Can anyone tell me the purpose of the white circle directly underneath the vertical speed window on the 737NG Collins MCP?
Posted by HenryMcKenna1@reddit | aviation | View on Reddit | 82 comments
I've always wondered what the purpose of this is, but not been able to find any reference to it in the 737NG Flight Crew Operations Manual.
Thanks.
Charming-Oven-3391@reddit
Photovoltic sensor, just like on the PFD/ND to control brightness based on ambient light.
Full bright during night ops is different than day ops, despite being manually controlled.
pilot_96@reddit
I’m a 737 pilot and didn’t know this, thanks lol
Temporary_Mongoose34@reddit
That's a bit concerning
pilot_96@reddit
I’d be more concerned about Boeing not telling us about MCAS or the Load Reduction Device
day25@reddit
But you're proving his point. Those pilots didn't understand even basic stuff about how their plane worked. Even without knowing about MCAS they should've known basic stuff like the trim wheels, that the autpilot turns them, you can turn that off, etc. And after the first crash what's the excuse for not knowing about MCAS if you're a 737 Max Pilot? There's a reason it was indonesia and ethipia airlines where it happened... airlines known for poor piloting. Not saying it's only their responsibility but it is still their responsibility and a good pilot would know these things and as a result not effectively caused hundreds of people to die.
pilot_96@reddit
It’s a bit more subtle than that. You can’t just say that it was the pilot’s fault that those planes crashed.
day25@reddit
Yeah we can. Why did no quality airlines have this problem? It was just the bottom tier with the worst safety records. It's pretty basic that if you pull the nose up and the plane pushes it down you would start troubleshooting by disabling the automated system that's doing that. The trim wheels are very loud when the autopilot turns them it's not even subtle.
And I never said it was just their fault. It was a mistake to have the system tied to only one sensor and was poorly documented (likely to avoid excessive red tape). It could have been engineered better. But that's always true it's why there are pilots there in the first place. Otherwise why have pilots at all if not to make up for limitations in engineering?
Whatever. It was cool to blame boeing all the get the man evil corporations and so on made people feel good. In reality the pilots were bad and that's why it happened. You know I'm right.
beepbeebboingboing@reddit
It's like having a driving license and not being able identify the accelerometers for the airbags triggers.
robertson4379@reddit
Hey - I drive a car, and I didn’t know there were accelerometers for the airbag triggers! 😂👍🏽
ClearlyCylindrical@reddit
That's a bit concerning
PatrickSutherla@reddit
It's like having a dog and not knowing which neuron fires when you throw the tennis ball in your yard
Stable_Hot@reddit
Hey im a dog, and i dont which neuron fired everytime my human throws ball
nchls_gh1@reddit
That's a bit concerning
dcs173198@reddit
Hey, I'm a ball and didn't know dogs had neurons.
PatrickSutherla@reddit
All of them, buddy. All of them.
day25@reddit
Such an obvious false equivalence. First of all, the accelerometer is a hidden - not a component visible right on your dash. Second, it would be more like driving a giant bus where you have many passengers who depend on your driving for their safety. Third, with a car the primary danger is from other traffic. In a plane the primary danger is from your operation of the aircraft (statistics back this up). Factually you are wrong and logically what you wrote is falacious. A good pilot will understand their plane and that includes knowing basic stuff like what does everything in the cockpit do... and yes there are a lot of bad pilots who get away with it thanks to engineering picks up their slack.
TheFourTruthz@reddit
It's a bit concerning that a pilot doesn't know what a specific sensor that isn't relevant for his daily use is?
It's time for you to get a job.
day25@reddit
How does he know it's not relevant if he doesn't know what it is?
TheFourTruthz@reddit
It's not relevant if he's not taught what it is or in the Flight Crew Operations Manual.
Temporary_Mongoose34@reddit
What a bizarre response
TheFourTruthz@reddit
You're making obtuse comments on someone else's job.
Do you not see the relevance?
Do I have to spell it out for you?
Temporary_Mongoose34@reddit
PUTTING things in CAPS doesnt make you sound clever
TheFourTruthz@reddit
Is that REALLY everything you got from that?
ArthurBurtonMorgan@reddit
YES.
b3tchaker@reddit
Ahh, the “look over here!” strategy of debate.
Safe_Cabinet7090@reddit
Pilots don’t have access to AMMs which would allow him to find the description and Operation of this specific panel.
Existing-Help-3187@reddit
Not really true. Depends on the airline, I have had access in all my airlines. But as a pilot reading it is a waste of time other that to tick the cdl in performance applications.
HenryMcKenna1@reddit (OP)
Amazing, thank you!
Thiccy_ape@reddit
Can confirm as an A&P who has to test this feature.
Expensive-Meaning-85@reddit
Did they make you come in at night ?
Thiccy_ape@reddit
No we use blackout curtains and a flashlight
Expensive-Meaning-85@reddit
😁
kevcubed@reddit
That's a screw, you're welcome!
RetaRedded@reddit
FPA on a 737ng? 😳
bravogates@reddit
What I was thinking as well, 737s don't have FPA.
Existing-Help-3187@reddit
It has, its not on MCP and you cannot set one. But you have FPV button on EFIS where you can see the bird.
LongjumpingPaint2226@reddit
Oh shit button
willwu555@reddit
Does it work on Winwing mcp too? That would be so cool.
AdAdministrative5330@reddit
This looks so clean. Is it brand new?
yetiflask@reddit
Scroll down bruf
https://ca.winwingsim.com/view/
derekbox@reddit
This is from a flight simulator. Real aviation wouldn't have those 2 screws in the middle of the panel.
Anderty@reddit
Wait, flight simulators use such high quality panels?
VegaGPU@reddit
A few plastic shroud not that expensive if it's made at mass like those folks do in China
VHSVoyage@reddit
They’re used as much as the actual planes really
elmwoodblues@reddit
May I ask why not? As a layman i assumed every effort went into having a sim mirror the real thing
Bluehornet007@reddit
They would be painted screw the same color of the panel reducing the risk of reflection/glaring.
Squawk1000@reddit
Yeah, that's the Winwing MCP, not the real Collins.
HenryMcKenna1@reddit (OP)
Yep, this.
Amazing bit of kit!
AdAdministrative5330@reddit
Looks great, TBH
Squawk1000@reddit
It's pretty neat. Their FMC too.
Motorsav@reddit
If it's loose, then a few screws and a hammer solves anything.
AdAdministrative5330@reddit
Thanks, yes, those screws did look off.
toad__warrior@reddit
I am not sure why, but it bothers me that there is a dial to go up and down.
Buzz_Buzz_Buzz_@reddit
Those arrow labels are cognitively unsettling. Like seeing the word "red" written in blue next to "blue" written in red.
durandal@reddit
To a pilot, this is the sensible way.
SourceBrilliant4546@reddit
Down for up, up for down is also unsettling.
Buzz_Buzz_Buzz_@reddit
That's what I meant -- the arrows being labeled the wrong way. I think it would be a little less unsettling just with up on the top and down on the bottom.
747ER@reddit
It makes sense if you imagine that rocker as the plane on its pitch axis. When you push down on the back of the plane/switch, you are causing the plane to go up. Keep in mind that the elevators are at the back of the plane.
Spin737@reddit
Do you fly planes?
vctrmldrw@reddit
It's not unsettling to someone who uses a yoke or joystick. It is spatially consistent.
flightist@reddit
It never even occurred to me that it’s weird. Huh.
mkosmo@reddit
Because it's not to pilots. It's intuitive.
Only engineers who have never flown airplanes think that -- and you'll find they've more than once come up with a design that reversed control or instrumentation logic that had to be caught by pilots.
SourceBrilliant4546@reddit
True.
QuailImpossible3857@reddit
Nose down nose up
Hexpul@reddit
Anybody have a link to this panel? Oddly I didnt find a store page when googling it
HenryMcKenna1@reddit (OP)
https://winwingsim.com/view/goods-details.html?id=1085&disableSelectArea=true
Alone_Dragonfly8215@reddit
It's the "MEOW" button for when you're on 121.5!
Can_Not_Double_Dutch@reddit
Light sensor
b_vitamin@reddit
It’s a Hydrocoptic Marzle Vane
haarschmuck@reddit
No you're confusing it with the magnetic diractance interceptor.
ManifestDestinysChld@reddit
Wait, WHAT?! That would cause so much side-fumbling! LOL Boeing does it again.
DocWilly84@reddit
Yeah, but installing a baseplate of prefabulated amulite will effectively negate that.
ANewStartAtLife@reddit
Boeing haven't worked with Rockwell encabulators for years.
noway110@reddit
Pitch
Traditional_Hunter81@reddit
Never seen a photovoltaic sensor on a collins FCP
chrivasintl@reddit
Ambient light sensor, used to regulate the integral panel lights
FMC_Speed@reddit
As others said it’s a light sensor for the display units, You can notice it suddenly increasing in brightness when turning and direct sunlight hits the cockpit displays
DarkGinnel@reddit
As others have already answered, if you want to test it, shine your torch into it and watch the displays change brightness.
Potential_Wish4943@reddit
If im not mistaken, you use it depending on the mode to either control the vertical speed by setting it on the dial above, or simply by pitching the nose up and down.
Chaxterium@reddit
Nope. Just a light sensor.
contrail_25@reddit
Could be a light sensor that helps set the panel/instrument lighting under certain settings?
Some planes I’ve flown have something similar, so that’s my best guess.
saml01@reddit
Thats a Philips head screw. Probably holds the panel on.