A C172 instructor reported a gear up landing.

Attributes
ACN	890972
Time
Date	201005
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	None
Flight Plan	None
Component
Aircraft Component	Landing Gear
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 7630 Flight Crew Type 30
Events
Anomaly	Ground Event / Encounter Gear Up Landing

Narrative:

Pilot failed to extend gear during an instructional/evaluation flight. Weather was VFR with only a slight (less than 5 KTS) crosswind component. The approach was a normal approach to a slip landing. The approach was intentionally started a little high to demonstrate the slip. Task fixation on the slip prevented both pilots from hearing the gear warning horn (the horn was previously written up for not going out when the gear was up and locked; which may have contributed to a more laxed approach to the situation; although given that this was an evaluation flight; it is more likely that the student was concentrating on accomplishing the slip thereby preventing him from hearing the horn).

Original NASA ASRS Text

Title: A C172 Instructor reported a gear up landing.

Narrative: Pilot failed to extend gear during an instructional/evaluation flight. Weather was VFR with only a slight (less than 5 KTS) crosswind component. The approach was a normal approach to a slip landing. The approach was intentionally started a little high to demonstrate the slip. Task fixation on the slip prevented both pilots from hearing the gear warning horn (the horn was previously written up for not going out when the gear was up and locked; which may have contributed to a more laxed approach to the situation; although given that this was an evaluation flight; it is more likely that the student was concentrating on accomplishing the slip thereby preventing him from hearing the horn).

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.