Wake encounter -- air carrier encounters the wake of a preceding air carrier with very little distur...

Attributes
ACN	314422
Time
Date	199508
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : stl
State Reference	MO
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : stl
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : flight engineer
Experience	flight time last 90 days : 250 flight time total : 20000 flight time type : 3300
ASRS Report	314422
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	inflight encounter other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Being vectored to runway 12R ILS final for a visual approach. Encountered wake turbulence of preceding B727, 8 mi ahead. Aircraft was on autoplt. Aircraft banked sharply left, reaching about 30 degrees before autoplt input caught it, then about 30 degrees right. Autoplt did fine job. Relatively smooth. Callback conversation with reporter revealed the following: the reporter was flying a DC9-30 and he was behind a B727-200 by about 4.5 nms. The wake encounter occurred with no warning, although the B727-200 was in sight. At the onset the DC9-30 was on autoplt and it rolled sharply to the left and then sharply to the right reaching approximately 30 degrees in each direction before returning to a zero degree bank flight. All of this occurred while on autoplt and no further wake encounter occurred. There were no complaints or comments from the passenger or flight attendants afterwards.

Original NASA ASRS Text

Title: WAKE ENCOUNTER -- ACR ENCOUNTERS THE WAKE OF A PRECEDING ACR WITH VERY LITTLE DISTURBANCE.

Narrative: BEING VECTORED TO RWY 12R ILS FINAL FOR A VISUAL APCH. ENCOUNTERED WAKE TURB OF PRECEDING B727, 8 MI AHEAD. ACFT WAS ON AUTOPLT. ACFT BANKED SHARPLY L, REACHING ABOUT 30 DEGS BEFORE AUTOPLT INPUT CAUGHT IT, THEN ABOUT 30 DEGS R. AUTOPLT DID FINE JOB. RELATIVELY SMOOTH. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: THE RPTR WAS FLYING A DC9-30 AND HE WAS BEHIND A B727-200 BY ABOUT 4.5 NMS. THE WAKE ENCOUNTER OCCURRED WITH NO WARNING, ALTHOUGH THE B727-200 WAS IN SIGHT. AT THE ONSET THE DC9-30 WAS ON AUTOPLT AND IT ROLLED SHARPLY TO THE L AND THEN SHARPLY TO THE R REACHING APPROX 30 DEGS IN EACH DIRECTION BEFORE RETURNING TO A ZERO DEG BANK FLT. ALL OF THIS OCCURRED WHILE ON AUTOPLT AND NO FURTHER WAKE ENCOUNTER OCCURRED. THERE WERE NO COMPLAINTS OR COMMENTS FROM THE PAX OR FLT ATTENDANTS AFTERWARDS.

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.

Wake encounter -- air carrier encounters the wake of a preceding air carrier with very little disturbance.