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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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A VFR descending small aircraft is stopped at 4500 ft for an opposite direction C130 aircraft climbing to 4000 ft. Radar equipment indicated that the small aircraft was at the same altitude as the C130, however, the small aircraft reporter claims that the lowest altitude was 4400 ft. The reporter further claims that the C130 was in sight and not a factor. Mode C was later checked and found to be only 100 ft off.
| Attributes | |
| ACN | 371248 |
| Time | |
| Date | 199706 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : lit |
| State Reference | AR |
| Altitude | msl bound lower : 4000 msl bound upper : 4500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : lit |
| Operator | general aviation : personal |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | Part 91 |
| Flight Phase | descent other |
| Flight Plan | None |
| Aircraft 2 | |
| Operator | other |
| Make Model Name | Hercules (C-130) |
| Operating Under FAR Part | other : other |
| Flight Phase | climbout : intermediate altitude |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : single pilot |
| Qualification | pilot : instrument pilot : commercial |
| Experience | flight time last 90 days : 10 flight time total : 850 flight time type : 200 |
| ASRS Report | 371248 |
| Person 2 | |
| Affiliation | government : military |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : military |
| Events | |
| Anomaly | aircraft equipment problem : less severe conflict : airborne less severe |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance |
| Consequence | faa : reviewed incident with flight crew |
| Miss Distance | horizontal : 1000 vertical : 400 |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
While approaching little rock, I had been cleared to descend to 4000 ft. When I got to 4550 ft, approach leveled me off at 4500 ft and told me to watch for traffic at 10 O'clock position climbing from 3000 ft to 4000 ft. I leveled off immediately but got as low as 4400 ft. Then ATC repeated the altitude and traffic warning, but I still couldn't see traffic yet. ATC sounded worried, seemed to think I was still descending, but I still hadn't gotten below 4400 ft despite the turbulence, and my altimeter was set correctly to ATIS 29.86 inches. Then ATC said 'traffic alert, traffic alert,' and then I heard traffic pilot asking if he should descend. Then I saw the traffic, a C130 below me at 10 O'clock position climbing, but I couldn't find a break in the conversation to announce that I had a visual. Meanwhile, the ATC controller and C130 pilot were having a panicky discussion about the situation. The C130 passed slowly below and behind me from 10 O'clock position to 6 O'clock position. He didn't evade but appeared to continue climb. Separation appeared generous to me and my passenger. By the time I managed to get a word in edgewise to ATC, he was pretty scared. He told me later he showed me and traffic both at 4100 ft. Next day, I checked my encoder with approach and ZME and it was showing 100 ft lower to them than to me. Maybe the C130 was reading high as well. This crisis apparently existed only on the radar screen, and not at all in real physical terms. But why did they clear us to cross over the same point at the same time if that scares them?
Original NASA ASRS Text
Title: A VFR DSNDING SMA IS STOPPED AT 4500 FT FOR AN OPPOSITE DIRECTION C130 ACFT CLBING TO 4000 FT. RADAR EQUIP INDICATED THAT THE SMA WAS AT THE SAME ALT AS THE C130, HOWEVER, THE SMA RPTR CLAIMS THAT THE LOWEST ALT WAS 4400 FT. THE RPTR FURTHER CLAIMS THAT THE C130 WAS IN SIGHT AND NOT A FACTOR. MODE C WAS LATER CHKED AND FOUND TO BE ONLY 100 FT OFF.
Narrative: WHILE APCHING LITTLE ROCK, I HAD BEEN CLRED TO DSND TO 4000 FT. WHEN I GOT TO 4550 FT, APCH LEVELED ME OFF AT 4500 FT AND TOLD ME TO WATCH FOR TFC AT 10 O'CLOCK POS CLBING FROM 3000 FT TO 4000 FT. I LEVELED OFF IMMEDIATELY BUT GOT AS LOW AS 4400 FT. THEN ATC REPEATED THE ALT AND TFC WARNING, BUT I STILL COULDN'T SEE TFC YET. ATC SOUNDED WORRIED, SEEMED TO THINK I WAS STILL DSNDING, BUT I STILL HADN'T GOTTEN BELOW 4400 FT DESPITE THE TURB, AND MY ALTIMETER WAS SET CORRECTLY TO ATIS 29.86 INCHES. THEN ATC SAID 'TFC ALERT, TFC ALERT,' AND THEN I HEARD TFC PLT ASKING IF HE SHOULD DSND. THEN I SAW THE TFC, A C130 BELOW ME AT 10 O'CLOCK POS CLBING, BUT I COULDN'T FIND A BREAK IN THE CONVERSATION TO ANNOUNCE THAT I HAD A VISUAL. MEANWHILE, THE ATC CTLR AND C130 PLT WERE HAVING A PANICKY DISCUSSION ABOUT THE SIT. THE C130 PASSED SLOWLY BELOW AND BEHIND ME FROM 10 O'CLOCK POS TO 6 O'CLOCK POS. HE DIDN'T EVADE BUT APPEARED TO CONTINUE CLB. SEPARATION APPEARED GENEROUS TO ME AND MY PAX. BY THE TIME I MANAGED TO GET A WORD IN EDGEWISE TO ATC, HE WAS PRETTY SCARED. HE TOLD ME LATER HE SHOWED ME AND TFC BOTH AT 4100 FT. NEXT DAY, I CHKED MY ENCODER WITH APCH AND ZME AND IT WAS SHOWING 100 FT LOWER TO THEM THAN TO ME. MAYBE THE C130 WAS READING HIGH AS WELL. THIS CRISIS APPARENTLY EXISTED ONLY ON THE RADAR SCREEN, AND NOT AT ALL IN REAL PHYSICAL TERMS. BUT WHY DID THEY CLR US TO CROSS OVER THE SAME POINT AT THE SAME TIME IF THAT SCARES THEM?
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.