B737-700
Flight Crew Air Transport Pilot (ATP)
Workload; Situational Awareness
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Aircraft Equipment Problem Dissipated; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Departure Airport; Flight Crew Took Evasive Action; General Declared Emergency
Aircraft
We were level at 22;000 in IMC when ATC cleared us to FL400. As we were climbing through FL230 I heard loud; rapid; snapping sounds. I asked the First Officer if he also heard it? He replied that he did. We tried to figure out its cause when I noticed a strong electrical burning smell. I asked him if also could smell it which initially he replied no. Then a resounding yes! He quickly donned his mask while I declared an emergency with an immediate turn back to the airfield. The First Officer turned toward the departure airport while I ran the Smoke; Fire and Fumes Checklist. The First Officer told me that he had momentarily seen smoke coming from the glareshield. At this time the smoke and snapping sound had stopped. And the fumes had dissipated. I called the flight attendants and gave then the emergency landing signal. We continued our precautionary landing with the emergency equipment standing by. We landed and arrived at the gate without further incident.
Continuing the climb with Engine Anti-Ice on; at approximately FL240 we heard a series of pops coming from behind the instrument panel. This was followed by a strong electrical odor. As I was looking around; I saw a momentary wisp of white/grey-ish smoke coming from up from the area between the windshield and the glare shield. I immediately donned my mask; while the Captain declared an emergency requesting lower and a turn. We executed a turn back to the airport and an emergency descent. The fumes did subside as we made our way back.
A B737-700 climbing through FL230 developed an electrical burning smell accompanied by a momentary bluish/grey smoke near the windshield; so an emergency was declared and the flight returned to the departure airport.