On March 11, 2005, at 1720 Pacific standard time, a Mitsubishi MU-2B-26A, N333WF, landed with the landing gear retracted at the Blythe Airport, Blythe, California. Jaax Flying Service, Inc., was operating the privately registered airplane under the provisions of 14 CFR Part 135 as an on-demand air taxi flight. The airline transport pilot and three passengers were not injured; the airplane sustained substantial damage. Visual meteorological conditions prevailed, and a company flight plan had been filed and activated. The pilot departed Banning Municipal Airport, Banning, California, about 1645. In the pilot's written statement, he stated that during his approach into Blythe, the flaps were extended to 20 degrees but would not lock into position. The pilot decided to perform a no flap landing and referred to the emergency checklist. The checklist advised the pilot to extend the landing gear; however, the pilot skimmed over the information thinking that the gear was already down and locked, and focused on the stabilized approach into the airport. The airplane touched down with the gear in the retracted position. According to the operator, the purpose of the first portion of the flight from Blythe to Banning was to transport a prisoner. On the return leg with one correctional officer and two nurses onboard, the pilot forgot to lower the landing gear prior to landing on runway 8. The damage to the airplane included internal rib damage near the belly of the airplane. No mechanical problems with the landing gear system were noted, and a ground test run of the flaps did not reproduce the flap locking failure encountered in flight.