Swedish CRJ-200 Cargo Crash Norway

[GyvAir]

Would that also affect the engine operation or just the indication ?

The negative g would cause the oil to migrate to the top of the oil reservoir area. The pickup or pump inlet will be situated near the bottom of the reservoir, so it would no longer be submerged in oil and would suck air in instead.

Indication system probably wouldn't be affected.

[pelmet]

Would that also affect the engine operation or just the indication ?

The negative g would cause the oil to migrate to the top of the oil reservoir area. The pickup or pump inlet will be situated near the bottom of the reservoir, so it would no longer be submerged in oil and would suck air in instead.

Indication system probably wouldn't be affected.

Apparently this is true. On a turboprop type I was current on several years back, another crew tried to go between two CB's while on descent into an American airport and got into some bad conditions involving negative g. They ended up shutting an engine down due to low oil pressure. No faults found after landing.

[arctic_slim]

The report gives nothing of a possible cause but we will have to wait until they do their investigation. I hope they can figure it out since they seem to have the FDR and CVR data.

Whatever happened seemed to be pretty sudden, I wonder if there was some sort of collision.

[pelmet]

Instrument malfunction led to West Atlantic CRJ200 freighter crash

Swedish air accident investigators have concluded that an instrument failure was the root cause of the crash of a Swedish cargo aircraft in January 2016.

The West Atlantic Sweden Bombardier CRJ 200, SE-DUX, crashed Jan. 8 while on a night flight from Oslo Gardermoen airport to Tromsø Langnes airport in the far north of Norway. The aircraft came down just over the border in Sweden.

Both pilots, the only people on board, died in the crash.

The investigators have called for the implementation – throughout the commercial air transport industry – of a system of initial standard calls for the handling of abnormal and emergency procedures.

The final accident report by Statens Haverikommission (SHK), the Swedish Accident Investigation Authority, says that flight was uneventful until the approach briefing for Tromsø, in level flight at FL 330.

The night was moonless, without clouds or turbulence. This lack of external visual references rendered the pilots totally dependent on their instruments, which included three independent attitude indicators.

According to information from the flight data recorder, a very fast increase in pitch was displayed on the left attitude indicator. The displayed pitch change meant that the pilot in command, who was the pilot flying, was subjected to a surprise effect and a degradation of spatial orientation.

“The autopilot was, most probably, disconnected automatically, a ‘cavalry charge’ aural warning and a single chime was heard, the latter most likely as a result of miscompare between the left and right pilots’ flying displays (PFD),” the report said.

Both elevators moved towards nose down and nose down stabilizer trim was gradually activated. The aircraft started to descend.

“About 13 seconds after the start of the event the crew were presented with two contradictory attitude indicators with red chevrons pointing in opposite directions. Bank angle warnings were heard and the maximum operating speed and Mach number were exceeded 17 seconds after the start of the event, which activated the overspeed warning,” the report said. “The speed continued to increase, a distress call was transmitted and the engine thrust was reduced to flight idle.”

The report continued: “the crew was active during the entire event. The dialogue between the pilots consisted mainly of different perceptions regarding turn directions. They also expressed the need to climb. At this stage, the pilots were probably subjected to spatial disorientation.”

“The aircraft collided with the ground one minute and twenty seconds after the initial height loss,” the report said.

SHK’s investigation found that the erroneous attitude indication on PFD 1 was caused by a malfunction of the Inertial Reference Unit.

The pilots initially became “communicatively isolated” from each other, says the SHK and a system for efficient communication was not in place.

Among its recommendations, “SHK considers that a general system of initial standard calls for the handling of abnormal and emergency procedures and also for unusual and unexpected situations should be incorporated in commercial aviation.”

“The accident was caused by insufficient operational prerequisites for the management of a failure in a redundant system,” the report concluded. “Contributing factors were: the absence of an effective system for communication in abnormal and emergency situations; the flight instrument system provided insufficient guidance about malfunctions that occurred; and the initial maneuver that resulted in negative G-loads probably affected the pilots' ability to manage the situation in a rational manner.”

http://atwonline.com/daily-news/instrum ... da380a1f62

[EPR]

Was there no "stand-by" EAI onboard to refer to?

[Bolter]

Report states that there were 3 independent attitude indicators, which is the normal set up in a CRJ. The stay AI is located in the left centre of the instrument panel & easily viewed from either seat. When I did the CRJ course, students had to fly an ILS totally reliant on the stay AI (it incorporates an ILS & asi). Can't remember what the simulated failure was - likely a dual IRS failure as the engine instruments worked/not an EFIS panel failure issue.
Anyhow, I have flown several aircraft types which have had historical issues of AIs failing at inopportune times (rotate, top of descent, etc). Was taught, and training reinforced in sim/SOPs, to cross check AIs during unusual attitude recoveries, etc. NFP responsible to cross check AIs at rotate (standard industry SOP?). Helped save my ass at least once - FP's AI failed at rotate (night, high, hot) so I had to take control & return to land.
Sad way to relearn that particular lesson.

[EPR]

I wonder if their sim training covered such an event, hard to believe it wouldn't?
I mean like that's the whole reason why there's a stand-by EAI, no?
Or am I being too armchair'ish here?

[rippey]

I wonder if their sim training covered such an event, hard to believe it wouldn't?
I mean like that's the whole reason why there's a stand-by EAI, no?
Or am I being too armchair'ish here?

After reading this report a couple weeks ago I was thinking this exact scenario would be interesting to throw in the sim for unusual attitudes - obviously it wasn't an unusual attitude but I'd be curious to see what the reactions would be. Airspeed/Altitude would be a big help as well - and its right on the same display! Chilling to think that a professional flight crew took a serviceable, stable aircraft from level cruise to a smoking hole in 80 sec due to a single failure.