fuellevel

We are waiting for that initial Mooneyspace report as well - lots of Mooney sender sets now out there. STC will be signed on Monday - so the senders will be TSO'd and STC'd We need to work out the Millivolt output for those owners with resistance Aerospace Logic gauges already installed. We know the people @ EI and they are good. But we are working more closely with JPI to enhance fuel quantity warnings. JPI will annunciate if the fuel totalizer and fuel remaining are off by 5 gallons

The FAA indicated that Tuesday Nov. 1 would be the day for the STC. We held off after Oshkosh to capture any nuance Textron wanted to add to their aircraft. We have included a lot of new features. With all the variations in capability of filling aircraft - I find pilot reports of FF accuracy to be curious based on a relatively non precision procedure. So yes ramp or hanger floor angle makes a large difference in fuel level capability. The other element is gear set, when you fill one side of the aircraft, the gear on that side compresses and the opposite side extends. Venting s the other unknown as the ability to fill depends on the ability to remove air from that final pocket - there is always an expansion space Venting does not confuse any fuel quantity system The idea that floats impead fuel measurement in aircraft is a bit over reported, location is key. As there is unusable fuel at the bottom and vent space at the top, the float is usually not an issue. CiES uses this, as we maintain a neutral buoyancy. We use a denser float to give a measure of stability to output. Other measurement systems like capacitive have similar issues, you can't extend a capacitive probe to the top and bottom of the wing surface and you don't want to on the inbd end as water messes with the output. Equally due to lightning strike consideration it isn't a good idea to bring an isolated capacitive probe close to the top surface of the wing surface The more you know Good luck getting your full 76 gallon capacity - you will be on the right path - Leveled and jack supported aircraft, clear vent lines - +++++ Note - Typically for retrofit aircraft pilots report that the CiES fuel senders are inaccurate as the reported digital value conflicts with their fuel totalizer value. I have a standing offer of $1000 dollars that in an aircraft I have done or supervised the calibration, that displayed amount in a leveled aircraft will be the amount drained from the aircraft within a gallon, that $1000 is still firmly attached to my wallet. The reason being is that the assumptions pilots make about their starting and entered fuel value are not nearly as accurate as they believe. Those pilots are now our most fervent supporters.

Fuel Gauge Video

M20Doc: I used the stuff for a window on a Stellarator Plasma Physics Device in college I wholly believe we achieve the same result at a far far lower cost. ---------------------------------------------------------------- I spent the day discussing fuel quantity in GA with the FAA Small AIrcraft Directorate and the Seattle Aircraft Certification Office If you believe my opinion on fuel quantity accuracy to be - "Out there" You should have been a fly on the window here.

Well - the topic started out with the standard why do pilots run out of fuel. Typically this falls into the following dialogue only Lack of awareness Lack of training Lack of care This is well supported by AOPA, and the aviation editors of the various flying oriented magazines Reinforcement of checking starting fuel value (use of a stick) and planning are the two tools of preventing this incident from occurring It is widely reported that fuel totalizers help but they do not address all potential failure paths, confusingly the advent of fuel totalizers, while well liked and trusted have not moved the accident statistic in any great manner Several, Cirrus aircraft prior to 2012 have run out of fuel with a fuel totalizer and a traditional gauge, for example. Totalizers have not prevented fuel related accidents, even in technologically advanced aircraft. Given the unchanging statistic - you could state Neither education or totalizers have presented an answer to fuel related accidents. Yet we continue to reinforce these methods ------------------------------- It is widely reported that fuel indication lacks clarity and accuracy in aviation Aircraft with an operational low fuel warning and a high wing (Cessna) suffer almost zero (1 or 2) fuel starvation / exhaustion events Aircraft with a digital fuel quantity systems have to date - suffered zero fuel starvation / exhaustion events. It may be, but not proven at this time, that quality fuel indication may be the method that allows good pilots better tools and will provide a timely warning assist those careless pilots an opportunity to correct the preflight mistakes they may have made. Most new aircraft delivered have digital fuel quantity systems, and soon nearly all new aircraft will have a digital fuel quantity systems. If the current trend of no fuel starvation with digital fuel indication continues - fuel related accidents will go down. --------- If this is in any way compelling, Make the fuel quantity system in your aircraft functional If you can't make the fuel quantity system in your aircraft work Avail yourself of any number of other options, to make it work with the degree of accuracy intended by the manufacturer. To bonal's point, you can only determine if a system is not functioning when it deviates from normal operation. Trying to determine if a randomly operational system is operating in another random manner that signifies failure - is useless. That being said most digital systems are set up as life of aircraft 50,000 hr systems. Resistive senders are 2,000 to 3,000 hr systems in aircraft.

I started over in the commercial aspect. but yes in addressing each concern - it is a bit of a mishmash I deleted a lot of responses to clean it up if I was quoted.

Anthony - This is Scott Yes the first step, is getting a quality fuel sender in the wing tank. This is a monumental struggle because - no current pilot expected or expects performance from this aircraft system sector. That wouldn't be fair - If a Capacitance system were offered - Because of a large aircraft familiarity, that concept might gain traction Pennycap was introduced in 1969 by Cessna - It was not a well received solution - Cessna only. It wasn't an answer. We are more reliable and more accurate over a capacitive system - float guy has plane credibility. The concept of pushing intelligence to the sender level, gives a lot of flexibility for warnings and capabilities not considered today. It provides capabilities that make flying easier and yes with an increase in warning capability and monitoring - safer - Charles Beck - International Avionics - the manufacturer of the Mooney Master Caution Panel really advanced fuel safety with an advanced low fuel level warning for Mooney All of what you are asking has already occurred, in order to to make automated tank switching on a single engine a viable concept. We can monitor trends and direct appropriate warnings. We reviewed the egg timer solution of the TBM 900 or the much more sophisticated system on the Pilatus PC-12 It culminated in our own OEM single tank solution. Like I said before- We aren't here to keep bad pilots out of trouble - we make good pilots better.

Bennett - He crossed that decision airport with sufficient reserve and to his plan. He had 2 1/4 more hours time in the tanks for less than 50 minutes of flight. To your point - Plan C And Plan D were not evaluated. After I descend - all my fuel will be gone what next. I wouldn't fault him. I remember a very hairy sea kayak crossing on Lake Michigan - Fall day - fairly brisk wind and whitecaps we set out for a 20 mile crossing 10 miles off shore, We turned over and were swamped with a wave. I righted the boat and oriented the stern into the waves and directed the other person to start bailing after a few waves and after some heart lifting progress they lost the bailing bucket. I directed us both to get back in and paddle out of danger, that went OK and I was making some progress with the pump until we hit the reef. Standing waist deep in water and waves I made repairs, emptied the boat and busted my butt home shivering from the onset of hypothermia. As an offshore guy, I thought you'd appreciate that one, Some days - it just doesn't go your way. I had plans, gear, wearing a wetsuit, and I can still tell the story - I have not made an open water crossing since.

Bennett The pilot in the example said so as well. He used 13 gallons as his reserve in a Cherokee for this flight. Having that experience he would now stop in Brooks County no matter what. He said - now he would only fly 2.5 hrs effectively cutting range by a third. His passenger was his son in law, the implication was impactful. AOPA Safety - recommends in some aircraft examples not getting fuel closer than an hour to your destination - That person is now a Mooneyspace poster. I saw the statistics given, but can't remember the reasoning why. ---------------------------- This was an example of a very poor accident investigation, that ends up as a statistic supporting a conclusion. I know enough now to suspect every fuel accident report I read and look for inconsistencies. A self perpetuating bias

This was Cirrus forum discussion, so I animated it. 3 years ago on COPA - what is old is new

carusoam Doubling up is not necessary the Aerospace Logic gauge gives a trend function for fuel tank level over time (Fuel Flow) You can see the accelerated flow at the beginning (Climb) followed by cruise The Bar graph will actually warn you to switch tanks based on fuel volume so if you get a fuel imbalance warning - and it is happening faster than you planned problem

I am having a dialogue over accuracy and stability on COPA and this discussion on Mooneyspace On one hand - the accuracy deviations in flight of a gallon might be an issue Other hand - and this assessment of pilot responsibility Two sides to the Oreo - in the center is the good stuff

I have to redraft re-lable that as it really is pilot skill and plan difficulty - Hamburger run - full tanks - no or low risk - indication is a non factor Cross country - partial tanks - higher risk - no indication higher risk - and indication of any type (total or fuel tank amount) provides a warning or risk mitigation The fault Tree supports that component - a totalizer can intercept a few lines - a gauge can intercept any line less it has failed and then it contributes by mis information to a potential harmful conclusion The gauge on the bottom indicates it's mis information impact on the chain moving up carusoam - one tank emptied itself in excess of planned value, he nursed it to dry carefully watching fuel pressure, and then switched to the other tank and watched that tank fall precipitously to zero. (supports an issue downstream of the tank). He was lined up on the runway and saw the security fence and feared catching the fence and flipping over so he turned and landed in a fuel near the airport. This is from my interview notes. Remember - military experience. So yes multiple methods of ascertaining critical information are important - trust but verify - Time in tanks is excellent backed with starting fuel value and a watching time and remaining fuel alonf the way. One system is not a panacea or replacement for any of the others.

See above - It would have cost the owner to find the determination. No totalizer onboard. Rock solid gauges - little movement in turbulence but accurate reporting on prior flights.

Skill and Procedure - Planning Just got off the phone with the pilot The FAA inspector ran the numbers and said he should have 13 gallons in the tank - the pilot's own plan showed twelve No joy there ----------------------------------- What is really infuriating - is that if the pilot wanted to find out what caused the fuel loss - he would have to pay the fee for the teardown. A determination of cause had been made by the inspector when he arrived even after he ran the numbers. You can't find what you aren't looking for

Again - the different between my perspective flight engineer and pilot are -- apples and oranges Crap (engineer speak) - if the gauge oscillates - crap if 20 gallons is off 1/2 needle width of the 20 gallon tick mark - crap I deal with manufacturers - that is what they expect. That is what I have to expect. This is the calibration we had to meet with our floats for the Airbus AS350B3 helicopter - fuel weight 900 lbs - 150 gallons - single un baffled tank Crap is the indication that falls out of the blue and violet maximum error lines. We had to fix the deviation shown at full and bring the bottom closer to the perfect line. I have a different perspective and expectation of fuel quantity. Pretty much blows - "Only accurate at zero" out of the water --------------------------------------------- I chose this incident carefully Very clearly - fuel gauges were of little help to this pilot. He noted a bad trend and recorded it, but failed to act on the information in front of him and continued flight. He was using his watch as the indication of trust fuel wise. (not in the record, I asked) Nobody is out to fix bad pilots - bad pilots will do any number of things - Take drugs, drink and fly, defer maintenance, defer training and ignore indication meant to point out issues with the aircraft. Nothing will fix bad piloting, they shouldn't have been granted a license. The concept is to make good pilots better or more succinctly point out issues with the aircraft prior to an accident - break a link in the chain. I think the idea here is that you believe I didn't go to the same church as you or listen to the same sermon. (Synagogue, Mosque) That assumption is wrong. I am a bit more orthodox when it comes to any cockpit information, I have to be. Just like you have to be good pilots. There are no good alternatives. Trust but verify is an aviation watchword for any activity under the umbrella.

I was warned by the Director of Flight Operations at Cirrus to look at this from a pilot perspective Assume the fuel gauges are crap In this instance float guy (I prefer AMR guy) believes the pilot Pilot is ex military, wrote and taught classes on aircraft instrumentation. Aircraft is airworthy including working fuel indication. Non working instrumentation of any type was not acceptable The pilot made sure of that. The above assumption is a sad state of affairs So that premise that all fuel gauges are crap in aviation is a pilot perspective. In this case, that assumption is wrong So Yes he hit winds of 15 knots head on at the end of the trip on descent from 7,500 ft - his fuel burn was 20 gph increasing to 50 mph indicated But here fuel is moving away from the sender on descent - Gauge reading is compromised. Sender is on the aft wall of the tank Leveled out the fuel burn is now approx 40 gph Max fuel burn firewalled PA28-180D is 16 g/hr His gauges were calibrated per the Piper maintenance manual only better which lists a reasonably tight tolerance for gauging The gauges had proved to be accurate on other cross country flights - throughout the range, level flight Assume you aren't a pilot with a long history of looking at crappy fuel gauges. Assume you didn't tolerate faulty instrumentation in your aircraft. This pilot operated the aircraft uniformly - no need to adjust for this cross country flight, I did ask. Now what do you see.

I can only guess

I will make it simple and visual. The Belgians did this one. Where in the tree would you place accurate fuel level indication as an adequate warning of the issues presented. We help good pilots make better decisions - Bad pilots are not our market

DXB - the level of discourse is important. I am presenting a very unique perspective to shine a light on an alternative way of thinking about these problems. They are not so cut and dried as I think in your responses to me make me believe is your viewpoint. Your point of my extensive experience, which is correct. I am considered an expert in this field to to address difficult system problems and come up with viable solutions. Mooney management brought this opportunity to my table because they trusted me to make it a solution for their needs. So let me lift the curtain a bit. I am definitely expecting a typical response on this article. But it is not all you see and it makes a good example for illustrating how hard we cling to the opinion most fuel accidents are a pilot issue. My point is that you can't find, what you aren't looking for. So that you know that I am listening to you carefully - of the 44 records of Mooney Exhaustion event in the NTSB record - almost 20 have some element of aircraft failure as a link in the chain. Granted some of those are non functional fuel indication - empty tank full gauge reading for example. I have had extensive conversations with the pilot of this accident, who also doesn't have a physical answer about why this happened, only that it happened in real time before his eyes. He was frustrated as well by the pencil whip investigation, the engine settings he was in control of did not change in the direction or as radical as the record indicates. Believe me - this pilot has credentials and awards we would all hope for and he is still an active pilot. Hopefully I can divulge more. So as an engineer - do I know exactly what happened, no - did I cross everything else off the list, yes I did. Be careful what you ask of an engineer - Am I 90% sure - hell yes, am I 99.9% sure ???? . DXB, No, I don't have a credible physical mechanism for removing that much fuel in that time frame. I am looking and there are clue crumbs out there, but no smoking gun. It is difficult to deal with inadequate investigative efforts as you have to laboriously piece together evidence. The Cherokee on the roadway in California is another example, where the plan and facts divulge to create a very public accident. But to illustrate the bias inherent in discussing these incidents - that pilot is not the pilot example I chose to use to illustrate. I highly doubt that I am reprehensible. I fee that you are sifting through information to vilify me and my purpose here. Work with me and maybe tomorrow I will be 99.9% sure. I believe I have a key to more informed solution, But my greatest fear that the ingrained bias in the aviation community won't let that message be heard.

Yes - actually they are reasonable on Ebay - typically with rips in the attachment holes. On Ebay I am seeing lots of issues Fuel staining around the sender, torn and broken flexible lines. broken fuel vent tubes. The vent is high up and so is the check valve. I actually found a Mooney example in the record - where blue stains were present around the vent tube. No explanation why - lots of fuel missing I am finding a few PIREPS - especially on Archers for fuel loss anomalies that occur at 9000 ft and then cure themselves on the next flight at 3000 ft Something on the order of 10 to 20 gallons - startling I am really at a loss for rational ideas: fuel slosh from turbulence reaching the vent . - My Cirrus Garmin data illustrates pretty wild fluid motion down low in turbulent conditions. A lot of vents nearly all for sale were compromised in some manner The Mandatory Service bulletin should have addressed these issues and also established the function of the fuel sender. My father - a really old A&P and former IA when all of these were new - says he has seen blocked vents allow the draw atomized fuel off the top of the fuel tank I have seen this dramatically displayed on a loose fitting cap on Beechtalk - full tanks however I the not seen this happen - and there should be a tell tail somewhere. Fuel loss at the pump ( the engine ran - however) I will find it - I always do

carusoam They didn't look in either case. In the record the owner indicated that a fuel flow warning would be nice. Interesting fact is that due to the SB for the wing spar the tank was to be removed and the vent lines check and the fuel sender gaskets replaced. The fuel sender fiction is to be checked as well. This is to be done at 7 yr intervals. Trolling the Piper forum lots of leakage descriptions and blue stains, some of which occur through the sender wire attachment and sender gasket This is a leather seal on Stewart Warner senders. I need a tank to play with and pressurize and depressurize at that critical fuel volume. I am doubly curious now. Worth buying a tank to find out. It has to be pretty low in the tank. I forgot that I should look at the Canadian reports - they do a very good job with fuel related incidents The oblong float is a issue - I have received these in the mail frozen in manner the picture shown

I have been transparent in this - the only thing you can surmise from afar is that fuel left the aircraft, or got burned up in the engine. I am emphasizing this element - It is a conclusion but there only very narrow causes for an aircraft to dramatically change fuel flow in flight. It may not be the only conclusion to support the record presented and I am open to speculation from any quarter. It may just be me - but I see no evidence to support a pilot caused starvation issue from Brooks County to just shy of his destination. We have a clear record of fuel burned from this pilot referencing a gauge - that fuel burn changes dramatically without any change in airspeed in that he is where he is supposed to be by plotting his course at his average airspeed. No dramatic change in engine power. But his fuel burn as indicated by his declarations of fuel onboard are not consistent at the last leg of his trip, and everything else is. There isn't a clear visual reason for this just looking at the Fuel system diagram because I am not the FAA investigator not was I on the scene. At this point, I can't see the mechanism to allow that venting to happen. We do have on the Piper forum, lots of discussion of a venting issues that don't make sense looking at the diagram. In both cases it was a reported pilot error. And I see no clear evidence for pilot error other than trying to use the capability of the aircraft. My feeling, but I don't know is that you are arguing equally for pilot issues being the primary reason in this case. I am emphasizing that the pilot made no adverse decision from the record.