Narrative:

Approaching iad from clt on coatt 3 arrival. Painted WX line paralleling arrival route. WX was narrow (5-10 mi) by 100 mi long, with widely scattered cells. Asked center for 20-30 degree deviation right of course to avoid WX. ATC advised another carrier passed through an area off our left at same flight level (FL220) just a min before and experienced 'just a few bumps.' I saw nothing on radar more than rain showers (green) and visually observed a valley with cumulus tops not more than 1000-2000 ft above our altitude. Based on this, I elected to traverse the line which appeared no more than 4 mi in width. I previously had asked the first officer to seat the people and ask the flight attendants to discontinue service. Just prior to entering the clouds I asked the first officer to turn on engine, wing and tail anti-ice as the outside air temperature was plus 5 degrees. As we began our 90 degree turn, the radar began to paint red where it was previously green and we encountered heavy precipitation and moderate turbulence. We exited the WX in approximately 1 1/2 mins and continued a normal VFR approach and landing. Although no one was injured, some coffee was spilled and a disconcerting ride was experienced. Upon post-flight inspection, it was discovered that our aircraft experienced hail damage which necessitated radome replacement and a number of minor sheet metal repairs before further revenue service. 2 known, but graphically reiterated lessons were reinforced here. Never be persuaded by ATC to do something your first judgement inclines you not to do -- especially in WX which their radar does not adequately depict and, severe WX can and does exist in rather passive looking forms. Evidently we topped a developing hail shaft and even at FL220, it's best to avoid all convective activity. Supplemental information from acn 246094: as we entered the clouds, we encountered moderate turbulence and heavy rain which also had some hail which we didn't realize until much later. After clearing the WX, we advised ATC not to send any other aircraft through that area. On post-flight, damage was noted on radome, leading edges and navigation lights.

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Original NASA ASRS Text

Title: ACFT DAMAGED AFTER ENCOUNTERING HAIL FROM ASSOCIATED TSTM ACTIVITY.

Narrative: APCHING IAD FROM CLT ON COATT 3 ARR. PAINTED WX LINE PARALLELING ARR RTE. WX WAS NARROW (5-10 MI) BY 100 MI LONG, WITH WIDELY SCATTERED CELLS. ASKED CTR FOR 20-30 DEG DEV R OF COURSE TO AVOID WX. ATC ADVISED ANOTHER CARRIER PASSED THROUGH AN AREA OFF OUR L AT SAME FLT LEVEL (FL220) JUST A MIN BEFORE AND EXPERIENCED 'JUST A FEW BUMPS.' I SAW NOTHING ON RADAR MORE THAN RAIN SHOWERS (GREEN) AND VISUALLY OBSERVED A VALLEY WITH CUMULUS TOPS NOT MORE THAN 1000-2000 FT ABOVE OUR ALT. BASED ON THIS, I ELECTED TO TRAVERSE THE LINE WHICH APPEARED NO MORE THAN 4 MI IN WIDTH. I PREVIOUSLY HAD ASKED THE FO TO SEAT THE PEOPLE AND ASK THE FLT ATTENDANTS TO DISCONTINUE SVC. JUST PRIOR TO ENTERING THE CLOUDS I ASKED THE FO TO TURN ON ENG, WING AND TAIL ANTI-ICE AS THE OUTSIDE AIR TEMP WAS PLUS 5 DEGS. AS WE BEGAN OUR 90 DEG TURN, THE RADAR BEGAN TO PAINT RED WHERE IT WAS PREVIOUSLY GREEN AND WE ENCOUNTERED HVY PRECIPITATION AND MODERATE TURB. WE EXITED THE WX IN APPROX 1 1/2 MINS AND CONTINUED A NORMAL VFR APCH AND LNDG. ALTHOUGH NO ONE WAS INJURED, SOME COFFEE WAS SPILLED AND A DISCONCERTING RIDE WAS EXPERIENCED. UPON POST-FLT INSPECTION, IT WAS DISCOVERED THAT OUR ACFT EXPERIENCED HAIL DAMAGE WHICH NECESSITATED RADOME REPLACEMENT AND A NUMBER OF MINOR SHEET METAL REPAIRS BEFORE FURTHER REVENUE SVC. 2 KNOWN, BUT GRAPHICALLY REITERATED LESSONS WERE REINFORCED HERE. NEVER BE PERSUADED BY ATC TO DO SOMETHING YOUR FIRST JUDGEMENT INCLINES YOU NOT TO DO -- ESPECIALLY IN WX WHICH THEIR RADAR DOES NOT ADEQUATELY DEPICT AND, SEVERE WX CAN AND DOES EXIST IN RATHER PASSIVE LOOKING FORMS. EVIDENTLY WE TOPPED A DEVELOPING HAIL SHAFT AND EVEN AT FL220, IT'S BEST TO AVOID ALL CONVECTIVE ACTIVITY. SUPPLEMENTAL INFO FROM ACN 246094: AS WE ENTERED THE CLOUDS, WE ENCOUNTERED MODERATE TURB AND HVY RAIN WHICH ALSO HAD SOME HAIL WHICH WE DIDN'T REALIZE UNTIL MUCH LATER. AFTER CLRING THE WX, WE ADVISED ATC NOT TO SEND ANY OTHER ACFT THROUGH THAT AREA. ON POST-FLT, DAMAGE WAS NOTED ON RADOME, LEADING EDGES AND NAV LIGHTS.

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.