Welcome Guest. Sign in or Signup

1 Answers

Oil pressure drop

Asked by: 15946 views Aircraft Systems, Aviation Headsets, Flight Instructor, General Aviation

b777-400 on take off and landing had a normal oil pressure. but in cruising the oil pressure drop below normal. how could this happen?

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

1 Answers



  1. Chris Polek on May 30, 2014

    I am not all too familiar with a B777-400 engine. But I have a lot of PT6A experience and what initially comes to mind is temperature. On takeoff the engine has not had too much time to heat up. There would be something to help regulate the temperature of the oil. At a higher power setting there could be something stuck that fixes itself at the lower power settings of landing.

    It would be interesting to see what the oil temperature is doing when the pressure changes. If the temp is going up with pressure drop and temp is going down with pressure increase you have a oil temp problem (something in the oil cooler system). If the Temp does not change with Pressure then you could also have an indication problem at the higher airspeeds of cruise flight moving a wire harness at the pressure sending unit. and the slower speeds of takeoff and landing you don’t have as much airflow in the engine cowling causing the movement of the wires.

    In my experience troubleshooting engine issues one thing rings true. If you have one parameter moving it’s 90% of the time indication issue nothing wrong with the engine. If you have two or more parameters (i.e. oil pressure and oil temperature) moving you have engine issues.

    Hope this helps.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.