Narrative:

On departure from jnw airport on special departure was unable to maintain VFR to required altitude of 4500 ft. WX reported at time of departure was 1500 ft scattered, 3500 ft scattered, 4500 ft overcast. Used runway 8 departure due to takeoff weight. Ceiling was reported and looked high enough for the procedure. At 3500 ft entered clouds, continued climb without terrain issues using enhanced GPWS display as backup. After consideration I would not use this procedure unless tops of surrounding terrain was visible. Callback conversation with reporter revealed the following information: reporter was concerned that he flew a departure procedure that required VFR to 4500 ft altitude but clouds were at 3500 ft. This is a special departure used by the air carrier. It is published on their airport pages, but is not available to other air carrier companies. The reporter assumes the departure procedure is approved by the FAA. The problem with the procedure is that no one can tell with certainty how high the clouds are along the route of the departure. So, when a flight crew accepts such a departure, they may not be able to comply with the en route restrs of the departure. In this case, the aircraft had new enhanced GPWS and the flight crew used its mapping ability to assure clearance from mountains.

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Original NASA ASRS Text

Title: A B737-400 DEPARTS JNU, AK, TO FLY A VFR DEP. DEP CANNOT BE FLOWN COMPLETELY VFR BECAUSE OF CLOUDS BELOW THE VFR LIMITS OF THE DEP.

Narrative: ON DEP FROM JNW ARPT ON SPECIAL DEP WAS UNABLE TO MAINTAIN VFR TO REQUIRED ALT OF 4500 FT. WX RPTED AT TIME OF DEP WAS 1500 FT SCATTERED, 3500 FT SCATTERED, 4500 FT OVCST. USED RWY 8 DEP DUE TO TKOF WT. CEILING WAS RPTED AND LOOKED HIGH ENOUGH FOR THE PROC. AT 3500 FT ENTERED CLOUDS, CONTINUED CLB WITHOUT TERRAIN ISSUES USING ENHANCED GPWS DISPLAY AS BACKUP. AFTER CONSIDERATION I WOULD NOT USE THIS PROC UNLESS TOPS OF SURROUNDING TERRAIN WAS VISIBLE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR WAS CONCERNED THAT HE FLEW A DEP PROC THAT REQUIRED VFR TO 4500 FT ALT BUT CLOUDS WERE AT 3500 FT. THIS IS A SPECIAL DEP USED BY THE ACR. IT IS PUBLISHED ON THEIR ARPT PAGES, BUT IS NOT AVAILABLE TO OTHER ACR COMPANIES. THE RPTR ASSUMES THE DEP PROC IS APPROVED BY THE FAA. THE PROB WITH THE PROC IS THAT NO ONE CAN TELL WITH CERTAINTY HOW HIGH THE CLOUDS ARE ALONG THE RTE OF THE DEP. SO, WHEN A FLC ACCEPTS SUCH A DEP, THEY MAY NOT BE ABLE TO COMPLY WITH THE ENRTE RESTRS OF THE DEP. IN THIS CASE, THE ACFT HAD NEW ENHANCED GPWS AND THE FLC USED ITS MAPPING ABILITY TO ASSURE CLRNC FROM MOUNTAINS.

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.