Altitude deviation altitude excursion.

Attributes
ACN	234372
Time
Date	199302
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : abe
State Reference	PA
Altitude	msl bound lower : 14000 msl bound upper : 15700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	enroute airway : zny
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 60 flight time total : 17800 flight time type : 1700
ASRS Report	234372
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance non adherence : required legal separation other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : overcame equipment problem
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 700
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Aircraft was in level flight at 14000 ft in the clear. Aircraft started to lose airspeed. At that time traffic was pointed out to us at 15000 ft. As we looked at it we were above the aircraft, went to alternate air and altitude (altimeter readout), went to 15700 ft. After going by the pointed-out traffic, told ATC we had bad indication and would be getting back to 14000 ft. Encoder read 14000 ft normal static. When we went to alternate air, encoder readout was 15700 ft. After pilot complaints of erroneous airspeed and altitude indications, inspection of static system found a leaking connection at the pilot's airspeed indicator. Replaced defective fitting and a leak was also found on the copilot's altimeter barometric scale knob. Replaced copilot's altimeter with overhauled unit. Conducted static leak test. All tests ok.

Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION.

Narrative: ACFT WAS IN LEVEL FLT AT 14000 FT IN THE CLR. ACFT STARTED TO LOSE AIRSPD. AT THAT TIME TFC WAS POINTED OUT TO US AT 15000 FT. AS WE LOOKED AT IT WE WERE ABOVE THE ACFT, WENT TO ALTERNATE AIR AND ALT (ALTIMETER READOUT), WENT TO 15700 FT. AFTER GOING BY THE POINTED-OUT TFC, TOLD ATC WE HAD BAD INDICATION AND WOULD BE GETTING BACK TO 14000 FT. ENCODER READ 14000 FT NORMAL STATIC. WHEN WE WENT TO ALTERNATE AIR, ENCODER READOUT WAS 15700 FT. AFTER PLT COMPLAINTS OF ERRONEOUS AIRSPD AND ALT INDICATIONS, INSPECTION OF STATIC SYS FOUND A LEAKING CONNECTION AT THE PLT'S AIRSPD INDICATOR. REPLACED DEFECTIVE FITTING AND A LEAK WAS ALSO FOUND ON THE COPLT'S ALTIMETER BAROMETRIC SCALE KNOB. REPLACED COPLT'S ALTIMETER WITH OVERHAULED UNIT. CONDUCTED STATIC LEAK TEST. ALL TESTS OK.

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.