Fuel starvation

[Ed Cesnalis]

I flew yesterday for 1.2 hours and before I left I glanced at my sight tubes ( they are new and have different markings ) and thought I saw 10 gallons.

 

The entire flight I watched the sight tubes and on my way back I knew my fuel was getting critical. I really didn't want to land on a road in remote Nevada/California mountains so I kept going but always with a landing zone and always with some fuel showing in 1 site tube.

 

I flew in a slip sufficient to keep fuel visible ( which looked like 3-4 gallons because it was sloshed inboard ) once abeam the numbers I forgot about the fuel and turned base and final coordinated.

 

I taxied to my hangar and then looked again. Both site tubes show zero, dipping the tanks show zero as well. I would have to drain the fuel to see how much is left and after sitting in the hangar its possible I could drain some that wasn't usable in flight.

 

I never thought about it before but if I have a chance of making it to an airport and if I can see fuel and if I have reasonable landing options I will continue. I would have landed if the visible fuel was exhausted. Another reason I would land is if the terrain ahead became unfriendly for landing.

 

Any thoughts?

[FlyingMonkey]

I have a related question...in CTs with a glass panel, does the Dynon have fuel level indicators, or are the sight tubes the only way of seeing fuel state?

[Jim]

Lots of thoughts. Only one comment. Glad it turned out good. My personal "unusable fuel" specification is 5 gallons.

[Jim]

I have a related question...in CTs with a glass panel, does the Dynon have fuel level indicators, or are the sight tubes the only way of seeing fuel state?

 

The Dynon does not have tank level sensors for the CT. What it does have is an accurate fuel flow sensor and software to track fuel fills and consumption. It takes a bit of calibration in the beginning, but is quite accurate once it's properly set up.

[FlyingMonkey]

The Dynon does not have tank level sensors for the CT. What it does have is an accurate fuel flow sensor and software to track fuel fills and consumption. It takes a bit of calibration in the beginning, but is quite accurate once it's properly set up.

 

Cool, thanks.

[chanik]

I've landed as low as 2-3 Gal when over 'benign' terrain with lots of nearby airports. On long flights, starting with full tanks, it is common for me to end up with one side empty and as much as 7Gal in the other. So need to fly coordinated to be sure not to unport the one side. And if you dive too steeply, the 3Gal will look like 1Gal in the sight tubes as the fuel sloshes forward. The Dynon fuel flow is very accurate I have found. Unlike their voltmeter.

[Ed Cesnalis]

Lots of thoughts. Only one comment. Glad it turned out good. My personal "unusable fuel" specification is 5 gallons.

 

I can imagine your "thoughts", I like coming home with 2 hours in reserve but there is something about local trips that makes me comfortable with shorter reserves.

 

I have/had 35 gallons in the hangar too. I never felt at risk because I have so many off field landings in this area. In fact one of my options as fuel was becoming critical was the old dirt runway at Janie's Ranch. There are a couple old "ranches" with runways around but the ladies are gone and the runways are decaying.

 

In recent years they snow staked all the roads and leave them up in the summer. It takes some crow hopping to land and some stake bending to prepare for take-off, not worth if just to pee

 

In retrospect what was interesting was that it was reasonable for me to continue due to the rural area and fact that I could see a fuel level. The difficulty came from the fact that I was only willing to continue in a slip so I could see fuel and it looked like a lot when in fact it was very little.

 

 

[Runtoeat]

I happened to be able to examine a CTSW which had crashed and which had the "A" pillar torn open. This provided me with the opportunity to look at what is in the "A" pillar regarding fuel lines. A square steel tube approximately 3/4" cross section ran the length of the "A" pillar and it is assumed that another similar square tube runs down the other pillar. A steel fuel line is welded at each end of this square tube to allow attachment of inlet fuel line at the wing root and outlet fuel line at the firewall. This system appears to hold a fair amount of fuel. Some time ago, I was curious how much flight time I might have, should I happen to glance up and notice that both sight tubes were indicating zero fuel remaining (CT, does this sound familiar?:unsure: ) I emptied both wing tanks and put fuel back into one wing just to the point where fuel could be seen at the bottom of the sight tube. The gascolator drain was then opened and the time it took to drain the fuel was recorded. It took about 10 minutes for just the one side to drain. Of course, the flow was governed by the gascolator drain and this might be more or less flow than what a Rotax may require. However, the flow of fuel during the draining appeared to my non-expert eye to be adequate to keep a Rotax engine running - especially if it were running at reduced throttle setting.

[C ICEY]

Flying with litres up here in BC makes time management a bit easier.

 

mostly looks like all unlandable terrain below, the one forced landing exception proves the theory (btw, not fuel starvation)

 

anyways, with tanks empty, I have filled with 10 litres each left and right tanks and clearly marked the site tube levels on level ground : one half hour for each tank.

filled to twenty litres each side and marked again: one hour each tank.

 

I calculate at twenty litres per hour and round distance to 100nm, and knowing that there is an unuseable portion, that makes the 10 litre indicated line my limit for comfort. Considering the range and efficiency of CT's, I don't think there are many excuses for flying below that 10 litre mark, especially in the mountains.

 

my fuel fills are in multiples of ten litres, sufficient for and typically just prior to the planned flight, with at least 1 hr reserve. I was once a passenger in a 172 over certifiable unlandable terrain, in which fuel was filled the night before and not dipped that morning. we returned on fumes, where it was realized that 5 gallons had been siphoned off that night for some quad or dirt bike.....

 

However you do it, know what you've got, and how long you have to use it.

[Ed Cesnalis]

... A square steel tube approximately 3/4" cross section ran the length of the "A" pillar and it is assumed that another similar square tube runs down the other pillar. A steel fuel line is welded at each end of this square tube to allow attachment of inlet fuel line at the wing root and outlet fuel line at the firewall. This system appears to hold a fair amount of fuel...

 

Dick,

 

Thanks,

 

I knew I had fuel in the air all the way to closing the throttle abeam but when I got on the ground there was little evidence of it. It sounds as though I was looking at fuel that would have occupied the square tubes if I wasn't slipping.

[Ed Cesnalis]

...Flying with litres up here in BC makes time management a bit easier...

 

If you say so, at my age my brain is simply too full to think about learning to convert liters.

 

Thanks for the tip on adding some meaningful marks.

[knolde]

I flew yesterday for 1.2 hours and before I left I glanced at my sight tubes ( they are new and have different markings ) and thought I saw 10 gallons.

 

The entire flight I watched the sight tubes and on my way back I knew my fuel was getting critical. I really didn't want to land on a road in remote Nevada/California mountains so I kept going but always with a landing zone and always with some fuel showing in 1 site tube.

 

I flew in a slip sufficient to keep fuel visible ( which looked like 3-4 gallons because it was sloshed inboard ) once abeam the numbers I forgot about the fuel and turned base and final coordinated.

 

I taxied to my hangar and then looked again. Both site tubes show zero, dipping the tanks show zero as well. I would have to drain the fuel to see how much is left and after sitting in the hangar its possible I could drain some that wasn't usable in flight.

 

I never thought about it before but if I have a chance of making it to an airport and if I can see fuel and if I have reasonable landing options I will continue. I would have landed if the visible fuel was exhausted. Another reason I would land is if the terrain ahead became unfriendly for landing.

 

Any thoughts?

 

 

I would like to quote the words of an Aviation Cadet Instructor and my first B-52 Aircraft Commander "There are only two things that your wings require for a successful career: "NEVER FORGET THAT, IN THE BIG SCHEME OF THINGS, YOU CAN NEVER, EVER, JUSTIFY, RUNNING OUT OR FUEL OR GETTING LOST!" You might look at the article I wrote on cross country flying--I emphasized "never, ever, out fly your fuel!

 

I do as I say and I know how much fuel I have on board by dipping the tanks, check progress with the Dynon, but I rely on the stop watch! In the CT I can not say that I can ever remember looking at the fuel tubes, my normal flight begins with full tanks. However, if I do not have full tanks, I dip the tanks before I push the aircraft out of the hanger. Planning what to do if you run out of fuel seems less than rational to me, I say again: THERE IS NO EXCUSE FOR RUNNING OUT OF FUEL or, that matter, getting lost! I used to fly RF-4Cs and in combat, the only reason for flying the mission was to get the photos and other data back for analysis--everything else was moot, bingo fuel figures were figured and you simply did not ignore that figure! B-52s were a different mission, but fuel was a critical matter, which was why the nav layed out a mission and then he and the copilot figured the fuel--then the rest of the crew got busy. Point here is that we fly for the joy of it, but fuel is a critical factor that can ruin your day or p[ossibly your future! Nuf said, I'm off my soap bow! See ya, Dr. Ken Nolde, N840KN, 500+ hours of fun

[coppercity]

I would like to quote the words of an Aviation Cadet Instructor and my first B-52 Aircraft Commander "There are only two things that your wings require for a successful career: "NEVER FORGET THAT, IN THE BIG SCHEME OF THINGS, YOU CAN NEVER, EVER, JUSTIFY, RUNNING OUT OR FUEL OR GETTING LOST!" You might look at the article I wrote on cross country flying--I emphasized "never, ever, out fly your fuel!

 

I do as I say and I know how much fuel I have on board by dipping the tanks, check progress with the Dynon, but I rely on the stop watch! In the CT I can not say that I can ever remember looking at the fuel tubes, my normal flight begins with full tanks. However, if I do not have full tanks, I dip the tanks before I push the aircraft out of the hanger. Planning what to do if you run out of fuel seems less than rational to me, I say again: THERE IS NO EXCUSE FOR RUNNING OUT OF FUEL or, that matter, getting lost! I used to fly RF-4Cs and in combat, the only reason for flying the mission was to get the photos and other data back for analysis--everything else was moot, bingo fuel figures were figured and you simply did not ignore that figure! B-52s were a different mission, but fuel was a critical matter, which was why the nav layed out a mission and then he and the copilot figured the fuel--then the rest of the crew got busy. Point here is that we fly for the joy of it, but fuel is a critical factor that can ruin your day or p[ossibly your future! Nuf said, I'm off my soap bow! See ya, Dr. Ken Nolde, N840KN, 500+ hours of fun

 

 

Hi Ken,

I agree with your comments with the exception of not checking your sight tubes occasionally. I would add it to your scan periodically as the Dynon or stop watch cannot detect a leak in a tank thru say the fuel cap or vent since we have no sensors in the tank. The Dynon only knows about fuel going to the engine but not elsewhere. We know of one CT that lost an entire fuel cap assembly, I'm sure a great amount of fuel would be sucked out the low pressure top side of the wing!

[Roger Lee]

Hi Guys,

 

I'm with Eric. There have been a few that forgot to put the cap back on and fuel does get sucked and or spilled out the open cap hole. Dynon does only read what goes through the fuel transducer and leaks happen. Fuel just disappearing out of the sight tube means about 1 gal in a wing and that's the plane is sitting .perfectly flat. As a few have learned the hard way with a CT allowing that kind of low fuel level has caused several crashes around the world. All fuel isn't usable so looking at the sight tubes may give a false reading especially if you are slightly out of trim. Allowing fuel to get that low may not cause a crash today, but keep that practice up and one day I believe it will. It's just as easy to manage a flight to either carry enough fuel or land and fill up. The aircraft can carry the extra weight even if you are over by more than 130+ lbs. I know from experience and so do many others here so don't put set yourself up for failure with marginal fuel on board.

 

Low fuel that is getting near the very bottom of both sight tubes is just asking to have an engine out. Pick up a little wind, have an airport close on you, get there and have too much wind to land, get a little lost, have to detour around a peak with high winds or have to divert to another airport is looking for a painful experience. None of us was taught that way and we have all read about low fuel crashes. That might equate to playing Russian roulette with 4 rounds chambered.

[Runtoeat]

Hi Ken. I greatly respect the advice you provide based on your experience flying military aircraft. B-52's and Phantom's don't work too well as gliders and knowing to the minute how much fuel is available is of paramount importance. I must agree with Eric though in saying that one of the best things about our CT's is the fact that we have a visual indication of how much fuel remains on our fuel tanks due to the fuel sight tubes our planes have. Before departing, the minium amount of fuel that must be in my fuel tanks is 10 gallons and I dip the tanks before each flight to verify this. This minimum amount of fuel gives me 3 hours flight time with one hour reserve if running at WOT the total time I'm in the air, which is something I never do. Consequently, I burn, on average, about 3 GPH, which gives me about 5 hours with over one hour of reserve. The main thing though, regardless of the type of flying that is being done, is the fact that we are able, at any time, to glance at our sight tubes and visually see a "honest to God" amount of fuel that is in our tanks. Personally, I have put "3 gallons remaining" marks on each sight tube. By knowing that I have my minimum of 10 gallons at the start and knowing if I am approaching or at the "6 gallons of fuel remaining - land now and get some" mark at any point in my flight, the possibility of running out of fuel, for me, is not a concern.

[sandpiper]

Except for the past 8 years living in Oregon plus the three years I worked for my uncle flying the Huey, all of my flying was in Alaska. Early on I learned that pushing fuel, especially in a country with few fueling opportunities and hostile terrain, was not in my best interest nor compatable with my physcological makeup. About 10 years in to my flying career I ran out of fuel in a C-180 after touchdown in Fort Nelson, B.C. before I could get to the pumps. By keeping the tail up, power up, and using brakes, i was able to get to the pumps. In other words, there was enough fuel if the plane was level but not in a 3 point. All this with wife and kids aboard.

 

At that point things changed. No more pushing fuel. I want to see an hour fuel remaining when I land. It helped that, at that point in my life, I could begin to afford nicer & newer planes and planes with long range tanks. That C-180 was a 1955 and had something like 60 total gallons. One of the reasons I bought the CT is due to the fuel available.

 

I firmly beleive in the old saying that "the only time you can have too much fuel is if you are on fire"

 

For me, pusing fuel limits is simply not an option.

[C ICEY]

For the math challenged, it doesn't get easier than metric! especially with consumption at a nice round number like 20/hr. (borne out from 1000hrs of logbook records)

 

{thats great, until Deb saw that 1000 hr number and easily crunched how many litres (and dollars) that has actually been fed into my hobby .

mayby youguys are on to something down there.....

grin}

 

 

Powers of ten!!! ten litres is one half hour.

 

besides, whose gallons are you talkin' about, anyways??????? :huh:

 

I understand the difficulty of trying to calculate gallons: 25 litres is 6.6 US gallons or 5.5 imperial gallons

yikes.

4.what per hour of whose gallons? the math students I tutor cringe at the thought (and they usually respond really well to the "flying colours" reward that they are offered for producing!)

 

I fill with 25 litre jerry cans, usually consider one jerry can to be an hour with a reserve.

fresh.

certain.

marked on the sight tubes for the approach to empty.

[knolde]

Hi Ken. I greatly respect the advice you provide based on your experience flying military aircraft. B-52's and Phantom's don't work too well as gliders and knowing to the minute how much fuel is available is of paramount importance. I must agree with Eric though in saying that one of the best things about our CT's is the fact that we have a visual indication of how much fuel remains on our fuel tanks due to the fuel sight tubes our planes have. Before departing, the minium amount of fuel that must be in my fuel tanks is 10 gallons and I dip the tanks before each flight to verify this. This minimum amount of fuel gives me 3 hours flight time with one hour reserve if running at WOT the total time I'm in the air, which is something I never do. Consequently, I burn, on average, about 3 GPH, which gives me about 5 hours with over one hour of reserve. The main thing though, regardless of the type of flying that is being done, is the fact that we are able, at any time, to glance at our sight tubes and visually see a "honest to God" amount of fuel that is in our tanks. Personally, I have put "3 gallons remaining" marks on each sight tube. By knowing that I have my minimum of 10 gallons at the start and knowing if I am approaching or at the "6 gallons of fuel remaining - land now and get some" mark at any point in my flight, the possibility of running out of fuel, for me, is not a concern.

 

Dick, Eric, Roger etal: I, of course, recognize the sight tubes, but I only seem to "use" them when I precdict I will have 15 gals or less. Point here is that in reviewing the comments, I see that the tube can be an indicator of fuel lost in a wing. So, I will in future ensure that I keep an eye on the tubes, but I will also plan flights to ensure that I do not run out. I again will let the secret formula that most, if not all, military pilots and navigators learned; the 5 "Ps" PRIOR PLANNING PREVENTS POOR PERFORMANCE, so I am old and I cling to some of the old stuff.

 

If I might answer the original question of when y]one should look to put it on the ground in a low fuel situation--I think the question should be when did you realize you were short of fuel? Tthat is the point at which you should be looking to get it on the ground. I apologize if I seem a bit "edgy" at times, but I really do believe that there is no excuse for running out of fuel or getting lost--yes i know there are reasons why, but why!

 

See ya, Dr. Ken Nolde, N840KN 500+ hours and I intend to fly many more!!

[S3flyer]

I'll throw my $0.02 with Ken -start with a known amount and use a watch to determine your fuel. I'd also throw in cross check with gauges/site tubes and take the most conservative approach.

[Ed Cesnalis]

I drained my fuel to determine how much that I had after taxing back to the hangar. The result tells me that you can fly a CT in a slight slip ( one where the wings still appear pretty level but the slip skid ball is close to or touching a line ) and see fuel as high as 3-5 gallon marks at the leading wing's site tube and yet be far below 30 minute reserves. If this is your condition you need to compare the 3-5 reading in 1 wing with a level reading where both wings match, the 3-5 just might disappear entirely.

 

This speaks to fuel transferring in flight as well. If I can see fuel that high in one wing in a slight slip, when the wings are actually empty in level flight then I can reason that fuel transfers in flight at the same slight slip.

 

Lesson learned and I'm back to 2-hour reserves.

[CT4ME]

All this talk makes the CTLSi seem even more attractive.... 1 extra gallon of fuel, a selector switch, and a "header tank". Fuel mgmt should be much easier, and you won't have to worry so much about "unusable" amounts and slosh. Of course, you'll have to remember to manage the fuel selector switch.

Tim

[xlaxatc]

The stickers next to the glass tubes in the CTLS were mounted too low indicating about 3 gals more than the aircraft had. After landing we filled each tank with 3 gals and it indicated 5 to 6 gal. Be carefull. Better to stick the tanks and pay attention to your time vs consumption rate.

 

Stay Safe

Wizzer

[207WF]

Every time you change the fuel sight tubes a given amount of fuel in the tank will appear as a different level in the tubes, in my experience (third set of tubes). So it is important to mark right on the tubes some calibrated amounts. Don't use the stickers next to the tubes, except perhaps to help you remember what your marks on the tubes mean. WF

[Winger]

After putting dry wings (with new sight-tubes) back onto my CT2K, I wanted to accurately calibrate my sight-tube fuel levels. The most important levels are obviously the smaller levels of remaining fuel, so I looked around for an accurate 1-gallon container to fuel the tanks in 1-gallon increments. The attached photo shows the only container that I could find around the house that was exactly 1-gallon.

[coppercity]

That brings back some physically demanding College memories! I just had a Phantom hangover...