Narrative:

Our caravan 208 collided with a cessna 172 on short final to an uncontrolled airport runway, at approximately 150 ft AGL. I was returning from a skydive drop from 13500 ft MSL, was in contact with approach control on our assigned discrete transponder code until I signed off from approach at about 3500 ft MSL. I joined the downwind, flew a base and final making broadcasts on position and intention at each leg. I had a visual on a piper pawnee glider tow plane entering the downwind from upwind and communicated with him my position and flight path. No other aircraft made radio calls on the frequency while I was monitoring during my approach. My GPS receives traffic display from our GPS datalink mode south transponder. While there were multiple targets in the vicinity, no targets appeared on the final approach path to runway 36 as I made my base, and base to final turns. Collision impact occurred at approximately 150 ft AGL on short final to runway 36. Wind was 20-25 KTS from 360 degrees. Both aircraft were able to land immediately after the collision with minor damage to both aircraft, no injuries. I feel that the other aircraft had established a wide traffic pattern to the airport, as he stated that he had called a 1 mi final radio call. Since I never heard this call, and he did not respond to my calls, either he was broadcasting on the wrong frequency or was distraction by his student, possibly giving instruction. This put him below my traffic information display and below my optical scan mixing in with terrain visually. I do not know why he did not observe a caravan on base and final, or why he did not respond to my radio calls. A witness, a glider school instructor ATP/CFI on the ground close to the landing runway said my downwind, approach, and final looked like a normal approach. He did not observe the cessna 172 below me until after the collision took place. I fly approximately 150 plus approachs to the airport monthly. I frequently see aircraft fly downwind and base legs to final over 2 1/2 to 3 mi away from the airport, which I consider unsafe for engine failure and visibility reasons. Most of these wide patterns are flown by flight school aircraft that come from nearby airport, which are larger with a class D control tower operation airspace. They are used to large wide traffic patterns to a much larger airport with tower assisted traffic separation.

Google
 

Original NASA ASRS Text

Title: C208 COLLIDES WITH A C172 ON FINAL TO ZZZ.

Narrative: OUR CARAVAN 208 COLLIDED WITH A CESSNA 172 ON SHORT FINAL TO AN UNCTLED ARPT RWY, AT APPROX 150 FT AGL. I WAS RETURNING FROM A SKYDIVE DROP FROM 13500 FT MSL, WAS IN CONTACT WITH APCH CTL ON OUR ASSIGNED DISCRETE XPONDER CODE UNTIL I SIGNED OFF FROM APCH AT ABOUT 3500 FT MSL. I JOINED THE DOWNWIND, FLEW A BASE AND FINAL MAKING BROADCASTS ON POS AND INTENTION AT EACH LEG. I HAD A VISUAL ON A PIPER PAWNEE GLIDER TOW PLANE ENTERING THE DOWNWIND FROM UPWIND AND COMMUNICATED WITH HIM MY POS AND FLT PATH. NO OTHER ACFT MADE RADIO CALLS ON THE FREQ WHILE I WAS MONITORING DURING MY APCH. MY GPS RECEIVES TFC DISPLAY FROM OUR GPS DATALINK MODE S XPONDER. WHILE THERE WERE MULTIPLE TARGETS IN THE VICINITY, NO TARGETS APPEARED ON THE FINAL APCH PATH TO RWY 36 AS I MADE MY BASE, AND BASE TO FINAL TURNS. COLLISION IMPACT OCCURRED AT APPROX 150 FT AGL ON SHORT FINAL TO RWY 36. WIND WAS 20-25 KTS FROM 360 DEGS. BOTH ACFT WERE ABLE TO LAND IMMEDIATELY AFTER THE COLLISION WITH MINOR DAMAGE TO BOTH ACFT, NO INJURIES. I FEEL THAT THE OTHER ACFT HAD ESTABLISHED A WIDE TFC PATTERN TO THE ARPT, AS HE STATED THAT HE HAD CALLED A 1 MI FINAL RADIO CALL. SINCE I NEVER HEARD THIS CALL, AND HE DID NOT RESPOND TO MY CALLS, EITHER HE WAS BROADCASTING ON THE WRONG FREQ OR WAS DISTR BY HIS STUDENT, POSSIBLY GIVING INSTRUCTION. THIS PUT HIM BELOW MY TFC INFO DISPLAY AND BELOW MY OPTICAL SCAN MIXING IN WITH TERRAIN VISUALLY. I DO NOT KNOW WHY HE DID NOT OBSERVE A CARAVAN ON BASE AND FINAL, OR WHY HE DID NOT RESPOND TO MY RADIO CALLS. A WITNESS, A GLIDER SCHOOL INSTRUCTOR ATP/CFI ON THE GND CLOSE TO THE LNDG RWY SAID MY DOWNWIND, APCH, AND FINAL LOOKED LIKE A NORMAL APCH. HE DID NOT OBSERVE THE CESSNA 172 BELOW ME UNTIL AFTER THE COLLISION TOOK PLACE. I FLY APPROX 150 PLUS APCHS TO THE ARPT MONTHLY. I FREQUENTLY SEE ACFT FLY DOWNWIND AND BASE LEGS TO FINAL OVER 2 1/2 TO 3 MI AWAY FROM THE ARPT, WHICH I CONSIDER UNSAFE FOR ENG FAILURE AND VISIBILITY REASONS. MOST OF THESE WIDE PATTERNS ARE FLOWN BY FLT SCHOOL ACFT THAT COME FROM NEARBY ARPT, WHICH ARE LARGER WITH A CLASS D CTL TWR OP AIRSPACE. THEY ARE USED TO LARGE WIDE TFC PATTERNS TO A MUCH LARGER ARPT WITH TWR ASSISTED TFC SEPARATION.

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.