Investigators Have Duplicated Problem Twice

The National Transportation Safety Board is investigating an incident in Boston that occurred on June 20, in which an American Eagle Embraer ERJ-135 regional jet briefly touched down on the runway without the landing gear extended before initiating a go-around and completing a second landing attempt. 

None of the 37 passengers or three crewmembers was injured, though the aircraft sustained minor damage during the first landing attempt. The event is being investigated as an incident.

Prior to the first landing attempt in which the gear was not extended, the crew stated that the three landing gear indicator lights were all green, indicating that the gear was down and locked. Shortly before touchdown they noticed a "landing gear lever disagree" message on a flight computer console.

After the jet contacted the runway, a go-around procedure was initiated. The crew extended the gear by following the emergency abnormal landing gear procedure, then flew by the control tower twice for a visual inspection to ensure the gear was down prior to the second landing attempt.

So far in the investigation, officials have been able to recreate the problem on the aircraft involved. The aircraft was placed on jacks, and investigators duplicated the in-flight situation: Three green lights in the cockpit indicated the gear was down and locked, but none of the gear extended.

The cockpit voice recorder and flight data recorder were sent to the Safety Board's laboratory in Washington last week, where the content of each is being evaluated. Both members of the flight crew were interviewed this week.

An electronic component of the landing gear control system, made by Parker Aerospace, was bench tested this week at their facility in New York. The same unit, with small modifications, was then placed in a different airplane and the indications were once again duplicated.

Embraer issued a "Field Service Letter" late last week to all operators of the EMB-135, -140, and -145 models, reminding pilots to follow the checklist in the case of a "landing gear disagree" message.

The Federal Aviation Administration, Parker Aerospace, American Eagle and Embraer are working with the Safety Board as the investigation continues.

FMI: www.ntsb.gov