This page last updated on 04/17/2017.
Copyright © 2001-2017 by Russ Meyer
The preflight ritual didn't reveal any obvious problems with the plane. We should have plenty of gas for the return trip. Nevertheless, just to be on the safe side, I climbed up to the top of the wing, opened the fuel caps, and peered inside with my flashlight. Yep, plenty of gas alright. We said our good-byes, clambered in, and took off into the dim twilight. The flight would take us over somewhat inhospitable terrain. We would generally be paralleling the Snake river all the way back to Kennewick. There would be few roads or settlements along our route.
It was a very dark, moonless night. We hummed along for about 35 minutes, chatting about this and that. As I scanned the instruments for the 100th time, something caught my eye. The fuel gauges were indicating only about ¼ full, when the tanks should have had been almost ¾ full. What had happened to all our gas? I found it very disturbing that we had lost a half tank of fuel in 35 minutes of flying. It would be dreadfully inconvenient to run out of gas at night over this kind of terrain. In the gloom, it would be very difficult to locate a suitable field for an emergency landing. Well, things weren't critical yet. The fuel we had should be enough to get us safely back to Kennewick.
A troubling thought occurred to me. During flight training, my instructor had warned me not to forget to replace the fuel caps after checking the tanks. In flight, a low pressure area develops on top of the wing and literally sucks the wing, with airplane attached, up into the air. If the fuel caps are not securely fastened, this low pressure can also suck all the gas out of the tanks. Maybe I had somehow forgotten to replace one of the fuel caps, allowing our gas to be siphoned out and blown away in the slipstream.
Training my flashlight on the trailing edge of the wing, I tried to descry a dribble of gas, a patch of moisture, anything that might indicate leakage of our lifeblood. Everything looked clean and dry. This was puzzling, that ½ tank of fuel had gone somewhere. Maybe fuel was leaking in the engine compartment. I didn't smell any gas, but just in case, I mentally rehearsed what I would do in the event of an engine fire...mixture to idle cut-off, fuel shut-off valve off, electrical system master off, cabin heat and air off, dive to try blowing the fire out, land anywhere as soon as possible. The fuel gauges could also simply be inaccurate.1 Still, from experience, I knew Cessna fuel gauges were usually pretty good.
I decided to watch the fuel level for another few minutes before concluding we really had a problem. Both Pullman and Kennewick were about 50 nautical miles distant at this point. There are little airstrips near each dam along the Snake river. Little Goose dam was only about 10 miles behind us and Lower Monumental was 16 miles ahead. These strips were unlighted and surrounded by high tension lines. With no moon, a small miracle would be required to land safely at one of them. The nearest safe harbor was Walla Walla; its lights visible about 20 nautical miles upwind to the South. Not within easy gliding distance at the moment. I decided that while everything was still going relatively well, I would angle somewhat South to bring us closer to Walla Walla and climb as much as I could. If we really were losing fuel, these measures would better position us to deal with the emergency. I didn't tell Jane what was happening, because I didn't want to alarm her until I was sure we really had a problem. I turned the plane very gradually and crept the power up, nosing into a climb.
For the next 5 minutes, the gauges continued to sink. They were now bobbing just above empty. It looked like we were in trouble. We had climbed to 8500 feet. Enough to glide about eight miles against the wind. Walla Walla was still 15 miles away. I wasn't sure our fuel would hold out all the way to Walla Walla, but it appeared it would last until we were within gliding distance. I told Jane about our predicament and she took it well. It was now just a wait and see kind of thing. I nosed the plane over and leveled off, picking up as much speed as possible. The extra speed would enable us to better penetrate against the wind. I wanted to get as close to Walla Walla as I could before the engine quit.
I was engaged in getting Walla Walla weather on the radios, when they began acting up. Strange squeals, pops, and crackles. I twisted knobs and clicked switches to no avail. The radios screeched once more then died. They became totally inert; no display, noise, or anything. I checked the circuit breakers and found nothing amiss. It now seemed like it was getting harder to see the instruments, so I cranked the cockpit lights up. After another minute or two, I was straining to see the instruments again. I turned the cockpit lights full on, but they still seemed very dim. Finally, the lights faded and went out altogether. It was now totally dark in the cockpit. What could possibly happen next! We flew along shrouded in inky blackness. I got my flashlight out and panned it over the instrument panel. All switches and circuit breakers were properly positioned. I turned off all the electrical equipment thinking maybe there had been a major short somewhere. I tried cycling the alternator and battery master switches. None of these measures had any effect. Stumped and a little stunned, I brooded for a minute before concluding that we had irretrievably lost all available electrical power for some reason. I then realized the electrical system trouble was probably responsible for the puzzling radio behavior.
The electrical problems were a minor annoyance compared to our fuel situation. What was going on with that? Was the electrical system failure just a freak coincidence or was it related to the fuel loss somehow? Perhaps the fuel leak really was in the engine compartment. If so, maybe it was shorting out the electrical system...but, that seemed a little far fetched. We flew along for a couple of minutes as I grappled to understand what was happening to the aircraft. Finally, I realized what was going on. The electrical system...of course! In a flash, I understood the whole thing. It was the electrical system all along! The alternator or regulator had failed some time back, probably shortly after takeoff. The airplane continued to operate just fine on the battery, and I had failed to notice a discharge on the ammeter. The fuel gauges are electrically operated. As battery voltage declined, the gauge readings had also gone down, giving the impression that we were losing fuel. In fact, we probably had plenty of fuel; there just wasn't enough juice to run the gauges! A bit longer and there wasn't enough electricity to operate the radios or lights either.
If a lead-acid battery has fully discharged, it can sometimes recover some of its capacity when the load is removed for a few minutes. I rechecked the switches to make sure all electrical systems were turned off then waited. After a few minutes, I turned the cockpit lights back on. They sluggishly came up to half-brightness. I looked at the fuel gauges and found them reading slightly less than ¾ full, right where they should be. So in fact it WAS entirely a problem with the electrical system. Whew! An electrical failure is not really a serious threat, just an inconvenience. By design, all the important systems in the airplane run just fine without electrical power.
I turned back on course for Kennewick. On approach to the field, it would be very helpful to have external navigation lights so other aircraft could see me. I would also like to be able to deploy the electrically operated flaps on landing. I decided to keep all the electrical systems shutdown enroute, saving the last bit of power for position lights and flaps. We flew along in darkness, checking the instruments periodically by flashlight.
As we drew near to Kennewick, I couldn't believe my eyes when I noticed lightning ahead. The forecast had not called for weather of any kind. This thunderstorm was a complete surprise. Furthermore, it was only about seven miles Southwest of the field and closing. Man, were we having bad luck tonight! One isolated thunderstorm in all of Eastern Washington, and it is parked almost on top of our destination...sheezh! I briefly considered turning back to Walla Walla, but the storm was small, isolated, and didn't seem very threatening. I decided to have a go at landing.
I entered the pattern at Vista Field in Kennewick as fast as I could. I needed to hustle to beat the thunderstorm to the runway with some room to spare. On approach I turned on only the anti-collision light and left the rest off. In the pattern, there was enough juice to deploy half flaps, after that, the battery was totally dead. We landed without problem, taxied to parking, and shut down. I got out and inspected the alternator. Everything looked OK. It had not thrown the drive belt, nor did it seem damaged in any way. I figured the voltage regulator must have fried. Ah well.
For me, this was an enlightening incident,
especially as an inexperienced pilot. I knew things could go wrong, but up
to this point, the worst that had happened to me was a fried RADAR transponder.
Even though nothing was seriously wrong, I didn't know that while in the midst
of the "emergency." I
think it rattled my attitude about flying out of a slumber. I am now much
more alert to problems developing with the aircraft. It also caused me to
start doing more contingency planning on cross country flights. There's no
substitute for actual experience!
This portion of the story originally read as follows:
"The fuel gauges could also simply be inaccurate. The FAA only requires the gauges to read accurately when the tanks are empty. Yeah, you're right, that's really stupid, but it's the law. If the tanks have any appreciable gas in them at all, the gauges could read anywhere between slightly above empty to full. Still, from experience, I knew Cessna fuel gauges were usually pretty good."
On 4/27/2005 I received an E-mail from Bob Moore which read:
Bob is right, of course. I never bothered to look up the regulation myself. While getting my private certificate, my instructor told me this and it stuck in my brain because I thought it was odd. Reading the regulation, I can see how it can be incorrectly interpreted to mean the gauges are only accurate (calibrated) when there is no usable fuel left. It's wrong, but understandable.
Hats off to Bob; a good catch! I suspect many pilots harbor this misconception...certainly, my CFI did his part to perpetuate the myth.
A Personal Side Note
I find it surprising that a few people read the stuff I post here! I've often wondered if anyone actually read my articles. I had pretty well concluded that no one bothered. Most of my hit counters seem to be incremented by web crawlers like Google, etc., not by human visitors.
I've frequently wondered why I get so much joy from maintaining this web site, especially since few people actually read it. I think it's a way I can make a statement to the world. It doesn't really matter if anyone reads it or not, it's the act of telling my story that gives me satisfaction. It's a totally personal, irrational, emotional motivation. Even I don't really understand it. I just feel like I have to write something once in a while. Building the web site has opened up a whole world of experience for me.
A friend of mine, Ed Ansong, was in O'Hare airport one day waiting for a flight. A guy came up to him and handed him a book. It was his autobiography and he wanted Ed to have it. He didn't want any money or anything else. The guy said he usually passed out about a half dozen copies per day. He had personally paid for the books to be published and bound. "Everyone has a story to tell, and other people are interested in hearing it," the guy said. Ed took the book and read it. It was very simple. There was a chapter on where he was born, another few chapters about his childhood, a chapter about meeting his wife, establishing a career, raising kids, buying a car, etc. Nothing really Earth shattering...just an ordinary life. It was fascinating reading.
I've always remembered the story about that guy. You there...reading this...you're an ordinary person, right? And yet, you have an interesting, extraordinary life that other people want to hear about. Sure, not everyone wants to hear it, but some people do! Your story has merit and it doesn't have to be exciting, successful, or unusual. Even if your life seems sad, empty, or desperate, it's an intense human experience. People want to hear about it.
Everyone has a story to tell...everyone.