 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A cessna citation lost the air data input for a few mins during turbulence and lightning causing the loss of captain's airspeed and altimeter. First officer's altimeter being used during this time had an error of 200-400 ft.
| Attributes | |
| ACN | 374979 |
| Time | |
| Date | 199707 |
| Day | Tue |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : elp |
| State Reference | TX |
| Altitude | msl bound lower : 43000 msl bound upper : 43000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tower : mem |
| Operator | general aviation : corporate |
| Make Model Name | Citation III, VI, VII |
| Operating Under FAR Part | Part 91 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Route In Use | enroute airway : zab |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 120 flight time total : 9300 flight time type : 800 |
| ASRS Report | 374979 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other |
| Independent Detector | other flight crewa other other : unspecified cockpit |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | Other |
| Supplementary | |
| Air Traffic Incident | Pilot Deviation |
Narrative:
On a flight from scottsdale, az, to austin, tx, about 60 mi east of el paso, tx, we encountered some WX at FL430. We were above the tops, but the clouds got higher than we were and encountered severe turbulence and lightning below, which made our air data computer to go off for a few mins, which made our pilot's altitude and airspeed to red flag. When the air data computer came back up, the pilot altimeter was off 400 ft low but the copilot's altimeter read FL430 -- but it's not calibrated and always reads 200-400 ft high at altitude, which makes it difficult to hold altitude. With the right altitude, when you don't know whether it was 200-400 ft off when you have a problem like this. It makes it difficult to be precise with holding your altitude in severe turbulence. I don't know how cessna got the plane certified with this big altimeter deviation.
Original NASA ASRS Text
Title: A CESSNA CITATION LOST THE AIR DATA INPUT FOR A FEW MINS DURING TURB AND LIGHTNING CAUSING THE LOSS OF CAPT'S AIRSPD AND ALTIMETER. FO'S ALTIMETER BEING USED DURING THIS TIME HAD AN ERROR OF 200-400 FT.
Narrative: ON A FLT FROM SCOTTSDALE, AZ, TO AUSTIN, TX, ABOUT 60 MI E OF EL PASO, TX, WE ENCOUNTERED SOME WX AT FL430. WE WERE ABOVE THE TOPS, BUT THE CLOUDS GOT HIGHER THAN WE WERE AND ENCOUNTERED SEVERE TURB AND LIGHTNING BELOW, WHICH MADE OUR AIR DATA COMPUTER TO GO OFF FOR A FEW MINS, WHICH MADE OUR PLT'S ALT AND AIRSPD TO RED FLAG. WHEN THE AIR DATA COMPUTER CAME BACK UP, THE PLT ALTIMETER WAS OFF 400 FT LOW BUT THE COPLT'S ALTIMETER READ FL430 -- BUT IT'S NOT CALIBRATED AND ALWAYS READS 200-400 FT HIGH AT ALT, WHICH MAKES IT DIFFICULT TO HOLD ALT. WITH THE RIGHT ALT, WHEN YOU DON'T KNOW WHETHER IT WAS 200-400 FT OFF WHEN YOU HAVE A PROB LIKE THIS. IT MAKES IT DIFFICULT TO BE PRECISE WITH HOLDING YOUR ALT IN SEVERE TURB. I DON'T KNOW HOW CESSNA GOT THE PLANE CERTIFIED WITH THIS BIG ALTIMETER DEV.
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.