A cessna 560X on a visual approach at 3000 ft had the emergency pressure valve cycle open and close ...

Attributes
ACN	480614
Time
Date	200007
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ism.airport
Altitude	msl single value : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Citation Excel
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	descent : vacating altitude
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 100 flight time total : 16000 flight time type : 460
ASRS Report	480614
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : overcame equipment problem
Consequence	other
Supplementary
Problem Areas	FAA Maintenance Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

When approaching ism we were at 3000 ft and told to report ism for the visual approach we saw the airport and called in sight, I expected to be cleared for visual and at the time of ATC answer we had an emergency pressure valve open in the aircraft and shut off automatic (it cycled) on and off. With no warning light. Because this was not addressed in possible chklst procedure,. We stumped and distracted. I assumed we were cleared for the visual to runway 15 but my copilot did not advise that we were to maintain 3000 feet. We left 3000 ft for 2000 ft and then canceled IFR and was told that we should not have left 3000 ft. Cessna says excels (560) are experiencing bad emergency pressure valves. Callback conversation with reporter revealed the following information: the reporter stated the emergency pressure valve opens when a loss of cabin pressure occurs and dumps engine bleed air directly into the cabin. The reporter said this airplane is on its third valve and will need another valve when cessna comes up with a modified valve to correct its current problems. The reporter said the problem is the spring pressure in the valve is not adequate mainly because the airplanes have had uprgraded higher thrust engines installed. The reporter stated this is an ongoing problem with the 560X model. The reporter stated that when this valve opens up the noise is almost unbearable and the cabin gets real warm.

Original NASA ASRS Text

Title: A CESSNA 560X ON A VISUAL APCH AT 3000 FT HAD THE EMER PRESSURE VALVE CYCLE OPEN AND CLOSE WITH A DEAFENING ROAR CAUSING A LOSS OF COMMUNICATION.

Narrative: WHEN APPROACHING ISM WE WERE AT 3000 FT AND TOLD TO REPORT ISM FOR THE VISUAL APCH WE SAW THE ARPT AND CALLED IN SIGHT, I EXPECTED TO BE CLEARED FOR VISUAL AND AT THE TIME OF ATC ANSWER WE HAD AN EMER PRESSURE VALVE OPEN IN THE ACFT AND SHUT OFF AUTO (IT CYCLED) ON AND OFF. WITH NO WARNING LIGHT. BECAUSE THIS WAS NOT ADDRESSED IN POSSIBLE CHKLST PROC,. WE STUMPED AND DISTRACTED. I ASSUMED WE WERE CLEARED FOR THE VISUAL TO RWY 15 BUT MY COPLT DID NOT ADVISE THAT WE WERE TO MAINTAIN 3000 FEET. WE LEFT 3000 FT FOR 2000 FT AND THEN CANCELED IFR AND WAS TOLD THAT WE SHOULD NOT HAVE LEFT 3000 FT. CESSNA SAYS EXCELS (560) ARE EXPERIENCING BAD EMER PRESSURE VALVES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE EMER PRESSURE VALVE OPENS WHEN A LOSS OF CABIN PRESSURE OCCURS AND DUMPS ENG BLEED AIR DIRECTLY INTO THE CABIN. THE RPTR SAID THIS AIRPLANE IS ON ITS THIRD VALVE AND WILL NEED ANOTHER VALVE WHEN CESSNA COMES UP WITH A MODIFIED VALVE TO CORRECT ITS CURRENT PROBLEMS. THE RPTR SAID THE PROBLEM IS THE SPRING PRESSURE IN THE VALVE IS NOT ADEQUATE MAINLY BECAUSE THE AIRPLANES HAVE HAD UPRGRADED HIGHER THRUST ENGS INSTALLED. THE RPTR STATED THIS IS AN ONGOING PROBLEM WITH THE 560X MODEL. THE RPTR STATED THAT WHEN THIS VALVE OPENS UP THE NOISE IS ALMOST UNBEARABLE AND THE CABIN GETS REAL WARM.

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 cessna 560X on a visual approach at 3000 ft had the emergency pressure valve cycle open and close with a deafening roar causing a loss of communication.