Thanks Brian…
My dad has always poked fun at me for filling the plane so full. I’ve aleays told him that I never want to “wish” I’d put that last gallon in.
I am OVERLY cautious with my fuel reserves and this has become a bit of a joke between us, but I’ve always wondered what the definition of true full was… thanks!
Same here. Fuel is the one thing you can control basically 100% of the time!
Hi Mark,
Are you happy with your CIES digital fuel gauges?
I installed mine in my G2 SR22 and am getting a 5-20 gallons difference vs. OCD indication on ground (leveled in hangar) and 1-5 gallons in-flight vs. OCD.
I don’t get it, are the gauges supposed to be correct only during perfectly leveled flight!!??
My shop has no clue - they just look dumb and don’t have any answers.
How does your perform?
When i have to fill to the tabs (whole family on board) i fill it up so that the horizontal part of the tab is slightly submerged - then i check that with the calibrated dipstick i bought at Aircraftspruce. I has a floating inner part that will slide up and show the precise fuel.
I also always put in about a gallon more for taxi and then add the amount i refilled to the totalizer.
My G3 gauges hung up through the transition zone around tabs. The gauges on my G6 do not. The gauge indications remain within a couple of gallons of my calculated values based on starting fuel and fuel burn.
The G2 installations apparently went through some iterations that modified the sensor/sensor placement, as Scott Philibin explained in a 2016 thread. My reading is that some early adopters were not happy.
Not a direct answer to the question of tabs, but related in the sense that the ultimate goal is know the fuel quantity/weight. The previous owner of my plane installed the CIES fuel gauges on my G3. I never knew I needed these, now I’d be uncomfortable without them. They are very accurate and provide piece of mind that I never knew I needed.
As has been said, the fuel totalizer is very accurate unless you have a leak (or someone siphons fuel), or it gets inadvertently mis-set (accidentally adding fuel to the totalizer, but not the plane).
Relying on the tabs or fuel stick works on the ramp subject to the accuracy of the calibration of the measurement device. That’s a point in time measurement.
The totalizer and fuel stick are what I used the majority of my flying hours. I flew Cessnas so I personally didn’t switch tanks (I set the selector to both). Having accurate gauges in each tank makes the fuel timer obsolete for me. I don’t have to switch based on time. I switch based on fuel balance as indicated by the gauges. I still set up a fuel timer for 30 minutes, but rarely is that when I want to switch due to differences in fuel burn in climb/cruise/decent.
Prior to flying with CIES gauges I probably wouldn’t have thought they were needed. My fuel management strategy worked fine with the fuel stick and fuel totalizer. I’m happy the previous owner installed them, but I am now stuck upgrading (and paying for) CIES gauges if I ever get a new plane that doesn’t have accurate fuel readings.
Off topic, but the previous owner also put in an accurate AOA with HUD. I never knew that I needed one of those too. I’ve been spoiled by the upgrades my plane had installed prior to my ownership.
Be careful, always good to visually verify and reset the totalizer starting point regularly. Filling the tanks occasionally is a great way to do this. Fuel totalizers are a great idea but will inevitably drift if you never reset based on a known quantity.
Hate to rain on that parade but I am rather frustrated by the CIES gauges. In the G5 and G6 airplanes I fly there are built in CAS messages to warn about fuel imbalance. On numerous flights that message goes off when 5 minutes earlier the tanks were absolutely even on the CIES fuel gauges. All of a sudden one tank reads higher or lower for no reason. Switch to the now fuller tank and 10 minutes later thee other tank is now showing a higher level triggering yet another imbalance message.
These gaiges are not as precise as they are made out to be. They still have to be cross referenced with other methods. The fuel totalizer remains the most accurate tool.
Most of the issue is around the 30g mark I believe. Higher or lower should not have that issue. Get your students to fly smoother Brian.
All sunshine on this parade. I have Avidyne. It has stand alone fuel gauges. I do cross check with totalizer and visual inspection and it was on that basis that for me in my plane they are accurate. They are not instantaneously accurate. Turning while taxiing will cause the readings to change in each tank, but it will always settle out (in my plane at least).
I didn’t mean to derail the original purpose of this post. My apologies to the OP.
Geez Brian - let it go already. Just because I posted a comic parody of you 10 yrs ago about your reticence to embrace a new paradigm in having accurate fuel indication, you spend endless energy dogging the system.
Cirrus isn’t too terribly keen to rip us out of their aircraft - Fuel accidents on new aircraft went away Same dumb pilots (your words) - just better information to make good decisions on. This is true on Cirri Beech - (Check Beechtalk some day) Piper, Cessna, Grumman, Rockwell, Tecnam , Robin, Zlin, Embraer… Maybe one day the Wing Derringer … I have definitively made my point This works
I have told you multiple times if what you are saying is occurring, drag the aircraft to a service center and have it fixed. You don’t fly with crap instrumentation In the words of Frank Sinatra - It isn’t legal and it isn’t right. The Garmin gives you the ability to illustrate the issue Make use of it and fix it
Martin - Who did the installation and when was it done ? There are a few G2 iterations. None but the latest (since may) were really were effective as there were many issues as Jim Barker will attest to
with having a Sender in the collector tank and one in the main tank. While this is done on other aircraft the lines between tanks are substantially larger - magnitudes larger. I felt all we were doing prior to May of this year is accurately illustrating why it was a bad idea to have a separated set of senders and 1/2 inch line connecting those tanks together , not even mentioning the venting system for the collector.
Yes it did occur - we did what was asked of us to do in placing hard stops on the sender to control the range of motion. Basically Cirrus got better making wings - more uniformity & tighter tolerances in the G5 forward. There are many variables - surface finish of the rib , perpendicular tolerance wing to rib, rib placement, gasket compression … and then there are field installations. To achieve accuracy - one we had to have the right technology and two we need to have a level of care on the install - one does not trump the other.
Hi Scott!
Thanks so much for taking the time to write!
The installation was done by Aero Poznan, Poland an authorized Cirrus service center.
Installation was done beginning May 2020.
The set was ordered from Cirrus end of April / beginning of May 2020.
They definitely installed the senders in place of the factory ones. They did not move the sender from the collector tank to the main tank - that I’m sure as when they initially installed the collector tank sender it turned out that it was to long and got stuck in one position. They eventually shortened the senders rod to gain movement.
The biggest irregularities are when the aircraft is on the ground and can be as high as 10-20 gallons vs what the MDF is showing on the totalizer. I always reset the totalizer to full fuel after filling the tanks up to the caps so I have a good reference based on fuel burn.
Inflight, the differences are smaller but still significant.
I would greatly appreciate your help with this, really don’t know to whom to turn for help.
I also have a full report where I took measurements of fuel in tanks and compared it with the CIES fuel gauge indications. Unfortunately I can’t share it in this reply as a new user.
Marcin
That configuration definitely won’t work - I am not surprised by the outcome
This is what has to be done - amazing that they got the arm into the collector
So here it is installed in the Main tank
Please Show them these pictures and we will send you new arms - they should have the
nutrings and the adhesive in the kit
The other issue is that unfortunately most shops don’t remove the fiberglass support on the outbd
as well
Bryan:
You are right. It never happens when full but it is in that middle zone. The question is why does it happen. Either way it displays a great degree of inaccuracy that is not nearly as good as the fuel totalizer. The old original fuel gauges are a bit worse but these are far from perfect.
“a bit” c’mon, that’s a huge understatement!
I have a friend who would have landed under caps if he had used the totalizer, I have no doubt the CIES gauges saved the airframe. I believe the fuel return line wasn’t connected after annual.
I own two G3’s and have now added CIES gauges to both. I agree with the occasional 30 gal fuel imbalance, but that negative is far outweighed by the positives when I top off the tanks at self serve back at my home airport and each tank confirms for me just how accurate the readings were. I didn’t like that feeling in my TN the first few weeks waiting for the CIES install appointment. Perfect, probably not. Well worth decreasing the load on me at certain times … I think they are and will be.
Also remember that you can check your tabs accuracy by getting to tabs, then measuring the incremental to full … I know, captain obvious…
