Fuel Caps

[donv]

Twin Commander posted a link to this (older) article on FaceBook, about a guy who took off without a fuel cap, the anti-siphon failed (on a 690-- important, as the outcome would be different on a Jetprop*), ran out of gas, and dead-sticked to a successful landing at night.

https://flightlevelsonline.com/2022/control-column-why-you-should-check-fuel-tank-caps-on-your-twin-commander-3/?fbclid=IwAR2JZ6_B3bsAYT9TyUWp33k0p_mmD0kNOvDjQM_nywiQJ3CJ3cIS9CVVi2w

Seems crazy to me, but I guess maybe it happened?

*On a 690, if the center cap is missing and the anti-siphon valve doesn't work, all the fuel will siphon out. On a Jetprop, there is no center cap so worst case is you lose all the fuel on one side... unless you keep opening the interconnect to correct the fuel imbalance, that is. And don't believe the gauges, which are also much more reliable on a Jetprop.

[Adam Frisch]

That's why I love the low fuel warning light/annunciator. When that alights, it's time got get on the ground promptly. In mine it's when there's 50 gals in the main tank left, if I recall correctly.

[donv]

I just had my airplane fueled at an FBO I use a lot (not Aero Air, FYI), and it's my practice to always feel the fuel caps to make sure they are properly screwed closed. The left one was popped! The FBO apologized, but it is important to make that a regular preflight practice.

[Adam Frisch]

Yeah, I always reach up and feel mine.

[donv]

I lost one a few days ago, after a quick turn. Arrgh! I make it a habit of feeling them, and I think (could be wrong) that I did so in this case, so maybe it just wasn't turned the full quarter turn...

Anyway, the anti-siphon valve worked fine and I never noticed until I ordered fuel the next day at my destination, and they discovered it.

Aero Air was able to send me one early the next day, so it only cost me a day... and $965 for a fuel cap!

I'm planning to order another one and keep it in the baggage just in case. I figure it's insurance, and if I have one, I will never lose another one!

[donv]

I ended up getting a spare fuel cap, and it's now in my baggage along with my spare gear bungee-- hopefully I won't need either one!

[seanmcgillivray]

I lost one somewhere along a 4hr trip, Never noticed until I went to fly next.

Eric Dapp saved the day with a loaner and I bought extras. Now one lives in the baggage compartment.

[donv]

The caps can wear out if they are old enough. This is worst on the center cap on the 690s because you always use that one, but the wings much less often. We had a spate of lost ones at Aero Air way back when, and we were definitely checking them. Once they started rotating them, the problem went away.

[Adam Frisch]

Nio good options for fuel caps, in my view. I wish someone would STC something newer that's easy to get off and doesn't go missing...

[donv]

The Twin Commander caps work fine, and unless you have a high tempo operation (like we did with the medevac, and the fire guys probably as well) they are fine. Just keep a screwdriver in the baggage, and always, always check them before takeoff.

[Bruce Byerly]

There’s an STC for flip caps but it’s really a solution that never made much sense.