Small transport aircraft following B757 wake turbulence incident.

Attributes
ACN	302659
Time
Date	199504
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dca
State Reference	DC
Altitude	agl bound lower : 50 agl bound upper : 100
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : dca
Operator	other
Make Model Name	Baron 58/58TC
Operating Under FAR Part	Part 91
Flight Phase	descent : approach landing other
Route In Use	approach : visual arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach landing other
Route In Use	approach : visual arrival other
Flight Plan	IFR
Person 1
Affiliation	government other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time total : 1350 flight time type : 250
ASRS Report	302659
Person 2
Affiliation	government other
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Events
Anomaly	inflight encounter other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

I was PF, first officer, on BE58 returning to base in dca at night with clear skies and unrestricted visibility. We were vectored downwind and cleared visual approach to follow B757 on 5 mi final. ATC provided all the proper cautions -- 'caution wake turbulence, B757' 'altitude 1500 ft over the wilson bridge.' I was very familiar with wake turbulence avoidance procedures and crossed the wilson bridge at 1700 ft to stay above the B757 flight path. We observed B757 touchdown point and planned to land beyond it. I also felt that the 757's faster approach speed would put us almost 1 min or so in trail, so the wake would have dissipated as well as be below our glidepath. Upon our landing flare, we encountered gentle rocking motion from the wake. I elected to go around as I was concerned that we would hit the wake core. A normal approach and landing were subsequently made. The wake persisted because I had forgotten that the ATIS had winds at 130 degrees at 3 KTS (a slight tailwind for landing on runway 36). I was amazed at the longevity of the wake under these quartering tailwind conditions. Ironically, I had attended a meeting on B757 wake the afternoon of the incident. Callback conversation with reporter revealed the following: reporter stated that, although he was knowledgeable about wake turbulence, he would remain higher on glidepath and land longer when in the same situation. He believes ATC should give surface wind conditions more often when wake turbulence could be a factor. Reporter was a structured callback participant.

Original NASA ASRS Text

Title: SMT ACFT FOLLOWING B757 WAKE TURB INCIDENT.

Narrative: I WAS PF, FO, ON BE58 RETURNING TO BASE IN DCA AT NIGHT WITH CLR SKIES AND UNRESTRICTED VISIBILITY. WE WERE VECTORED DOWNWIND AND CLRED VISUAL APCH TO FOLLOW B757 ON 5 MI FINAL. ATC PROVIDED ALL THE PROPER CAUTIONS -- 'CAUTION WAKE TURB, B757' 'ALT 1500 FT OVER THE WILSON BRIDGE.' I WAS VERY FAMILIAR WITH WAKE TURB AVOIDANCE PROCS AND CROSSED THE WILSON BRIDGE AT 1700 FT TO STAY ABOVE THE B757 FLT PATH. WE OBSERVED B757 TOUCHDOWN POINT AND PLANNED TO LAND BEYOND IT. I ALSO FELT THAT THE 757'S FASTER APCH SPD WOULD PUT US ALMOST 1 MIN OR SO IN TRAIL, SO THE WAKE WOULD HAVE DISSIPATED AS WELL AS BE BELOW OUR GLIDEPATH. UPON OUR LNDG FLARE, WE ENCOUNTERED GENTLE ROCKING MOTION FROM THE WAKE. I ELECTED TO GAR AS I WAS CONCERNED THAT WE WOULD HIT THE WAKE CORE. A NORMAL APCH AND LNDG WERE SUBSEQUENTLY MADE. THE WAKE PERSISTED BECAUSE I HAD FORGOTTEN THAT THE ATIS HAD WINDS AT 130 DEGS AT 3 KTS (A SLIGHT TAILWIND FOR LNDG ON RWY 36). I WAS AMAZED AT THE LONGEVITY OF THE WAKE UNDER THESE QUARTERING TAILWIND CONDITIONS. IRONICALLY, I HAD ATTENDED A MEETING ON B757 WAKE THE AFTERNOON OF THE INCIDENT. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR STATED THAT, ALTHOUGH HE WAS KNOWLEDGEABLE ABOUT WAKE TURB, HE WOULD REMAIN HIGHER ON GLIDEPATH AND LAND LONGER WHEN IN THE SAME SIT. HE BELIEVES ATC SHOULD GIVE SURFACE WIND CONDITIONS MORE OFTEN WHEN WAKE TURB COULD BE A FACTOR. RPTR WAS A STRUCTURED CALLBACK PARTICIPANT.

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.