History of Flight
On June 5, 2015, at about 1215 Eastern daylight time, a Bombardier DHC-8-202 airplane, registration N363PH, experienced an in-flight cockpit fire during approach to Bradley International Airport (BDL) in Windsor Locks, Connecticut. The flight was operated by Champlain Enterprises, Inc., doing business as CommutAir – United Express, as a scheduled passenger flight under 14 CFR Part 121. The airplane originated from Newark Liberty International Airport (EWR) at 1134 EDT. The first officer, who was pilot flying, heard a pop and observed arcing at the right windshield terminal block while about 15–20 miles from the initial approach fix PENNA. A fire developed, and the captain, who was pilot monitoring, declared an emergency with approach control. Both crew members donned oxygen masks. Control was transferred to the captain while the first officer attempted to extinguish the fire. The flight attendant was instructed to prepare for an emergency evacuation after landing. The crew performed a successful emergency landing and cleared the runway at the first available taxiway, where an emergency evacuation was conducted with no reported injuries. Airport fire personnel confirmed no continued fire. The crew noted no caution or warning lights illuminated, and no circuit breakers had popped.
Personnel Information
The captain, aged 28, held an Airline Transport Pilot certificate with a DHC-8 type rating and an FAA first-class medical certificate issued October 22, 2014, without limitations. Her most recent proficiency check was January 29, 2015. She reported a total flight time of 2,860 hours, with 2,000 hours in the incident airplane make and model.
The first officer, aged 46, held an Airline Transport Pilot certificate with DHC-8 and B-737 type ratings and an FAA first-class medical certificate issued January 26, 2015, without limitations. His most recent proficiency check was February 26, 2015. He reported a total flight time of 2,995 hours, with 1,100 hours in the incident airplane make and model.
Aircraft Information
The airplane, a Bombardier DHC-8-202, serial number 520, was manufactured in 1998 and had accumulated 31,984.1 flight hours and 42,579 cycles. The right windshield, installed at manufacture, had the same time and cycles. The windshield is a laminated glass configuration with multiple layers, including a conductive heating film for anti-ice. The windshield heat system is controlled by a rotary switch on the left overhead console with positions OFF, WARM UP, and NORM. The WARM UP position applies partial power; NORM applies full power to maintain 108°F ±4°F. Sensors cut power if temperature reaches 122°F ±4°F. An amber caution light illuminates for overheat conditions and extinguishes if the switch is placed in WARM UP.
After the incident, a Federal Aviation Administration representative noted that the windshield heat switch was in the NORM position.
Meteorological Information
At 1151 EDT, about 24 minutes before the incident, an automated weather observation at BDL reported wind variable at 3 knots, visibility 10 statute miles, few clouds at 4,500 feet, scattered clouds at 14,000 and broken at 25,000 feet, temperature 21°C, dew point 9°C, altimeter 30.07 inches Hg. Visual meteorological conditions prevailed for the flight.
Wreckage and Impact Information
The right windshield sustained burning and charring damage at the terminal block area, with the inner glass ply fractured. Adjacent interior trim components near the forward upper edge of the windshield also showed burning and charring. The windshield was removed for examination.
Tests and Research
The damaged windshield (P/N NP157901-12, S/N 97316H9791) was examined under NTSB direction with representatives from PPG Aerospace, CommutAir, and the Air Line Pilots Association present. Examination revealed sparse fractures of the inner glass pane in the upper aft quadrant, cloudiness and cracking of interlayer material (indicating moisture ingression) around the entire periphery about 1 inch wide, and evidence of repaired moisture seal along upper and aft edges with erosion. The lower bus bar was discolored, and the upper bus bar was slightly discolored. The terminal block remained attached but showed burning, charring, and sooting concentrated at the aft end. Screws at power and sensor connections were installed with lock washers; no cross-threading was noted. The L1 power braid wire was melted through adjacent to the terminal block. Extensive burning and charring was present at the bottom of the terminal block around the L1 location and above it. A 1-inch-diameter area of damaged and melted glass was found in the same area; all inner glass pane fractures originated from that point.
Additional Information
A search of Bombardier, FAA, Transport Canada, and TSB databases from 2000 to the present yielded 77 events involving arcing, smoke, fire, or overheating at windshield terminal blocks similar to this incident. No other NTSB investigations focused on DHC-8 windshields were found. Bombardier revised the maintenance manual in 2003 for correct screw and washer part numbers and in 2005 for proper installation torque values. Transport Canada issued civil aviation safety alert CASA 2012-01 recommending detailed inspection of terminal blocks.
The operator's maintenance program includes general visual inspections of windshields from inside every 10,000 flight hours and from outside every 5,000 hours, plus a detailed inspection of terminal blocks every 12,000 hours. The most recent inside inspection was April 4, 2011 (24,776.5 hours), and outside inspection and terminal block inspection were April 9, 2013 (28,401.3 hours); all had no findings. The moisture seal was noted eroded and repaired during the April 9, 2013 C-check.
The operator's emergency and abnormal checklist for aircraft fire or smoke does not specifically mention the windshield heating system or terminal blocks, and there are no instructions to turn off windshield heat in such events. No specific crew training for windshield arcing, smoke, fire, or overheat events is provided.