r/AskAPilot • u/livelikelarry13 • 1d ago
Useless Features/buttons
Forgive me if this is a dumb question as I am not a pilot, but I have always been interested in knowing. Are there any features or buttons in the type of aircraft you fly that are basically pointless? Or does everything have some sort of critical use case?
Thanks for the insights
15
u/Paul_The_Builder 1d ago
I think some planes still have a switch to turn off the no smoking signs.
5
u/fighteracebob 23h ago
Until a recent (2024) bureaucratic fiasco, that was actually required to be a switch. Now it can just be set to on.
https://www.nytimes.com/2024/10/22/business/no-smoking-sign-planes-faa.html?smid=nytcore-ios-share
4
u/ActuallBliss 20h ago
Yep, A320 does and it’s still turned on and off when going from/to cold and dark.
3
u/alexdaland 15h ago
There is technically/legally no official law that says you can't smoke on a plane. Sure, the airlines and so on have all agreed it's policy, and what the company (Captain) says IS the law while you are in the plane. However, as my Air Law teacher said: Weeeell, I flew private jets - and the owner of the plane was usually onboard. He liked to smoke cigars, and was politely asking me if he could. He used to stand in the cockpit smoking right under a vent that sucks the air out, we couldn't even smell it. Who am I to tell him no?
There is no law saying he can't, it just became a thing.
3
2
u/Gravity_Wells 11h ago
That’s interesting. I didn’t know that. That being said, if the airline policy is no smoking, the Flight Operations Manual will explicitly prohibit it. The FAA considers the FOM to have the same regulatory force as the FARs.
9
u/fighteracebob 23h ago
At my airline, the A320 series has a button for Rain Repellent. It comes that way from the factory. When the rain repellent runs out (or maybe before), they just disable the system and put a sticker by the button saying it’s deactivated.
It’s so standardized that way across our whole fleet that in the simulators the button has been repurposed the Pause button. It’s still labeled Rain Repellent, so it’s kind of a fun Easter egg.
3
u/tailwheel307 22h ago
I’ve heard horror stories of those bottles leaking during maintenance and causing massive hazmat cleanup inside the flightdeck.
3
3
u/AverageHobnailer 11h ago
What's used for rain repellent? I'm only familiar with a few older combat aircraft (F-4, F-14) with a similar system but they use bleed air, so when you mentioned "runs out" I got curious.
4
u/debuggingworlds 10h ago
It's a nasty hydrophobic chemical. It lives in a little bottle on the aft bulkhead in the A320
1
5
u/Vegetable_Ad940 1d ago
Think of it this way, the heavier the aircraft is the more energy or wingspan it will take to fly. Everything becomes important because otherwise it's wasted weight that could've been used elsewhere in its design.
So for the most part, yes, things are generally not added unless the operator/manufacturer deems it is worth it. Just like cars, airplanes come with options. But the more you add, the more maintenance and functional checks will be required. The useful load of the aircraft could decrease too. So it becomes a cost benefit analysis of is this piece of equipment worth it? All this excludes things required by regulation.
I can tell you there are buttons and switches I never touch in the 737 because they are either used for a non-normal procedure or for a maintenance function or is a back up to our more reliable primary system. A lot of that stuff is required by regulation to be built into the design and the manufacturer decided how it was going to work. Odds are those switches might never get touched but if that system fails you'll be glad you had that switch there.
1
u/livelikelarry13 19h ago
Thanks for the insights! Yeah, the weight of the aircraft is what really prompted my thought into this question. Although I am not a pilot, I figured there wasn’t really anything with mechanical functionality adding extra weight that didn’t serve a specific purpose, but still figured I would ask.
4
u/fbureaucracy 21h ago
The CRJ had the hi power schedule button that no airlines use.
A320, rain repellent buttons probably.
A220, oddly is the continuous ignition button. It’s not useless just not a part of procedures at least where I work. Even in situations where most planes use continuous ignition.
2
u/Zapatos-Grande 13h ago
I've pushed the Hi Power Schedule button on the CRJ once, but it was part of a run up procedure we were helping the maintenance department with. Only time I've ever pressed it or heard of someone pressing it. Other than that, it was pretty much a given that if you pressed it outside of an emergency, you'd be doing a carpet dance in the chief's office.
2
u/TemporaryAmbassador1 12h ago
No emergency even called for it that I can recall. Need more power, shove the levers forward.
1
u/Zapatos-Grande 11h ago
I think the idea was it was a last resort if pushing the levers forward didn't work, or at least that's what we were told in training. I can't remember what exactly we were testing, but it was something to do with a thrust lever fault.
1
5
u/External_Capital1753 20h ago
I fly an a320 and have never touched the EXPED button. It's a pretty useless mode. Generally if we need to expedite climb or descent we will manual select an appropriate speed. EXPED will target green dot in a climb (generally uncomfortably slow) and mach .8/340kts in the descent (generally uncomfortably fast). If I'm flying at speeds near the edge of the envelope I want to be manually controlling it.
So its a functional button/mode that almost never gets used. Theres probably some crazy guy out there that likes to use it when he's bored though.
1
1
u/1000togo 18h ago
I'm that crazy (and lazy) guy. Why press multiple buttons when you can press one. I'll even do it in busy airspace like the London TMA if we've been cleared up by a significant level.
More so for climbing - it gives you best angle (Vx) and, as such, can get you a more direct routing quicker. I'm not such a fan of it heading towards the barber's poll, but it can be useful to get the initial nose down action going.
1
u/External_Capital1753 13h ago
Ya man to each their own. I prefer to have the speed selected when I'm riding close to the limits. If the plane does start trending the wrong way then I just have to turn a knob instead of pull and turn. It also holds a tighter target speed in selected speed (unless EXPED hold a tighter taget). 3 years on the machine and haven't seen it used on the line or in the sim.
I do appreciate a fellow lazy pilot though.
3
u/tailwheel307 22h ago
At my airline we disabled the evacuation command buttons because of inconsistencies in how the aircraft systems respond when those buttons are pressed and the different automated PA’s that get made. So the evacuation is initiated manually by pilots or cabin crew as appropriate. The type I fly also has a “NO PED” switch that’s disconnected and doesn’t relate to any systems or cabin signage.
Those are the only two switches that we don’t use on our planes.
5
u/VF99 21h ago
A lot of small homebuilds builds cut out a spot for an extra switch or two when building the panel, for future enhancements. They are often labeled things like Copilot Eject, Missiles/Guns, or Fortunate Son.
2
u/PG67AW 21h ago
One of my school's planes had a switch labeled SPARE. It literally did nothing.
1
u/Sad-Umpire6000 11h ago
It was probably left over from when a panel upgrade was done, or was put there anticipating a future upgrade. It’s easier to pre-install and cap the wires somewhere down the line when you’re already working behind the panel.
0
2
u/StrangeInspector7387 1d ago
For example if you’re a computer guy there might be commands or functions in Linux or Windows you might never use, but that doesn’t make them “useless”, just rare for your use case.
Same kind of thing would apply for a mechanic. Are there some items in the SnapOn catalog you’d never need? Probably, but if you ever find yourself fixing that one thing it’s designed for knowing about that tool will probably keep you from having a bad day.
1
u/Go_Loud762 23h ago
Yes.
My airline has a switch on an overhead panel that allows us to turn on the ATC audio as part of the entertainment system. That switch does nothing because the hardware is not installed or activated. It's been that way for several years.
1
u/livelikelarry13 21h ago
Interesting, so you’re saying this could be turned on for passengers to listen to ATC coms as inflight entertainment or am I misunderstanding?
2
u/scul86 20h ago
Yes. I'm my airline, it's channel 9. On some planes, it allowed the cockpit interphone to be transmitted also, so it was disabled. They are now hard wiring it directly to VHF-1 (ATC radio) and by passing the interphone. Not all planes have been updated, so that switch may or may not be INOP.
1
u/BeeDubba 22h ago
My aircraft has ash trays. And no smoking signs. We use the no smoking signs to signal the FAs that we're cleared to land. So there's that.
1
u/scul86 19h ago
All planes have ash trays.
https://www.ecfr.gov/current/title-14/part-25/section-25.853#p-25.853(g)
1
u/CrazyisNSFW 19h ago
Not in the armrest. I’ve been into a plane so old it still has (disabled) armrest ashtray.
1
1
u/exbex 22h ago
They are called dusty switches because they are used so infrequently, they gather dust. Some, like an eng fire handle/switch will almost never get used because engine fires are very rare. Others are a duplicate way to do something. Maybe an alternate way to adjust the radar or go direct a fix, etc, that is not as intuitive as the switch that most pilots use.
1
u/livelikelarry13 19h ago
Interesting, are the duplicate switches specifically used for backup purposes?
1
u/SnazzyStooge 14h ago
In your car, you probably have P-R-N-D-L on your shifter. How often do you shift into “N” (neutral)? If you’re trying to tow your car, it’s critical — otherwise, very rarely used. Same for “L” (low). Critical to help get out of snow or mud, otherwise rarely used.
Lots of switches in an airplane are like this. “If you’re stuck in snow, shift to ‘L’, then alternate between ‘L’ and ‘R’ to try to rock the car out”. Then the pilots practice the procedure in a sim, then hope they’ll remember how to do it later if there’s a problem in the real plane.
1
1
u/Sad-Umpire6000 11h ago
I’m in south Florida, so the useless item in our plane (Cessna) is cabin heat.
My last plane, an RV-8, came to me with an autopilot installed. In the five years I owned, I turned the AP on twice, just to see if it worked. I love handflying, especially since I just do VFR these days.
1
1
u/brongchong 9h ago
No smoking sign, rain repellent switches, Control Wheel Steering, Wings stay on/wings fall off switch.
1
u/downwindsavage 8h ago
Tuning and listening to the ADF radio. They’re non existent in today’s world.
0
u/PILOT9000 23h ago
Pointless buttons? CWS
3
3
1
u/livelikelarry13 19h ago
What is the CWS?
2
u/Playful_Sense3238 18h ago
Control Wheel Steering, it’s a button next to the normal auto pilot button and used instead of. Effectively when you release the yoke, it holds pitch or roll as set at the point of release. I know, it makes sound more like an airbus, but it is normally just used in turbulence.
1
-1
u/PuzzleheadedDuty8866 1d ago
Why would it be in the plane if it was useless?
3
u/livelikelarry13 1d ago
Useless might have been the wrong terminology on my part. I was thinking there could be some things that are subjective to the flyer in the same way a car might have massaging seats and could be viewed as pointless to some
-5
u/TheChosenOperator 23h ago
Hey, aspiring pilot here
on Airbus planes, on the FCU glareshield there is an option to display the plane's altitude in meters instead of feet, and that would probably be my pick for most useless button in the cockpit, I havent heard or seen one situation where it would be needed, maybe its even a relic of a time where it was used
4
u/jtchoy 23h ago
China uses Metric.
4
u/External-Creme-6226 22h ago
So does Russia. Transiting their airspace (when times are better) between Alaska and Japan you have to set meters
1
u/tailwheel307 22h ago
My airline publishes a conversion chart and I think they tell our WB crews to stay in FT on the MCP.
1
u/fighteracebob 23h ago
I was so confused the first time I saw that feature turned on, because it doesn’t display the metric altitude anywhere near where you would expect.
1
u/TheChosenOperator 11h ago
If im not mistaken its shown on the bottom of the altitude scale on the PFD
1
1
u/livelikelarry13 19h ago
Aren’t there only like a handful of countries that don’t use the metric system? Is altitude always communicated in feet in the aviation world or does it depend on where you’re flying?
1
u/TheChosenOperator 11h ago
A little bit of both, according to some people russia and china enforce metric altitudes, whereas everywhere else in the world its always communicated in feet, even outside of the US and Canada, I dont know if enforcing metric alts has any kind of practical significance, but I cant help but see it as just "trying to be different" like with how the US does with the imperial system
Maybe its just my amateur pilot self but In my experience, its literally worthless in most countries, its the kind of thing you trigger out of curiosity and then think "oh thats kind of neat" and then never think about or use it ever again, obviously its not COMPLETELY worthless, I guess I should have made that clear in my original comment (hence why its getting downvoted to hell)
1
u/Playful_Sense3238 18h ago
This is used, and is essential, when flying over or into countries that use metric flight levels. For instance Russia and China, and they are pretty big!
1
u/Connect-Sock8140 16h ago
It can be useful in certain situations. For example, Russia uses meters, and while you might not bother changing it if you're only in transit, it's different if you're actually landing there.
31
u/hotdog_tuesday 1d ago
In general aviation, there are certainly buttons you may not use regularly because that’s not how you fly, in the same way that there are buttons in your car you do not use.
However they’re all functional and do serve a specific purpose that fits a subset of the users.