Airplane Landing Questions -- How can the pilot see the ground?

[Tiran]

The ideal here is a conservative approach to avoid a stall, as some aircraft can't recover from a spin (for example, the Piper Cherokee Warrior is not certified for spins). 3 to 5 degrees nose up on approach (while descending at 3 degrees) should be slow enough to land on a longer runway. A pilot could try mostly holding attitude at 3 to 4 degrees nose up while following the glide slope, mostly using throttle to stay on the glide slope. There are exceptions, the twin engine civilian aircraft at a local (to me) airport land on a runway shared by commercial aircraft, and approach at a faster than normal speed (almost nose down) to avoid interfering with the airliner traffic, but the runway is long enough (since it's meant for commercial airliners) for the twins to bleed off speed once they're near the end of the runway, and land with margin to spare. In an emergency, with airliners put in a holding pattern, that runway would be more than long enough for something like a Cessna 182 to approach at 5 degrees nose up and land with margin to spare.

Spin and stall aren't the same thing. Stalling in level flight should not induce a spin, it just causes the nose to fall suddenly. Some planes can't even be made to stall.

And not all aircraft approach nose up - it depends on configuration and approach speed. Put the nose 5° up with no flaps and you'll either climb or get too slow.

Planes are mostly flown by observing some preferred airspeed and altitude (or descent rate) and putting the nose and power wherever they might need to be to keep those and go to where you want to get to. The pilot may have no or even the wrong feeling about the nose attitude because that's not what they are looking at.

 

[jrmichler]

A pilot is expected to know the correct speeds for takeoff and landing before starting the engine. That's federal law, or at least an FAA regulation. Europeans have similar rules. In case the pilot forgets, they have only to look at the airspeed indicator:

The white arc shows the allowable speed range with the flaps fully down, from stall to maximum allowable. The green arc starts at the stall speed with flaps up, and extends to maximum speed in rough air. Yellow arc speeds are only for use in smooth air. The red line is the red line, bad things happen above that speed. These markings are specific to the airplane in which that airspeed indicator is installed.

 

[rcgldr]

Spin and stall aren't the same thing. Stalling in level flight should not induce a spin

Some aircraft (usually aerobatic) may go into a snap roll if stalled.

And not all aircraft approach nose up

True, I'll amend my prior posts. The idea behind 3 to 5 degrees nose up in level flight while trimmed for approach was to determine an airspeed slow enough for approach on a long runway, but fast enough to avoid a stall, and use that airspeed for approach speed regardless if nose up or down.

However, as posted by jrmichler, the airspeed indicator would be the best reference for the airspeed ranges of an aircraft, and the airspeed at the mid point of flaps fully down would be safe enough for a long runway.

 

[seazal]

I didn't really address this directly: The plane won't do anything on its own. The pilot will recognize that the landing spot is rising in the windscreen and add power to level out until the appearance of proper glideslope is back in view.

Please understand this is just how things are done normally. You could also land by flying the last five miles 10 feet above the ground at landing speed and pull power off when you get to the runway. But that just isn't practical.

We were told that high above in the clouds. A plane wouldn't stall even if power is cut off or airspeed reduced (because it is traveling way faster than the stall speed (90% above stall speed?). But during landing when the speed is 30% above stall speed. What if the pilot suddenly (accidentally) pulled up the lever to decrease throttle (equivalent to say half the stall speed), would the plane falls down or stall.. or would it maintain speed or momentum just like high above in the clouds? My worry for over 30 flights I rode was when landing and what if the speed was decrease suddenly (accidentally). Earlier in the thread one has answered that it won't suddenly fall down but this is from the context of high in the clouds at higher speed. But it was not addressed during landing scenerio. Thanks.

 

[jrmichler]

When a jet (business jet or airliner) descends from cruising altitude, the pilot reduces power all the way to idle. The airplane glides the last 100 miles or so, depending on the exact cruise altitude. Airplanes, especially airliners, cannot change speed suddenly because they have mass. They also have potential energy from their altitude. There is a famous case where an airliner ran out of fuel, and glided to a safe landing: https://en.wikipedia.org/wiki/Gimli_Glider. They glided for 17 minutes before making a safe landing.

The big challenge when landing is getting the airplane to slow down, not keeping it moving.

 

[Tiran]

A pilot is expected to know the correct speeds for takeoff and landing before starting the engine. That's federal law, or at least an FAA regulation.

That isn't true. Take off and landing speeds are condition dependant and vary widely. It is calculated shortly before take off or landing based on the most current conditions.

The gauge markings are generally never-exceed speeds for flaps or landing gear.

We were told that high above in the clouds. A plane wouldn't stall even if power is cut off or airspeed reduced (because it is traveling way faster than the stall speed (90% above stall speed?). But during landing when the speed is 30% above stall speed. What if the pilot suddenly (accidentally) pulled up the lever to decrease throttle (equivalent to say half the stall speed), would the plane falls down or stall.. or would it maintain speed or momentum just like high above in the clouds?

You have to do something to stall, like pull the nose up or keep it up when the plane is slowing. And stall is a temporary condition, just a bad one when you are very low. Airplanes already on final are unlikely to stall - there is no reason for it to happen and losing a bunch of airspeed is actually hard to do.

On the other hand, the higher a plane flies, the higher the stall speed as the air gets thinner. The U2 flies in a 10kt range between stall and transonic at 90,000 feet. I doubt stall is 10% of airspeed at 35,000 feet.

 

[seazal]

That isn't true. Take off and landing speeds are condition dependant and vary widely. It is calculated shortly before take off or landing based on the most current conditions.

The gauge markings are generally never-exceed speeds for flaps or landing gear.You have to do something to stall, like pull the nose up or keep it up when the plane is slowing. And stall is a temporary condition, just a bad one when you are very low. Airplanes already on final are unlikely to stall - there is no reason for it to happen and losing a bunch of airspeed is actually hard to do.

On the other hand, the higher a plane flies, the higher the stall speed as the air gets thinner. The U2 flies in a 10kt range between stall and transonic at 90,000 feet. I doubt stall is 10% of airspeed at 35,000 feet.

Wished I knew this 20 years ago so all my flight would have been more enjoyable. I got nervous at every landing thinking that the plane was moving so slowly, and engine power is decreasing. Although I knew about airfoil principle, I forgot about it because I couldn't imagine that mere air was enough to lift an airplane. It's not intuitive that was why no one thought heavier than air can fly before the Wright Brothers.

Do you know what brand and model of commercial airliner has the redundant double fly by wire systems used in fighter jets? My other worries are lost of control of the flaps, etc.. For example. What if the motors controlling the rudder or up/down no longer works. Don't they fail?

 

[Tiran]

Do you know what brand and model of commercial airliner has the redundant double fly by wire systems used in fighter jets? My other worries are lost of control of the flaps, etc.. For example. What if the motors controlling the rudder or up/down no longer works. Don't they fail?

There probably hasn't been a jet or turboprop airplane designed in the last 70 years that didn't have redundant flight control systems.

This thread is an expression of your phobia, not a learned discussion about aviation safety and engineering. You know very well how safe flying is.

 

[seazal]

There probably hasn't been a jet or turboprop airplane designed in the last 70 years that didn't have redundant flight control systems.

This thread is an expression of your phobia, not a learned discussion about aviation safety and engineering. You know very well how safe flying is.

I read that fighter jets have many fly by wire backups so if a part was hit, other parts can work. They also did this to airliners? I didn't know that. As a normal citizen who reads a lot about airplanes. I missed this part. So this is part of learning about aviation safety and engineering. It's not a serious phobia. But learning about it can decrease any concern.

So I guess the focus or emphasis must be how to increase aviation safety in newer aircrafts.

 

[rcgldr]

Camcorder recording from the cockpit of a 747 approach and landing at Kaitak in 1998. The plane heads towards a checkerboard on a hillside, then makes a 47 degree right turn to line up with the runway. Skip to 3:40 into the video to see the turn. The runway is clearly visible. You can also hear the altitude call out starting at 60 feet.

 

[Tom.G]

For a pilots-eye view of landing an Airbus A380, see:
https://www.youtube.com//watch?v=ENe89j89tBA

 

[seazal]

For a pilots-eye view of landing an Airbus A380, see:
https://www.youtube.com//watch?v=ENe89j89tBA

In a single day, hundreds of planes land in the same runway and take the same landing path, so I guess the tower directs all traffic so if there are many still trying to land, the plane circles around. But I don't experience much circling, does it mean even the arrival is scheduled?

But far away from airport, when planes move through clouds. How do they know there are no planes nearby? Do all of them have some kind of radar? Or is it just randomly path? Whenever the plane I'm riding move through dense clouds, I wonder how they could know if no other planes in the path. Radar, Beacon, random?

 

[Tiran]

In a single day, hundreds of planes land in the same runway and take the same landing path, so I guess the tower directs all traffic so if there are many still trying to land, the plane circles around. But I don't experience much circling, does it mean even the arrival is scheduled?

But far away from airport, when planes move through clouds. How do they know there are no planes nearby? Do all of them have some kind of radar? Or is it just randomly path? Whenever the plane I'm riding move through dense clouds, I wonder how they could know if no other planes in the path. Radar, Beacon, random?

This really isn't a topic for a thread anymore. The aviation system is over a century old and very well thought out. Start with Wikipedia then go to the library.

To answer your most basic question, virtually nothing that happens is left to chance, last minute decisions or near-superhuman skill. It is all boringly standardized, methodical, redundant and safe.

 

[seazal]

This really isn't a topic for a thread anymore. The aviation system is over a century old and very well thought out. Start with Wikipedia then go to the library.

To answer your most basic question, virtually nothing that happens is left to chance, last minute decisions or near-superhuman skill. It is all boringly standardized, methodical, redundant and safe.

But for 20 years ever since playing MS Flight Simulator or F-15 Strike Eagle. All I know is that only fighter jets have onboard radar. I know old airliners have no on board radar system. But for new versions, they may have them? I hope they can retrofit the old aircrafts with radar too.

This is my concern when flying through dense clouds for 20 years. Next year during the 2 year LHC shutdown. I'll take long trip to Europe so need all concerns addressed. I guess many from elsewhere want to visit LHC too.

 

[Tiran]

But for 20 years ever since playing MS Flight Simulator or F-15 Strike Eagle. All I know is that only fighter jets have onboard radar. I know old airliners have no on board radar system. But for new versions, they may have them? I hope they can retrofit the old aircrafts with radar too.

This is my concern when flying through dense clouds for 20 years. Next year during the 2 year LHC shutdown. I'll take long trip to Europe so needs all concerns addressed. I guess many from elsewhere want to visit LHC too.

Well, you might also have concerns about how blenders manage to blend liquids despite being electrical, or how glass floors don't break or how you might get radiation poisoning from smoke detectors. But that doesn't mean your fears are grounded.

 

[OCR]

But that doesn't mean your fears are grounded.

No, but he might wish they were....
.

Carry on...

.

 

[CWatters]

In a single day, hundreds of planes land in the same runway and take the same landing path, so I guess the tower directs all traffic so if there are many still trying to land, the plane circles around.

Read up about stacking. At busy times they make planes fly an oval track like a raceway some distance from the airfield. Pilots have to take enough fuel with them to allow a wait of perhaps 20-30mins. If they are made to wait longer they have to fly to an alternative airfield. They must take enough spare fuel with them for that as well. These are just two of the extra bits of fuel they take.

But I don't experience much circling, does it mean even the arrival is scheduled?

Yes. They try to minimise waiting/circling as it costs $.

But far away from airport, when planes move through clouds. How do they know there are no planes nearby? Do all of them have some kind of radar? Or is it just randomly path? Whenever the plane I'm riding move through dense clouds, I wonder how they could know if no other planes in the path. Radar, Beacon, random?

They mostly stick to airways which are managed by air traffic controllers. Pilots ask if they can go to point abc at height xyz and are either given permission or are offered an alternative. In some area (eg Europe) planes are given a slot when they can enter that area. At very busy times or when there is a system problem planes can be told not to take off because they won't be able to enter an area somewhere along their route. They also have collision avoidance systems onboard.

Gliders I flew had virtually no instruments, not even a radio. You keep your eyes open.

 

[seazal]

Read up about stacking. At busy times they make planes fly an oval track like a raceway some distance from the airfield. Pilots have to take enough fuel with them to allow a wait of perhaps 20-30mins. If they are made to wait longer they have to fly to an alternative airfield. They must take enough spare fuel with them for that as well. These are just two of the extra bits of fuel they take.
Yes. They try to minimise waiting/circling as it costs $.
They mostly stick to airways which are managed by air traffic controllers. Pilots ask if they can go to point abc at height xyz and are either given permission or are offered an alternative. In some area (eg Europe) planes are given a slot when they can enter that area. At very busy times or when there is a system problem planes can be told not to take off because they won't be able to enter an area somewhere along their route. They also have collision avoidance systems onboard.

How far from the coastline before air traffic controllers can still talk with pilots? They could still somehow do it at the middle of the pacific ocean perhaps via satellite? Mid-air collisions still occur.. here are 20 of the deadliest:

Gliders I flew had virtually no instruments, not even a radio. You keep your eyes open.

 

[berkeman]

Camcorder recording from the cockpit of a 747 approach and landing at Kaitak in 1998.

Very cool, thanks. What was the brief alarm for around 2:25?

 

[rcgldr]

Very cool, thanks. What was the brief alarm for around 2:25?

Possibly deploying flaps or reducing throttle beyond some threshold before deploying landing gear. Alarms like this are usually like reminders, and that one probably is always triggered during approach and can't be disabled in advance. Sink rate will do an audio call out to pull up, so the alarm you hear in the video wasn't that.

 

[seazal]

I found out there is this great series called Mayday (or Air Crash Investigations in other regions) that started in 2003. Great to watch one episode every night. Maybe it can remove fear of flying or make it worse, lol. https://en.wikipedia.org/wiki/List_of_Mayday_episodes



I need to know the best movies about airplane crashes too.

 

[berkeman]

Possibly deploying flaps or reducing throttle beyond some threshold before deploying landing gear. Alarms like this are usually like reminders, and that one probably is always triggered during approach and can't be disabled in advance.

I'd figure out how to disable it (way too stressful for a simple reminder chime, IMO), but once I taped over that speaker, I suppose I might miss something important... Jeeze!

 

[rcgldr]

I'd figure out how to disable it (way too stressful for a simple reminder chime, IMO), but once I taped over that speaker, I suppose I might miss something important...

The pilots are probably used to it, and assuming that alarm normally goes off on every approach, they'd probably be concerned if it didn't trigger.

 

[Tiran]

I'd figure out how to disable it (way too stressful for a simple reminder chime, IMO), but once I taped over that speaker, I suppose I might miss something important... Jeeze!

Some alarms like this have a button to cancel/prevent it from sounding.

 

[sandy stone]

Seems like poor ergonomic design to have an alarm that sounds during a normal approach. I'm not a pilot, but I did operate a refinery process control console. Unecessary alarms can be pretty distracting.

 

[CWatters]

It's an autopilot disconnect alarm. You need to know if George (DeBeeson) is no longer flying the plane for you :-)

 

[sandy stone]

Gotcha, thanks.

 

[russ_watters]

...I did operate a refinery process control console. Unecessary alarms can be pretty distracting.

Yeah, this is a common problem in any industrial automation, including my field, HVAC. Some systems are set up to alarm every time something mildly concerning happens (temperature too high for a minute?), generating dozens of alarms a day, all of which are ignored.

A good rule of thumb is that if a piece of information does not require a near immediate response, it is unworthy of an alarm.

 

[rcgldr]

They mostly stick to airways which are managed by air traffic controllers. Pilots ask if they can go to point abc at height xyz and are either given permission or are offered an alternative.

Air traffic control systems in some areas have been improved to allow more point to point paths instead of using airways (and still manage to avoid potential collisions). I don't know how much of the USA airspace is now covered by these improved systems. A local airport in my area is John Wayne airport in Santa Ana (at the border with Costa Mesa). Before the system upgrade, airliners had to enter an approach corridor about 15 miles or so away from the airport (where the 91 and 55 freeways intersect). These days, airliners may enter the corridor about 6 miles away from the airport (where the 5 and 55 freeways intersect), from various directions. This would also allow airliners to leave the departure corridor sooner, but the city under the departure corridor, Costa Mesa, wants the airliners to continue using the old corridor so the noise doesn't affect neighborhoods that weren't being affected before the system upgrades.

 

[seazal]

I found the above F-16 flight control stick in my attic when I was playing F-15 Strike Eagle and related.

F-16 uses it:

I'd like to know the following:

1. I noticed I can no longer use it in my current pc which doesn't have joystick port. What do they use now in place of the joystick port?

2. What is the pc flight control stick or yoke you are using in your flight simulator games? What do flight simulator gamers use now?

3. In airliner such as the 737, they use yoke or control wheel like the following. Doesn't any aircraft use the stick control system like in the F-16? And won't it be more difficult to control stick control system in the F-16 than using the 737 yoke?

 

[russ_watters]

I'd like to know the following:

1. I noticed I can no longer use it in my current pc which doesn't have joystick port. What do they use now in place of the joystick port?

You can install a joystick port or use a USB port via a converter. Do some research on them before buying anything though - there's almost certainly help out there for this specific issue.

2. What is the pc flight control stick or yoke you are using in your flight simulator games? What do flight simulator gamers use now?

This is what I use:

http://www.saitek.com/uk/prod-bak/yoke.html

3. In airliner such as the 737, they use yoke or control wheel like the following. Doesn't any aircraft use the stick control system like in the F-16? And won't it be more difficult to control stick control system in the F-16 than using the 737 yoke?

Airbus uses them. Sticks are probably more difficult, but allow for more responsiveness -- less motion of the stick for more motion of the plane. That's important for fighter aircraft. I'm not sure why Airbus uses them when most other civil aircraft don't. I'm not sure if there are advantages for airliners, but several crashes have been caused in part by issues with the side stick controls.

 

[Filip Larsen]

3. In airliner such as the 737, they use yoke or control wheel like the following. Doesn't any aircraft use the stick control system like in the F-16? And won't it be more difficult to control stick control system in the F-16 than using the 737 yoke?

For F-16 the stick is a force-sensing stick meaning that the pilot must input control by applying pressure to it and not by deflecting the stick a certain amount. It is my understanding that the initial version didn't flex at all, but pilots found this unnatural and a bit of flexing in the stick was added. This type of stick control works for planes like F-16 because they are essentially flown by the computer which will maintain attitude in most flight regimes when no force is applied to the stick by the pilot. At least one force-sensing joystick was made (I forgot the manufacturer) but I never got around to try it.

In other (real) airplanes, with traditional mechanical or hydraulic link, the pilot can sense the force of moving stick or yoke as a measure of the forces on the control surfaces when controlling away from trim. For simulators of this type of airplane a force-feedback joystick can make the experience much more realistic than the fixed-force feedback of regular joysticks. For instance, during landing of a small stick-and-rudder plane the pilot can feel the softening of the stick as speed is reduced, which is a important pilot feedback in real plane (it allows pilot in a way to "feel" the magnitude of the forces on plane directly and thus react much faster that waiting for change in attitude or speed to "deduce" the same information).

Most gaming joysticks are "in between" in the sense that they have a fixed force response from springs as you tilt them away from zero. Fixed in the sense that the force it is unrelated to what the force would be in the real stick. This also means that you cannot feel the actual trim of the aircraft making it unrealistic difficult to trim out.

My experience with real and "simulated" yokes are very limited so I will not comment on those, except saying that they have the nice feature of separate aileron and elevator axis forces, making the trim problem I mentioned above for joysticks must less of a problem. The one I had (from CH, I believe) allowed free elevator movement (no return-to-center spring forces). That alone I think, is good reason to use a yoke instead of a stick for GA and similar flights where trimming has to be done by the pilot at all times.

 

[seazal]

For F-16 the stick is a force-sensing stick meaning that the pilot must input control by applying pressure to it and not by deflecting the stick a certain amount. It is my understanding that the initial version didn't flex at all, but pilots found this unnatural and a bit of flexing in the stick was added. This type of stick control works for planes like F-16 because they are essentially flown by the computer which will maintain attitude in most flight regimes when no force is applied to the stick by the pilot. At least one force-sensing joystick was made (I forgot the manufacturer) but I never got around to try it.

In other (real) airplanes, with traditional mechanical or hydraulic link, the pilot can sense the force of moving stick or yoke as a measure of the forces on the control surfaces when controlling away from trim. For simulators of this type of airplane a force-feedback joystick can make the experience much more realistic than the fixed-force feedback of regular joysticks. For instance, during landing of a small stick-and-rudder plane the pilot can feel the softening of the stick as speed is reduced, which is a important pilot feedback in real plane (it allows pilot in a way to "feel" the magnitude of the forces on plane directly and thus react much faster that waiting for change in attitude or speed to "deduce" the same information).

Most gaming joysticks are "in between" in the sense that they have a fixed force response from springs as you tilt them away from zero. Fixed in the sense that the force it is unrelated to what the force would be in the real stick. This also means that you cannot feel the actual trim of the aircraft making it unrealistic difficult to trim out.

My experience with real and "simulated" yokes are very limited so I will not comment on those, except saying that they have the nice feature of separate aileron and elevator axis forces, making the trim problem I mentioned above for joysticks must less of a problem. The one I had (from CH, I believe) allowed free elevator movement (no return-to-center spring forces). That alone I think, is good reason to use a yoke instead of a stick for GA and similar flights where trimming has to be done by the pilot at all times.

I stopped playing flight simulators decades ago because the screen was just 2D and very limiting (even now). But I'll return to it when we have VR headset closer to the resolution of vision so it's like actual cockpit and plane you are flying. See:

https://www.wired.co.uk/article/this-finnish-startup-makes-vr-at-human-eye-resolution

When you have those yokes and flight control wheel/joysticks integrated into the VR headset with vision resolution. It would be almost indistinguishable from reality.

Doesn't the US Navy have its own or also developing vision resolution VR headset or do they have to rely on commercial VR technology or development? This would very superb in flight simulators.

 

[russ_watters]

For simulators of this type of airplane a force-feedback joystick can make the experience much more realistic than the fixed-force feedback of regular joysticks. For instance, during landing of a small stick-and-rudder plane the pilot can feel the softening of the stick as speed is reduced, which is a important pilot feedback in real plane (it allows pilot in a way to "feel" the magnitude of the forces on plane directly and thus react much faster that waiting for change in attitude or speed to "deduce" the same information).

Most gaming joysticks are "in between" in the sense that they have a fixed force response from springs as you tilt them away from zero. Fixed in the sense that the force it is unrelated to what the force would be in the real stick.

My experience with real and "simulated" yokes are very limited so I will not comment on those, except saying that they have the nice feature of separate aileron and elevator axis forces, making the trim problem I mentioned above for joysticks must less of a problem. The one I had (from CH, I believe) allowed free elevator movement (no return-to-center spring forces). That alone I think, is good reason to use a yoke instead of a stick for GA and similar flights where trimming has to be done by the pilot at all times.

I've used a number of flight simulators over the years and concur with all of that, and want to double that bit about the yoke feel. I just started taking flying lessons and the lack of proper yoke response makes the experiences very incompatible. Ironically, the fly-by-wire makes the airbus simulator flying experience closer to the reality than the Cessna experience!

The yoke I use does not have a free elevator axis. Also, true feedback yokes do exist, but there aren't many and they are very expensive (thousands of dollars).

 

[russ_watters]

I stopped playing flight simulators decades ago because the screen was just 2D and very limiting (even now). But I'll return to it when we have VR headset closer to the resolution of vision so it's like actual cockpit and plane you are flying.

I bought an Oculus Rift primarily for flight simulators and unfortunately it is nowhere near ready. It is both too low a resolution and too poor in performance. That said...

When you have those yokes and flight control wheel/joysticks integrated into the VR headset with vision resolution. It would be almost indistinguishable from reality.

...this really is true, at least in the sense that you are immersed in the simulated reality. The Oculus rift is not yet usable, but I could see the potential when I tried. If you've never put on a VR headset, it's worth trying the experience.

There are still some problems with the simulation itself though. The control feel is one, but another significant issue is the lack of gravity feedback and that one can't easily be overcome.

Doesn't the US Navy have its own or also developing vision resolution VR headset or do they have to rely on commercial VR technology or development? This would very superb in flight simulators.

I'm not sure, but the military has long gotten around the issue of immersiveness by making their simulators half physical instead of totally virtual. When you are sitting in a real cockpit with all the windows replaced with screens, there's no need for a headset. The impracticality of building a cockpit and driving 6 projection monitors at a time for a home user is what makes the VR attractive.