rv8ch

rv8ch

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I have a FF sensor but I'm considering not installing it. While I think I would like the information it would provide, I'm struggling with installing something in my fuel system that is not really needed. It just seems like another device that could fail or cause the big fan to stop turning.

My question is how much do you guys actually use your FF information? Is it really worth installing a FF sensor? It seems like after a few flights, you'd know your FF for a particular temperature/altitude/RPM/MP combination and after that it would not add a lot of value.

I've never flown an aircraft with FF info, so I'm sure I'm missing some amazing feature.

Thanks for any tips.
 
rv8ch said:
I have a FF sensor but I'm considering not installing it. While I think I would like the information it would provide, I'm struggling with installing something in my fuel system that is not really needed. It just seems like another device that could fail or cause the big fan to stop turning.

My question is how much do you guys actually use your FF information? Is it really worth installing a FF sensor? It seems like after a few flights, you'd know your FF for a particular temperature/altitude/RPM/MP combination and after that it would not add a lot of value.

I've never flown an aircraft with FF info, so I'm sure I'm missing some amazing feature.

Thanks for any tips.
Click to expand...

My FF indicator (and resulting data on fuel used for each flight) is extremely accurate...especially as I've gathered the data to refine it's settings for even more precision. I can pretty much predict how much gas I'm going to have to pump to the nearest quart...sometimes, even more precisely than that.

My fuel gauges, on the other hand...well, not so much.

While you can get by without it, I think if you take the leap and install it, you'll find the data it provides very valuable.

My dos centavos,

Rob
 
I consider Fuel Flow a must have.

In addition to a much more accurate track of fuel remaining, it is required tool for things like balancing cylinder injector nozzles. It is also the way to standardize LOP operations.

Add it and build on.

Carl
 
I've got one, and I wouldn't do without it. The one time I thought it was failed, it was actually just a bad wire connection.

What type of indicator is it? The device should be fail-safe intrinsically, meaning that even if the moving parts lock up it still passes fuel without restriction and cannot cause a fuel stoppage. Assuming, of course, you don't use RTV to seal your line connections...
 
Assuming you have a fuel computer/totalizer, as a minimum, and engine monitoring equipment. FF by itself is not very useful.
Today's engine monitoring equipment also ties to your GPS for automatic estimates of required fuel to destination, reserves, etc... which can not be done without fuel flow data.
Makes enroute flight planning/changes much easier.

Otherwise, a power chart, a watch, and a whiz wheel. Don't need no stink'in computers.
 
Fuel Flow

The fuel flow information is "instant" and I use it regularly for engine operations. I know that my IO-320 peaks at 7.5 gals/hr and that 100+ ROP requires at least 9.6 gals/hr. Quick and dirty safe operation LOP is 7gals/hr or less and ROP is 9.6 or more. Also, the EMS automatically calculates range and time remaining from the FF info.

You can use conservative planning numbers and compare them to "pump to pump" actual consumption for refinement. If all of your "missions" are similar, then that might be all that you need.

It is true that you are adding a single point of failure to the fuel system. I believe we lost an RV10 due to improper installation of the FF sensor.

My experience only. Hope this helps.
 
Fuel flow is essential for making sure you don't end up as a statistic (ie, running out of gas). As noted above, having the EFIS calculate all of your remaining range and time in real time as you play with the throttle and mixture is wonderful. This last weekend on our return from Harris Ranch, we were going to aim for Cable to get cheap gas. We could have made it (barely), but looking at the numbers I made the correct decision to divert to Shafter and put 10 gallons in for my comfort and safety. When we got to Cable it took 21 more gallons. I figure I would have made it there with only about 4 gallons left, which is NOT enough (better to have 6+ gallons which is an hour reserve).
 
Leaning

Hate to admit this but more than once the FF display reminded me to lean!
Agree with other posters....now that I have it, love it, do not want to be without it. But certainly not required, but either is underwear!:eek:
 
Bob Martin said:
Hate to admit this but more than once the FF display reminded me to lean!
Agree with other posters....now that I have it, love it, do not want to be without it. But certainly not required, but either is underwear!:eek:
Click to expand...

Guilty (the leaning part not the underwear part)
 
I use my FF extensively. Obviously not necessary for leaning, but it gives me a good understanding of the over all input into the engine, which then translates to CHT, oil temp, etc...

I consider it almost like a primary instrument, although, if it were to fail (and it has a couple of times), I would not be grounded (since I flew for 25 years w/o one).

Check up on them...there seems to be little/no chance of engine stoppage with one if these in line, as long as it is installed properly (be aware of the now famous fatal RV crash associated with fuel blockage).
 
I use my FF data every power change on every flight and many times in between!

A famous and wise Russian once told me, "The black knob is how you spend it, the red knob is how you save it"!

I believe him!

The FF allows me to save gas and in conjunction with 4 EGT sensors, I all the data needed to fly efficiently.

These instruments certainly pay their own way!

:) CJ
 
rv8ch said:
?..My question is how much do you guys actually use your FF information? Is it really worth installing a FF sensor? It seems like after a few flights, you'd know your FF for a particular temperature/altitude/RPM/MP combination and after that it would not add a lot of value...
Click to expand...

I use it as a cross reference on every flight. Yes, you can (and should) rely on flight time to determine your fuel state, but a FF indicator adds considerable refinement to that determination. This is a "nice to have" on local breakfast flights, but essential on max effort cross country missions.

As it shows instantanious conditions, it is also is a valuable in flight troubleshooting tool. If you have a leaking hose downstream of the transducer or cracked injector line it will likely show up as a higher than normal fuel flow, as one example.

Finally, if coupled to a EMS, it provides a plethora of valuable calculations without having to do the mental gymnastics. MPG, duration, distance, fuel remaining... All continuously updated and right there on the screen, right when you need it.
 
fuel flow

Thanks for the feedback, gents, and of course for the reminder about no RTV. I've read this in many places for years, and had thought that it was "common knowledge" to never let RTV or teflon tape near a fuel system.

Regular reminders of this kind of thing can be very helpful.
 
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