Narrative:

Flight from ZZZ1 to ZZZ2 began with normal pre-departure preparation. A check of en route and ZZZ2 WX showed no 'tp's' were in effect and had no WX abnormalities or LLWS advisories. Aircraft had no outstanding write-ups and only MEL/cdl item was two -15A engine confign. Departed and used the radar to navigation and avoid convective buildups en route south of airport. En route, received an ACARS message from dispatch that destination had previously had cumulonimbus activity in the area and that it had moved past the destination and would not be a factor by our arrival time. Arrival was a vector to intercept the arrival into airport. During descent abeam airport ATC advised of light to moderate turbulence below 8000 ft. Descent was without significant turbulence and arrival procedures were normal. Approach was to runway 19L and a visual approach was accepted at approximately 10-12 mi on final. Confign was begun to aid descent and base turned with an angling intercept to ILS final approach course and GS. After final confign and at approximately 1200-1500 ft AGL I felt and observed a reduction in indicated airspeed and associated seat of the pants feel. I announced to the first officer 'windshear' as the loss was between 5-15 KTS total and added power and leveled the aircraft. Immediately an additional 10-15 KTS of loss was observed and airspeed was 125 KIAS. I advanced the thrust levers to the mechanical stops and executed a windshear recovery. At that instant the reactive windshear red performance decreasing warning annunciated. Recovery from airspeed decay was immediate with application of maximum thrust and first officer relayed the increasing parameters. Aoa (angle of bank) was reduced with airspeed gain and confign maintained. After several mi a confign cleanup was performed. ATC was advised of the go around for windshear and we requested extended local area vectors. We asked and received current conditions and wind information and were advised that there were no LLWS advisories. As the normal engine operating parameters had been exceeded, we had a requirement to land at the nearest suitable airport in point of time. Part 121 operations were continuously in operation at current airport and runway 19R had no report of windshear from subsequent arrs. I elected to approach runway 19R following the report of an air carrier MD80 and his encountered conditions. On his rollout he reported a 5 KT loss of airspeed on approach to runway 19R. I began a visual approach to runway 19R. I had previously briefed the cabin crew and passenger of the reason for the go around. Very shortly after acceptance of approach clearance we encountered another windshear with less than 10 KIAS change and a more immediate red windshear warning. A windshear recovery again was initiated with maximum thrust and climb, and recovery of any decay was immediate. Following this approach we contacted dispatch and advised them of our intentions. We took vectors west of airport and briefed the passenger and cabin crew. In that time an assessment of conditions was made. We had an airport below us reporting no adverse meteorological conditions. We were VMC with all the latest WX avoidance capabilities from ATC. We had positive PIREPS from part 121 operators and the requirement to land as soon as possible. I asked for an approach to runway 9 and we were vectored to the final approach course. The crosswind component was 9 KTS and the distance from the north/south runways would give us an approach flight path 8-10 mi diagonally from the encountered shear. After alignment with the runway 9 flight path we received a yellow windshear performance increasing warning with little change to aircraft speed or pitch. I executed a normal go around and climb/cleanup and advised ATC. I informed them we wanted to land at the nearest suitable airport other than current airport and I asked them as to the availability of a local airport just south. It has closed since my last military experience there. I contacted dispatch and advised them of our diversion and intentions. The dispatcher provided alternates of ZZZ3 and ZZZ4. I declined those alternates due to exceeding normal engine parameters in a mechanical stop thrust go around. There was disagreement from the dispatcher, and maintenance control confirmed the requirement to land at the nearest suitable airfield, in point of time. I asked approach for that airfield and they advised it was a military base. I asked for direct vectors to the AFB. At this time we experienced violent rotational turbulence at approximately 4000 ft and I took the aircraft controls again. The experience was similar to wake turbulence encountered behind a heavy jet. It required continuous control input to prevent lateral roll. It abated after 10-15 seconds. I briefed the cabin crew and passenger that we were diverting to the AFB and that conditions were excellent and we would land in about 15 mins. I declared an emergency and received landing clearance at the AFB and flew a visual approach to runway with ILS backup. Approach was uneventful and we rolled to the end and cleared the runway. The passenger were briefed and I deplaned. He provided every conceivable assistance to us and the passenger. I received a phone call immediately from the FAA in washington. She advised me that there were no adverse meteorological conditions noted by the FAA at prior destination, and I reported my encounters with windshear. We arrived at destination at approximately XH30 CDT. My crew deadheaded to ZZZ5 and were relieved for company business from further scheduling (pilots only). Supplemental information from acn 625076: missed 2 approachs due to windshear at ZZZ1. Crew advanced the throttles to the mechanical stops in the process (twice). Crew considered ZZZ2 the nearest suitable airport, and attempted a third approach to another runway. ZZZ2 was VFR (140 degrees 10 KTS 10 SM-RA few 060 overcast 140 22/19). The radar painted light rain in the area. A third approach was discussed and started before I received the 'twip' for windshear. A few mins later the crew called to advise of their third missed approach to runway 9, due to windshear. At this point, the crew deemed ZZZ3 the nearest suitable airport and wanted the field conditions and NOTAMS. Before I was able to obtain this information, the crew called to say that ZZZ3 was closed. Before I was able to get a closer, suitable alternate for the crew, they departed for ZZZ4, located about xx mi southeast of ZZZ2. This was an unauthorized airport. I stated that the captain was exercising his emergency authority/authorized. I sent as much information about ZZZ4 to the crew via ACARS before the crew arrived. During this event, I assisted the crew as much as possible. I tried to get maintenance help for the crew, and searched excessively for the reference that the crew was using (aom). I was not able to find a closer, more suitable, and authority/authorized diversion alternate for the crew due to time constraints and lack of information.

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Original NASA ASRS Text

Title: DC9-30 CREW DIVERTED TO A MIL AIR FORCE BASE AFTER ENCOUNTERING 3 WINDSHEAR EVENTS AT THE DEST ARPT.

Narrative: FLT FROM ZZZ1 TO ZZZ2 BEGAN WITH NORMAL PRE-DEP PREPARATION. A CHK OF ENRTE AND ZZZ2 WX SHOWED NO 'TP'S' WERE IN EFFECT AND HAD NO WX ABNORMALITIES OR LLWS ADVISORIES. ACFT HAD NO OUTSTANDING WRITE-UPS AND ONLY MEL/CDL ITEM WAS TWO -15A ENG CONFIGN. DEPARTED AND USED THE RADAR TO NAV AND AVOID CONVECTIVE BUILDUPS ENRTE S OF ARPT. ENRTE, RECEIVED AN ACARS MESSAGE FROM DISPATCH THAT DEST HAD PREVIOUSLY HAD CUMULONIMBUS ACTIVITY IN THE AREA AND THAT IT HAD MOVED PAST THE DEST AND WOULD NOT BE A FACTOR BY OUR ARR TIME. ARR WAS A VECTOR TO INTERCEPT THE ARR INTO ARPT. DURING DSCNT ABEAM ARPT ATC ADVISED OF LIGHT TO MODERATE TURB BELOW 8000 FT. DSCNT WAS WITHOUT SIGNIFICANT TURB AND ARR PROCS WERE NORMAL. APCH WAS TO RWY 19L AND A VISUAL APCH WAS ACCEPTED AT APPROX 10-12 MI ON FINAL. CONFIGN WAS BEGUN TO AID DSCNT AND BASE TURNED WITH AN ANGLING INTERCEPT TO ILS FINAL APCH COURSE AND GS. AFTER FINAL CONFIGN AND AT APPROX 1200-1500 FT AGL I FELT AND OBSERVED A REDUCTION IN INDICATED AIRSPD AND ASSOCIATED SEAT OF THE PANTS FEEL. I ANNOUNCED TO THE FO 'WINDSHEAR' AS THE LOSS WAS BTWN 5-15 KTS TOTAL AND ADDED PWR AND LEVELED THE ACFT. IMMEDIATELY AN ADDITIONAL 10-15 KTS OF LOSS WAS OBSERVED AND AIRSPD WAS 125 KIAS. I ADVANCED THE THRUST LEVERS TO THE MECHANICAL STOPS AND EXECUTED A WINDSHEAR RECOVERY. AT THAT INSTANT THE REACTIVE WINDSHEAR RED PERFORMANCE DECREASING WARNING ANNUNCIATED. RECOVERY FROM AIRSPD DECAY WAS IMMEDIATE WITH APPLICATION OF MAX THRUST AND FO RELAYED THE INCREASING PARAMETERS. AOA (ANGLE OF BANK) WAS REDUCED WITH AIRSPD GAIN AND CONFIGN MAINTAINED. AFTER SEVERAL MI A CONFIGN CLEANUP WAS PERFORMED. ATC WAS ADVISED OF THE GAR FOR WINDSHEAR AND WE REQUESTED EXTENDED LCL AREA VECTORS. WE ASKED AND RECEIVED CURRENT CONDITIONS AND WIND INFO AND WERE ADVISED THAT THERE WERE NO LLWS ADVISORIES. AS THE NORMAL ENG OPERATING PARAMETERS HAD BEEN EXCEEDED, WE HAD A REQUIREMENT TO LAND AT THE NEAREST SUITABLE ARPT IN POINT OF TIME. PART 121 OPS WERE CONTINUOUSLY IN OP AT CURRENT ARPT AND RWY 19R HAD NO RPT OF WINDSHEAR FROM SUBSEQUENT ARRS. I ELECTED TO APCH RWY 19R FOLLOWING THE RPT OF AN ACR MD80 AND HIS ENCOUNTERED CONDITIONS. ON HIS ROLLOUT HE RPTED A 5 KT LOSS OF AIRSPD ON APCH TO RWY 19R. I BEGAN A VISUAL APCH TO RWY 19R. I HAD PREVIOUSLY BRIEFED THE CABIN CREW AND PAX OF THE REASON FOR THE GAR. VERY SHORTLY AFTER ACCEPTANCE OF APCH CLRNC WE ENCOUNTERED ANOTHER WINDSHEAR WITH LESS THAN 10 KIAS CHANGE AND A MORE IMMEDIATE RED WINDSHEAR WARNING. A WINDSHEAR RECOVERY AGAIN WAS INITIATED WITH MAX THRUST AND CLB, AND RECOVERY OF ANY DECAY WAS IMMEDIATE. FOLLOWING THIS APCH WE CONTACTED DISPATCH AND ADVISED THEM OF OUR INTENTIONS. WE TOOK VECTORS W OF ARPT AND BRIEFED THE PAX AND CABIN CREW. IN THAT TIME AN ASSESSMENT OF CONDITIONS WAS MADE. WE HAD AN ARPT BELOW US RPTING NO ADVERSE METEOROLOGICAL CONDITIONS. WE WERE VMC WITH ALL THE LATEST WX AVOIDANCE CAPABILITIES FROM ATC. WE HAD POSITIVE PIREPS FROM PART 121 OPERATORS AND THE REQUIREMENT TO LAND ASAP. I ASKED FOR AN APCH TO RWY 9 AND WE WERE VECTORED TO THE FINAL APCH COURSE. THE XWIND COMPONENT WAS 9 KTS AND THE DISTANCE FROM THE N/S RWYS WOULD GIVE US AN APCH FLT PATH 8-10 MI DIAGONALLY FROM THE ENCOUNTERED SHEAR. AFTER ALIGNMENT WITH THE RWY 9 FLT PATH WE RECEIVED A YELLOW WINDSHEAR PERFORMANCE INCREASING WARNING WITH LITTLE CHANGE TO ACFT SPD OR PITCH. I EXECUTED A NORMAL GAR AND CLB/CLEANUP AND ADVISED ATC. I INFORMED THEM WE WANTED TO LAND AT THE NEAREST SUITABLE ARPT OTHER THAN CURRENT ARPT AND I ASKED THEM AS TO THE AVAILABILITY OF A LCL ARPT JUST S. IT HAS CLOSED SINCE MY LAST MIL EXPERIENCE THERE. I CONTACTED DISPATCH AND ADVISED THEM OF OUR DIVERSION AND INTENTIONS. THE DISPATCHER PROVIDED ALTERNATES OF ZZZ3 AND ZZZ4. I DECLINED THOSE ALTERNATES DUE TO EXCEEDING NORMAL ENG PARAMETERS IN A MECHANICAL STOP THRUST GAR. THERE WAS DISAGREEMENT FROM THE DISPATCHER, AND MAINT CTL CONFIRMED THE REQUIREMENT TO LAND AT THE NEAREST SUITABLE AIRFIELD, IN POINT OF TIME. I ASKED APCH FOR THAT AIRFIELD AND THEY ADVISED IT WAS A MIL BASE. I ASKED FOR DIRECT VECTORS TO THE AFB. AT THIS TIME WE EXPERIENCED VIOLENT ROTATIONAL TURB AT APPROX 4000 FT AND I TOOK THE ACFT CTLS AGAIN. THE EXPERIENCE WAS SIMILAR TO WAKE TURB ENCOUNTERED BEHIND A HVY JET. IT REQUIRED CONTINUOUS CTL INPUT TO PREVENT LATERAL ROLL. IT ABATED AFTER 10-15 SECONDS. I BRIEFED THE CABIN CREW AND PAX THAT WE WERE DIVERTING TO THE AFB AND THAT CONDITIONS WERE EXCELLENT AND WE WOULD LAND IN ABOUT 15 MINS. I DECLARED AN EMER AND RECEIVED LNDG CLRNC AT THE AFB AND FLEW A VISUAL APCH TO RWY WITH ILS BACKUP. APCH WAS UNEVENTFUL AND WE ROLLED TO THE END AND CLRED THE RWY. THE PAX WERE BRIEFED AND I DEPLANED. HE PROVIDED EVERY CONCEIVABLE ASSISTANCE TO US AND THE PAX. I RECEIVED A PHONE CALL IMMEDIATELY FROM THE FAA IN WASHINGTON. SHE ADVISED ME THAT THERE WERE NO ADVERSE METEOROLOGICAL CONDITIONS NOTED BY THE FAA AT PRIOR DEST, AND I RPTED MY ENCOUNTERS WITH WINDSHEAR. WE ARRIVED AT DEST AT APPROX XH30 CDT. MY CREW DEADHEADED TO ZZZ5 AND WERE RELIEVED FOR COMPANY BUSINESS FROM FURTHER SCHEDULING (PLTS ONLY). SUPPLEMENTAL INFO FROM ACN 625076: MISSED 2 APCHS DUE TO WINDSHEAR AT ZZZ1. CREW ADVANCED THE THROTTLES TO THE MECHANICAL STOPS IN THE PROCESS (TWICE). CREW CONSIDERED ZZZ2 THE NEAREST SUITABLE ARPT, AND ATTEMPTED A THIRD APCH TO ANOTHER RWY. ZZZ2 WAS VFR (140 DEGS 10 KTS 10 SM-RA FEW 060 OVCST 140 22/19). THE RADAR PAINTED LIGHT RAIN IN THE AREA. A THIRD APCH WAS DISCUSSED AND STARTED BEFORE I RECEIVED THE 'TWIP' FOR WINDSHEAR. A FEW MINS LATER THE CREW CALLED TO ADVISE OF THEIR THIRD MISSED APCH TO RWY 9, DUE TO WINDSHEAR. AT THIS POINT, THE CREW DEEMED ZZZ3 THE NEAREST SUITABLE ARPT AND WANTED THE FIELD CONDITIONS AND NOTAMS. BEFORE I WAS ABLE TO OBTAIN THIS INFO, THE CREW CALLED TO SAY THAT ZZZ3 WAS CLOSED. BEFORE I WAS ABLE TO GET A CLOSER, SUITABLE ALTERNATE FOR THE CREW, THEY DEPARTED FOR ZZZ4, LOCATED ABOUT XX MI SE OF ZZZ2. THIS WAS AN UNAUTH ARPT. I STATED THAT THE CAPT WAS EXERCISING HIS EMER AUTH. I SENT AS MUCH INFO ABOUT ZZZ4 TO THE CREW VIA ACARS BEFORE THE CREW ARRIVED. DURING THIS EVENT, I ASSISTED THE CREW AS MUCH AS POSSIBLE. I TRIED TO GET MAINT HELP FOR THE CREW, AND SEARCHED EXCESSIVELY FOR THE REF THAT THE CREW WAS USING (AOM). I WAS NOT ABLE TO FIND A CLOSER, MORE SUITABLE, AND AUTH DIVERSION ALTERNATE FOR THE CREW DUE TO TIME CONSTRAINTS AND LACK OF INFO.

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.