Bus Failure

[pelmet]

Only ever lost one once but it was intermittent with all left side instruments(except one) gyrating autopilot off with horn and Terrain, terrain alerts among other things like pressurization issues. Actually, it was intermittently failing with lots of blinking lights and clicking relays on the overhead panel in addition to engine power fluctuations, then after the generator was turned off, then the bus was lost.

C-FSAO, a Beech 200 operated by Keewatin Air LP as flight Blizzard 214, was enroute from
Thompson (CYTH), MB to Lac Brochet (CZWH), MB with a crew of 2 and 2 passengers onboard.
While on approach into CZWH, the crew extended the landing gear and the aircraft experienced
the loss of the following equipment: Nav 2, Com 2, AFCS, AHRS 2, Landing gear control/position
indicators, PFD 2 radar altimeter, cabin temperature controller, pressurization controller, windshield
wipers, right hand engine instruments and right-hand engine ice vanes. After conducting a missed
approach, the aircraft entered a holding pattern to assess the issues. The crew decided to return to
CYTH where an emergency was declared and the aircraft then landed safely.

An inspection of the aircraft by the operators maintenance personnel revealed an incomplete
assembly and diode failure of the #2 dual fed bus. The system was repaired and the aircraft was
returned to service.

[DHC-1 Jockey]

I was an F/O and lost a whole bus in a Metro half way between Ottawa and North Bay. We were in light daytime convective turbulence and we got a decent moderate bump. Right after that bump, we started losing systems and the annunciator started to light up like a Christmas tree. A few moments later we started to smell smoke, and I knew that Pembroke (CYTA) wasn't far away with a runway long enough for us. I told the Captain that I was asking for vectors for a straight-in approach and I flew it while she worked the checklists. I asked for a vector direct YTA, did a straight-in VFR landing and we rapidly deplaned the passengers, about 10-15 minutes after the initial issue. Thank goodness it was daytime VMC otherwise it would have been a different story doing an IFR approach.

After being stuck there for 3 days with a mechanic trying to troubleshoot where the issues was, we ended up finding a partially melted paperclip that was bouncing around in the F/O circuit breaker panel.

The mechanic said that if we tried to continue to North Bay or return to Ottawa, we probably would have burned up en-route. Diverting direct to Pembroke was still the best decision I think I've made during my flying career.

[pelmet]

After being stuck there for 3 days with a mechanic trying to troubleshoot where the issues was, we ended up finding a partially melted paperclip that was bouncing around in the F/O circuit breaker panel.

Interesting. I was told that my case was a generator cable making occasional contact with something. Maybe the protective cover wore through. But it did confirm what a training guy said to me. That most of the issues I would have on the line would be different from the sim and maybe with no associated checklist, like the fault I had. You just have to try to do your best. I turned the left generator off because the flickering lights were on that side of the electrical panel. Then all the commotion stopped with some inoperative items and a steady LH DC Bus light. Fortunately, no smoke.

[DHC-1 Jockey]

I forgot to mention that the mechanic also found a couple dollars worth of loose change in there as well, although I never saw any of that after it got fished out!

[co-joe]

C-FSAO, a Beech 200 ...
An inspection of the aircraft by the operators maintenance personnel revealed an incomplete
assembly and diode failure of the #2 dual fed bus. The system was repaired and the aircraft was
returned to service.

Old Slave Air machine.

No mention if a 50 Amp bus tie breaker popped.

Would think that dropping the gear and losing half the panel would be pretty disheartening to say the least. Sounds like it was well handled.

[pelmet]

Multiple instruments suddenly lost power? Suspect a lost bus.......

"C-FMCN, a Pacific Coastal Airlines Beech 1900D was conducting flight PCO9192 from Victoria
International (CYYJ), BC, to Vancouver International (CYVR), BC, with 2 crew members and 5
passengers on board. Immediately after aircraft rotation, the aircraft experienced an electrical
failure. Multiple annunciator lights illuminated, including the L GEN TIE OPEN, BATT TIE OPEN,
and R GEN TIE OPEN caution lights. The flight crew continued the takeoff, but could not retract the
landing gear and determined multiple flight instruments were providing erroneous indications.
Following the checklists, it was determined that the electrical voltage of the aircraft's center bus
was zero. After consulting with maintenance, the flight crew declared PAN PAN with air traffic
control and continued to CYVR under visual flight conditions. The flight landed without further
incident. There were no injuries.
Subsequent maintenance activities by the operator could not duplicate the failure after aircraft
electrical power was reset. The operator removed and replaced the main battery and the bus tie
printed circuit boards for evaluation. The aircraft has been returned to service."