ALT EXCURSION FROM PUBLISHED PROC TURN ALT. WX FACTORS.

Narrative

DURING A PROC TURN TO INBND COURSE AT EVW; TURB WAS ENCOUNTERED AND THE ACFT DSNDED BELOW THE MINIMUM ALT AT THAT SEGMENT OF THE APCH FOR ABOUT 30 OR 40 SECS. I ADDED PWR AND CLBED BACK TO THE APPROPRIATE ALT AND CONTINUED THE APCH TO A LNDG. WIND ON THE GND WAS GUSTING TO 335 KTS AND CRAB CORRECTION WAS 25 DEGS. THE AREA; GEOGRAPHICALLY IS ON THE BACKSIDE OF A RIDGE AND I SUSPECT THERE WAS SOME WAVE ACTIVITY ASSOCIATED WITH THE TURB. THE ONLY REASON FOR THIS IS THAT; SINCE THE COMPUTER SOMEWHERE MAY HAVE RECORDED AN ALT BUST; THERE IS NOT MUCH I CAN SEE IN HINDSIGHT THAT I COULD HAVE DONE TO CHANGE THE SITUATION; OTHER THAN KNOW AHEAD OF TIME THAT THERE WOULD HAVE BEEN SIGNIFICANT DOWNDRAFT. I BELIEVE WE WENT DOWN TO ABOUT 8600' IN A 9300' MEA AREA; BUT RECOVERED SOON AND CONTINUED THE APCH AT APPROPRIATE ALTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR WAS ON A MISSED APCH AND PROC TO ATTEMPT A SECOND APCH. HE WAS OPERATING IN AND OUT OF CLOUDS AND FELT ON HIS FIRST APCH IT WOULD HAVE REQUIRED TO SEVERELY MANEUVER TO GET LINED UP. ELECTED TO MISS. DID NOT CLEAN THE ACFT UP AND IN GENERAL WAS NOT FOLLOWING ESTABLISHED PROC FOR A MISS. FELT HE KNEW HIS POS AND WAS KEEPING THE ACFT SLOW AND IN CONFIGN FOR THE SECOND APCH. CENTER CTLR NOTED THE ALT DEVIATION AND THAT IS WHEN HE TOOK ACTION TO CORRECT THE ALT. ACFT DOES NOT HAVE GPWS; BUT THEY DO USE RADIO ALTIMETER AS A BACK UP IN OPS IN THE MOUNTAINOUS TERRAIN. DID NOT NOTICE THE ALT READOUT; HOWEVER. WAS JUST INTERCEPTING THE INBND R WHEN THE DOWNDRAFT ENCOUNTERED. WX WAS NEAR 1000' AND 1 MI. COUNSELED TO BE MORE AGGRESSIVE APPLYING PWR ON A MISS AND THAT ASRS IS INTERESTED IN ALL TYPES OF RPTS; NOT JUST IMMUNITY RELATED.