MD80 flight crew reacts to GPWS terrain warning on departure from bur at 3200 ft. Heavy rain showers...

Narrative:

Level 3 rain shower approximately 5 NM sse was moving towards the field. This is an old non-EFIS MD80; so we chose to select WX radar vice egpws due to WX on departure. Tower cleared us for takeoff heading 210 degrees; 4000 ft MSL; and then changed takeoff clearance to heading 320 degrees; 5000 ft MSL due to the WX on the departure end. At 200 ft AGL; captain selected heading select of 320 degrees; 15 degrees bank. At 1000 ft AGL; captain called for flaps up and climb power. The slats remained extended. Tower handed us off to departure and first officer checked in normal. About 1 min after takeoff; at approximately 180 KTS; climbing right 15 degree bank turn; 3200 ft MSL; the GPWS system announced 'terrain; terrain;' followed by 'pull up' and 'too low terrain.' we accomplished the red box items except used climb power; and then first officer selected mct. The radar altimeters were both very erratic and indicated 1000-800 ft and got as low as 400 ft. First officer was calling out radar altimeter altitudes and the captain was flying the flight director to about 20-25 degrees pitch; V2 + 20 KTS; rolling out to about 270 degree heading and climbing to 5000 ft MSL. The 'event' warning ceased after about 15-20 seconds. The mountains just north and west of the field were a concern and briefed earlier. Departure said 'turn right to 320 degrees and climb to 13000 ft.' we accomplished normal clean-up and after takeoff checklist items. During the climb; the first officer asked departure for the MVA right behind us and they said 3000 ft and indicated no problems. First officer told departure we just had a 'possible false terrain warning.' later during climb out; first officer called back to departure and asked them to mark their tapes and xchk our ground track due to our 'terrain warning' on departure. After much conversation about this event; captain and first officer both thought this was probably a false warning due to the heavy rain shower just left of the aircraft in our right 15 degree bank turn. But; we had to execute the proper procedure no mater what! Upon landing; captain called departure operations manager. He said he reviewed our departure with his supervisor and controllers and said our departure track was normal and had no alerts of any kind! The captain wrote up the GPWS system in log book.

Original NASA ASRS Text

Title: MD80 FLT CREW REACTS TO GPWS TERRAIN WARNING ON DEP FROM BUR AT 3200 FT. HVY RAIN SHOWERS IN VICINITY AND DEP RADAR GND TRACK INDICATED NO TERRAIN CONFLICT.

Narrative: LEVEL 3 RAIN SHOWER APPROX 5 NM SSE WAS MOVING TOWARDS THE FIELD. THIS IS AN OLD NON-EFIS MD80; SO WE CHOSE TO SELECT WX RADAR VICE EGPWS DUE TO WX ON DEP. TWR CLRED US FOR TKOF HDG 210 DEGS; 4000 FT MSL; AND THEN CHANGED TKOF CLRNC TO HDG 320 DEGS; 5000 FT MSL DUE TO THE WX ON THE DEP END. AT 200 FT AGL; CAPT SELECTED HDG SELECT OF 320 DEGS; 15 DEGS BANK. AT 1000 FT AGL; CAPT CALLED FOR FLAPS UP AND CLB PWR. THE SLATS REMAINED EXTENDED. TWR HANDED US OFF TO DEP AND FO CHKED IN NORMAL. ABOUT 1 MIN AFTER TKOF; AT APPROX 180 KTS; CLBING R 15 DEG BANK TURN; 3200 FT MSL; THE GPWS SYSTEM ANNOUNCED 'TERRAIN; TERRAIN;' FOLLOWED BY 'PULL UP' AND 'TOO LOW TERRAIN.' WE ACCOMPLISHED THE RED BOX ITEMS EXCEPT USED CLB PWR; AND THEN FO SELECTED MCT. THE RADAR ALTIMETERS WERE BOTH VERY ERRATIC AND INDICATED 1000-800 FT AND GOT AS LOW AS 400 FT. FO WAS CALLING OUT RADAR ALTIMETER ALTS AND THE CAPT WAS FLYING THE FLT DIRECTOR TO ABOUT 20-25 DEGS PITCH; V2 + 20 KTS; ROLLING OUT TO ABOUT 270 DEG HDG AND CLBING TO 5000 FT MSL. THE 'EVENT' WARNING CEASED AFTER ABOUT 15-20 SECONDS. THE MOUNTAINS JUST N AND W OF THE FIELD WERE A CONCERN AND BRIEFED EARLIER. DEP SAID 'TURN R TO 320 DEGS AND CLB TO 13000 FT.' WE ACCOMPLISHED NORMAL CLEAN-UP AND AFTER TKOF CHKLIST ITEMS. DURING THE CLB; THE FO ASKED DEP FOR THE MVA RIGHT BEHIND US AND THEY SAID 3000 FT AND INDICATED NO PROBS. FO TOLD DEP WE JUST HAD A 'POSSIBLE FALSE TERRAIN WARNING.' LATER DURING CLBOUT; FO CALLED BACK TO DEP AND ASKED THEM TO MARK THEIR TAPES AND XCHK OUR GND TRACK DUE TO OUR 'TERRAIN WARNING' ON DEP. AFTER MUCH CONVERSATION ABOUT THIS EVENT; CAPT AND FO BOTH THOUGHT THIS WAS PROBABLY A FALSE WARNING DUE TO THE HVY RAIN SHOWER JUST L OF THE ACFT IN OUR R 15 DEG BANK TURN. BUT; WE HAD TO EXECUTE THE PROPER PROC NO MATER WHAT! UPON LNDG; CAPT CALLED DEP OPS MGR. HE SAID HE REVIEWED OUR DEP WITH HIS SUPVR AND CTLRS AND SAID OUR DEP TRACK WAS NORMAL AND HAD NO ALERTS OF ANY KIND! THE CAPT WROTE UP THE GPWS SYS IN LOG BOOK.

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.

Attributes
ACN	675171
Time
Date	200510
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : vny.vor
State Reference	CA
Altitude	msl single value : 3200
Environment
Weather Elements	Rain Thunderstorm
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	675171
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude inflight encounter : weather
Independent Detector	aircraft equipment : gpws
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Weather
Primary Problem	Aircraft

MD80 flight crew reacts to GPWS terrain warning on departure from bur at 3200 ft. Heavy rain showers in vicinity and departure radar ground track indicated no terrain conflict.