|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||airport : 1v5|
|Altitude||agl bound lower : 150|
agl bound upper : 1000
|Operator||general aviation : personal|
|Make Model Name||PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior|
|Operating Under FAR Part||Part 91|
|Flight Phase||descent : approach|
|Make Model Name||Cessna Single Piston Undifferentiated or Other Model|
|Operating Under FAR Part||Part 91|
|Flight Phase||landing other|
|Function||flight crew : single pilot|
|Qualification||pilot : private|
|Experience||flight time last 90 days : 30|
flight time total : 140
flight time type : 140
|Function||flight crew : single pilot|
|Qualification||pilot : student|
|Anomaly||conflict : nmac|
non adherence : far
other anomaly other
|Independent Detector||other other : unspecified|
|Resolutory Action||none taken : detected after the fact|
|Miss Distance||horizontal : 0|
vertical : 150
|Primary Problem||Flight Crew Human Performance|
I was piloting a PA28-151/a on a filed VFR flight plan from bff to 1v5. I was utilizing flight following by denver control and had been monitoring the boulder CTAF frequency for about 5 mins to familiarize myself with current local traffic. Radar service was terminated by denver control, and I then broadcast on boulder's CTAF frequency. I stated, 'boulder traffic, cherokee is 5 mi to the northeast. I'll be entering a left downwind for zero- eight, any traffic in the area, please advise.' there was no reply to this inquiry. I was then preparing to make a 45 degree entry to a left downwind approach at 1000 ft AGL. Traffic was a red and white cessna in view about 2 NM ahead which reported downwind at that time and was approximately 700 ft AGL. I also made another position report at that time, and was between 2 and 3 NM northeast of the airport visually and by GPS. The traffic ahead appeared to be mid-field. I flew a standard l-hand pattern. Being unfamiliar with the area and mindful of local noise abatement procedures. I scanned the ground to orient myself. When I looked ahead, traffic was no longer in view. I continued to actively scan for the traffic, and reported mid- field left downwind, turn to left base and turn to final. Traffic was not in sight at any point. On turning final, the entire runway was in view and there was no traffic on the active. The traffic ahead did not transmit position after reporting downwind. The reason I specifically reported each leg of my approach, despite tying up the CTAF/unicom frequency, was that I did not have the traffic in sight. I flew a 1000 ft AGL pattern with a 500 FPM rate of descent from 1000 ft short of the runway end. My approach speed was 85 mph. What I did to avoid traffic was report each leg of my approach. What I did not do that could have been helpful was specifically request the traffic ahead to report its position when I no longer had it in sight. I did not perform a go around for 2 reasons. One, the traffic ahead did not report a position in the pattern that would have suggested a conflict. Two, while I was on downwind, about to turn base, other traffic self-reported approach from the southeast, with intent to enter mid-field for a left downwind approach. Agar at that point would have required maneuvering to avoid a potential collision hazard with this in-coming traffic. This would have placed my aircraft below 1000 ft AGL over a residential area at a time I did not have reason to believe the traffic ahead was a hazard. Because no aircraft were on the active, or visible aloft during my final approach and there were no remarks from traffic in response to my position reports, I supposed the traffic ahead was already clear of the active and taxiing. Because the GA ramp is adjacent to the runway in boulder, it would not have been possible to locate the traffic on the ground, although I looked. I landed normally and afterwards was informed by ground personnel I had 'landed right over' the cessna traffic ahead. Ground personnel estimated there may have been as little as 150 ft vertical separation between aircraft. Ground personnel also indicated the pilot of the other aircraft was a student pilot. I do not know why he made only the single downwind position report, and failed to respond when I reported being on the same leg of the landing approach as he (as we must have been, at least on final). I also do not know any particulars of the student's training, log-time or the like. Naturally, I have some concerns whether the student knew the names of the various legs of an approach at the time he made this flight. I imagine he is quite familiar with them now. This would be a possible explanation for the failure to report position, or to report the conflict with my position. Clearly, a contributing factor was the student pilot's flying a lower-than-normal approach. The fact my aircraft was a long-wing, and his a high- wing aggravated the situation. The FARS state that the pilot of the other aircraft had the right-of-way by virtue of being lower in the pattern. Certainly I would have altered my own approach had I any indication traffic was below me and a potential hazard due to proximity. The most important fact in any midair collision is that both pilots are equally dead afterwards, whether they were at fault or not. At relatively high traffic, uncontrolled airports such as boulder, the only separation of aircraft is by pilot vigilance and self-report of position. I see my own failure in this situation to have been failing to specifically ask the other pilot's position, and initiate a go around had there been no reply. Because of the low pattern flown by the other aircraft, visual contact was not possible. I place a high priority to bettering myself as a pilot. I was going to boulder to take the instrument-rating, airplane pilot knowledge test, which I passed despite my considerable distraction at the time. I plan IFR flight-training aug xa to xi. I am also scheduled to do a small amount of aerobatic training. Because I fly a small fixed-gear, normal category aircraft, I will find little actual application for IFR flight, and none for aerobatic flight. I am pursuing these in order to become a better and safer pilot. Should you have any other particular area you would recommend I work to become more proficient in, I would greatly value your input. Possible administrative or regulatory solutions to such sits, any one of which would have averted this near-collision: require pilots to maintain continuous visual contact with any traffic ahead in the pattern. Require pilots to make a visual contact with any traffic that preceded them in the pattern prior to landing, whether the traffic remains aloft, or is on the ground. Require a specified distance between the GA ramp and runways at uncontrolled airports. Review student pilot training procedures at boulder. Suspend student solo flts at boulder. Change boulder's airspace classification. Require responding to position inquiries by other aircraft when in the area of an airport. Require reporting position inquiries by other aircraft when in the area of an airport. Require reporting position in the landing pattern, downwind, base and final or any combination of two of these when there is other traffic in the pattern. Require student pilots to so identify themselves when transmitting by radio.
Original NASA ASRS Text
Title: NMAC. AT UNCTLED ARPT, RPTR PLT LANDED OVER THE TOP OF ANOTHER ACFT ON SHORT FINAL AND NEVER DID SEE IT. NON TWR ARPT UNICOM.
Narrative: I WAS PILOTING A PA28-151/A ON A FILED VFR FLT PLAN FROM BFF TO 1V5. I WAS UTILIZING FLT FOLLOWING BY DENVER CTL AND HAD BEEN MONITORING THE BOULDER CTAF FREQ FOR ABOUT 5 MINS TO FAMILIARIZE MYSELF WITH CURRENT LCL TFC. RADAR SVC WAS TERMINATED BY DENVER CTL, AND I THEN BROADCAST ON BOULDER'S CTAF FREQ. I STATED, 'BOULDER TFC, CHEROKEE IS 5 MI TO THE NE. I'LL BE ENTERING A L DOWNWIND FOR ZERO- EIGHT, ANY TFC IN THE AREA, PLEASE ADVISE.' THERE WAS NO REPLY TO THIS INQUIRY. I WAS THEN PREPARING TO MAKE A 45 DEG ENTRY TO A L DOWNWIND APCH AT 1000 FT AGL. TFC WAS A RED AND WHITE CESSNA IN VIEW ABOUT 2 NM AHEAD WHICH RPTED DOWNWIND AT THAT TIME AND WAS APPROX 700 FT AGL. I ALSO MADE ANOTHER POS RPT AT THAT TIME, AND WAS BTWN 2 AND 3 NM NE OF THE ARPT VISUALLY AND BY GPS. THE TFC AHEAD APPEARED TO BE MID-FIELD. I FLEW A STANDARD L-HAND PATTERN. BEING UNFAMILIAR WITH THE AREA AND MINDFUL OF LCL NOISE ABATEMENT PROCS. I SCANNED THE GND TO ORIENT MYSELF. WHEN I LOOKED AHEAD, TFC WAS NO LONGER IN VIEW. I CONTINUED TO ACTIVELY SCAN FOR THE TFC, AND RPTED MID- FIELD L DOWNWIND, TURN TO L BASE AND TURN TO FINAL. TFC WAS NOT IN SIGHT AT ANY POINT. ON TURNING FINAL, THE ENTIRE RWY WAS IN VIEW AND THERE WAS NO TFC ON THE ACTIVE. THE TFC AHEAD DID NOT XMIT POS AFTER RPTING DOWNWIND. THE REASON I SPECIFICALLY RPTED EACH LEG OF MY APCH, DESPITE TYING UP THE CTAF/UNICOM FREQ, WAS THAT I DID NOT HAVE THE TFC IN SIGHT. I FLEW A 1000 FT AGL PATTERN WITH A 500 FPM RATE OF DSCNT FROM 1000 FT SHORT OF THE RWY END. MY APCH SPD WAS 85 MPH. WHAT I DID TO AVOID TFC WAS RPT EACH LEG OF MY APCH. WHAT I DID NOT DO THAT COULD HAVE BEEN HELPFUL WAS SPECIFICALLY REQUEST THE TFC AHEAD TO RPT ITS POS WHEN I NO LONGER HAD IT IN SIGHT. I DID NOT PERFORM A GAR FOR 2 REASONS. ONE, THE TFC AHEAD DID NOT RPT A POS IN THE PATTERN THAT WOULD HAVE SUGGESTED A CONFLICT. TWO, WHILE I WAS ON DOWNWIND, ABOUT TO TURN BASE, OTHER TFC SELF-RPTED APCH FROM THE SE, WITH INTENT TO ENTER MID-FIELD FOR A L DOWNWIND APCH. AGAR AT THAT POINT WOULD HAVE REQUIRED MANEUVERING TO AVOID A POTENTIAL COLLISION HAZARD WITH THIS IN-COMING TFC. THIS WOULD HAVE PLACED MY ACFT BELOW 1000 FT AGL OVER A RESIDENTIAL AREA AT A TIME I DID NOT HAVE REASON TO BELIEVE THE TFC AHEAD WAS A HAZARD. BECAUSE NO ACFT WERE ON THE ACTIVE, OR VISIBLE ALOFT DURING MY FINAL APCH AND THERE WERE NO REMARKS FROM TFC IN RESPONSE TO MY POS RPTS, I SUPPOSED THE TFC AHEAD WAS ALREADY CLR OF THE ACTIVE AND TAXIING. BECAUSE THE GA RAMP IS ADJACENT TO THE RWY IN BOULDER, IT WOULD NOT HAVE BEEN POSSIBLE TO LOCATE THE TFC ON THE GND, ALTHOUGH I LOOKED. I LANDED NORMALLY AND AFTERWARDS WAS INFORMED BY GND PERSONNEL I HAD 'LANDED RIGHT OVER' THE CESSNA TFC AHEAD. GND PERSONNEL ESTIMATED THERE MAY HAVE BEEN AS LITTLE AS 150 FT VERT SEPARATION BTWN ACFT. GND PERSONNEL ALSO INDICATED THE PLT OF THE OTHER ACFT WAS A STUDENT PLT. I DO NOT KNOW WHY HE MADE ONLY THE SINGLE DOWNWIND POS RPT, AND FAILED TO RESPOND WHEN I RPTED BEING ON THE SAME LEG OF THE LNDG APCH AS HE (AS WE MUST HAVE BEEN, AT LEAST ON FINAL). I ALSO DO NOT KNOW ANY PARTICULARS OF THE STUDENT'S TRAINING, LOG-TIME OR THE LIKE. NATURALLY, I HAVE SOME CONCERNS WHETHER THE STUDENT KNEW THE NAMES OF THE VARIOUS LEGS OF AN APCH AT THE TIME HE MADE THIS FLT. I IMAGINE HE IS QUITE FAMILIAR WITH THEM NOW. THIS WOULD BE A POSSIBLE EXPLANATION FOR THE FAILURE TO RPT POS, OR TO RPT THE CONFLICT WITH MY POS. CLRLY, A CONTRIBUTING FACTOR WAS THE STUDENT PLT'S FLYING A LOWER-THAN-NORMAL APCH. THE FACT MY ACFT WAS A LONG-WING, AND HIS A HIGH- WING AGGRAVATED THE SIT. THE FARS STATE THAT THE PLT OF THE OTHER ACFT HAD THE RIGHT-OF-WAY BY VIRTUE OF BEING LOWER IN THE PATTERN. CERTAINLY I WOULD HAVE ALTERED MY OWN APCH HAD I ANY INDICATION TFC WAS BELOW ME AND A POTENTIAL HAZARD DUE TO PROX. THE MOST IMPORTANT FACT IN ANY MIDAIR COLLISION IS THAT BOTH PLTS ARE EQUALLY DEAD AFTERWARDS, WHETHER THEY WERE AT FAULT OR NOT. AT RELATIVELY HIGH TFC, UNCTLED ARPTS SUCH AS BOULDER, THE ONLY SEPARATION OF ACFT IS BY PLT VIGILANCE AND SELF-RPT OF POS. I SEE MY OWN FAILURE IN THIS SIT TO HAVE BEEN FAILING TO SPECIFICALLY ASK THE OTHER PLT'S POS, AND INITIATE A GAR HAD THERE BEEN NO REPLY. BECAUSE OF THE LOW PATTERN FLOWN BY THE OTHER ACFT, VISUAL CONTACT WAS NOT POSSIBLE. I PLACE A HIGH PRIORITY TO BETTERING MYSELF AS A PLT. I WAS GOING TO BOULDER TO TAKE THE INST-RATING, AIRPLANE PLT KNOWLEDGE TEST, WHICH I PASSED DESPITE MY CONSIDERABLE DISTR AT THE TIME. I PLAN IFR FLT-TRAINING AUG XA TO XI. I AM ALSO SCHEDULED TO DO A SMALL AMOUNT OF AEROBATIC TRAINING. BECAUSE I FLY A SMALL FIXED-GEAR, NORMAL CATEGORY ACFT, I WILL FIND LITTLE ACTUAL APPLICATION FOR IFR FLT, AND NONE FOR AEROBATIC FLT. I AM PURSUING THESE IN ORDER TO BECOME A BETTER AND SAFER PLT. SHOULD YOU HAVE ANY OTHER PARTICULAR AREA YOU WOULD RECOMMEND I WORK TO BECOME MORE PROFICIENT IN, I WOULD GREATLY VALUE YOUR INPUT. POSSIBLE ADMINISTRATIVE OR REGULATORY SOLUTIONS TO SUCH SITS, ANY ONE OF WHICH WOULD HAVE AVERTED THIS NEAR-COLLISION: REQUIRE PLTS TO MAINTAIN CONTINUOUS VISUAL CONTACT WITH ANY TFC AHEAD IN THE PATTERN. REQUIRE PLTS TO MAKE A VISUAL CONTACT WITH ANY TFC THAT PRECEDED THEM IN THE PATTERN PRIOR TO LNDG, WHETHER THE TFC REMAINS ALOFT, OR IS ON THE GND. REQUIRE A SPECIFIED DISTANCE BTWN THE GA RAMP AND RWYS AT UNCTLED ARPTS. REVIEW STUDENT PLT TRAINING PROCS AT BOULDER. SUSPEND STUDENT SOLO FLTS AT BOULDER. CHANGE BOULDER'S AIRSPACE CLASSIFICATION. REQUIRE RESPONDING TO POS INQUIRIES BY OTHER ACFT WHEN IN THE AREA OF AN ARPT. REQUIRE RPTING POS INQUIRIES BY OTHER ACFT WHEN IN THE AREA OF AN ARPT. REQUIRE RPTING POS IN THE LNDG PATTERN, DOWNWIND, BASE AND FINAL OR ANY COMBINATION OF TWO OF THESE WHEN THERE IS OTHER TFC IN THE PATTERN. REQUIRE STUDENT PLTS TO SO IDENT THEMSELVES WHEN XMITTING BY RADIO.
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.