SDR CA980513014

Service difficulty report · Encoder · Dhav DHC6300

Difficulty date: April 22, 1998
Submitted: March 26, 2000
Operation: Air carrier
Make and model: Dhav DHC6300
Engine: Pwa PT6A27
System (JASC): 3416 · Altimeter, Barometric/Encoder
Part: Encoder
Part number: 10220011821
Condition: Malfunctioned
Location: Cockpit
Component: Aerosonic
Stage of operation: NR
Nature of condition: O
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) MODE 'C' INFORMATION BEING GIVEN TO ATC GIVES INCORRECT ALTITUDES. PILOT TOOK SOME READINGS. ALTIMETER INDICATOR AT 4,500, WHILE MODE C' AT 4,400, AND SO ON UP TOTAL. INDICATION AT 10,500 WHILE MODE 'C' AT 9,300. DURING DESCENT, MODE 'C' WAS SHOWING A CLIMB. COPILOT'S ALTIMETER WITHIN 50 FEET OF THE ENCODING ALTIMETER READING.