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GA small aircraft altitude deviation excursion from clearance altitude as pilot contemplates an intermittent loss of navigation radio.
| Attributes | |
| ACN | 126409 |
| Time | |
| Date | 198910 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : bfi |
| State Reference | WA |
| Altitude | msl bound lower : 1900 msl bound upper : 2200 |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : sea |
| Operator | general aviation : personal |
| Make Model Name | Small Aircraft, High Wing, 1 Eng, Fixed Gear |
| Flight Phase | cruise other |
| Route In Use | enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : single pilot |
| Qualification | pilot : instrument pilot : private |
| Experience | flight time last 90 days : 15 flight time total : 251 flight time type : 8 |
| ASRS Report | 126409 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Qualification | controller : radar |
| Events | |
| Anomaly | aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance |
| Independent Detector | other controllera |
| Resolutory Action | flight crew : returned to intended course or assigned course none taken : anomaly accepted other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
While on an IFR flight from paine field (pae) to boeing field, washington (bfi), I inadvertently dropped 200' below my assigned altitude of 2200'. I and a colleague had been on a multi-segment IFR practice flight. I had assumed the left seat (PIC) in bellingham (bli) and flown to pae through building clouds. About 10 mi north of ritz the IAF for pae, seattle center began vectoring to intercept the ILS 16 approach. For unclear reasons, all navigation (2 vors and ADF) quit functioning. After proceeding on assigned course another 3 mins (seemed forever) the #2 VOR, then ADF, then #1 VOR returned to functioning. Even though I then intercepted the localizer and completed the ILS to a touch-and-go, the experience disarmed me. I then transitioned to an ADF approach to arlington during which I regained some confidence. On missed approach at arlington, I was vectored first toward the ILS then north for spacing. This course took me back into the area where my navs had failed. The same sequence occurred. All navs inoperative but with recovery near the IAF. Again I recovered my shock and shot the ILS to a touch-and-go. I then proceeded on the next segment with radar vectors to bfi. When being vectored toward nolla (the IAF) I fixated on the navs and checking their operation. My copilot and I noticed I was under assigned altitude at the same moment and I initiated a climb. Seattle approach contacted me at that time indicating I was 300' low. The remainder of the intercept and ILS approach went well. I checked vors and vot at bfi on landing and rechecked ADF. All worked normally. My only explanation for navigation failure was meteorologic electrical condition. My failure to maintain altitude occurred because I had not put these mishaps behind me which caused me to fixate rather than maintain scan. I learned from the experience. Have reviewed lost navigation procedures. Have reviewed my scan procedures and am continuing flying in WX with colleagues and instructor to build IFR capabilities.
Original NASA ASRS Text
Title: GA SMA ALT DEVIATION EXCURSION FROM CLRNC ALT AS PLT CONTEMPLATES AN INTERMITTENT LOSS OF NAVIGATION RADIO.
Narrative: WHILE ON AN IFR FLT FROM PAINE FIELD (PAE) TO BOEING FIELD, WASHINGTON (BFI), I INADVERTENTLY DROPPED 200' BELOW MY ASSIGNED ALT OF 2200'. I AND A COLLEAGUE HAD BEEN ON A MULTI-SEGMENT IFR PRACTICE FLT. I HAD ASSUMED THE LEFT SEAT (PIC) IN BELLINGHAM (BLI) AND FLOWN TO PAE THROUGH BUILDING CLOUDS. ABOUT 10 MI N OF RITZ THE IAF FOR PAE, SEATTLE CENTER BEGAN VECTORING TO INTERCEPT THE ILS 16 APCH. FOR UNCLEAR REASONS, ALL NAV (2 VORS AND ADF) QUIT FUNCTIONING. AFTER PROCEEDING ON ASSIGNED COURSE ANOTHER 3 MINS (SEEMED FOREVER) THE #2 VOR, THEN ADF, THEN #1 VOR RETURNED TO FUNCTIONING. EVEN THOUGH I THEN INTERCEPTED THE LOC AND COMPLETED THE ILS TO A TOUCH-AND-GO, THE EXPERIENCE DISARMED ME. I THEN TRANSITIONED TO AN ADF APCH TO ARLINGTON DURING WHICH I REGAINED SOME CONFIDENCE. ON MISSED APCH AT ARLINGTON, I WAS VECTORED FIRST TOWARD THE ILS THEN N FOR SPACING. THIS COURSE TOOK ME BACK INTO THE AREA WHERE MY NAVS HAD FAILED. THE SAME SEQUENCE OCCURRED. ALL NAVS INOPERATIVE BUT WITH RECOVERY NEAR THE IAF. AGAIN I RECOVERED MY SHOCK AND SHOT THE ILS TO A TOUCH-AND-GO. I THEN PROCEEDED ON THE NEXT SEGMENT WITH RADAR VECTORS TO BFI. WHEN BEING VECTORED TOWARD NOLLA (THE IAF) I FIXATED ON THE NAVS AND CHECKING THEIR OPERATION. MY COPLT AND I NOTICED I WAS UNDER ASSIGNED ALT AT THE SAME MOMENT AND I INITIATED A CLIMB. SEATTLE APCH CONTACTED ME AT THAT TIME INDICATING I WAS 300' LOW. THE REMAINDER OF THE INTERCEPT AND ILS APCH WENT WELL. I CHECKED VORS AND VOT AT BFI ON LNDG AND RECHECKED ADF. ALL WORKED NORMALLY. MY ONLY EXPLANATION FOR NAV FAILURE WAS METEOROLOGIC ELECTRICAL CONDITION. MY FAILURE TO MAINTAIN ALT OCCURRED BECAUSE I HAD NOT PUT THESE MISHAPS BEHIND ME WHICH CAUSED ME TO FIXATE RATHER THAN MAINTAIN SCAN. I LEARNED FROM THE EXPERIENCE. HAVE REVIEWED LOST NAV PROCS. HAVE REVIEWED MY SCAN PROCS AND AM CONTINUING FLYING IN WX WITH COLLEAGUES AND INSTRUCTOR TO BUILD IFR CAPABILITIES.
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.