|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||airport : orl|
|Altitude||msl bound lower : 1000|
msl bound upper : 2000
|Controlling Facilities||tracon : mco|
|Operator||general aviation : personal|
|Make Model Name||Small Aircraft, Low Wing, 1 Eng, Retractable Gear|
|Flight Phase||descent : approach|
|Route In Use||approach : straight in|
|Function||flight crew : single pilot|
|Qualification||pilot : instrument|
|Experience||flight time last 90 days : 20|
flight time total : 360
flight time type : 20
|Function||other personnel other|
|Qualification||pilot : private|
|Anomaly||altitude deviation : excursion from assigned altitude|
non adherence : published procedure
other anomaly other
other spatial deviation
|Independent Detector||other controllera|
|Resolutory Action||flight crew : returned to intended course or assigned course|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
Cleared for ILS 7 approach to orl, to maintain 2000' until G/south intercept. Received apparent G/south intercept and started to descend. Had needles crossed when controller called, said he had low altitude alert on me and asked to confirm that I was at 1000'. I confirmed 1000', he said I was to be at 2000'. I immediately commenced climb to approximately 1600'-1700' when actual G/south was intercepted. Copilot/safety pilot confirmed that I had the needles crossed descending prematurely to 1000'. Landing took place west/O incident. No conflict with terrain or obstacles. Continued descent west/O correction would have been serious but with safety pilot do not believe problem would have resulted. Problem caused by exclusive use of G/south indicator west/O considering DME or OM reading. Lesson learned not to rely on single indicator. Plane has single G/south receiver. I thought I was flying a perfect ILS approach and was unpleasantly surprised at low altitude alert. Very valuable lesson. Will have G/south checked/repaired.
Original NASA ASRS Text
Title: GA-SMA WITH FAULTY GLIDESLOPE INDICATION GETS LOW ALT ALERT FROM CONTROLLED FLT TOWARD TERRAIN.
Narrative: CLRED FOR ILS 7 APCH TO ORL, TO MAINTAIN 2000' UNTIL G/S INTERCEPT. RECEIVED APPARENT G/S INTERCEPT AND STARTED TO DSND. HAD NEEDLES CROSSED WHEN CTLR CALLED, SAID HE HAD LOW ALT ALERT ON ME AND ASKED TO CONFIRM THAT I WAS AT 1000'. I CONFIRMED 1000', HE SAID I WAS TO BE AT 2000'. I IMMEDIATELY COMMENCED CLB TO APPROX 1600'-1700' WHEN ACTUAL G/S WAS INTERCEPTED. COPLT/SAFETY PLT CONFIRMED THAT I HAD THE NEEDLES CROSSED DSNDING PREMATURELY TO 1000'. LNDG TOOK PLACE W/O INCIDENT. NO CONFLICT WITH TERRAIN OR OBSTACLES. CONTINUED DSCNT W/O CORRECTION WOULD HAVE BEEN SERIOUS BUT WITH SAFETY PLT DO NOT BELIEVE PROB WOULD HAVE RESULTED. PROB CAUSED BY EXCLUSIVE USE OF G/S INDICATOR W/O CONSIDERING DME OR OM READING. LESSON LEARNED NOT TO RELY ON SINGLE INDICATOR. PLANE HAS SINGLE G/S RECEIVER. I THOUGHT I WAS FLYING A PERFECT ILS APCH AND WAS UNPLEASANTLY SURPRISED AT LOW ALT ALERT. VERY VALUABLE LESSON. WILL HAVE G/S CHKED/REPAIRED.
Data retrieved from NASA's ASRS site as of August 2007 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.