Incident Summary
On 3 July 2018, an Airbus A320-214 aircraft, registration EC-JFN, operated by Iberia L.a.e., S.A., as flight IBE-3214 from Adolfo Suárez Madrid-Barajas Airport (LEMD) to Brussels, Belgium. During the ascent, at an altitude of 3,500 feet, the flight crew detected an intense smell of burning and observed smoke in the cockpit emanating from the air conditioning outlets. The captain declared an emergency and requested a return to the departure airport. Smoke was also reported in the passenger cabin, and the captain instructed the use of oxygen masks. The aircraft was cleared to return to LEMD and landed without incident. After landing, the smoke had completely dissipated, though the smell of burning persisted. While waiting on the stand, a maintenance technician informed the captain of an obvious hydraulic fluid leak in one of the engines.
Injuries and Damage
Neither the crew members (6) nor the passengers (168) were harmed. The aircraft did not sustain any damage during the incident.
Investigation Findings
The investigation determined that the incident was most likely caused by an inadequate maintenance practice, which led to the contamination of the bleed air from engine 1, resulting in the smoke and odour in the cockpit and cabin.
Background Information
The aircraft, an Airbus A320-214 with serial number 2391, was on a scheduled international passenger flight under IFR rules. The flight crew consisted of two pilots and cabin crew. The incident occurred during the climb phase of flight. No further details about the maintenance practice were specified in the report.