IAD02IA046

The flight crew experienced a strong odor and smoke in the cockpit, followed by a loss of flight displays during flight in instrument meteorological conditions. The captain declared an emergency, and the first officer flew the airplane referencing the stand-by instruments. Shortly after declaring the emergency, the crew made a right 360 degree turn to avoid severe weather. However, near the completion of the turn, the crew entered VIP 4 and 5 intensity level weather, and reported moderate to severe turbulence. The airplane was then vectored to an airport east of the severe weather, executed an instrument approach and landed without incident. While on approach, the crew reported that all flight displays had returned back to normal. Twenty-seven days later, another crew, who were flying the same airplane, also experienced a loss of flight displays. Approximately 2 minutes after the failure, the displays returned to normal and the flight landed without incident at its intended destination. Examination of electrical components revealed no discrepancies. In addition, the manufacturer reviewed the design of the electrical system and could not identify a design failure.

History of flight

On May 2, 2002, at 0830 eastern daylight time, a Fairchild Dornier DO-328-300, N429FJ, operated by Atlantic Coast Airlines (ACA) d/b/a Delta Connection flight 6110, was not damaged after the crew reported a strong odor of smoke in the cockpit. The captain declared an emergency and landed without incident at Atlantic City International Airport (ACY), Atlantic City, New Jersey. The certificated airline transport pilot captain, commercial rated first officer, flight attendant, and 33 passengers were not injured. An instrument flight rules (IFR) flight plan was filed for the flight between Piedmont Triad International Airport (GSO), Greensboro, North Carolina, and La Guardia Airport (LGA), New York City, New York. Instrument meteorological conditions prevailed for the flight conducted under 14 CFR Part 121.

During an interview, the captain and first officer both said that they were established on a published arrival procedure into La Guardia and were about 20-30 miles east of Baltimore, Maryland, when air traffic control (ATC) instructed them to descend from 27,000 feet to 22,000 feet. During the descent, they began to smell a strong odor in the cockpit, which they described as something electrical burning. They did not know where the odor emanated from, and could not confirm that there was any smoke associated with the odor.

The odor dissipated, but returned just as strong a few minutes later. At this point, the crew said they donned their oxygen masks.

According to the captain, he thought that there was an in-flight fire and immediately declared an emergency. Shortly after declaring the emergency, he said that the air data computer (ADC) #1 and #2 screens displayed red "x's", and the information of the displays was intermittent. The flight director and the attitude heading reference systems (AHRS) #1 and #2 also went off-line. The engine parameters page on the engine indication and crew alerting system (EICAS) was empty, but the cautions page continued to load. The captain could not recall what cautions were posted, but said that there was no pattern to them.

While on approach to Atlantic City, the captain said the flight display screens returned to normal.

According to the first officer, he was flying the airplane. He said the first signs of electrical failures began when the autopilot disconnected, followed by the flight director. He said that his flight display screens never went blank, but were missing information. He saw a flight director fail warning light illuminated for a while, but it reset itself by the time they landed in Atlantic City. He said his attitude director indicator (ADI) turned blue. He also noticed there were red "x's" on the captain's displays for the flaps, ADC #1 and #2, airspeed and altitude. On the EICAS, the engine parameters page was empty, and he saw "empty shells and dashed lines." The caution page was full and continued to load. He said that he saw "lots" of 1's and 2's on the screen.

The first officer also said that due to the loss of flight display information, he flew the airplane on the stand-by instruments with the auto pilot off for the remainder of the flight. However, on approach into Atlantic City, he said the flight display screens had returned to normal.

A Federal Aviation Administration (FAA) inspector performed an examination of the airplane on the evening of the incident. According to the inspector the airplane was towed to Mid Atlantic Jet fixed base operator. ACA also dispatched two maintenance personnel to work on the airplane. The maintenance personnel performed a lightning strike inspection, partial airframe structural inspection, and a visual inspection for overheated wires and chaffing. All systems were checked with power on and both engines running. No discrepancies were noted during these checks.

The airplane was ferried to Dulles, Virginia, on May 4, 2002. One of the pilot's who ferried the airplane back to Virginia was the operator's supervisor of flight standards for the Dornier 328. According to the supervisor, the ferry flight was normal and there were no discrepancies noted with any of the airplane's flight systems or display units.

Examination of maintenance records indicated that the de-ice and ice detection system were also examined after the occurrence with no discrepancies noted. Additionally, the airplane was checked for structural damage and no discrepancies were noted. The airplane was returned to service.

Meteorological information

A National Transportation Safety Board meteorologist conducted a study of the weather conditions at the time of the incident. The Doppler Weather Radar images he used were generated from data downloaded from Unidata, and the airplane's radar track was plotted on the Weather Radar images. The data revealed that after declaring an emergency, the pilot started a right turn in order to fly away from the weather, which were VIP intensity levels 2 and 3. However, the airplane continued to make a 360 degree turn, and by the end of the complete circle, the airplane had turned back into weather of VIP intensity levels 4 and 5. At that point, the airplane was approximately 30 seconds away from entering VIP intensity levels 6.

Air traffic control

A Safety Board Air Traffic Control (ATC) specialist reviewed the involvement and actions of ATC in this incident , and did not find any discrepancies in their handling of the emergency.

Additional information

On May 29, 2002, an ACA flight crew reported a loss of flight display information and odor while in cruise flight on the same airplane, N429FJ. Examination of the airplane's flight log revealed that the captain reported multiple failures during the flight. These failures included several EICAS messages, and a loss of all data on the first officer's #2 multi-function display (MFD) screen and #2 primary flight display (PFD). The data on these screens was replaced with red "x's". Also, the autopilot disconnected. The captain reported that these messages lasted for approximately 2 minutes, during which time there was static heard on the #1 communication frequency. After 2 minutes, the EICAS messages cleared up except for the "ice detector fail" caution.

The airplane landed without incident at the intended destination.

Tests and research

The DC Junction Box (1VE panel), and Bus Power Control Unit (BCPU), and the #1and #2 integrated avionics computers were retained and examined.

The BPCU was examined and tested at Thales Avionics Electrical Systems under the supervision of the Bureau Enquetes - Accidents (BEA), with representatives from the Civil Aviation Authority-United Kingdom (CAA-UK) and Fairchild Dornier also present.

A review of maintenance records found no history of repairs at the manufacturer. Visual examination of the unit found traces of varnish on the J1A and J1B pins. Functional testing of the unit, including thermal heating, produced no discrepancies.

The DC Junction Box (1VE Panel), was designed to ensure the connection of power supplied to the distribution busses; connection of the APU to MAIN BUS 2; switching of power sources onto loads; protection of batteries against reverse current; control of generators or battery contactors; control of the APU contactor; primary protection of the power feeder lines by fuses; and passive protection of components housed within the junction boxes.

The DC Junction box was installed inside the pressurized airframe, under the cabin floor, between frame 23 and frame 24, in front of the main landing gear area. This area had ventilation air from the front through the rear of the airframe.

The DC Junction Box, was tested at Barfield Avionics, Miami, Florida, under the supervision of the Safety Board. The initial inspection revealed a missing fuse holder and 11 missing washers and bolts. During functional testing, the unit was found t