Date: 201812
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: Airliner 99
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Training
Flight phase: Landing
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Indicating and Warning - Landing Gear
Component problem: Improperly Operated
Reporter organization: Air Taxi
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Training / Qualification; Situational Awareness; Distraction
Second reporter function: Pilot Flying; Trainee
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown; Ground Event / Encounter Gear Up Landing
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; General Maintenance Action
Contributing factors: Procedure; Human Factors; Chart Or Publication
Primary problem: Chart Or Publication

Narrative: I was PIC supervising a Trainee on an FAR 135 Cargo only flight. Trainee was manipulating the controls. Nearing our destination airport (about 10 to 15 miles out) my Trainee reported the airport in-sight to approach control anticipating being cleared for a visual approach via the right downwind for runway XX. When the visual approach clearance did not come; I suggested we cancel our IFR flight plan and start our descent because we were still at cruise altitude and needed to descend over 6000 feet to enter the pattern. Approach control acknowledged our IFR cancellation and instructed us to enter the right downwind for runway XX and contact the tower. Trainee contacted the tower; reported we were VFR entering the right downwind for runway XX; but also asked if runway XY was available. The tower responded with 'Cleared to land Runway XY'. This compounded the altitude we needed to descend so I suggested a no flap approach and landing (A training event we were going to complete later in the day). Trainee reduced power and increased propeller R.P.M. to full. This increased drag to aid in our descent but also increases ambient noise in the cockpit which produces air noise through our voice activated intercom. Another power reduction was made and we eventually captured the glideslope for the ILS approach for runway XY. I estimate we were stabilized on the glideslope at our target airspeed for the remaining 5 miles to the airport. I watched my trainee pickup and read the ZERO FLAP LANDING checklist and stow it. Unfortunately neither of us utilized the BEFORE LANDING checklist and we landed with the gear in the retracted position. I learned later that a gear warning horn that would have alerted us that the gear was not in the down position was silenced by my trainee when it sounded after the first or second power reduction. A normal procedure for a normal approach and landing but not for a zero flap landing. Touchdown Inattentive supervision disbelief I need more time to think about that. 1. I should have turned off the cabin heat to increase my alertness. 2. I should have refused the Rwy XY landing clearance and continued onto the downwind for Rwy XX 3. I should have turned down the squelch on the intercom to resume normal communications with my trainee. 4. Sunglasses may have helped instead of using my hand to block the rising sun that was in the direction of my trainee.


Second narrative: We were approaching ZZZ at 5;000 feet with Approach in a BE-99 C model. Because we were approaching the airport environment at a relatively high altitude; I asked the Captain if he thought I should cancel the IFR clearance or stay with approach. After briefly discussing it; I elected to cancel the IFR and descend. We were instructed to enter a right downwind for runway XX and I immediately asked if runway XY was available. We were cleared to land runway XY. I reduced power initially to approximately 400 torque; and then to flight idle; and was descending at approximately 1;500 - 2000 fpm at 180 - 185 kts while maneuvering to the right to intercept the ILS runway XY. When I reduced power for the descent the gear warning horn sounded and I silenced it by pressing the Gear Warn Silence button. As we were approaching the ILS I began reducing the airspeed and descent rate with pitch and then applied power to become established on the glideslope. We were conducting a no flap landing so I transitioned to the props full forward and airspeed at blue line (115 kts) configuration. I completed the Zero Flap Landing abnormal procedures checklist and continued the VFR approach to landing; backed up with the ILS. We touched down on runway XY centerline without the landing gear down at approximately 2;500 feet from the threshold and slid on the cargo pod in a slightly curved path to the right coming to rest approximately halfway between the runway centerline and the edge of the runway; adjacent to taxiway X. We moved the condition levers to cutoff; and then accessed each other's physical condition. The Captain communicated with ATC; while I referenced the emergency procedures checklist to secure the aircraft. There were no injuries.   Normally; when I'm using the abnormal procedures checklist on final approach it's because I'm doing a single engine approach and landing. Right after I completed the Zero Flap Landing checklist my mindset was that I wasn't single engine; so I'm done with the checklist. Done with the abnormal procedures checklist on final normally means that I'm configured to land. I focused on aircraft control and missed the 1;000 foot above touchdown call out. Secure the engines to prevent injury or further damage. As the Captain recommended; changing the Zero Flap Landing checklist to include the landing gear; and a note about the gear warn silence button; may be beneficial.


Synopsis: BE99 flight crew reported a gear up landing while training; as a result of inattentive supervision and an incomplete abnormal procedures checklist.