As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - FLT 971 - EN ROUTE MIA-MGA AT 35,000 FEET, LEFT HYDRAULIC SYSTEM FAILED. EMERGENCY DECLARED. AIRCRAFT RETURNED AND LANDED AT MIA WITHOUT INCIDENT. TROUBLESHOT AND FOUND TO BE AN INDICATION FAULT. REPLACED PRESSURE SWITCH ON LEFT ENGINE DRIVEN PUMP. ALSO, REPLACED PRESSURE SWITCH ON POWER TURBINE UNIT AS A PRECAUTION. SYSTEM GRUOND CHECKED NORMAL OPERATION. (M)