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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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GA small aircraft wake turbulence encounter as air carrier widebody transport descended across his track.
| Attributes | |
| ACN | 121452 |
| Time | |
| Date | 198906 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : bdf |
| State Reference | IL |
| Altitude | msl bound lower : 12500 msl bound upper : 12500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zau |
| Operator | general aviation : personal |
| Make Model Name | Small Aircraft, High Wing, 1 Eng, Retractable Gear |
| Flight Phase | cruise other |
| Flight Plan | None |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Widebody, Low Wing, 3 Turbojet Eng |
| Flight Phase | descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : single pilot |
| Qualification | pilot : private pilot : instrument |
| Experience | flight time last 90 days : 100 flight time total : 2700 flight time type : 1500 |
| ASRS Report | 121452 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | inflight encounter other |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | Other |
| Miss Distance | horizontal : 12000 vertical : 0 |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | other |
Narrative:
Cruising at 12,500 MSL en route nwbnd (from jvy to rie) working with chicago center, VFR traffic advisories. Center calls widebody transport traffic at my 10 O'clock, 5 mi, northbound at 13,000. I see and call traffic immediately. Controller just as quickly clears the widebody transport to descend to a lower altitude, right in front of me! I am flabergasted as I watch widebody transport start his descent (I believe that he was inbound to ord on J26). He passes in front of me, my 12 O'clock position at less than 2 mi. About 30 seconds later, I hit his vortex before I have time to tighten seat belt of dozing passenger next to me. Severe instantaneous turbulence. Aircraft uncontrollable. My front seat passenger hits overhead with her head. Occurrence lasts less than 1 second. We arrive on the other side in a stable attitude with no apparent damage to aircraft. I should have instituted an immediate 90 degree turn to the right. Based upon his closure rate I knew there was never a problem regarding a midair, but that jet wake turbulence would be a real factor for me. It really surprised me that the controller cleared the widebody transport to descend that close in front of me. Admittedly he was real busy, but no excuse in my opinion.
Original NASA ASRS Text
Title: GA SMA WAKE TURBULENCE ENCOUNTER AS ACR WDB DESCENDED ACROSS HIS TRACK.
Narrative: CRUISING AT 12,500 MSL ENRTE NWBND (FROM JVY TO RIE) WORKING WITH CHICAGO CENTER, VFR TFC ADVISORIES. CENTER CALLS WDB TFC AT MY 10 O'CLOCK, 5 MI, NBOUND AT 13,000. I SEE AND CALL TFC IMMEDIATELY. CTLR JUST AS QUICKLY CLEARS THE WDB TO DSND TO A LOWER ALT, RIGHT IN FRONT OF ME! I AM FLABERGASTED AS I WATCH WDB START HIS DSCNT (I BELIEVE THAT HE WAS INBOUND TO ORD ON J26). HE PASSES IN FRONT OF ME, MY 12 O'CLOCK POSITION AT LESS THAN 2 MI. ABOUT 30 SECONDS LATER, I HIT HIS VORTEX BEFORE I HAVE TIME TO TIGHTEN SEAT BELT OF DOZING PAX NEXT TO ME. SEVERE INSTANTANEOUS TURBULENCE. ACFT UNCONTROLLABLE. MY FRONT SEAT PAX HITS OVERHEAD WITH HER HEAD. OCCURRENCE LASTS LESS THAN 1 SECOND. WE ARRIVE ON THE OTHER SIDE IN A STABLE ATTITUDE WITH NO APPARENT DAMAGE TO ACFT. I SHOULD HAVE INSTITUTED AN IMMEDIATE 90 DEG TURN TO THE RIGHT. BASED UPON HIS CLOSURE RATE I KNEW THERE WAS NEVER A PROBLEM REGARDING A MIDAIR, BUT THAT JET WAKE TURBULENCE WOULD BE A REAL FACTOR FOR ME. IT REALLY SURPRISED ME THAT THE CTLR CLRED THE WDB TO DSND THAT CLOSE IN FRONT OF ME. ADMITTEDLY HE WAS REAL BUSY, BUT NO EXCUSE IN MY OPINION.
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.