Wake turbulence encounter shortly after takeoff.

Attributes
ACN	312966
Time
Date	199508
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : pit
State Reference	PA
Altitude	agl bound lower : 500 agl bound upper : 700
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : pit
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : initial
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
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 : 160 flight time total : 17000 flight time type : 2000
ASRS Report	312966
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	inflight encounter other
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

During the initial turn to on course we encountered wake turbulence of another departing aircraft. Normally on takeoff runway 28R we are given a 360 degree heading and then direct ewc. But with this clear WX we were given direct slt which was about a 060 degree heading. At about 500-700 ft AGL we encountered a strong wake turbulence which caused a strong rolling motion to the outside of the turn and about a 40 degree roll (left). Before we could complain to ATC we heard our company complain about encountering wake turbulence from the aircraft in front of him! We also let ATC know about our encounter. This was a very clear, still night and we were in a big push out of pit (last of the night) and ATC was just slinging us out and getting us on our way. When ATC heard our complaints they apologized and said they wouldn't keep us so close next time. Callback conversation with reporter revealed the following information: reporter participated in the wake turbulence structured callback. Reporter was surprised at the encounter as there was no warning to his aircraft approaching any turbulence. As he reflected on the environment of that evening, the air was still and visibility very good. Another aircraft ahead of him complained of wake turbulence during his climb out, but he had no knowledge of the location of the turbulence. These 2 facts should have alerted him that he might encounter some turbulence as all departures were taking off west with an immediate right turn to the east. The departures had close ground tracks. When he encountered the turbulence it rolled him from a right bank to a left bank, a total of 40 degrees change. He put control inputs in to oppose the effect of the turbulence but it still rolled him the opposite way. Although the turbulence effect only lasted 5-6 seconds, he was bothered by the fact that the aircraft was rolling against his control inputs. Full control resumed immediately after the encounter and everything else continued normally.

Original NASA ASRS Text

Title: WAKE TURB ENCOUNTER SHORTLY AFTER TKOF.

Narrative: DURING THE INITIAL TURN TO ON COURSE WE ENCOUNTERED WAKE TURB OF ANOTHER DEPARTING ACFT. NORMALLY ON TKOF RWY 28R WE ARE GIVEN A 360 DEG HDG AND THEN DIRECT EWC. BUT WITH THIS CLR WX WE WERE GIVEN DIRECT SLT WHICH WAS ABOUT A 060 DEG HDG. AT ABOUT 500-700 FT AGL WE ENCOUNTERED A STRONG WAKE TURB WHICH CAUSED A STRONG ROLLING MOTION TO THE OUTSIDE OF THE TURN AND ABOUT A 40 DEG ROLL (L). BEFORE WE COULD COMPLAIN TO ATC WE HEARD OUR COMPANY COMPLAIN ABOUT ENCOUNTERING WAKE TURB FROM THE ACFT IN FRONT OF HIM! WE ALSO LET ATC KNOW ABOUT OUR ENCOUNTER. THIS WAS A VERY CLR, STILL NIGHT AND WE WERE IN A BIG PUSH OUT OF PIT (LAST OF THE NIGHT) AND ATC WAS JUST SLINGING US OUT AND GETTING US ON OUR WAY. WHEN ATC HEARD OUR COMPLAINTS THEY APOLOGIZED AND SAID THEY WOULDN'T KEEP US SO CLOSE NEXT TIME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR PARTICIPATED IN THE WAKE TURB STRUCTURED CALLBACK. RPTR WAS SURPRISED AT THE ENCOUNTER AS THERE WAS NO WARNING TO HIS ACFT APCHING ANY TURB. AS HE REFLECTED ON THE ENVIRONMENT OF THAT EVENING, THE AIR WAS STILL AND VISIBILITY VERY GOOD. ANOTHER ACFT AHEAD OF HIM COMPLAINED OF WAKE TURB DURING HIS CLBOUT, BUT HE HAD NO KNOWLEDGE OF THE LOCATION OF THE TURB. THESE 2 FACTS SHOULD HAVE ALERTED HIM THAT HE MIGHT ENCOUNTER SOME TURB AS ALL DEPS WERE TAKING OFF W WITH AN IMMEDIATE R TURN TO THE E. THE DEPS HAD CLOSE GND TRACKS. WHEN HE ENCOUNTERED THE TURB IT ROLLED HIM FROM A R BANK TO A L BANK, A TOTAL OF 40 DEGS CHANGE. HE PUT CTL INPUTS IN TO OPPOSE THE EFFECT OF THE TURB BUT IT STILL ROLLED HIM THE OPPOSITE WAY. ALTHOUGH THE TURB EFFECT ONLY LASTED 5-6 SECONDS, HE WAS BOTHERED BY THE FACT THAT THE ACFT WAS ROLLING AGAINST HIS CTL INPUTS. FULL CTL RESUMED IMMEDIATELY AFTER THE ENCOUNTER AND EVERYTHING ELSE CONTINUED NORMALLY.

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.