Narrative:

During straight-in landing approach, tower advised of floatplane traffic on base leg for the float pond which is parallel to the runway. I began looking for this traffic, which would be crossing my final approach path. After extending approach flaps, I became concerned that I did not have the crossing traffic in sight. The tower was fairly busy, and I did not ask for an update on the crossing traffic's position. Eventually, I saw the floatplane on final approach to the floatpond and preferred to land. At about 100 ft AGL, another aircraft radioed, 'check gear' and I then noticed that I had failed to extend the landing gear. A go around was commenced, and I returned for a normal landing. 1) the 'before landing' checklist was in front of me on the glare shield, but I did not complete the checklist due to the distraction of crossing traffic. 2) I am in the habit of making a 'pre-flare' check of the landing gear position lights. Because I was warned by the radio call from the other aircraft, I don't know if I would have caught the error before landing with this check. 3) it is common knowledge that the landing gear warning system on the PA31 is ineffective in preventing gear up landing accidents. The warning horn is activated only by closing the throttles to near idle. This doesn't normally happen until well into the landing flare or sometimes after the wheels touch (power on landing). 4) have flown other PA31's that were equipped with an after-market voice annunciator that gives a voice warning if the flaps are extended beyond the approach setting without the landing gear extended. 5) I reviewed several NTSB accident reports involving gear up lndgs in PA31's. There were several cases where the pilot was distraction, failed to complete the before landing check, and the landing gear warning horn failed to sound. 6) the PA31 is normally flown single-pilot in commuter service, using an autoplt in lieu of an sic. Conclusion: in spite of several yr's experience, good training, and considerable time in type, I nearly had an accident due to distraction. In the single-pilot environment, there is no backup 'line of defense' (sic) to catch errors. The pilot is on his or her own. This, combined with the PA31's inadequate landing gear warning system, has resulted in a number of gear up lndgs. The incident described here could have been avoided if there had been an sic (generally considered to be unfeasible in the industry), or if the airplane had been equipped with the after-market voice warning system described earlier.

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Original NASA ASRS Text

Title: A PA31 GEAR UP LNDG IS PREVENTED BY A TIMELY CALL ON THE RADIO FROM AN OUTSIDE OBSERVER AS THE ACFT DSNDED THROUGH 100 FT.

Narrative: DURING STRAIGHT-IN LNDG APCH, TWR ADVISED OF FLOATPLANE TFC ON BASE LEG FOR THE FLOAT POND WHICH IS PARALLEL TO THE RWY. I BEGAN LOOKING FOR THIS TFC, WHICH WOULD BE XING MY FINAL APCH PATH. AFTER EXTENDING APCH FLAPS, I BECAME CONCERNED THAT I DID NOT HAVE THE XING TFC IN SIGHT. THE TWR WAS FAIRLY BUSY, AND I DID NOT ASK FOR AN UPDATE ON THE XING TFC'S POS. EVENTUALLY, I SAW THE FLOATPLANE ON FINAL APCH TO THE FLOATPOND AND PREFERRED TO LAND. AT ABOUT 100 FT AGL, ANOTHER ACFT RADIOED, 'CHK GEAR' AND I THEN NOTICED THAT I HAD FAILED TO EXTEND THE LNDG GEAR. A GAR WAS COMMENCED, AND I RETURNED FOR A NORMAL LNDG. 1) THE 'BEFORE LNDG' CHKLIST WAS IN FRONT OF ME ON THE GLARE SHIELD, BUT I DID NOT COMPLETE THE CHKLIST DUE TO THE DISTR OF XING TFC. 2) I AM IN THE HABIT OF MAKING A 'PRE-FLARE' CHK OF THE LNDG GEAR POS LIGHTS. BECAUSE I WAS WARNED BY THE RADIO CALL FROM THE OTHER ACFT, I DON'T KNOW IF I WOULD HAVE CAUGHT THE ERROR BEFORE LNDG WITH THIS CHK. 3) IT IS COMMON KNOWLEDGE THAT THE LNDG GEAR WARNING SYS ON THE PA31 IS INEFFECTIVE IN PREVENTING GEAR UP LNDG ACCIDENTS. THE WARNING HORN IS ACTIVATED ONLY BY CLOSING THE THROTTLES TO NEAR IDLE. THIS DOESN'T NORMALLY HAPPEN UNTIL WELL INTO THE LNDG FLARE OR SOMETIMES AFTER THE WHEELS TOUCH (PWR ON LNDG). 4) HAVE FLOWN OTHER PA31'S THAT WERE EQUIPPED WITH AN AFTER-MARKET VOICE ANNUNCIATOR THAT GIVES A VOICE WARNING IF THE FLAPS ARE EXTENDED BEYOND THE APCH SETTING WITHOUT THE LNDG GEAR EXTENDED. 5) I REVIEWED SEVERAL NTSB ACCIDENT RPTS INVOLVING GEAR UP LNDGS IN PA31'S. THERE WERE SEVERAL CASES WHERE THE PLT WAS DISTR, FAILED TO COMPLETE THE BEFORE LNDG CHK, AND THE LNDG GEAR WARNING HORN FAILED TO SOUND. 6) THE PA31 IS NORMALLY FLOWN SINGLE-PLT IN COMMUTER SVC, USING AN AUTOPLT IN LIEU OF AN SIC. CONCLUSION: IN SPITE OF SEVERAL YR'S EXPERIENCE, GOOD TRAINING, AND CONSIDERABLE TIME IN TYPE, I NEARLY HAD AN ACCIDENT DUE TO DISTR. IN THE SINGLE-PLT ENVIRONMENT, THERE IS NO BACKUP 'LINE OF DEFENSE' (SIC) TO CATCH ERRORS. THE PLT IS ON HIS OR HER OWN. THIS, COMBINED WITH THE PA31'S INADEQUATE LNDG GEAR WARNING SYS, HAS RESULTED IN A NUMBER OF GEAR UP LNDGS. THE INCIDENT DESCRIBED HERE COULD HAVE BEEN AVOIDED IF THERE HAD BEEN AN SIC (GENERALLY CONSIDERED TO BE UNFEASIBLE IN THE INDUSTRY), OR IF THE AIRPLANE HAD BEEN EQUIPPED WITH THE AFTER-MARKET VOICE WARNING SYS DESCRIBED EARLIER.

Data retrieved from NASA's ASRS site as of July 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.