In-Flight Fires Wreak Havoc With Systems Reliability

Air Safety Week, Sept 22, 2003

"The R1 windshield ... was spitting out black pieces all over the right cockpit area. The next thing we noticed was a substantial amount of smoke.

"A large blowtorch type flame erupted and then almost seemed to recede into the upper corner of the windshield/foam-core in that area followed immediately by another shorter flame that began to continuously burn.

"I turned to the mechanic and told him 'do whatever you need to do to get this under control.' He was checking CBs on both sides of the cockpit [and] a couple minutes later said the power was off to the window heat. He had the fire extinguisher out of its harness and ready to be used if necessary."

"The red rubber boot covering the window heat power terminal was charred to a cinder. Maintenance believes corrosion of the power terminal caused a short circuit."

Issues:

* Note seductive, teasing nature of in-flight fire, flaring, receding, only to return again.

* Implications for clearing smoke when cockpit doors are locked on revenue flights.

* Can secure cockpit doors be opened from the cabin once pilots start shutting off electrical busses? Most cockpit doors feature a manual reversionary opening mode (after electrical failure or turning off busses) that allow pilots to open up from the inside. What about when the captain collapses from smoke in the E&E bay and there's no autopilot (due to electrical failures)?

* Mechanic's actions almost like having a flight engineer in the cockpit.

'Retracting and extending on their own'

Case: A320 in cruise experiences severe arcing.

Details: "I began to notice the cockpit lights (overhead and panel lights background) flicker as if there were a power interruption. There weren't any ECAM messages.

"The purser called and informed us that the right side cabin lights were flickering on and off. Additionally, the video screens on the right side were retracting and extending on their own. At the same time the FO's navigation display and PFD [primary flight display] flickered on and off, including moments of loss of flight data ... The ECAM began to cycle messages about the number 2 yaw damper, pack control, pitch trim, flight warning computer, autopilot and possibly others. The purser then informed us he smelled smoke.

"At this time, we began an immediate diversion.

"At no time during this event did the ECAM indicate this was a generator loss of phase problem ... Maintenance found a feeder wire pin in the firewall connector burned with evidence of severe arcing. The reporter stated the failure of the ECAM system to warn of a right bus intermittent loss of phase was ... discussed with the company."

Issue: One cannot expect a failing electrical system to have the integrity to drive the ECAM warning system and "tell on itself." The situation is analogous to the fire truck that is itself on fire. Pilots may be back to "20 guesses" about the true nature of the problem.

[Copyright 2003 PBI Media, LLC. All rights reserved.]