Left damaged pavement on the pad near the end of the runway and blew debris onto a service road, officials said.
An inspection turned up structural problems with the pavement, Cunningham said.
The damage occurred in an area where crews are building an aircraft arresting bed, made of crushable concrete, to safely stop planes that run off the end of the runway.
Installation of Midway's first aircraft arresting bed was completed in November just beyond the end of Runway 31 Center, less than a year after a Southwest Airlines plane skidded off the end of a snowy runway on Dec. 8, 2005, killing a child in a car outside the airport on Central Avenue.
Arresting bed work is scheduled for completion on three additional runway ends this year, city officials said.