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Flight crew of a beech 400 experienced erratic altimeter readings of all 3 altimeters during climb to cruise. After leveloff, ARTCC radar controller intervened and advised them that they were shown at 600 ft above altitude. Subsequently, during a visual approach, the same disagreement showed up, so they had maintenance check the system and found blockage in the primary static system.
| Attributes | |
| ACN | 420438 |
| Time | |
| Date | 199811 |
| Day | Tue |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : sdl |
| State Reference | AZ |
| Altitude | msl bound lower : 33000 msl bound upper : 33600 |
| Environment | |
| Flight Conditions | Mixed |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zab |
| Operator | general aviation : personal |
| Make Model Name | Light Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Route In Use | departure other departure sid : sid enroute airway : zab |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Experience | flight time last 90 days : 50 flight time total : 2100 flight time type : 205 |
| ASRS Report | 420438 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : cfi pilot : atp |
| Experience | flight time last 90 days : 60 flight time total : 9000 flight time type : 240 |
| ASRS Report | 420356 |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa |
| Resolutory Action | flight crew : returned to intended course or assigned course other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Climbing out of scottsdale, airplane missed assigned altitude by 300 ft. PF corrected. I was surprised because I thought the autoplt was on. I expected the airplane to have leveled at the altitude I had set in the alerter. The PF pointed at the standby altimeter during climb and said it had jumped a couple of times. After a couple of leveloffs, we got to FL330 with a split between 3 altimeters. Suddenly the electronic altimeter showed us at FL336. The PF corrected. On approach to tex, in visual conditions, all 3 altimeters disagreed when there was time to read them in the turbulence. After a miss and cancellation, we went VFR to santa flight engineer. There, maintenance found same solid matter in the PF's side static system. The pilot's side static system in this airplane feeds the primary altimeter, the standby altimeter, and the air data computer and the encoder. This we traced out of diagrams later on the ground.
Original NASA ASRS Text
Title: FLC OF A BEECH 400 EXPERIENCED ERRATIC ALTIMETER READINGS OF ALL 3 ALTIMETERS DURING CLB TO CRUISE. AFTER LEVELOFF, ARTCC RADAR CTLR INTERVENED AND ADVISED THEM THAT THEY WERE SHOWN AT 600 FT ABOVE ALT. SUBSEQUENTLY, DURING A VISUAL APCH, THE SAME DISAGREEMENT SHOWED UP, SO THEY HAD MAINT CHK THE SYS AND FOUND BLOCKAGE IN THE PRIMARY STATIC SYS.
Narrative: CLBING OUT OF SCOTTSDALE, AIRPLANE MISSED ASSIGNED ALT BY 300 FT. PF CORRECTED. I WAS SURPRISED BECAUSE I THOUGHT THE AUTOPLT WAS ON. I EXPECTED THE AIRPLANE TO HAVE LEVELED AT THE ALT I HAD SET IN THE ALERTER. THE PF POINTED AT THE STANDBY ALTIMETER DURING CLB AND SAID IT HAD JUMPED A COUPLE OF TIMES. AFTER A COUPLE OF LEVELOFFS, WE GOT TO FL330 WITH A SPLIT BTWN 3 ALTIMETERS. SUDDENLY THE ELECTRONIC ALTIMETER SHOWED US AT FL336. THE PF CORRECTED. ON APCH TO TEX, IN VISUAL CONDITIONS, ALL 3 ALTIMETERS DISAGREED WHEN THERE WAS TIME TO READ THEM IN THE TURB. AFTER A MISS AND CANCELLATION, WE WENT VFR TO SANTA FE. THERE, MAINT FOUND SAME SOLID MATTER IN THE PF'S SIDE STATIC SYS. THE PLT'S SIDE STATIC SYS IN THIS AIRPLANE FEEDS THE PRIMARY ALTIMETER, THE STANDBY ALTIMETER, AND THE ADC AND THE ENCODER. THIS WE TRACED OUT OF DIAGRAMS LATER ON THE GND.
Data retrieved from NASA's ASRS site as of July 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.