Bob Hoover in front of his twin
In case the link disappears from the web, that’s a story about the legendary airshow pilot Bob Hoover. He is, arguably, the best stick-and-rudder pilot to have ever flown an airplane. He could do things with a plane that no one else could and none have done since. He only died recently and I got to met him. A friend made a nice documentary about him. If you want to know about a great pilot, watch the film.
The important parts of the story are this: Bob climbed in his twin engine plane in San Diego after his usual pre-flight checks. He took off and at 300 feet both engines stopped turning. Being Bob Hoover, he glided to a spot that allowed him to put the plane back on solid ground. Like I said, he was an amazing pilot. He went back and smelled the gas in the tanks and realized that they had put JetA fuel in a plane that burns 110LL. The reason the story is famous is that Bob went back to the kid who had fueled the plane and said, “Mistakes happen. I’m pretty sure you’ll never make that particular mistake again. I want you to be the one fueling my plane tomorrow.” He was a nice guy, even through all the fame and adulation.
I’m not Bob Hoover.
I flew Dexter up to Oakland on Wednesday and landed in the rain. In order to avoid the parking fee I needed to buy twenty gallons of fuel. My plan was to have them put the minimum fuel in at their high price (six bucks a gallon) and then I’d taxi over to the cheaper fuel on Saturday when I was flying out. (Almost half the price per gallon, but their overnight parking fees are crazy.) So I told them as I was leaving that I’d need ten gallons in each side, but I didn’t really expect them to do that right then, since I told them I was leaving Saturday and it was pouring rain.
I had an excellent time at SICB 2018. If you have any interest in science you should get yourself to one of these meetings.
On Saturday morning I returned to the airport and was at the counter getting to pay my bill for fuel and parking. I might have been a little antennae-up about the fuel since my usual rule is to make sure I see the correct fuel truck pull up to the plane (a rule Mr. Hoover probably started using soon after San Diego). As they were gathering my paperwork I saw folded into the desk report a fuel card. Those are made out by the line personnel as they fuel the craft. They are often color coded. This one was pale yellow and sad “AvGas” in faded grey letters on the background. So even before she started to ring me up I said, “That looks like they fueled the plane wrong and they will have to drain the tanks.”
So I am on a Spirit Airlines Airbus A319 down to LAX, and I am sure there are a lot of people that would have been angry, might have yelled at people, or tried to find the kid that fueled the plane. But here are some things I know: my usual thorough pre-flight would not have discovered this issue. I would have done that before starting the engines. There were still at least four gallons of JetA on each side and the jet fuel is heavier than the 110LL AvGas fuel. So although the AvGas has a distinctive blue tint, I would not have seen it. Four gallons is almost an hour of the engines running at cruise power, so I would not have known before I took off. My plan was to fuel the plane at another location on the field, so I’m not sure when the bad fuel would have found its way to the engines. Maybe over Santa Barbara?
Both engines would have stopped at the same time. I train a little for that and I even did some of that training with my CFII back in October. But with a twin you focus more on “what if one engine stops…” because it’s very unusual to lose both engines.
I like to think my training would have kicked in, that with the engines stopped and the electronics dying (I have half an hour with the screens on), I would have set up a glide to Santa Barbara’s airport or Oxnard’s, and I would have been able to extend the gear manually (without the electrical system running my little switch doesn’t lower them), and I would have glided safely to the ground.
But I’m not Bob Hoover. So I am pretty happy to have two twenty-year old whippersnappers piloting this bus down to Los Angeles with me on board. Back in Oakland there’s a mechanic working on someone else’s dime to get my fuel tanks all cleaned out. I will return in a couple weeks to fly it home after I’ve gone to see the winter storm effects on the East Coast.
Flying Summers Brothers 
So many things can go wrong! AV gas error seems like a persistent potential hazard unique to the Diamond twins, maybe add ‘sniff fuel fumes’ to pre-flight? Also I presume you would’ve caught it with the fuel tester both color and smell?
I always sniff the tanks in the hope that if a bunch of water got in there it would smell a little different than the straight kerosene I smell. The fuel tester (dumping a quarter pint from the sumps under each wing) is part of my pre-flight. And, yes, if that was blue I would know. But JetA is heavier than AvGas, so I would only drained out JetA. I did sniff the tanks and they smelled like they usually do, so I guess there were enough JetA fumes floating around in there for it to smell right.
Just found this blog, thinking of getting back into flying after selling my plane five years ago to help finance my house.
You will find that 100 LL and Jet A will happily mix (as will many petroleum distillates), so you may, or may not, have detected the misfuel by color depending on how much 100 LL was in the tanks, and how well your eyes detect color. I think the smell would have caught your attention; I always smell the fuel, but there’s not much chance of Jet A making its way into a Skyhawk.
This is my nightmare scenario with the 42. Glad you caught it made it out alive Colin, had you been tired/fatigured, or the paperwork/fuel tag not been evident…
I’m totally over the top OCD on this and NO ONE fuels “my” (read: ACF’s) turbodiesel piston twin without me standing right there. This as you can imagine has lead to some discomfort in 110 degree midday desert weather in various locales, and delays where the wife says “how come that guy in the Aerostar just told them to “fill her up” and walked off to have it ready to go when he returns, and we always have to wait when we come back to leave for them to fill up while you stand there”. My answer is now THIS IS WHY =)
I’ve asked various 42 “experts” at ACF what the best glide for a 42 is, and the answer is always “unpublished, but I would fly vyse”. Let’s hope neither of us ever get to test pilot it because my guess is the thing glides like a brick compared to a single!
I think making sure the correct truck has pulled up would be enough. The manager for the FBO said that they do training over and over on the placards and double-checking and all of that, but they had a few new guys on the line and this is their nightmare scenario. (As far as I could tell they drained the takes of thirty gallons each side (fifteen twice) using a GATTS jar. Probably a pretty good way to remember to read the placard.
If you dial an engine back to 10% that’s meant to be the drag when it is feathered. So we should be able to find the best glide with both engines at 10%. Although the gear horn will be going off…
*Shudder*
That’s terrifying, especially considering that the sump test so many of us GA pilots rely on to verify fuel quality / correctness would not have detected a problem in your scenario. Congratulations on exercising good situational awareness outside the cockpit as well as within.
Get a piece of clear rigid tubing and stick your tanks. Slide stick of tubing in the tank, hold a thumb over the end, pull it out. I calibrated mine with marks to check fuel quantity, but you could just do this to check color. When done, take thumb off and contents go right back into your tank.
Glad you were safe!!
Great post. I wrote about Hoover’s admirable response to the error in a post last year called “When Things Go Sideways”.
Anyway, after Hoover’s incident, he promoted the use of fuel rings and nozzles of were different shapes in order to prevent this kind of mis-fueling. But in his case — and in most wrong-fuel type incidents — it’s Jet-A being pumped into an avgas aircraft rather than 100LL being poured into an airplane which requires Jet-A. Does the Hoover Nozzle/Ring not prevent it going in the other direction? I’m guessing it does not. Which sort of makes sense. Back when Hoover’s airplane was mis-fueled, there were no turbodiesel powerplants. If it took jet fuel, it was a turbine engine of some sort, and most of them will at least run on 100LL, even if it’s not good for them.
I suppose the ultimate solution would be to have underwing fueling capability on the DA42. Then you could lock the gravity fueling ports on top of the wing and not worry that your airplane was going to be filled with the wrong substance.
Best Pilot ever I got to see him fly the Sabre liners at that point I knew I was flying the safest planes in the world.