What was found
LEFT CSD TEMP INCREASED TOWARDS RED MARK. LEFT CSD PRESS LOW LIGHT AND MASTER CAUTION LIGHT ILLUMINATED. APU FAILED TO START CAUSING AIR TURN-BACK.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
LEFT CSD TEMP INCREASED TOWARDS RED MARK. LEFT CSD PRESS LOW LIGHT AND MASTER CAUTION LIGHT ILLUMINATED. APU FAILED TO START CAUSING AIR TURN-BACK.