Fuel cut-off switch query
Posted by seniorpolecat9@reddit | aviation | View on Reddit | 13 comments
I read somewhere that the design philosophy between Boeing and Airbus are fundamentally different with Boeing giving ultimate control to the humans. I was wondering if Airbus also allows pilots to cut-off fuel to both engines at the critical TOGA phase or are there some protections built around it?
escape_your_destiny@reddit
The fuel switches are fairly similar in both Boeing and Airbus. They both have fuel switches that you need to lift and move.
In both planes, the engine will shutdown when you move the switch to off.
stoatwblr@reddit
Lift and move toggles are nice but I've run into far too many of them which are jammed in the lifted position (usually needing a jiggle to restore the spring action) to trust them on safety-of-life controls
Something like this needs a secondary cover that has to be positively opened (preferably with a loud click to grab attention) before the toggle can be touched - and on some equipment I've worked on that's exactly that's fitted over such toggles to ensure that they're only touched when you REALLY want to touch them (think of things like fire-control switch covers)
Personally I feel this is a case of terrible ergonomics that's persisted "Because this is the way we've always done it"(*) rather than taking a look at the risks and moving the cutoffs to the overhead panel adjacent to the startup and/or fire extinguisher controls.
The report yesterday (Febrruary 2026) of an Air India pilot reporting that the toggle locks weren't working when he tested them on the ground at Heathrow doesn't overly surprise me and nor does the maintenance crew returning "no fault found" - see my comments regarding jammed locking sliders - and the instant airline/community reaction blaming pilot error is pretty typical too.
Mechanical devices like this are prone to developing intermittent faults which the average maintenance crew aren't going to replicate unless they get the angle of pressure "just right" (or just wrong) when jiggling the things. I've encountered myriad times when I've isolated an intermittent fault in a particular piece of equipment in the faulty state and the first thing that the next guy along does is kick it, causing the fault to clear, then declares "nothing wrong with it" (in fact I developed somewhat of a reputation of being the go-to guy when people had difficult faults that they couldn't nail down, but that was a long time and 3 careers ago)
(*) I can understand it stemming from mechanical cutoffs on smaller, older aircraft needing to be under the throttle quadrant for mechanical reasons, but these aren't mechanical controls and can be better placed if needed. The problem in aviation is that the adage "rules are written in tombstones" skips over the issue that many issues are flagged by pilots or safety observers for years before things go wrong and someone actually dies - because of the "This is the way we've always done it (and nobody's died yet)" mentality.
Snoo-50263@reddit
THIS. Boeing is equally as much to blame as the pilot/s for the crash. And Airbus is equally as negligent for not offering an alternate location for the cutoff switches.
Srihari_stan@reddit
The fuel switches work the same way in both Boeing and Airbus flights.
The big difference is, Airbus calls it Engine Master switches (labelled as Eng 1, Eng 2) with ON and OFF positions. Boeing calls it ‘Fuel’ switches, with ON and CUTOFF positions.
Essentially, both the switches do the same thing: start the engines.
stoatwblr@reddit
They don't start the engines. That's what the overhead panel "start/stop engine" button is for.
Locking toggles aren't reliable in my experience. The pullout mechanism has a long-term tendency to become sticky on the toggle shaft if regularly used or excess pressure slightly bends the toggle shaft. Intermittent jamming shouldn't be dismissed as "pilot error" by maintenance crews just because they can't replicate the issue.
Aviation switches are (usually) built to a higher standard but the basic fault susceptibility is always there waiting to bite the unwary on the *ss
These switches need to be at least fitted with flip up covers or ideally repositioned out of harm's way with the rest of the engine start/stop/fire controls on the overhead panel. They don't belong on the pedestal with frequently used controls.
I get that pilots may need to be able to flip the switches in flight but in such circumstances they're going to be reaching up anyway.
Independent-Reveal86@reddit
For every protection you put in against switching something off at the wrong time, you risk a fault preventing you from being able to turn it off at the right time.
stoatwblr@reddit
If the engines fail to shut off when parking there are other ways of achieving the desired result but they involve the pilots getting out of their seats. More importantly that's going to cause an INOP for the aircraft
In flight, hitting the extinguishers usually shuts off the fuel in most designs, so the switches are redundant. The times when fuel shutoff is going to happen inflight outside of emergency conditions are virtually non-existent and the overhead panel is where the important emergency engine controls are anyway, along with the standard start/stop switches
It's effectively "never the right time" to be shutting off fuel in-flight and when it's the "right time" there's a good chance that the fuel shutoff valve is no longer on the wing anyway.
seniorpolecat9@reddit (OP)
I fundamentally agree, however, the flight computer needs to be smarter in knowing the implication of certain actions on certain flight phases. Both engine cut off just after rotate is a disaster so even if the fault occurs it potentially is a lower or equal risk.
Free-Version-2967@reddit
While I understand your intent, what you risk is systems intervening when they are not needed, sometimes catastrophically. Boeing famously had issues with its MCAS system doing this in the 737 Max. The only real safeguard against this error is training and putting competent, safe people in charge of the airframe. Competent safe operation happens an overwhelming majority of the time.
Lucas_Owners@reddit
The flight computer needs to be smarter to keep pilots from intentionally crashing airplanes into the side of a mountain too. Yet here we are.
Instinctive_Banana@reddit
Here's a video from a 787 mechanic describing how the fuel cut-off switches work and how their signals act to cut-off the fuel, and how their positions get reported to the software. He also mentions scenarios where it's important for pilots to be able to flip the switches in the air.
https://www.youtube.com/watch?v=-ur234kwnhk&t=896s
spacecadet2399@reddit
Yes, of course Airbus lets pilots cut off fuel to the engines. It would be a disaster waiting to happen to not give pilots control over the fuel going to the engines.
sloppyrock@reddit
A320 fuel switches in the centre of the console marked ENG1 ENG2.
https://static.thisdayinaviation.com/wp-content/uploads/tdia/2013/01/Airbus-A320-214-N108UW-U.S.-Airways-%C2%A9-Quinn-Savit.jpg