Sunday, January 15, 2012

Hydrualic System-Functional Tests

After installation & reinstallation/Major maintenance of components it may be necessary to carry out adjustments to micro-switches,limiters,sensors...etc and to ensure the correct operation of warning devices and instrumentation, also operating systems will need to be tested to check for correct operation. This is generally referred to as functional testing
 All system functional tests will be specified in maintenance manuals and these must be always done in accordance with maintenance manuals(IAW MM) . Prior to any functional tests it will be necessary to inspect the system(s) to be operated, this inspection should generally cover the followings,
  • Quality and completeness of the maintenance task requiring a functional test.
  • Checking of reservoir levels.
  • Checking of accumulator pressures.
  • Applying external gas pressure to reservoirs, if required.
  • Thorough check of the area around services to be operated, to check for clearance,FOD,tools...etc.
  • Correct connection of appropriate power sources (electrical and hydraulic).
It should be noted that the specific tests applied to particular aircraft and systems will be stated in the maintenance manual and all the steps must be done accordance with the Manual only. 
     Functional tests are designed to test for correct sequence and speed of operation. Usually if major component replacement has taken place the system will be operated at low pressure/slow speed, to ensure correct operation before the full pressure/flow tests. During these tests all aspects of the system operation will be tested, this may include timing of the operating sequence. The results of the functional test as Sluggish, slow,erratic operation or high temperature of fluid during operation gives indications of the faults in the system such as Aeration,Internal Leakages....etc. where it may cause further inspection of the maintenance job.

2 comments: said...

I was having a chat with my friend who is a beginner in testing. He was sharing his problem with me on how to initiate testing. Although there are many books and articles on theories and concepts of testing but there is no help or information available on how to start testing and how a tester should proceed with the same. This is one excellent article you put together.

also if you do not mind here is another article which talks about the basic steps of functional testing:

Basic steps of Functional Testing

Hope this will also help.


Yasantha Pathirana said...

Thanks Dave for the shared article.....good to know that my article was helpful.

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