Narrative:

While climbing through approximately FL260 the standby HSI flickered once or twice and then went blank. Immediately thereafter; we noted strong electrical burning fumes. We completed memory items; notified ATC of situation; declared an emergency; and our intent to immediately divert and land at [an airport] which was approximately 20 miles from our current position. During my initial calls to ATC; the frequency was congested and I had difficulty establishing contact. I then changed the transponder frequency to 7700 which succeeded in gaining the controller's attention and establishing voice communications. We initiated an emergency descent and began preparation for an emergency landing. Approximately 20-30 seconds after initiating our descent; I turned off the standby HSI power and the strong electrical fumes seemed to dissipate after that point. We briefed the passengers briefly via cabin speaker; letting them know we would be making a 'precautionary' landing; directing them to remain seated with seat belts fastened; and that we would give them a full brief and update once we landed. During our descent and approach we requested that the fire trucks meet us; and confirmed this with tower on final approach; though fumes had mostly dissipated upon landing. ATC cleared us for visual approach; we landed; taxied off the runway; and evacuated the passengers. Because of our close proximity to the airport when the event occurred; time compression was an issue. From event occurrence until landing; total time was not much more than 5-7 minutes. We were unable to listen to ATIS prior to landing; so we obtained basic airport/weather info from tower control. One difficulty we both raised when we debriefed after the event was the proper use of the microphone switch when the mic is in the 'oxygen mask' position. Leaving the switch in the constant on position (for the crew intercom) allows the crew's breathing noises to drown out nearly all conversation and communication between one another and ATC. It is necessary to switch the mic/intercom switch on and off each time one speaks or communications become exceptionally difficult to hear.

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Original NASA ASRS Text

Title: When the airplane began to fill with smoke the flight crew of a CE-560XL declared an emergency; made a rapid descent; and diverted to a nearby airport where they evacuated the aircraft after landing.

Narrative: While climbing through approximately FL260 the standby HSI flickered once or twice and then went blank. Immediately thereafter; we noted strong electrical burning fumes. We completed memory items; notified ATC of situation; declared an emergency; and our intent to immediately divert and land at [an airport] which was approximately 20 miles from our current position. During my initial calls to ATC; the frequency was congested and I had difficulty establishing contact. I then changed the transponder frequency to 7700 which succeeded in gaining the Controller's attention and establishing voice communications. We initiated an emergency descent and began preparation for an emergency landing. Approximately 20-30 seconds after initiating our descent; I turned off the standby HSI power and the strong electrical fumes seemed to dissipate after that point. We briefed the passengers briefly via cabin speaker; letting them know we would be making a 'precautionary' landing; directing them to remain seated with seat belts fastened; and that we would give them a full brief and update once we landed. During our descent and approach we requested that the fire trucks meet us; and confirmed this with Tower on final approach; though fumes had mostly dissipated upon landing. ATC cleared us for visual approach; we landed; taxied off the runway; and evacuated the passengers. Because of our close proximity to the airport when the event occurred; time compression was an issue. From event occurrence until landing; total time was not much more than 5-7 minutes. We were unable to listen to ATIS prior to landing; so we obtained basic airport/weather info from Tower Control. One difficulty we both raised when we debriefed after the event was the proper use of the microphone switch when the mic is in the 'oxygen mask' position. Leaving the switch in the constant on position (for the crew intercom) allows the crew's breathing noises to drown out nearly all conversation and communication between one another and ATC. It is necessary to switch the mic/intercom switch on and off each time one speaks or communications become exceptionally difficult to hear.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.