Narrative:

While at cruise at FL190 we heard a loud bang followed by a rush of air and momentary fog. My headset came off and the aircraft pitched down and responded strangely to elevator and stabilizer trim control. The copilot hollered, 'what the hell was that! What happened?' I told him that we had a sudden decompression and to call center and declare an emergency and that we will be making an emergency descent to 9000' on a heading of 090 degree, tell them that now. As he talked to center I checked all the systems and instruments to determine what if any other failures or problems may exist. I asked him what center said and he said that they acknowledged and cleared us. I turned left to 090 degree and started to descend. I could see ground lights on that heading and we could maintain VFR conditions if we had to. I then asked him to read the emergency checklists. I had put my headset back on at some point but could not hear well. I then sent the copilot to the cabin to check for injuries to the passengers and structural damage. He reported neg on his return. A short while later on his second or third trip back to the cabin he found that a cabin window had blown out. At that point we elected to change our destination to our maintenance airport. A few days later while discussing the situation I asked him if he was positive that he declared an emergency. He said he wasn't sure what he said or how he said it but center understood and cleared us. Failure to readback, confirm, and use standard phraseology by all concerned could have led to a conflict and further complicated an emergency situation. A return to basics in communication is essential. Safety is being compromised.

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Original NASA ASRS Text

Title: LOSS OF CABIN PRESSURE RESULTING IN DECLARING EMERGENCY AND EMERGENCY DESCENT.

Narrative: WHILE AT CRUISE AT FL190 WE HEARD A LOUD BANG FOLLOWED BY A RUSH OF AIR AND MOMENTARY FOG. MY HEADSET CAME OFF AND THE ACFT PITCHED DOWN AND RESPONDED STRANGELY TO ELEVATOR AND STAB TRIM CTL. THE COPLT HOLLERED, 'WHAT THE HELL WAS THAT! WHAT HAPPENED?' I TOLD HIM THAT WE HAD A SUDDEN DECOMPRESSION AND TO CALL CTR AND DECLARE AN EMER AND THAT WE WILL BE MAKING AN EMER DSNT TO 9000' ON A HDG OF 090 DEG, TELL THEM THAT NOW. AS HE TALKED TO CTR I CHKED ALL THE SYSTEMS AND INSTRUMENTS TO DETERMINE WHAT IF ANY OTHER FAILURES OR PROBS MAY EXIST. I ASKED HIM WHAT CTR SAID AND HE SAID THAT THEY ACKNOWLEDGED AND CLRED US. I TURNED L TO 090 DEG AND STARTED TO DSND. I COULD SEE GND LIGHTS ON THAT HDG AND WE COULD MAINTAIN VFR CONDITIONS IF WE HAD TO. I THEN ASKED HIM TO READ THE EMER CHKLISTS. I HAD PUT MY HEADSET BACK ON AT SOME POINT BUT COULD NOT HEAR WELL. I THEN SENT THE COPLT TO THE CABIN TO CHK FOR INJURIES TO THE PAXS AND STRUCTURAL DAMAGE. HE RPTED NEG ON HIS RETURN. A SHORT WHILE LATER ON HIS SEC OR THIRD TRIP BACK TO THE CABIN HE FOUND THAT A CABIN WINDOW HAD BLOWN OUT. AT THAT POINT WE ELECTED TO CHANGE OUR DEST TO OUR MAINT ARPT. A FEW DAYS LATER WHILE DISCUSSING THE SITUATION I ASKED HIM IF HE WAS POSITIVE THAT HE DECLARED AN EMER. HE SAID HE WASN'T SURE WHAT HE SAID OR HOW HE SAID IT BUT CTR UNDERSTOOD AND CLRED US. FAILURE TO READBACK, CONFIRM, AND USE STANDARD PHRASEOLOGY BY ALL CONCERNED COULD HAVE LED TO A CONFLICT AND FURTHER COMPLICATED AN EMER SITUATION. A RETURN TO BASICS IN COM IS ESSENTIAL. SAFETY IS BEING COMPROMISED.

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.