Narrative:

Slowed back to 225 KTS for anticipated holding going into ZZZ from west arrival at FL300; had a momentary airframe shutter/shake suspected from 2 pops that all crew members noted. Felt like first flight attendant putting cart back into storage from the cockpit area. Called back of cabin and they noted the same. Had them survey the airplane from their locations and noted nothing. No cockpit abnormal indications on any instruments at any time! Suspected possible compressor stall on one or both engines; but most of crew felt it came from left engine but could not be certain. No other indications of any kind noted! Called dispatch with patch to maintenance to notify that upon arrival in approximately 20 mins that they should examine aircraft. No control problems noted at any time; no abnormal instrument indications noted at any time. Landed ZZZ uneventfully! Debriefed maintenance of noted shake/shudder. It was not caused by windshear at altitude or wake from other aircraft. Have had compressor stall in other aircraft before and it felt similar but no other indications. Could have also been from water in fuel but pure speculation on my part. Nothing further for this report.

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Original NASA ASRS Text

Title: A B737-500 SLOWING TO 225 KTS AT FL300 HAD 2 POPS WITH AIRFRAME SHUDDER OR SHAKE. SUSPECT COMPRESSOR STALL FROM L ENG. MAINT ADVISED.

Narrative: SLOWED BACK TO 225 KTS FOR ANTICIPATED HOLDING GOING INTO ZZZ FROM W ARR AT FL300; HAD A MOMENTARY AIRFRAME SHUTTER/SHAKE SUSPECTED FROM 2 POPS THAT ALL CREW MEMBERS NOTED. FELT LIKE FIRST FLT ATTENDANT PUTTING CART BACK INTO STORAGE FROM THE COCKPIT AREA. CALLED BACK OF CABIN AND THEY NOTED THE SAME. HAD THEM SURVEY THE AIRPLANE FROM THEIR LOCATIONS AND NOTED NOTHING. NO COCKPIT ABNORMAL INDICATIONS ON ANY INSTS AT ANY TIME! SUSPECTED POSSIBLE COMPRESSOR STALL ON ONE OR BOTH ENGS; BUT MOST OF CREW FELT IT CAME FROM L ENG BUT COULD NOT BE CERTAIN. NO OTHER INDICATIONS OF ANY KIND NOTED! CALLED DISPATCH WITH PATCH TO MAINT TO NOTIFY THAT UPON ARR IN APPROX 20 MINS THAT THEY SHOULD EXAMINE ACFT. NO CTL PROBS NOTED AT ANY TIME; NO ABNORMAL INST INDICATIONS NOTED AT ANY TIME. LANDED ZZZ UNEVENTFULLY! DEBRIEFED MAINT OF NOTED SHAKE/SHUDDER. IT WAS NOT CAUSED BY WINDSHEAR AT ALT OR WAKE FROM OTHER ACFT. HAVE HAD COMPRESSOR STALL IN OTHER ACFT BEFORE AND IT FELT SIMILAR BUT NO OTHER INDICATIONS. COULD HAVE ALSO BEEN FROM WATER IN FUEL BUT PURE SPECULATION ON MY PART. NOTHING FURTHER FOR THIS RPT.

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.