Beechcraft Twin Piston Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 169; Flight Crew Total 1683; Flight Crew Type 151
Situational Awareness; Distraction; Time Pressure
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Gear Up Landing
Human Factors
[In] my preflight noticed that both engines needed a quart of oil. Filled both back to the proper indication. Closed both engines then continued with my preflight. Found nothing else that needed attention. I took my first load. I noticed a slightly low oil pressure on that flight and called another King Air pilot that trained me to ask about it. As I got out of the plane the owner and I noticed that oil was all over the left wing. Opened it up and I did not properly secure the oil stick/cap. A small amount of oil was still visible on the stick. I called the A and P and we were advised to put oil back in the engine; clean it up out of the bay and try a run up. The start went normally; oil pressure was back. I taxied down to the end of XX did another run up. Everything was in the normal range. Did a normal takeoff left hand pattern while watching the left engine. Proceeded to a normal approach rounded out; pulled power back then heard the gear unsafe warning. A split second later heard tick of a prop hitting the ground. My initial reaction was to push the power forward and take off but reason took over and I pulled power all the way back and bellied the plane in. Then I secured the plane and got out.I did several things wrong that day most importantly I did not follow the checklist and I did not do a GUMPS (Gas; Undercarriage; Mixture; Prop; Switches) check. I also had been driving 4 hours prior to the event. I am devastated. I should have followed the checklist.
Pilot reported a gear up landing.