Date: 201701
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Daylight
Aircraft: Dash 8 Series Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Air Conditioning Compressor
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Distraction; Communication Breakdown; Time Pressure
Second reporter function: First Officer; Pilot Flying
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action; General Evacuated; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: On descent I smelled an odor that appeared to be coming from the lavatory. It became stronger and stronger; and smelled like an electrical smoke. Very shortly after; I noticed it becoming hazy in the cockpit quite quickly. There were no caution lights; master warning; nor was the lavatory smoke detector going off. We donned the oxygen mask and smoke goggles; and at that time the flight attendant called us. I was informed there was smoke in the cabin as well. I asked the flight attendant to try to locate a fire if able. The flight attendant was unable; I told him/her we had about 10 minutes until landing; bracing signals; and also that we were to evacuate the aircraft upon landing. We transferred controls to my side knowing that load shedding would shut down the FO's instruments. We ran the smoke in aircraft checklist; while doing that I [advised ATC] and asked [for] priority to land. The pilot not flying ran the checklist leaning towards electrical smoke because it had a electrical smell. The smoke didn't appear to be disappearing yet getting any worse. Due to the lack of time and low altitude; I was unable to inform dispatch or operations. Landing was imminent so we proceeded to land and evacuate on the runway. The evacuation went quickly and smoothly; and there were no injuries.The checklist for smoke is quite the long checklist with many trees. Being so close to [destination airport] and at a low altitude; problem solving isn't timely. Having a quick checklist such as load shedding; dumping pressurization and land immediately would be fantastic to be used only when over an airport in which you can land at and at a low altitude.

Callback: Reporter indicated the source of smoke and odor was a failed air cycle machine. He added that in hindsight it may have been more appropriate to have run the pneumatic smoke checklist. Reporter described the conditions after the load shed as no navigation in IMC with trouble communicating with the First Officer with oxygen masks on. Additionally; ATC communication was hampered by attempts from the Flight Attendant to call the cockpit. Also; ATC did not understand the situation and that changing runways increased the flight crew workload.

Second narrative: During descent to land an odor was detected in the cockpit which seemed to be electrical in nature. No warning or caution lights were observed. Very shortly faint smoke was detected in the cockpit at which point the captain and I switched flying duties so that I could run the emergency checklist. While the captain flew I ran the smoke in aircraft checklist while he took over communications with ATC. Based on the smell I followed the electrical side of the checklist. With the close proximity of the airport we prepared to land in accordance with ATC requests. After landing we evacuated the aircraft on the runway. The flight attendant and emergency responders were prompt and efficient in their actions. No passengers were injured in the evacuation. Smoke in aircraft checklist needs to provide for unknown source of smoke. Choices are only given for electrical or pressurization.


Synopsis: Dash 8 flight crew and Flight Attendant reported smoke and odor during descent that was hampered by communication issues; checklist confusion; and high workload.