Narrative:

Climbing out of elp and passing through around 25;000 feet; my GPS unit flagged an integrity message. At the time of the GPS losing signal; I was direct to ink vor. I reported the failure to ATC (with the understanding that there was a NOTAM for GPS jamming being conducted). The controller gave me a vector direct when able to my destination. As a result of my GPS losing signal the autopilot went into 'roll hold' a basic level that the autopilot defaults to. I placed the autopilot into heading mode and rolled to the assigned heading. What I failed to notice was that the autopilot had also dropped 'altitude select'. This mode is responsible for capturing the assigned altitude. In this case; that altitude was 27;000 feet. I recall acknowledging the altitude alerter at the 1000 feet prior annunciation. However; instead of focusing on the level off I left my attention to resetting the GPS and tuning in frequencies to ground based navigation facilities. As I was looking up a frequency to tune; I noticed the amber light from the altitude alerter was still illuminated. Through all of my previous flying experience I instantly knew that we should have already leveled off. I looked at the altimeter and we were 800 feet higher than our assigned altitude of 27;000 feet. I immediately disengaged the autopilot and corrected to the assigned altitude.contributing factors include distraction from losing GPS. Fixation while attempting to find other means of navigation; even though the controller gave me an initial vector and I had plenty of time to wait until level off to determine frequencies. In addition; I was approaching the end of my duty day so fatigue may have contributed to my error.

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Original NASA ASRS Text

Title: King Air 200 pilot experienced loss of GPS signal after departing ELP and passing through FL250. The failure was due to NOTAMed GPS jamming in the area and ATC assigned a heading to destination. With the loss of NAV capability the autopilot also lost altitude capture; resulting in an 800 foot overshoot of FL270.

Narrative: Climbing out of ELP and passing through around 25;000 feet; My GPS unit flagged an integrity message. At the time of the GPS losing signal; I was direct to INK vor. I reported the failure to ATC (with the understanding that there was a NOTAM for GPS jamming being conducted). The controller gave me a vector direct when able to my destination. As a result of my GPS losing signal the autopilot went into 'roll hold' a basic level that the autopilot defaults to. I placed the autopilot into heading mode and rolled to the assigned heading. What I failed to notice was that the autopilot had also dropped 'altitude select'. This mode is responsible for capturing the assigned altitude. In this case; that altitude was 27;000 feet. I recall acknowledging the altitude alerter at the 1000 feet prior annunciation. However; instead of focusing on the level off I left my attention to resetting the GPS and tuning in frequencies to ground based navigation facilities. As I was looking up a frequency to tune; I noticed the amber light from the altitude alerter was still illuminated. Through all of my previous flying experience I instantly knew that we should have already leveled off. I looked at the altimeter and we were 800 feet higher than our assigned altitude of 27;000 feet. I immediately disengaged the autopilot and corrected to the assigned altitude.Contributing factors include distraction from losing GPS. Fixation while attempting to find other means of navigation; even though the controller gave me an initial vector and I had plenty of time to wait until level off to determine frequencies. In addition; I was approaching the end of my duty day so fatigue may have contributed to my error.

Data retrieved from NASA's ASRS site 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.