A C525 crew, during cruise at FL390, experienced a door seal leak, spawning an immediate descent to ...

Attributes
ACN	550976
Time
Date	200206
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : atl.airport
State Reference	GA
Altitude	msl single value : 39000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc tower : sch.tower
Operator	general aviation : personal
Make Model Name	Citationjet, C525/C526
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 7000
ASRS Report	550976
Person 2
Affiliation	other
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : master caution light door seal annun. light other flight crewa
Resolutory Action	controller : provided flight assist flight crew : declared emergency flight crew : overcame equipment problem other
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Aircraft
Primary Problem	Aircraft

Narrative:

I was level at FL390. A master caution light came on and the door seal annunciator light illuminated and within 40 seconds heard the seal itself start leaking. I called ZTL and started an immediate descent. ATC asked if I needed lower, but I was already descending by that time. I asked for at least down to FL250. The aircraft is equipped with TCASII and never saw any conflicts. Upon passing through FL300, the seal reseated and I leveled off at FL250 and continued the flight at FL250. Upon landing, I left 1 engine running and tripped the door seal switch and blew out condensation which was the culprit when it froze at altitude. Sorry for any inconvenience this caused. ATC was fully cooperative and did a very good job.

Original NASA ASRS Text

Title: A C525 CREW, DURING CRUISE AT FL390, EXPERIENCED A DOOR SEAL LEAK, SPAWNING AN IMMEDIATE DSCNT TO A LOWER ALT.

Narrative: I WAS LEVEL AT FL390. A MASTER CAUTION LIGHT CAME ON AND THE DOOR SEAL ANNUNCIATOR LIGHT ILLUMINATED AND WITHIN 40 SECONDS HEARD THE SEAL ITSELF START LEAKING. I CALLED ZTL AND STARTED AN IMMEDIATE DSCNT. ATC ASKED IF I NEEDED LOWER, BUT I WAS ALREADY DSNDING BY THAT TIME. I ASKED FOR AT LEAST DOWN TO FL250. THE ACFT IS EQUIPPED WITH TCASII AND NEVER SAW ANY CONFLICTS. UPON PASSING THROUGH FL300, THE SEAL RESEATED AND I LEVELED OFF AT FL250 AND CONTINUED THE FLT AT FL250. UPON LNDG, I LEFT 1 ENG RUNNING AND TRIPPED THE DOOR SEAL SWITCH AND BLEW OUT CONDENSATION WHICH WAS THE CULPRIT WHEN IT FROZE AT ALT. SORRY FOR ANY INCONVENIENCE THIS CAUSED. ATC WAS FULLY COOPERATIVE AND DID A VERY GOOD JOB.

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.

A C525 crew, during cruise at FL390, experienced a door seal leak, spawning an immediate descent to a lower altitude.