I’m wondering why all the engine monitor manufacturers don’t have an engine oil quantity system?

Many in crash talk would have had more time for emergency descents etc. if they were alerted to excessive oil quantity loss.

Murray

Costs more, weighs more, requires more maintenance, requires certification failure consideration.

Also might be difficult to interpret since readings will be different with engine running versus not running.

Costs more, weighs more, requires more maintenance, requires certification failure consideration.

Also might be difficult to interpret since readings will be different with engine running versus not running.

They’re available for experimental for only a few hundred dollars!

AFaIK, the ones on automobile engines use sound (ultrasonic) to measure the depth in the sump but I think that only works when the engine isn't running. In an airplane there'd be issues with the level changing with oil temp, g-force, RPM, and aircraft pitch even if you could measure the level with the engine running.

A 1957 Bentley had a sensor in the oil pan like a fuel level sensor. You pushed a button on the dash below the fuel gauge and it read oil level on the fuel gauge. Works either engine running or stopped. I expect Bentley preferred that you use it engine off.
Excessive engine oil loss is quick and rare. Does anyone really see low oil pressure when it happens? I imagine most times there’s a surge or other indicators that make the pilot look at the oil pressure gauge and sees a problem.
I, like “most” pilots, check oil quantity during my pre-flight and expect quantity to remain the same for the duration of the flight.

I have a feeling these devices work a lot better (in aircraft) in the reservoir of a dry sump system than in the oil pan of a wet sump.

Jim, I’ll bet your right. Entirely different system from most. More layers of system to fail too.

I'd rather have a video camera view of the belly, underside, or outside of the cowling(s).Much easier to install, can also spot fuel and or Hyd leaks

BMW has been using oil level sensor for a while and it is actually opposite to what you state; oil level is measured in running steady-state condition (which would not be difficult in an aircraft since it is mostly at steady-state = cruise).

The BMW sensor also measures oil quality too (contaminant level) and uses capacitance (dielectric strength of the oil to be exact) to do both functions - not ultrasonics.

It would make sense in an aircraft from a utility and predictive maintenance standpoint (when to change the oil for example) except it adds weight and complexity as the sensor needs a computer to interpret the data and also control the measurement. In a car where you have a lot of controllers already, you can integrate the e-dipstick function without adding a dedicated controller; in an our aircraft it would have to be a separate box.

I know a lot of people hate the BMW design but in my experience it is both very reliable AND accurate in providing the info about oil level AND quality of the oil.

All my old Mercedes just have an oil level float sensor.



I've always thought it would be smart.

My other idea was a little V-channel on the belly leading to a passage and an optical sensor, when the fluid blocks the sensor the "belly warning" light goes on letting you know some crap is on the belly.

Or just a camera, which I now have so I can see my belly and gear in action.

TJ

BMW has been using oil level sensor for a while and it is actually opposite to what you state; oil level is measured in running steady-state condition (which would not be difficult in an aircraft since it is mostly at steady-state = cruise).

The BMW sensor also measures oil quality too (contaminant level) and uses capacitance (dielectric strength of the oil to be exact) to do both functions - not ultrasonics.

It would make sense in an aircraft from a utility and predictive maintenance standpoint (when to change the oil for example) except it adds weight and complexity as the sensor needs a computer to interpret the data and also control the measurement. In a car where you have a lot of controllers already, you can integrate the e-dipstick function without adding a dedicated controller; in an our aircraft it would have to be a separate box.

I know a lot of people hate the BMW design but in my experience it is both very reliable AND accurate in providing the info about oil level AND quality of the oil.

Seems like a gauge, even a not very accurate one would be helpful. Years ago on a bonanza, hand a bit leak open up on one of the tubes around the pushrods (don't know its formal name). Landed after a 2 hour flight to see oil all over the sides of the plane, and down a couple of quarts. No warning at all in flight. A bigger leak, or a long flight and it could have been bad.

My old 911 had an oil level gauge. Only accurate at idle and standing still. Same dry sump as Lycoming and Continental.