Narrative:

We were climbing through 15000 ft MSL with clearance to FL230. Our position was over the atlantic ocean between the new jersey shore and long island, heading east to join J121. With a cabin differential of 4.6 psi, a rapid decompression occurred, and the cabin altitude quickly climbed to the ambient altitude. We stopped the climb, then simultaneously informed ATC that we needed to descend immediately to 10000 ft MSL and began an expedited descent at 4000 FPM. ZNY cleared us initially to 12000 ft MSL. We responded by emphasizing a need to descend to 10000 ft MSL. In compliance with the memory action items from the emergency checklist for cabin decompression, I (as PNF) donned my oxygen mask first. We xferred control of the airplane, and then the first officer donned his mask. During the donning of the masks and xfer of controls, we announced to ZNY that we had to continue the descent to 10000 ft MSL due to a pressurization problem. However, once we both had our masks on, the radio was barely audible. This was due to a combination of factors including the noise of the air flow through the unpressurized cabin, the reduced noise attenuation capabilities of headsets worn over quick-don oxygen masks, the amplified noise of oxygen flowing through our masks which are equipped with microphones, and the increased noise of operating with propellers at maximum RPM (for the expedited descent). As a result, we continued to 10000 ft MSL uncertain of having a clearance to continue below 12000 ft MSL, having transmitted that intention twice, and not having heard a response. Once level at 10000 ft MSL, we discontinued oxygen use and resumed normal communications with ATC, explained that we had experienced cabin depressurization, and announced our intention to divert to lga. Although jfk was 4 mi closer than lga (DME indicated 51 NM and 55 NM, respectively), we chose lga. In choosing the nearest suitable airport, lga made more sense since it was familiar to both crew members, and neither crew member had ever landed at jfk before. In short, the extra 1 min of flying time to go to lga instead of jfk was a small tradeoff for greater familiarity. 15 mins after the decompression, we made a safe landing at lga.

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Original NASA ASRS Text

Title: AN LTT TURBOPROP ACR FLC LOST PRESSURIZATION AT 15000 FT DURING CLB. THEY OBTAINED A DSCNT CLRNC, BUT DURING THEIR MANEUVER THEY DISCOVERED THAT ATTEMPTING TO COM WHILE WEARING AN OXYGEN MASK, EVEN WITH HEADSETS, IS VERY DIFFICULT. THEY WERE ABLE TO SUCCESSFULLY DIVERT TO A SAFE LNDG.

Narrative: WE WERE CLBING THROUGH 15000 FT MSL WITH CLRNC TO FL230. OUR POS WAS OVER THE ATLANTIC OCEAN BTWN THE NEW JERSEY SHORE AND LONG ISLAND, HDG E TO JOIN J121. WITH A CABIN DIFFERENTIAL OF 4.6 PSI, A RAPID DECOMPRESSION OCCURRED, AND THE CABIN ALT QUICKLY CLBED TO THE AMBIENT ALT. WE STOPPED THE CLB, THEN SIMULTANEOUSLY INFORMED ATC THAT WE NEEDED TO DSND IMMEDIATELY TO 10000 FT MSL AND BEGAN AN EXPEDITED DSCNT AT 4000 FPM. ZNY CLRED US INITIALLY TO 12000 FT MSL. WE RESPONDED BY EMPHASIZING A NEED TO DSND TO 10000 FT MSL. IN COMPLIANCE WITH THE MEMORY ACTION ITEMS FROM THE EMER CHKLIST FOR CABIN DECOMPRESSION, I (AS PNF) DONNED MY OXYGEN MASK FIRST. WE XFERRED CTL OF THE AIRPLANE, AND THEN THE FO DONNED HIS MASK. DURING THE DONNING OF THE MASKS AND XFER OF CTLS, WE ANNOUNCED TO ZNY THAT WE HAD TO CONTINUE THE DSCNT TO 10000 FT MSL DUE TO A PRESSURIZATION PROB. HOWEVER, ONCE WE BOTH HAD OUR MASKS ON, THE RADIO WAS BARELY AUDIBLE. THIS WAS DUE TO A COMBINATION OF FACTORS INCLUDING THE NOISE OF THE AIR FLOW THROUGH THE UNPRESSURIZED CABIN, THE REDUCED NOISE ATTENUATION CAPABILITIES OF HEADSETS WORN OVER QUICK-DON OXYGEN MASKS, THE AMPLIFIED NOISE OF OXYGEN FLOWING THROUGH OUR MASKS WHICH ARE EQUIPPED WITH MICROPHONES, AND THE INCREASED NOISE OF OPERATING WITH PROPS AT MAX RPM (FOR THE EXPEDITED DSCNT). AS A RESULT, WE CONTINUED TO 10000 FT MSL UNCERTAIN OF HAVING A CLRNC TO CONTINUE BELOW 12000 FT MSL, HAVING XMITTED THAT INTENTION TWICE, AND NOT HAVING HEARD A RESPONSE. ONCE LEVEL AT 10000 FT MSL, WE DISCONTINUED OXYGEN USE AND RESUMED NORMAL COMS WITH ATC, EXPLAINED THAT WE HAD EXPERIENCED CABIN DEPRESSURIZATION, AND ANNOUNCED OUR INTENTION TO DIVERT TO LGA. ALTHOUGH JFK WAS 4 MI CLOSER THAN LGA (DME INDICATED 51 NM AND 55 NM, RESPECTIVELY), WE CHOSE LGA. IN CHOOSING THE NEAREST SUITABLE ARPT, LGA MADE MORE SENSE SINCE IT WAS FAMILIAR TO BOTH CREW MEMBERS, AND NEITHER CREW MEMBER HAD EVER LANDED AT JFK BEFORE. IN SHORT, THE EXTRA 1 MIN OF FLYING TIME TO GO TO LGA INSTEAD OF JFK WAS A SMALL TRADEOFF FOR GREATER FAMILIARITY. 15 MINS AFTER THE DECOMPRESSION, WE MADE A SAFE LNDG AT LGA.

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.