During final approach, aircraft encounters heavy rain and hail. Windshear warning sounded by aircraf...

Attributes
ACN	546787
Time
Date	200205
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iad.airport
State Reference	DC
Altitude	msl single value : 1400
Environment
Weather Elements	Windshear other
Aircraft 1
Controlling Facilities	tracon : iad.tracon
Operator	common carrier : air carrier
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	approach : instrument non precision
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : iad.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent : approach
Route In Use	approach : instrument non precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time type : 823
ASRS Report	546787
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe inflight encounter : weather inflight encounter other other anomaly
Independent Detector	aircraft equipment other aircraft equipment : wind shear warning other flight crewa other flight crewb
Resolutory Action	controller : provided flight assist flight crew : executed go around flight crew : exited adverse environment
Consequence	faa : reviewed incident with flight crew other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance Weather Environmental Factor
Primary Problem	Weather

Narrative:

The aircraft experienced an unanticipated hail encounter on approach to runway 19R at iad. While in the descent to iad, several small cells were observed on radar in the washington area. One cell, displayed in red, about 2 by 3 mi across was observed near the rinks LOM. Both pilots estimated the tops of the cells to be about 10000 ft or less. About 10 mi from rinks the captain, who was the PNF, asked approach about conditions on final approach. The controller responded that there were 'no complaints.' based on this report and by observing that other cells in the area had bases generally above 2000 ft, both pilots agreed that it was likely that VMC would be maintained for most of the approach. At 5 mi from the LOM, the captain again inquired about conditions on final. The response again was 'no complaints.' during this time, the crew observed 3-4 aircraft on TCASII transit final approach to landing. Approaching rinks, it was noted on radar that the cell had moved east and was mostly clear of the final approach course. At about this time, approach asked the aircraft ahead of us about conditions on final. He responded that aircraft 'would lose sight of the runway.' we could see now that we would enter IMC on the approach. Shortly after passing rinks, the aircraft entered rain, followed very shortly by what seemed to be small hail. The hail lasted for 5-10 seconds. It was followed by heavy rain. At this time, the autoplt disconnected and the flight director disappeared from view. Due to the rapidly deteriorating conditions, the captain instructed the first officer to initiate a go around. As the go around was initiated, a single windshear warning sounded. The aircraft quickly returned to VMC and stable flight conditions. An uneventful approach and landing was made. At the gate, an entry regarding hail encounter was made in the logbook. The crew observed no noticeable damage.

Original NASA ASRS Text

Title: DURING FINAL APCH, ACFT ENCOUNTERS HVY RAIN AND HAIL. WINDSHEAR WARNING SOUNDED BY ACFT GPWS SYS. FLC INITIATES GAR.

Narrative: THE ACFT EXPERIENCED AN UNANTICIPATED HAIL ENCOUNTER ON APCH TO RWY 19R AT IAD. WHILE IN THE DSCNT TO IAD, SEVERAL SMALL CELLS WERE OBSERVED ON RADAR IN THE WASHINGTON AREA. ONE CELL, DISPLAYED IN RED, ABOUT 2 BY 3 MI ACROSS WAS OBSERVED NEAR THE RINKS LOM. BOTH PLTS ESTIMATED THE TOPS OF THE CELLS TO BE ABOUT 10000 FT OR LESS. ABOUT 10 MI FROM RINKS THE CAPT, WHO WAS THE PNF, ASKED APCH ABOUT CONDITIONS ON FINAL APCH. THE CTLR RESPONDED THAT THERE WERE 'NO COMPLAINTS.' BASED ON THIS REPORT AND BY OBSERVING THAT OTHER CELLS IN THE AREA HAD BASES GENERALLY ABOVE 2000 FT, BOTH PLTS AGREED THAT IT WAS LIKELY THAT VMC WOULD BE MAINTAINED FOR MOST OF THE APCH. AT 5 MI FROM THE LOM, THE CAPT AGAIN INQUIRED ABOUT CONDITIONS ON FINAL. THE RESPONSE AGAIN WAS 'NO COMPLAINTS.' DURING THIS TIME, THE CREW OBSERVED 3-4 ACFT ON TCASII TRANSIT FINAL APCH TO LNDG. APPROACHING RINKS, IT WAS NOTED ON RADAR THAT THE CELL HAD MOVED E AND WAS MOSTLY CLR OF THE FINAL APCH COURSE. AT ABOUT THIS TIME, APCH ASKED THE ACFT AHEAD OF US ABOUT CONDITIONS ON FINAL. HE RESPONDED THAT ACFT 'WOULD LOSE SIGHT OF THE RWY.' WE COULD SEE NOW THAT WE WOULD ENTER IMC ON THE APCH. SHORTLY AFTER PASSING RINKS, THE ACFT ENTERED RAIN, FOLLOWED VERY SHORTLY BY WHAT SEEMED TO BE SMALL HAIL. THE HAIL LASTED FOR 5-10 SECONDS. IT WAS FOLLOWED BY HVY RAIN. AT THIS TIME, THE AUTOPLT DISCONNECTED AND THE FLT DIRECTOR DISAPPEARED FROM VIEW. DUE TO THE RAPIDLY DETERIORATING CONDITIONS, THE CAPT INSTRUCTED THE FO TO INITIATE A GAR. AS THE GAR WAS INITIATED, A SINGLE WINDSHEAR WARNING SOUNDED. THE ACFT QUICKLY RETURNED TO VMC AND STABLE FLT CONDITIONS. AN UNEVENTFUL APCH AND LNDG WAS MADE. AT THE GATE, AN ENTRY REGARDING HAIL ENCOUNTER WAS MADE IN THE LOGBOOK. THE CREW OBSERVED NO NOTICEABLE DAMAGE.

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.

During final approach, aircraft encounters heavy rain and hail. Windshear warning sounded by aircraft GPWS system. Flight crew initiates go around.