As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKE OFF RADAR ALT ACTING ERRATIC, SETTING OFF TERRAIN GPWS WARNING. ABOVE 2500' RAD ALT CLEARED OFF OF PFD. RETURNED TO AEX. AIRCRAFT REMOVED FROM SERVICE. REF WO 348640 MWC #3&4. R&R RADIO ALTIMETER TRANSCEIVER. IAW AMM 34-44-07 & SUP 07-034H. OPS CHECK GOOD AT THIS TIME.