Narrative:

I was given a direct approach and cleared to land by the tower while still 7 miles to the east; likely not visible to the tower. No further communication from the tower was received until I inadvertently landed with the gear retracted. No gear up warning horn was sounded. Upon stopping on the runway; I immediately reported the situation to the tower. He immediately replied that the emergency equipment was on the way. The FBO responded with a crew to jack up and remove the aircraft from the runway. But before doing so; the maintenance director tested the landing gear and found that the warning horn was inoperative. Obviously it's the pilot's responsibility to insure gear extension. However; the situation could have been prevented if one or more contributing factors were not in play: 1) gear extension is usually performed just before entering the downwind pattern. As a matter of habit; the approach to downwind triggers the gear down response. A near straight in approach was given instead. 2) aircraft given to land while not yet in sight. Apparently no further observation of the aircraft was made until too late. This was at a low traffic time with few planes on frequency. Tower could have instructed to continue towards the airport and cleared after confirming gear down when in sight. 3) controllers at a nearby airport usually use the expression 'check wheels down; cleared to land' as the landing clearance. This requires only 1.5 additional seconds yet keeps flying safe and the runway clear. Additionally; it relieves the tower from visually checking (as in 2 above). 4) when the mechanic checked the gear; he pointed out that pressing the gear down light should cause the warning horn to sound. That's a good feature; but its use and meaning are not explained in cessna's pilot's operating handbook. It is not listed on any procedure checklist in the poh. 5) the cowl has yet to be opened to inspect the cause of the warning horn failure. Further mechanical corrective actions may yet be disclosed.

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Original NASA ASRS Text

Title: A C172RG pilot reported landing gear up after being cleared to land seven miles from the airport with no further communications after landing clearance. The landing gear warning horn was subsequently found to be inoperative.

Narrative: I was given a direct approach and cleared to land by the Tower while still 7 miles to the east; likely not visible to the Tower. No further communication from the Tower was received until I inadvertently landed with the gear retracted. No gear up warning horn was sounded. Upon stopping on the runway; I immediately reported the situation to the Tower. He immediately replied that the emergency equipment was on the way. The FBO responded with a crew to jack up and remove the aircraft from the runway. But before doing so; the Maintenance Director tested the landing gear and found that the warning horn was inoperative. Obviously it's the pilot's responsibility to insure gear extension. However; the situation could have been prevented if one or more contributing factors were not in play: 1) gear extension is usually performed just before entering the downwind pattern. As a matter of habit; the approach to downwind triggers the gear down response. A near straight in approach was given instead. 2) Aircraft given to land while not yet in sight. Apparently no further observation of the aircraft was made until too late. This was at a low traffic time with few planes on frequency. Tower could have instructed to continue towards the airport and cleared after confirming gear down when in sight. 3) Controllers at a nearby Airport usually use the expression 'check wheels down; cleared to land' as the landing clearance. This requires only 1.5 additional seconds yet keeps flying safe and the runway clear. Additionally; it relieves the Tower from visually checking (as in 2 above). 4) When the mechanic checked the gear; he pointed out that pressing the gear down light should cause the warning horn to sound. That's a good feature; but its use and meaning are not explained in Cessna's Pilot's Operating Handbook. It is not listed on any procedure checklist in the POH. 5) The cowl has yet to be opened to inspect the cause of the warning horn failure. Further mechanical corrective actions may yet be disclosed.

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.