Avionics Failure and Smoke in Cockpit Lead to Emergency Diversion of Embraer 145

Casualties unknown • West of Coulommiers VOR Beacon, France, GB

An Embraer 145 passenger flight from Manchester to Venice was forced to divert to Paris after an avionics computer failure caused smoke in the cockpit and loss of flight displays.

What happened

On 20 February 2005, an Embraer 145EP, registration G-ERJG, was operating a scheduled passenger flight from Manchester to Venice. During the climb through FL100, the aircraft's autopilot disengaged. While climbing through FL200, the autopilot failed to re-engage, which prevented the aircraft from operating in RVSM airspace.

While cruising at FL270 near the Coulommiers VOR Beacon, the crew noticed an unusual smell in the flight deck, which a cabin crew member described as similar to nail varnish. Shortly after, smoke became visible beneath the commander's seat and briefly entered the passenger cabin. This was accompanied by a simultaneous failure of the commander's Primary Flight Display (PFD), Multi-function Display (MFD), Radio Management Unit, and the Engine Instrument and Crew Alerting System (EICAS).

In response to the smoke, the crew donned oxygen masks and smoke goggles, declared a MAYDAY, and diverted to Paris Charles de Gaulle Airport. During the descent, the co-pilot deployed the speed brakes to reduce airspeed, but these remained deployed after the aircraft had landed and shut down.

The investigation

The investigation focused on the source of the smoke and the loss of cockpit instrumentation. Maintenance personnel identified the cause as a failure within the number 1 IC-600 avionics integrated computer. Specifically, a transistor failure on a circuit card assembly caused a short circuit in the Yaw Damper Clutch line, leading to overheating and charring of components.

The investigation also examined why the crew did not attempt to restore the failed displays. It was found that while a simple procedure existed to restore information by pressing a single button, this procedure had been omitted from a previous revision of the Quick Reference Handbook (QRH). Additionally, the investigation looked into the flight data recorder (FDR) gaps, noting that the failure of the IC-600 prevented certain parameters from being recorded.

Findings

  • The smoke was caused by electrical overheating of a transistor within the number 1 IC-600 avionics integrated computer.
  • The failure of the IC-600 resulted in the loss of all cockpit displays and EICAS information associated with that computer.
  • The procedure to restore flight instrument information via the reversionary panel was missing from the aircraft's QRH due to an error in a manual revision.
  • The speed brakes remained deployed after landing, likely due to being selected during the approach and not stowing automatically as expected.

Probable cause

The primary cause of the incident was the failure of a transistor in the number 1 IC-600 avionics integrated computer, which led to electrical smoke in the cockpit and the loss of critical flight displays. A contributing factor was the omission of the correct reversionary procedure from the Quick Reference Handbook.

Frequently asked questions

What happened in the 2005-02-20 Embraer EMB-145EP accident near West of Coulommiers VOR Beacon, France, GB?

An Embraer 145 passenger flight from Manchester to Venice was forced to divert to Paris after an avionics computer failure caused smoke in the cockpit and loss of flight displays.

What aircraft was involved and where did it happen?

The accident on 2005-02-20 involved a Embraer EMB-145EP, registration G-ERJG, at West of Coulommiers VOR Beacon, France, GB.

What was the probable cause of the accident?

The primary cause of the incident was the failure of a transistor in the number 1 IC-600 avionics integrated computer, which led to electrical smoke in the cockpit and the loss of critical flight displays. A contributing factor was the omission of the correct reversionary procedure from the Quick Reference Handbook.

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