Daniel

Come on in, the water is warm.

This picture was today, 390kts ground speed. (Just a little help from a tailwind though )

This was in our -10 MU2, the F model would likely have been 30-40 kts slower, but still 350kts does shift your universe.

If you can find a MU2 with good maintenance history and all else being equal, engines over TBO would honestly not bother me.

Hilgard

Wow! That left engine is about twice as efficient as the right one! That's fantastic!!!

You need to make the right engine just as efficient and you will have tremendous range!

Mike C.

I knew someone would pick up on that, no surprise it's you

The left fuel flow gauge gradually decreases as we gain altitude slowly moving to zero after about 45 minutes of flight. The colder it is the quicker it "freezes up". On descent it "warms up" and reads accurate before we land. Fuel flow on the GPS' transducer and Foxboro totalizer remains accurate, so it must be a faulty gauge. IJSC will have to look at it again and perhaps replace the gauge at the next service, as they could not give me an answer for this last time.

Hilgard

I knew someone would pick up on that, no surprise it's you

The left fuel flow gauge gradually decreases as we gain altitude slowly moving to zero after about 45 minutes of flight. The colder it is the quicker it "freezes up". On descent it "warms up" and reads accurate before we land. Fuel flow on the GPS' transducer and Foxboro totalizer remains accurate, so it must be a faulty gauge. IJSC will have to look at it again and perhaps replace the gauge at the next service, as they could not give me an answer for this last time.

Hilgard

The -10 EGT limit in the 441 is 450°, I wonder what the difference is?
520° would be nice!

As a counterpoint to keep the discussion grounded in reality, headwinds happen too

I knew someone would pick up on that, no surprise it's you

The left fuel flow gauge gradually decreases as we gain altitude slowly moving to zero after about 45 minutes of flight. The colder it is the quicker it "freezes up". On descent it "warms up" and reads accurate before we land. Fuel flow on the GPS' transducer and Foxboro totalizer remains accurate, so it must be a faulty gauge. IJSC will have to look at it again and perhaps replace the gauge at the next service, as they could not give me an answer for this last time.

Seems unlikely that the gauge inside the cabin is responding to an OAT that it isn’t exposed to. My bet is the signal conditioner. The reading you see on your GPS likely comes from an air/fuel data computer which gets it signal before the signal conditioner 9theynare all wired that way) Swapping gauges side to side is easy and will provide useful information to IJSC

Hilgard

I knew someone would pick up on that, no surprise it's you

The left fuel flow gauge gradually decreases as we gain altitude slowly moving to zero after about 45 minutes of flight. The colder it is the quicker it "freezes up". On descent it "warms up" and reads accurate before we land. Fuel flow on the GPS' transducer and Foxboro totalizer remains accurate, so it must be a faulty gauge. IJSC will have to look at it again and perhaps replace the gauge at the next service, as they could not give me an answer for this last time.



Hilgard

450 is just an index number, it's not a real temperature. You have to turn the fuel computers off (and use the EGT chart) to see closer to the real numbers.

The reality is that both planes have a TAS of ~300kts without taking the wind into consideration. We have the privilege of generally travelling 5x faster compared to driving.

Compared to piston twins, with an average TAS of 200kts, the MU2 can easily keep up with that, even in a 100kt headwind. And then some days as a bonus you end up with that wind from behind.

Lastly the reality is that nothing is slower than a plane down for maintenance, the MU2 needs a lot less of that compared to anything piston driven. Also let's not forget the continued issues with Avgas.

Hilgard

Thanks Mike that's a good idea. I will swop the fuel gauges before I take it to IJSC.

Hilgard

Will

Welcome to Beechtalk!

After switching the fuel gauges I will give the inlet heat a try to see if that resolves the issue.

Where are you located? We would love to see some pictures of your Solitaire.

Hilgard

Jack

I suspect the EGT reading in the 441 is similar to the Solitaire, see the attached picture which helped me understand this. I've decided to run 15-20 degrees cooler than Max EGT, as I would I would rather be on the "safe" side in case the EGT compensator's setting is off. Using this I do get close enough to 300kts at altitude,which fully activates my satisfied button... (My -10 only has the EGT compensator, I believe yours has the SRL computer as well. As Jason said, both of these points can adjust the raw EGT coming from the probes.)

Hilgard

The fuel flow system on a MU2 is as follows:

1). An engine mounted transmitter that counts the revolutions of a free spinning wheel producing a frequency signal.

2) A center wing mounted signal conditioner that takes the two frequencies (R&L) and converts them to voltages for the fuel flow gauges to read. It also produces a combined output for the totalizer

3). The Fuel flow gauges and totalizer

If a fuel computer is installed, its input is the same transmitter as the stock system. The wires are spliced into the wires between the transmitters and the signal conditioner. It then converts the frequency to a fuel flow number and sends it to the avionics through a serial connection.

In the case of Hilgards plane where the FF on his GPS navigator is correct but the gauge reads incorrectly, the problem is either the signal conditioner or downstream in the wiring to the gauges

In Will’s case the problem is most likely at the engine, either in the transmitter or wiring

As long as you are gathering information to present to the service center, look to see if activating the ignition or the unfeather pump affect the fuel flow readings

Unfortunately, the manufacturer of the system Foxburo is now,another company and a signal conditioner with a new circuit board is $$$$

Thanks that is an excellent summary. I assume you acquired this by studying the maintenance manual?

Hilgard