Narrative:

I was turned onto approach at fnl and cleared for approach with traffic at 12 O'clock which turned out to be a high wing small aircraft executing the ILS west/O any radio contact. Just as I was turned onto final I was configuring aircraft for approach, gear and flaps and had hand on gear handle. I apparently failed to drop gear or it malfunctioned. I concentrated on seeing and avoiding traffic which required evasive action deviating up and to the right of ILS and failed to note lack of 3 green. Meanwhile ATC further distracted me with instructions as to how to cancel IFR. I landed gear up and no gear warning was heard (misrigged?). I had descended from 10000' cruise and wonder if I may have been mildly hypoxic on approach at 7000 down to 5000'. I was told but an uncertain of the accuracy that at a high altitude airport (e.g., fnl at greater than 5000' MSL) the gear warning which is synced to mp will not function as normal. I am having rigging of gear warning checked out. There is apparently no interlink between full flaps and gear warning which should be required so that gear horn will sound any time full flaps are deployed west/O gear extended regardless of mp. I was distracted by traffic on the ILS not in radio communication with unknown intentions. I don't know what the solution for that may be.

Related reports:

Google
 

Original NASA ASRS Text

Title: SMT PLT HAS GEAR UP LNDG ON ILS APCH.

Narrative: I WAS TURNED ONTO APCH AT FNL AND CLRED FOR APCH WITH TFC AT 12 O'CLOCK WHICH TURNED OUT TO BE A HIGH WING SMA EXECUTING THE ILS W/O ANY RADIO CONTACT. JUST AS I WAS TURNED ONTO FINAL I WAS CONFIGURING ACFT FOR APCH, GEAR AND FLAPS AND HAD HAND ON GEAR HANDLE. I APPARENTLY FAILED TO DROP GEAR OR IT MALFUNCTIONED. I CONCENTRATED ON SEEING AND AVOIDING TFC WHICH REQUIRED EVASIVE ACTION DEVIATING UP AND TO THE RIGHT OF ILS AND FAILED TO NOTE LACK OF 3 GREEN. MEANWHILE ATC FURTHER DISTRACTED ME WITH INSTRUCTIONS AS TO HOW TO CANCEL IFR. I LANDED GEAR UP AND NO GEAR WARNING WAS HEARD (MISRIGGED?). I HAD DSNDED FROM 10000' CRUISE AND WONDER IF I MAY HAVE BEEN MILDLY HYPOXIC ON APCH AT 7000 DOWN TO 5000'. I WAS TOLD BUT AN UNCERTAIN OF THE ACCURACY THAT AT A HIGH ALT ARPT (E.G., FNL AT GREATER THAN 5000' MSL) THE GEAR WARNING WHICH IS SYNCED TO MP WILL NOT FUNCTION AS NORMAL. I AM HAVING RIGGING OF GEAR WARNING CHKED OUT. THERE IS APPARENTLY NO INTERLINK BTWN FULL FLAPS AND GEAR WARNING WHICH SHOULD BE REQUIRED SO THAT GEAR HORN WILL SOUND ANY TIME FULL FLAPS ARE DEPLOYED W/O GEAR EXTENDED REGARDLESS OF MP. I WAS DISTRACTED BY TFC ON THE ILS NOT IN RADIO COM WITH UNKNOWN INTENTIONS. I DON'T KNOW WHAT THE SOLUTION FOR THAT MAY BE.

Data retrieved from NASA's ASRS site as of August 2007 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.