Wake encounter. Air carrier MD80 hits the wake of a B747 during final approach.

Attributes
ACN	316015
Time
Date	199509
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : iflq airport : dfw
State Reference	TX
Altitude	msl bound lower : 2800 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 5000 flight time type : 2500
ASRS Report	316015
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	inflight encounter other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Air Traffic Incident	other

Narrative:

7 NM behind B747 on visual to runway 17L encountered moderate wake turbulence. We climbed 200 to 300 ft to get out of it. Approach chastised us for climbing. Hey you got to do what you got to do to be safe. Callback conversation with reporter revealed the following information: the reporter was a captain flying an MD80, super 80, and he was about 10 mi out on final approach to runway 17L at dfw when he encountered the wake of a B747. He said that the aircraft rolled left then right to a maximum bank angle of about 15 degrees in spite of having full aileron deflection against the rolls. To escape the wake the captain said that he pitched up and climbed a few hundred ft and found smooth air. However the approach controller was a bit critical about this maneuver. The captain was able to continue the approach and landing by staying high on the GS. The captain said that the company responded to a further inquiry from the approach control facility and they were satisfied that his maneuver was in the interest of safety.

Original NASA ASRS Text

Title: WAKE ENCOUNTER. ACR MD80 HITS THE WAKE OF A B747 DURING FINAL APCH.

Narrative: 7 NM BEHIND B747 ON VISUAL TO RWY 17L ENCOUNTERED MODERATE WAKE TURB. WE CLBED 200 TO 300 FT TO GET OUT OF IT. APCH CHASTISED US FOR CLBING. HEY YOU GOT TO DO WHAT YOU GOT TO DO TO BE SAFE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS A CAPT FLYING AN MD80, SUPER 80, AND HE WAS ABOUT 10 MI OUT ON FINAL APCH TO RWY 17L AT DFW WHEN HE ENCOUNTERED THE WAKE OF A B747. HE SAID THAT THE ACFT ROLLED L THEN R TO A MAX BANK ANGLE OF ABOUT 15 DEGS IN SPITE OF HAVING FULL AILERON DEFLECTION AGAINST THE ROLLS. TO ESCAPE THE WAKE THE CAPT SAID THAT HE PITCHED UP AND CLBED A FEW HUNDRED FT AND FOUND SMOOTH AIR. HOWEVER THE APCH CTLR WAS A BIT CRITICAL ABOUT THIS MANEUVER. THE CAPT WAS ABLE TO CONTINUE THE APCH AND LNDG BY STAYING HIGH ON THE GS. THE CAPT SAID THAT THE COMPANY RESPONDED TO A FURTHER INQUIRY FROM THE APCH CTL FACILITY AND THEY WERE SATISFIED THAT HIS MANEUVER WAS IN THE INTEREST OF SAFETY.

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.