Narrative:

While being vectored to the final approach (ILS runway 18R) at mco in IMC conditions we encountered severe turbulence. The turbulence upset everything in the cockpit and caused our garmin 430 GPS navigation/communication (which was our primary navigation and communication equipment) to become dislodged from the panel plugs and its power source. During the confusing moments of diagnosing the garmin failure the s-tec 55X autoplt altitude hold function disengaged and the aircraft descended below the assigned altitude. When I realized the garmin was OTS I tuned the #2 navigation/communication kx 165 to the approach frequency to re-establish communications with mco approach control. The aircraft also overshot the localizer during the garmin disconnect. After landing at mco I determined that the garmin 430 disconnected due to the installation screw in the panel being loose. The problem was remedied by tightening the screw with adequate torque. There were no other aircraft affected; no damage to our aircraft or personal injury; however; the experience prompts the following recommendations. Safety recommendation: pilots should check the security of all radio equipment after it has been removed and replaced into the racks by maintenance to ensure security and continued continuity of sensitive connections. On all aircraft equipped with a single approach database the pilot should also have current printed approach plates open and available in the event the single electronic database is lost as in the above described event. We were equipped with approach plates however we did lose the runway 18R page during the encounter with turbulence.

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Original NASA ASRS Text

Title: C310 FLT CREW EXPERIENCES COURSE AND ALT DEVS WHEN GPS NAV AND COM IS DISLODGED FROM THE PANEL CONNECTION DUE TO SEVERE TURB.

Narrative: WHILE BEING VECTORED TO THE FINAL APCH (ILS RWY 18R) AT MCO IN IMC CONDITIONS WE ENCOUNTERED SEVERE TURB. THE TURB UPSET EVERYTHING IN THE COCKPIT AND CAUSED OUR GARMIN 430 GPS NAV/COM (WHICH WAS OUR PRIMARY NAV AND COM EQUIP) TO BECOME DISLODGED FROM THE PANEL PLUGS AND ITS PWR SOURCE. DURING THE CONFUSING MOMENTS OF DIAGNOSING THE GARMIN FAILURE THE S-TEC 55X AUTOPLT ALT HOLD FUNCTION DISENGAGED AND THE ACFT DSNDED BELOW THE ASSIGNED ALT. WHEN I REALIZED THE GARMIN WAS OTS I TUNED THE #2 NAV/COM KX 165 TO THE APCH FREQ TO RE-ESTABLISH COMS WITH MCO APCH CTL. THE ACFT ALSO OVERSHOT THE LOC DURING THE GARMIN DISCONNECT. AFTER LNDG AT MCO I DETERMINED THAT THE GARMIN 430 DISCONNECTED DUE TO THE INSTALLATION SCREW IN THE PANEL BEING LOOSE. THE PROB WAS REMEDIED BY TIGHTENING THE SCREW WITH ADEQUATE TORQUE. THERE WERE NO OTHER ACFT AFFECTED; NO DAMAGE TO OUR ACFT OR PERSONAL INJURY; HOWEVER; THE EXPERIENCE PROMPTS THE FOLLOWING RECOMMENDATIONS. SAFETY RECOMMENDATION: PLTS SHOULD CHK THE SECURITY OF ALL RADIO EQUIP AFTER IT HAS BEEN REMOVED AND REPLACED INTO THE RACKS BY MAINT TO ENSURE SECURITY AND CONTINUED CONTINUITY OF SENSITIVE CONNECTIONS. ON ALL ACFT EQUIPPED WITH A SINGLE APCH DATABASE THE PLT SHOULD ALSO HAVE CURRENT PRINTED APCH PLATES OPEN AND AVAILABLE IN THE EVENT THE SINGLE ELECTRONIC DATABASE IS LOST AS IN THE ABOVE DESCRIBED EVENT. WE WERE EQUIPPED WITH APCH PLATES HOWEVER WE DID LOSE THE RWY 18R PAGE DURING THE ENCOUNTER WITH TURB.

Data retrieved from NASA's ASRS site as of January 2009 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.