Fuel exhaustion event

S

Soybean killer

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I previously posted about this event. This is a more detailed account so others can learn from my lessons.

I was enroute to Oshkosh in my Decathlon with my son. We hit ugly weather the prior day, got separated from the other airplane in our flight, and spent the night at Rough River, KY. We were attempting to rendezvous in northern Illinois to fly the Airventure VFR arrival. We had a LOT of get-there-itis because we really wanted to make the Weds PM window.

I landed at a rural airfield in central IL. The fuel was full serve, so the line guy topped my tanks. I checked the caps afterward. I had 4 hours of fuel, and my next leg was a bit over 2 hours. Flying north, I hit frontal activity about 90 minutes into my flight. I diverted about 10 minutes east to a large surburban airport south of Chicago. About 15 minutes after we landed, a thunderstorm hit.

After the front passed over, I was eager to the next stop so we could stage the arrival flight. The airfield we were at had only full service fuel, but the line guy had left the FBO. The lady at the desk said she could call someone, but it might take a while. AVGAS was insanely expensive there, over 7 bucks a gallon, and my fuel monitor said I had 2+ hours of fuel remaining to fly a 45 minute leg. I departed without topping off.

I did not stick tanks during preflight. Accessing my tanks requires a ladder or stool. There was no ladder or stool visible on the ramp. I carry a milk crate for that purpose. BUT that milk crate was buried under a pile of camping equipment that would have to be unloaded.

I took off. Conditions were still a bit sketchy with lingering scattered/broken layer, which spooked me a bit since my son was onboard. I tried to climb over the clouds, but they were still rising at 5K, so I went through a hole and got under. Ceiling was about 3K MSL, which worked out to about 2200 AGL, so I was flying at about 1800 AGL over flat farmland.

About halfway into the leg, the engine stops. Then it restarts. Then it stops. Then it restarts. Again. Again.

As anyone who has been there understands, the first thing that does through your mind is denial. HFS. This. Is. Not. Happening. Especially with family on board.

The next is hope. Wishing it will magically fix itself. When the engine restarted and power surged, I thought "yay!!" ... followed by "aw." Then "yay". Then "aw".

My first thought was water from the thunderstorm. I guessed the surges might be the engine sucking up bits of water and burning it off. I checked controls, but TBH there isn't a lot to check or do in a Decathlon. Fuel on, mags not, mixture rich. Prop still spinning so nothing to restart.

This went on for maybe 15 seconds, before it was clear to me we were going down. With my son on board. F%@#.

I looked at my nav app. There was a private strip right off our nose. I looked down and identified a 2000' grass strip cut into a cornfield. I turned to align on downwind, made a quick attempt to deduce wind, then dropped that because math is hard when your brain is in fight or flee mode. My son asked what was happening. I said "I don't know", then "the engine is quitting, it's going to be fine, we are landing THERE" and pointed at the grass strip.

All this started at 1800' AGL. By the time I worked through denial and hope, I was probably around 1K AGL at midfield downwind. Except it was actually the upwind, which I didn't realize at the time.

At this point everything was happening fast. Very fast. I was abeam the touchdown point at 700-800 AGL and descending quickly. I did a tight 180 onto final, overshot the centerline, then brought it back to high short final.

I don't have flaps. At this point I tried to slip, which I do all the time. For some reason my hands and feet got all crossed up and I just said F It and pointed down the runway. I tried a wheel landing (which I suck at), bounced, then switched to 3 point attitude. It floated and floated and would not set down. In addition to carrying too much speed, I had a 5 knot tailwind and the airstrip was downhill in that direction.

Finally I realize I am going to run off the end of the runway into a low field covered with knee high plants. I yell to my son "brace yourself, we're going into the field". We float about 20 yards into the soybeans, touch down and ... poof. The softest, smoothest landing ever. Roll a few hundred yards to a stop, get out and check the plane. No damage, just green stains on the belly and a ton of plants on the wheel fairings and gear legs.

The farmer who owns the property showed up with a truck a few minutes later. We tied my tailwheel leaf spring to the hitch and walked the aircraft back to the grass airstrip. Then I start checking the plane. First I sump the fuel system. I am SHOCKED to find no water. Then I stick the tanks. Dink dink dink. Bone dry! The right wing has a wide blue stain in a fan pattern from the filler neck to the trailing edge. Pretty obvious what happened. The filler cap was not correctly sealed, which allowed roughly 15 gallons of fuel to be siphoned off during 2 hours of flight. I am going to withhold technical details on why that happened.

I text my IA buddy who is 30 minutes behind us. He lands at Dekalb, gets the crew car, buys gas cans at Walmart, fills with 100LL, and drives 10 minutes to where I am at. He checks the aircraft for damage and agrees with my assessment of cause. We gas it up and put my son and baggage in the crew car. Then I take off, circle to climb, and proceed 8 miles to Dekalb. The next morning we fly the approach uneventfully. I was AOG for maybe 2 hours.

Next post: lessons learned
 
Thanks for sharing. Glad it worked out. Hopefully your son wasn’t too shocked, put off, or scared.

Looking forward to your lessons.

PM me, happy to work with you (privately) on cause and corrective actions, if you’d like, and then share here if you wanted. I’ve done this for petrochemical manufacturing incidents, retired now.
 
Ok, let's talk about lessons learned.

1. Fuel monitors and burn calcs only account for fuel burned, not lost to system leaks. You must cross check your tank gauges against your burn calcs.

2. If your gauges are not in your normal scan pattern, you have to be deliberate about this. My single tank gauge is above and behind my right ear. I have to look up and over my shoulder. Easy to forget to do this when you are dealing with weather, etc.

3. Learn what fuel exhaustion sounds like. In hindsight, the stopping and starting makes perfect sense, as the remaining fuel sloshes over the fuel line intakes. I talked to friends with similar experiences and they said the engine did same thing. Wish someone had taught me that.

4. Frequently practice emergency landings. It is a very perishable skill. That is especially the case for aircraft without flaps.

5. Know where you are. Nav apps are great. Within 5 seconds I had located the nearest strip and visually identified it.

6. Periodically get surface winds and mentally orient them to your direction of flight. Very challenging to do this in an emergency.

7. Things happen FAST when the fan stops. Really fast. Don't plan on anything complex or extraneous when practicing emergency procedures.

8. Fly the plane. I made a lot of mistakes, but things turned out well because I focused on flying the plane to the runway.

9. Altitude is good. An extra 2K of altitude buys you 2 minutes to think, decide, and act.

10. Consider effect of minor changes to routine. Using a milk crate for a stool seemed like a great idea ... until it was packed under a pile of bags.

11. Little things can cause your engine to stop. It has caused me to reassess my risk tolerance for terrain and night flight.

12. Soybeans are great. So soft. Nature's foamed runway.
 
12. Soybeans are great. So soft. Nature's foamed runway.
Agreed, soybeans broke the fall of my iPhone I accidentally dropped out of the window in my Diamond at 11,500 feet. Tracked it down the next day, totally undamaged and used it for another 3 years ;-)
Glad they were there to catch you too!
 
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You are gonna skip the most important part of the story? So weird.

"The filler cap was not correctly sealed, which allowed roughly 15 gallons of fuel to be siphoned off during 2 hours of flight. I am going to withhold technical details on why that happened."
 
Glad that you are here to share the story, awesome work!
 
I'd had my 182 for a few months and I stopped somewhere that had full service fuel. I let them fill it up, didn't check it, got in, reset the engine monitor to show 55 gallons and flew to the next destination 3.5 hours away. I was shocked at how much fuel I took on. My lesson learned is, nobody fuels my plane but me. You have to put fuel to the point where it almost looks like it's going to run out and apparently the line guy didn't do that. He also put a nice scratch on the wing, so another reason nobody touches my plane but me.

On the way back from Oshkosh, I had one of those math moments. I flew a long leg and had calculated I would have slightly over 30 minutes of fuel left when we landed. When I was on downwind, I noticed it said I had 8 gallons of usable fuel and felt a moment of terror. I knew I had the airport made, but 9 gallons, wow. I made a comment about cutting it a little too close, when Leslie chimed in with the real math... you've been burning 10.5 gallons per hour in cruise, you're descending, and you have 8 gallons left... seems like you've got more fuel than you planned to have. Oh yeah... math!

Thanks for sharing your story. I've always said it's important to share our mistakes. It may save someone's life.
 
my fuel monitor said I had 2+ hours of fuel remaining
I think this is a major takeaway:
Fuel monitors are great. Extremely accurate. But we have to remember that all they do is measure fuel use by the engine. They are GIGO instruments only as good as the startup fuel you tell them and they don't account for leaks and loss which are not based on what the engine is using.
 
I think this is a major takeaway:
Fuel monitors are great. Extremely accurate. But we have to remember that all they do is measure fuel use by the engine. They are GIGO instruments only as good as the startup fuel you tell them and they don't account for leaks and loss which are not based on what the engine is using.

I think that is the most significant takeaway.

30 years ago in PPL training I was taught "never trust the gauges". But that does not mean don't CHECK the gauges. Cross checking the fuel gauge for conflict with the fuel monitor is essential.

In my aircraft, the gauge is not on the panel. It is on the wing root above and behind the pilot's head. Really easy to fixate on the monitor, which is right there in front of you.

One thing I forgot to mention. The line guy that filled the tanks overflowed the right wing, so I knew I was starting with full tanks.
 
Thanks for the excellent writeup! I too have been lax about using my fuel sticks sometimes. This encourages me to start doing it everytime. I do check my fuel caps myself when a lineman fills me. They often don’t get the full twist.

My C170 has fuel gauges in the wing roots behind my line of sight, so I have a 30 min reminder on my Aera660.

My tailwheel instructor always had me check fuel on downwind and I keep that habit today. That way I know if I have sufficient fuel for a go around. Maybe some siphoned off and I only have one shot.
 
I always use the most pessimistic of:
1. The fuel gauge
2. My fuel flow totalizer
3. My watch (based on my preflight planning).
 
30 years ago in PPL training I was taught "never trust the gauges".
"Never trust the gauges...unless they are reading lower than you expect."

The "only need to be accurate at zero" mythology aside, they are calibrated to be correct at zero usable. The closer they get to that, the more I believe them.
 
Glad you’re okay, and a very honest assessment. Shows how the holes in the swiss cheese can line up on any of us…
 
Glad to hear everything was OK! Judging by your description you must have gone down just a short drive from my house.
The only good news is that in this area (pretty much my entire AO), you'd have your pick of corn/soy fields in case that private rwy hadn't been there. Lots of forgiving places around here to make an unplanned, off-airport landing!
Glad it happened here and not over the lake or mountains or something! And good lessons learned :oops:
 
Reminds me of a plane that landed on a highway once and the newspaper said it departed again after the spark plugs were cleaned. Our conjecture was that they added a few gallons of spark plug cleaner to those tanks on the wing.
 
8. Fly the plane. I made a lot of mistakes, but things turned out well because I focused on flying the plane to the runway.
Repeating this because I hate it every time I read about someone stall spinning and killing themselves. Such a pointless avoidable thing.
 
So many reason to check. One FBO charged me to fill up a different airplane, neglecting to fill mine.
I landed at Gatlinburg-Pigeon Forge once. A lineman met me at the plane and I told him to fill the mains and there is one filler to do the mains on the Navion and you had to fill it slowly (since it drains across to the other tank). I then went into the counter and reiterated this whole instruction as I always do when letting someone else fill the Navion.

Great, we make a quick bathroom and weather check and go back out. Pay for the fuel and go back out. Since they claim to have given me 30+ gallons and its only an hour I didn't bother to check to see if they had fully topped the mains (usually what happens is some guy opens the nozzle full bore and the right main fills up before it has time to drain over to the left and you end up 16 gallons short). It's less than an hour to get home.

On the way out to the runway I note that the main tank gauge is way down. WTF did they do with those 30 gallons. Yeah, they put them in the TIP tanks. Thanks guys, that's a serious issue in the Navion. Not good to land with a load in the tips.
 
Ron, remember there is no requirement to NOT be doing weed when fueling the line.
It's just how it is now. I've been mistaken for needing JET A...and intercepted it just in time.

B
 
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WTF did they do with those 30 gallons. Yeah, they put them in the TIP tanks. Thanks guys, that's a serious issue in the Navion. Not good to land with a load in the tips.
Years ago, I was at an FBO in Green Bay when the pilot of a twin with tip tanks was reading the riot act to a line guy for filling the wing tanks instead of the tips. I forget what kind of twin it was, but he had instructed the line guy to fill the "mains" without explaining that the main tanks on that airplane were the tips.
 
Ron, remember there is no requirement to NOT be doing weed when fueling the line.
It's just how it is now. I'be been mistaken for needing JET A...and intercepted it just in time.

B
You betcha. I had a line guy at GYY offer to put JET A in the Navion once.
 
Years ago, I was at an FBO in Green Bay when the pilot of a twin with tip tanks was reading the riot act to a line guy for filling the wing tanks instead of the tips. I forget what kind of twin it was, but he had instructed the line guy to fill the "mains" without explaining that the main tanks on that airplane were the tips.
Cessna 310. The tips are the mains. The wing tanks are the auxiliary tanks. There's actually good reason for this. If your plane is set up properly for it, having that weight at the other end of the wing to counter the weight of the central fuselage load works out. In my plane you get a bump up in gross weight for the tip tanks provided that all the extra weight is fuel in the tips.
 
I am reminded of my (much) younger sister on her cross country student solo - landed at the far end and had to use the facilities - asked to have the airplane filled. Came out, didn't check to see if it had happened, ran out of gas halfway home and put in a farm field. I heard about it when the old man called to ask if I had any gas cans - he was collecting enough cans to to fill the airplane and fly it out of the field (which he did).

Then there was the time I went to the airport, stick a tank, WTF, it's empty. I don't know when the tank cracked - during the last flight or sitting in the hangar - but somewhere along the way probably 5 or 6 gallons of fuel (8.5 gallon tank, auto fuel so no tell-tale blue stain) decided to disappear.

Stuff happens, and sometimes, it's not even our own fault.
 
Wow. Nobody, but nobody, services my plane but me. "Full service" for me is the line guy hands me the fuel nozzle while I'm standing on the ladder.
 
If your plane has more than one hole that fuel can go in, the onus is on you to be clear about which hole(s) you want it in.
 
Complex fuel systems need the owner present during the entire fueling process. You are asking too much from a lineman otherwise.
 
One year our plane came out of annual the day before we were to leave for Oshkosh. I tanked it up and did a quick test flight. We opened up the cowling after the flight and looked for various leaks. Nothing visible. The next day we load up the plane and Margy is flying and I'm on the right side. We're departing from VKX (in the pre-9/11 days) so Margy is negotiating with Dulles Approach to let us skirt their airspace and generally set up flight following. I look down at the fuel gauge and we've now got just over half a tank. Hmm... I point this out and tell her I will keep an eye on it.

Just about the time she gets everything set up with Dulles, I am positive that we are going through fuel at an alarming rate. I tell her we need to land. Given our current position she's now looking at JYO to our left and FDK to the right. I say JYO looks closer. Dulles asks if we need help. I point out we still have 80 gallons left so I think we can make it.

We land and I go off to find a mechanic. Margy is now removing this PITA to get at access panel that allows access to the boost pump. This is what we think is the problem since he had it overhauled during the annual. I come back with the mechanic and he sees Margy sitting there taking apart the aircraft. "How do you get her to do that," he asks. I point out she just finished the annual. (Margy, a school teacher at the time had summers off so she worked at the maintenance shop helping get those ahead of us in line out the door and doing our planes grunt work).

With the cowling wide open and the access panel removed, he has her hit the boost pump. Fuel sprays out of one of the fuel lines up at the back of the engine (not down where the pump was). This was also replaced during the annual as we found that the hoses had date stamps on them from 1948 (in our 1950 aircraft). We figured it was time they were replaced. Apparently someone put it on finger tight and didn't get around to putting the wrench on it to tighten.

Anyhow. Put things back together. Topped off the tank. Computed that on our 20 minute flight we had used 20 gallons of fuel, 60 GPH. I wasn't able to see the leak after the test flight because fuel in the engine compartment vaporizes pretty quickly.

This is why I always use the most pessimistic of:

1. My fuel flow counter
2. My watch (and preflight planning)
3. The fuel gauges.
 
Another fuel flow story. Coming out of restoration where I had replaced the mechanical fuel gauges with an MVP50. I had started to calibrate them sitting at the self-serve pump at the Nebraska airport when the mechanic came out and yanked off a shunt I had put on to fix a problem with the gauges prior. This messed up the first ten or fifteen gallons calibration and I went back and interpolated (and fully intended to fix this later by draining the tanks and starting over). But anyhow, given the massive amounts of work done, even with the test flights, I decide to limit myself to 1.5 hour legs going home.

At my first fuel stop, after an hour, I go to fuel the plane and the tank is FULL. WTF? It's a new engine, but it really should be burning 13 GPH or so. My brain was still trying to understand this amazing efficiency when I went to the aux tank (which I presumably hadn't even touched) and it took 15 gallons. It then occurred to me. That tank drains into the main and the transfer valve must not have been fully closed.
 
Reminds me of a plane that landed on a highway once and the newspaper said it departed again after the spark plugs were cleaned. Our conjecture was that they added a few gallons of spark plug cleaner to those tanks on the wing.
We had a local pilot land on an un-opened stretch of highway. I got to the scene with a mechanic and some fuel and we made it very clear to the police that we were only adding fuel because the mechanic was going to fly the plane further than the original destination to get the plane to his shop. One cop was also a pilot and he laughed and said he understood completely! :)
 
IDK if it's just me being paranoid/risk adverse but I always check the tanks on the cherokee even if i've gone in and sat down to eat for one hour. I just remember reading The Killing Zone and there's a story in there where the guy was getting his plane filled up and mistakes were made thinking the plane had been fueled when it wasn't. I think due to some misunderstanding of a fuel cap being left off. Such a simple thing to check for low wing planes anyways.
 
... We float about 20 yards into the soybeans, touch down and ... poof. The softest, smoothest landing ever. Roll a few hundred yards to a stop, get out and check the plane. No damage, just green stains on the belly and a ton of plants on the wheel fairings and gear legs.
Hence your name - nice. Kudos for sharing, this can be a rough place but if you wear your thick skin you'll get good advice.

... I did not stick tanks during preflight. Accessing my tanks requires a ladder or stool. There was no ladder or stool visible on the ramp. I carry a milk crate for that purpose. BUT that milk crate was buried under a pile of camping equipment that would have to be unloaded. ...
Simple rule: always stick the tanks before every takeoff. Always = no exceptions.
Even though you had a fuel cap leak, sticking the tanks can also catch a cap that is not properly secured.
 
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