This is an excerpt from a report made to the Aviation Safety Reporting System. The narrative is written by the pilot, rather than FAA or NTSB officials. To maintain anonymity, many details, such as aircraft model or airport, are often scrubbed from the reports.
I planned a round trip flight from ZZZ to ZZZ1. I went through all my normal preflight planning procedures, which included obtaining a weather briefing, determining the fuel requirement for the round-trip flight, reviewing the POH, and utilizing the ForeFlight app.
This was my first time flying a Piper Archer.
Having used ForeFlight for the past three years, I have found that it has very good accuracy when it comes to performance predictions. Therefore I determined that I would be able to make the round-trip flight with more than 45 minutes of fuel remaining upon arriving back at ZZZ, which more than met the minimum VFR fuel reserve requirement per FAR regulations.
Upon arriving at ZZZ1, I visually inspected the fuel tanks, and per my estimation, the fuel remaining in both tanks was more than what I had expected and planned for.
On the flight to ZZZ1, my groundspeed was higher than anticipated by around 5 knots, which also led me to believe that what I was showing inside of the tanks was higher than what I had planned for.
On the flight back to ZZZ, I planned to climb up to 10,500 feet. Upon reaching 10,500 feet, I leaned the mixture to peak EGT.
About two hours into the flight the engine sputtered and my initial reaction was that there was carburetor icing, so I turned the carb heat on.
I then noticed that my fuel gauge was reading about 5 gallons, so I decided to switch to the other fuel tank.
At this point, the engine restarted and so I realized I had a fuel starvation issue and I immediately started looking for a place to land.
I had ZZZ2 in sight before the engine started sputtering again.
Once I knew I could make the runway, I requested priority handling with Approach, where they asked me if I had ZZZ2 in sight and how many souls I had on board, to which I replied I did and there were four souls on board.
They gave me the frequency change to the airport and advised me to call them once on the ground.
I landed the aircraft safely with no damage to the aircraft or any injury to any of the passengers.
From a human performance standpoint, the main issue was an expectation that the plane was to perform better than it did based on calculations from the operating handbook.
To prevent a recurrence of this event, I shouldn’t fly a single-engine piston aircraft for more than three cumulative hours without fueling up.
Having a personal minimum can standardize the manner in which I fly older general aviation aircraft that might not be relied upon based on their original performance data.
Primary Problem : Aircraft
ACN: 2030548
First time flying an Archer and had three passengers? Does not sound very wise to me.
There are relatively new types of gauges out there that seem to be relatively (I know – I shouldn’t use the same word twice in the same sentence) accurate. Magnetic float system versus the capacitive float system. I won’t name the company but you can easily find them online. They are suitable for retrofit in older aircraft.
My mind can’t get wrapped around the fact that the governing agencies don’t prescribe more modern, accurate and reliable technology in aircraft – especially life safety equipment! I don’t know but I wonder how many aviation crashes with fatalities are due to fuel management failures?
Fuel mismanagement is the 8th major cause of engines stopping, either fuel starvation or exhaustion.
The existing fuel senders are of the Rochester [ automotive] resistive type. there is a wire-wound resistive bar, which the wiper moves on to vary the resistance set to the gauge .
Automotive gauges are of the same type, but use a precision reference voltage and dampen the voltage sent to prevent the needle from wandering due to the fuel sloshing in the tank.
Aircraft fuel senders have none of the above, so the needle wavers, and with the bus voltage changing from 12.5 to 14.5 , engine off vs running, the needle can move about 1/4 tank….so who knows how much fuel the really is, without sticking the tank.??
The aftermarket fuel sender is of the magnetic, hall-effect design, and is accurate due to the precision voltage and filtering of the voltage sent.
Fuel starvation was not the main issue. Putting 4 people in a Piper Archer was the main issue.
You can’t just use time. Fix the fuel gages so they work correctly. Had a friend in a C182 run it out of gas and crash it. He topped it off so he had plenty of time. But not when you have a fuel leak like leaving the fuel cap off. Every time you fuel you should guess within 2 gallons of how much fuel you’re going to put on. And what you put on match the gages! Fix the plane, time by itself will not save you!
Analog fuel gauges can only be calibrated to empty, as is required by regs. Despite popular opinions the gauges are reliably repetitive. Although not particularly linear.
If it’s dropping faster than normal and mixture is set properly, time to land, you probably have a fuel leak.
Cessna POH have tables listing the fuel burn rate vs mixture setting, percent power and altitude.
The tables are quite accurate for a good running engine.
A Lycoming o-360 running at 75% power will burn close to 8.5 GPH at 2200 to2250 rpm.
So, for a 3 hour flight , the aircraft should use about 25.5 gallons, and would show about 1/2 tanks on each gauge.
The distance traveled in that 3 hours will depend on the wind direction and velocity.
The gauges can be inaccurate due to buss voltage variation, installation error of the float lever arm, and the sloshing of fuel makes the needle waver a lot.!
I read this with sympathy and interest as a relatively new pilot who learned entirely in Piper Warriors and Archers. Except for the one time I flew a 172 and experienced the “both” fuel selector variance. A few more learnings to offer from this story. If the inference is correct that the pilot didn’t switch tanks until the two hour mark (a pilot more familiar with a 172 or self balancing fuel airplane might not have this protocol by default ) than the plane was likely flying significantly out of balance for an hour. This would have negatively impacted performance in a way FF could not predict. It’s very possible that the calculations were correct, but a pilot without a habit of switching tanks every 30 mins of so would not necessarily be guided into factoring that in to preflight. It’s maybe important to note that not only does this protocol support better fuel efficiency as you aren’t correcting for a heavy wing v light wing, but also increases safety at slow speeds. Landing a plane dramatically out of balance is inherently trickier. My second point is on the use of gauges. Its unclear is how accurate the visual check of fuel was initially or if a dipstick was used. Assuming the weight of passengers prevented a full fuel takeoff, it means using another manner to determine fuel on board initially. As is now obvious, relying on guages alone is not great. It not shocking to me at all that the gauge would show five gallons but in fact be empty. We installed a JPI fuel and engine monitor that is very reliable for inflight calculations and is a great investment for this reason. I appreciate this story as I hope my future flying includes lots of other types of airplanes and it’s a good lesson in reviewing and learning protocols that aren’t found in a POH.