Dented 757 Radome A Mystery

Officials with the FAA are trying to figure what, if anything, impacted the nose of a Northwest Airlines plane at FL180 during a Sunday flight from Detroit to Tampa.

The Tampa Tribune reports the Boeing 757 landed without incident at Tampa International Airport just after 1300 EDT Sunday. The plane's flight crew notified controllers of a "bang" while descending through 18,000 feet, then discovered the plane's weather radar was inoperative.

"The crew did not report a bird strike but did tell ATC that the radome collapsed," FAA spokeswoman Kathleen Bergen said. "The crew suspected a radome issue and slowed speed."

No other anomalies were reported, and the aircraft made a routine landing at TPA. Photos show a symmetrical indentation at the top of the aircraft's nose.

So far, officials are at a loss to explain the incident. There's no sign of blood or feathers on the radome that would suggest a bird strike; for that matter, 18,000 feet is higher than most birds fly, anyway. And the pattern of the dent is too uniform for a lightning strike.

Another possibility may be some kind of structural failure in the radome assembly.

A spokesman for the Eagan, MN-based airline said the incident was a "minor maintenance issue, a rare occurrence."

"There is an ongoing investigation to determine the cause, and we don't want to speculate before that is completed," added Vin Parker, manager of media relations for Northwest.

The plane was repaired in Tampa, and was scheduled to fly to Minneapolis Monday.

IDENTIFICATION
  Regis#: NWA478        Make/Model: B757      Description: B-757
  Date: 07/06/2008     Time: 1707

  Event Type: Incident   Highest Injury: None     Mid Air: N    Missing: N
  Damage: Unknown

LOCATION
  City: TAMPA   State: FL   Country: US

DESCRIPTION
  NORTHWEST AIRLINES FLIGHT 478 REPORTED RAYDOME DENTED, LANDED WITHOUT
  INCIDENT, TAMPA, FL

INJURY DATA      Total Fatal:   0
                 # Crew:   0     Fat:   0     Ser:   0     Min:   0     Unk:   
                 # Pass:   0     Fat:   0     Ser:   0     Min:   0     Unk:   
                 # Grnd:         Fat:   0     Ser:   0     Min:   0     Unk:   

WEATHER: NOT REPORTED

OTHER DATA
  Activity: Business      Phase: Landing      Operation: Air Carrier

  FAA FSDO: TAMPA, FL  (SO35)                     Entry date: 07/07/2008

FMI: www.nwa.com, www.faa.gov