Vibrations? - Don't fly it like an R22. Learn how to carry a bit more speed and/or make the last part of your approach flat through the speed range you don't like.
Sometimes operationally it can't be done so ......................
Oil Level - Oil Level Check
CAUTION: DO NOT MIX DIFFERENT BRANDS OR TYPES OF OIL BECAUSE THEIR DIFFERENT CHEMICAL STRUCTURES CAN MAKE THEM INCOMPATIBLE. IF DIFFERENT TYPES OF OILS ARE MIXED TOGETHER, DRAIN AND FLUSH THE OIL SYSTEM AND FILL IT AGAIN WITH NEW OIL.
(1) After the engine shutdown, do a check of the contents of the oil tank through the oil level indicator.
NOTE: To reduce the possibility of filling the oil tank too much and to make sure that the indication to calculate the oil consumption is accurate,
it is recommended that you always do a check of the oil level 10 minutes after the engine shutdown.
(2) If the oil level is not visible in the oil level indicator, do as follows:
(a) Remove the filler cap from the oil filler extension.
(b) Fill the oil tank with an approved oil to between the MIN and MAX level indication.
NOTE: The correct oil level is between the MAX and MIN marks on the oil level indicator.
To fill the oil to MAX can possibly result in oil being vented overboard.
This can add an oily film build-up on the airframe.
Should this be seen monitor engine oil level without adding oil (unless the oil level falls below MIN)
to find if the oil level stabilizes at some point between MAX and MIN. When you find this level, fill the oil to and keep this level.
(c) Install and lock the oil filler cap on the oil filler extension. Make sure that the cap is correctly installed and locked.
(3) Do a check of the oil level (Ref. step (1)) through the oil level indicator, on the engines that are not operated for a period of 12 hours or more.
If the oil level is low, do the steps which follow:
(a) Start and operate the engine at a stabilized idle for five minutes (Ref. applicable aircraft manual). Stop the engine.
(b) Do a check of the oil level (Ref. step (1)), and fill with oil as necessary.