WestJet Boeing 737 – Flap Failure

C-GWSZ, a Boeing 737-800 aircraft operated by WestJet, was conducting flight WJA1701 from Los Angeles Intl, CA (KLAX) to Vancouver Intl, BC (CYVR). When the flight crew selected Flaps 30 during the approach sequence, the flaps did not move. A missed approach was initiated in order to complete the appropriate checklist and, once ready, the flight crew declared a PAN PAN. Runway 26L was requested for landing distance considerations, and an uneventful Flaps 15 landing was accomplished. Upon inspection, the operator’s maintenance found a fault with the left hand flap position transmitter. The unit was replaced and the aircraft was returned to service.