Pilot in C560 inbound to pit experienced severe wake turbulence when the flight was turned in approx...

Attributes
ACN	415016
Time
Date	199809
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pit
State Reference	PA
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pit tower : atl
Operator	general aviation : corporate
Make Model Name	Citation V
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar pilot : instrument
Experience	controller radar : 15 flight time total : 2500
ASRS Report	415016
Person 2
Affiliation	government : faa
Function	oversight : supervisor
Qualification	controller : radar
Events
Anomaly	inflight encounter other other anomaly
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : regained aircraft control other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

At approximately XA35 I cleared aircraft #2 for an ILS approach to runway 32 at pit. I advised he was 4 mi behind a B737 and believe I cautioned him about the wake turbulence. Very soon thereafter (less than 1 min), aircraft #2 said he had experienced severe turbulence and was moving off the runway 32 final. I proceeded to question him about his traffic and the airport to which he replied he had the airport in sight. I cleared him for a visual approach and switched him to the tower. Aircraft #2 mentioned being inverted on the frequency and later in a phone conversation confirmed he had been rolled inverted by what he believed was wake turbulence. Separation was at 4+ mi when the incident occurred and continued to increase as aircraft #2 slowed even further. Callback conversation with reporter revealed the following information: reporter stated at the time of the incident, conditions were from MVFR to IFR and that the traffic situation was becoming very busy. The B737 aircraft had started final approximately 30 mi from the airport and had been cleared for a straight-in approach. The C560 came in from the west and put on a vector to follow the B737. Very shortly after the C560 turned onto the final, the pilot advised he had encountered severe wake turbulence, recovered after becoming inverted, and moved off the right side of the localizer. He then sighted the airport and was cleared for a visual approach. After landing, the pilot contacted the approach facility and allegedly stated that he had been completely rolled by the wake encounter. No injuries or damage to the aircraft were reported.

Original NASA ASRS Text

Title: PLT IN C560 INBOUND TO PIT EXPERIENCED SEVERE WAKE TURB WHEN THE FLT WAS TURNED IN APPROX 4 MI BEHIND A B737 AND CLRED FOR AN ILS APCH. THE RPTR CLAIMS THE PLT STATED AFTER HE HAD LANDED THAT THE ACFT HAD MADE A COMPLETE ROLL AT 4000 FT.

Narrative: AT APPROX XA35 I CLRED ACFT #2 FOR AN ILS APCH TO RWY 32 AT PIT. I ADVISED HE WAS 4 MI BEHIND A B737 AND BELIEVE I CAUTIONED HIM ABOUT THE WAKE TURB. VERY SOON THEREAFTER (LESS THAN 1 MIN), ACFT #2 SAID HE HAD EXPERIENCED SEVERE TURB AND WAS MOVING OFF THE RWY 32 FINAL. I PROCEEDED TO QUESTION HIM ABOUT HIS TFC AND THE ARPT TO WHICH HE REPLIED HE HAD THE ARPT IN SIGHT. I CLRED HIM FOR A VISUAL APCH AND SWITCHED HIM TO THE TWR. ACFT #2 MENTIONED BEING INVERTED ON THE FREQ AND LATER IN A PHONE CONVERSATION CONFIRMED HE HAD BEEN ROLLED INVERTED BY WHAT HE BELIEVED WAS WAKE TURB. SEPARATION WAS AT 4+ MI WHEN THE INCIDENT OCCURRED AND CONTINUED TO INCREASE AS ACFT #2 SLOWED EVEN FURTHER. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED AT THE TIME OF THE INCIDENT, CONDITIONS WERE FROM MVFR TO IFR AND THAT THE TFC SIT WAS BECOMING VERY BUSY. THE B737 ACFT HAD STARTED FINAL APPROX 30 MI FROM THE ARPT AND HAD BEEN CLRED FOR A STRAIGHT-IN APCH. THE C560 CAME IN FROM THE W AND PUT ON A VECTOR TO FOLLOW THE B737. VERY SHORTLY AFTER THE C560 TURNED ONTO THE FINAL, THE PLT ADVISED HE HAD ENCOUNTERED SEVERE WAKE TURB, RECOVERED AFTER BECOMING INVERTED, AND MOVED OFF THE R SIDE OF THE LOC. HE THEN SIGHTED THE ARPT AND WAS CLRED FOR A VISUAL APCH. AFTER LNDG, THE PLT CONTACTED THE APCH FACILITY AND ALLEGEDLY STATED THAT HE HAD BEEN COMPLETELY ROLLED BY THE WAKE ENCOUNTER. NO INJURIES OR DAMAGE TO THE ACFT WERE RPTED.

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.

Pilot in C560 inbound to pit experienced severe wake turbulence when the flight was turned in approximately 4 mi behind a B737 and cleared for an ILS approach. The reporter claims the pilot stated after he had landed that the aircraft had made a complete roll at 4000 ft.