Background
On 5 August 2005, an Embraer 145EU registered G-EMBP was conducting a scheduled passenger flight from Frankfurt to Birmingham Airport, West Midlands. The aircraft, powered by two Allison AE 3007/A1/1 turbofan engines, had 4 crew and 18 passengers on board. The commander held an Airline Transport Pilot's Licence with 7,650 total flying hours, including 2,150 on type.
Events During Flight
While cruising at Flight Level 360, the cabin crew observed hazy smoke in the central cabin area. The senior crew member informed the flight deck, prompting the pilots to don oxygen masks and declare an emergency to air traffic control. Initial descent to FL240 was initiated due to information from an onboard positioning crew regarding a possible air conditioning pack problem earlier that day, anticipating single-pack operation. The crew carried out the emergency/abnormal procedure for 'Air Conditioning Smoke', after which the cabin crew reported the smoke had cleared. The commander decided to continue to Birmingham, and no further smoke occurred during the remainder of the cruise.
Approach and Landing
Descending through FL50 towards the final approach, the cabin crew informed the commander that the smoke had returned and was more prominent toward the front of the cabin. A 'PAN' call was made, and the flight crew again donned oxygen masks. ATC were advised that a passenger evacuation on the runway might be necessary. Shortly before landing, the cabin crew reported that the smoke had cleared.
Post-Landing Actions
After landing, the commander stopped the aircraft on the runway and coordinated with the Airport Fire Service (AFS), which was in attendance. AFS personnel boarded the aircraft and found no evidence of smoke or fire. As a precaution, the passengers were evacuated, and the aircraft was towed off the runway to a stand.
Investigation Findings
The source of the smoke was subsequently traced to a faulty bearing on the cabin air recirculation fan. The recirculation fan would have been turned off as part of the procedure carried out by the crew, effectively eliminating the smoke source.