TACLOBAN CITY, Philippines -- Over a hundred Manila-bound passengers were stranded for hours Monday at the Daniel Z. Romualdez (DZR) Airport this city when a Philippine Air Lines (PAL) plane developed an electrical problem.

PAL Tacloban manager Glen Vallecera said Flight 914 could not leave at 7:45 a.m. as scheduled because the plane's auxiliary power unit (APU) shut off.

According to Aerospaceweb.org website (www.aerospaceweb.org), an APU, which is a miniature jet engine, provides additional power source and is always in operation to supplement the primary power supply or replace it in case of engine failure.

PAL maintenance personnel arrived from Manila at 11 a.m. Tacloban City to fix the problem. The stranded flight finally took off at 4:20 p.m. minus 31 of its 130 passengers, who opted to take the 11 a.m. flight.