An LR55 first officer reported shutting down an engine for low oil pressure in cruise flight. The fl...

Narrative:

While at FL400 we noticed a low oil pressure indication on the left engine. There was no low oil pressure light at that time. We asked ARTCC to pass a message to our dispatch about the problem and have another aircraft standing by for our passengers. We watched the indication for a time and at approximately 200 miles out from destination we noted that the pressure had fallen to 25 psi or less. We decided to put the left engine at idle. As we reduced the throttle almost immediately the pressure dropped another 10 to 15 psi and the low oil pressure light illuminated. At that time we decided to complete the precautionary engine shutdown checklist. Prior to completing the shutdown we notified ARTCC that we would not be able to maintain altitude due to having to shut down an engine and they gave us discretion to 240. During the descent ATC asked us if we would like to declare an emergency and after discussing it amongst ourselves decided that that would be best due to the weather and traffic volume at the time. After receiving the ATIS we asked ATC for a runway that would preclude any unnecessary vectoring. After reviewing and discussing the abnormal landing procedure we were cleared for and completed a normal approach and landing. After vacating the runway we taxied back to the FBO ramp without any further incident.

Original NASA ASRS Text

Title: An LR55 First Officer reported shutting down an engine for low oil pressure in cruise flight. The flight crew declared an emergency and made a normal landing.

Narrative: While at FL400 we noticed a low oil pressure indication on the left engine. There was no low oil pressure light at that time. We asked ARTCC to pass a message to our Dispatch about the problem and have another aircraft standing by for our passengers. We watched the indication for a time and at approximately 200 miles out from destination we noted that the pressure had fallen to 25 PSI or less. We decided to put the left engine at idle. As we reduced the throttle almost immediately the pressure dropped another 10 to 15 PSI and the low oil pressure light illuminated. At that time we decided to complete the precautionary engine shutdown checklist. Prior to completing the shutdown we notified ARTCC that we would not be able to maintain altitude due to having to shut down an engine and they gave us discretion to 240. During the descent ATC asked us if we would like to declare an emergency and after discussing it amongst ourselves decided that that would be best due to the weather and traffic volume at the time. After receiving the ATIS we asked ATC for a runway that would preclude any unnecessary vectoring. After reviewing and discussing the abnormal landing procedure we were cleared for and completed a normal approach and landing. After vacating the runway we taxied back to the FBO ramp without any further incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	849914
Time
Date	200908
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Learjet 55
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Turbine Engine
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 3700 Flight Crew Type 500
Events
Anomaly	Aircraft Equipment Problem Critical

An LR55 first officer reported shutting down an engine for low oil pressure in cruise flight. The flight crew declared an emergency and made a normal landing.