B757 flight crew has a hard landing due to either wake turbulence or windshear during landing at phl...

Attributes
ACN	704506
Time
Date	200607
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : phl.airport
State Reference	PA
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Weather Elements	Thunderstorm
Aircraft 1
Controlling Facilities	tower : phl.tower tracon : mdsd.tracon
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : phl.tower
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
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
Experience	flight time last 90 days : 75 flight time total : 10122 flight time type : 75
ASRS Report	704506
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	inflight encounter : wake turbulence other anomaly
Independent Detector	aircraft equipment : gpws other flight crewa other flight crewb
Resolutory Action	none taken : insufficient time
Consequence	other
Supplementary
Problem Areas	Aircraft Environmental Factor Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

The approach was stable at 1000 ft. Another airplane was landing prior to us. There were thunderstorms in the surrounding area. At 200 ft the first officer declares that he was disconnecting the autothrottles. I concurred. At about 100 ft; I called out airspeed. The airspeed had instantly bled off. The first officer responded by advancing the thrust levers. At that point the descent rate had increased and he was not able to arrest the descent rate. We had what I would call a hard landing. The windshear warning system then went off. Fortunately the aircraft did not sustain any damage and was returned to service within 12 hours.

Original NASA ASRS Text

Title: B757 FLT CREW HAS A HARD LANDING DUE TO EITHER WAKE TURB OR WINDSHEAR DURING LNDG AT PHL.

Narrative: THE APCH WAS STABLE AT 1000 FT. ANOTHER AIRPLANE WAS LNDG PRIOR TO US. THERE WERE TSTMS IN THE SURROUNDING AREA. AT 200 FT THE FO DECLARES THAT HE WAS DISCONNECTING THE AUTOTHROTTLES. I CONCURRED. AT ABOUT 100 FT; I CALLED OUT AIRSPD. THE AIRSPD HAD INSTANTLY BLED OFF. THE FO RESPONDED BY ADVANCING THE THRUST LEVERS. AT THAT POINT THE DSCNT RATE HAD INCREASED AND HE WAS NOT ABLE TO ARREST THE DSCNT RATE. WE HAD WHAT I WOULD CALL A HARD LNDG. THE WINDSHEAR WARNING SYS THEN WENT OFF. FORTUNATELY THE ACFT DID NOT SUSTAIN ANY DAMAGE AND WAS RETURNED TO SVC WITHIN 12 HRS.

Data retrieved from NASA's ASRS site as of January 2009 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.