[muse]: annoyances
Sep. 18th, 2003 02:33 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
coronaviridaeIn a recent book I read (The Changeling Plague), there was a short sequence where the protagonist and a group of her allies took a couple of short plane rides to and from one of the book's main locations. The aircraft in question was a DeHavilland amphibian of some stripe or another; I'd need to go back and check for the actual model. This was all well and good, up until the point where the pilot had to land the plane.
Not once, but three times, the author made reference to the pilot 'pulling back on the flaps' to land. This is an example of something that bothers me about aviation in fiction--most authors don't actually spend the TIME to learn what the control surfaces of an aircraft ARE, or what they DO.
'Flaps' is not a generic term that refers to any of the control surfaces on the aircraft. It's an easy mistake to make, but still fundamentally incorrect.
The flaps, for those who aren't in the know about aircraft, are a part of the trailing edge of the wing on fixed-wing aircraft. They begin at the wingroot (where the wing joins the fusillage) and usually extend about half the length of the wing. Their primary purpose is to slow the plane down, but they also allow for more lift when the plane is flying very slowly (i.e., just prior to landing). They do this by increasing both the cord (width) of the wing, providing more flight surface, and the camber ('bend') of the wing.
The flaps operate on a hydraulic or electrical system; when the pilot flips a switch in the cockpit, the flaps extend/lower. They are NOT controlled from the yoke (the 'steering wheel', though it rarely resembles one, but is in an analogous position to that of a car's steering wheel) of the aircraft, so you can't 'pull back on them'.
Presumably, what this author--and many authors--are thinking of when they say 'flaps' are the ailerons, which begin midway through the wing (where the flaps END) and extend nearly to the wingtips. The ailerons are used for steering the aircraft, and operate differentially--when you turn the yoke one way, the aileron on that side of the aircraft goes up, and the opposite aileron goes down. This changes the conformation of the wings--and therefore the airflow over them--such that the plane turns in the direction you turn the yoke. However, you do not 'pull back on the flaps [ailerons]' when landing, so this description is ALSO inaccurate. The ailerons control roll, or movement rotationally around the centerline of the aircraft.
The third flight surface on the plane are the elevators. On most straight-tail aircraft, the elevators are at the base of the vertical stabilizer (the up and down part of the tail). In T-tail aircraft, the elevators are on the crosspiece of the tail. In V-tail aircraft like the V-class Bonanza, the elevators are combined with the rudder to form 'ruddervators'. (I'll discuss these and rudders in a bit.) The elevators control the pitch of the aircraft, or its orientation vertically.
When you push forward on the yoke, the elevators go down. The flow of air over the tail changes so that the tail pitches up, and the nose pitches down. The angle of attack of the entire plane changes, so that the plane begins to descend. When you pull back on the yoke, the elevators go up, and the tail pitches down. The plane ascends.
When landing, you flare using the elevators to slow the plane down to a touch-down speed. You do this by pulling back on the yoke once the plane is near stall speed, dropping the tail and inducing it to land on the main gear (in tricycle-gear aircraft, e.g., not taildraggers), as well as causing the aircraft to begin to stall (and NOT FLY). I can only think that this is what was meant by 'pulling back on the flaps', since flaring is the only reason to pull back on the yoke while landing the plane.
As an aside, in some old aircraft--old Cessna 182's and 185's, old Pipers--the flaps WERE controlled by a lever, but you pulled up on the lever to lower the flaps. So there is no way that 'pulling back on the flaps' is a reference to the control surfaces actually know as flaps by pilots and others involved with aircraft.
The other tail control surface is the rudder. On most aircraft, it is found on the back of the vertical stabilizer, or straight up and down part of the tail. The rudder controls yaw, or the side-to-side orientation of the aircraft's nose (and therefore the aircraft). In most aircraft, the rudder is controlled by foot pedals on the floor of the aircraft, not by the yoke. The foot pedals are also used for steering while taxiing the plane on the ground, as opposed to the yoke.
The rudder on a plane operates much like the rudder of a ship; turn it, and the flow of a fluid (water with a ship, air with a plane) around the plane changes, causing the plane to yaw in one direction or the other.
Ruddervators are a variant on V-tailed aircraft that combines the rudder and elevators of straight-tailed aircraft. They operate partially differentially; when they are functioning to control the pitch as elevators, they move together. When operating like the rudder to control the aircraft's yaw, they move separately. The largest problem V-tails have is they can't control the plane's yaw as well as straight-tailed aircraft can, and so tend to be somewhat more sensitive to turbulence.
There are two other control surfaces you can find on aircraft: trim tabs and spoilers.
Trim tabs are used to trim out control forces, or the tendancy of an aircraft to pitch, yaw, or roll when the controls are in a neutral position. Some varieties can be adjusted while in flight; others need to be trimmed manually prior to take off.
Spoilers, also known as speed brakes, are not common to all aircraft, though if you've sat over the wing of a jet plane and watched during the landing roll-out, you've probably seen spoilers in action. Spoilers are panels on the wing itself that spring up from the wing when activated, and serve to 'spoil' the lift over the plane's wing, thus helping faster aircraft slow down during landing and roll-out. Many smaller aircraft do not have spoilers, but you can get speed brakes/spoilers installed.
In summary:
Not all control surfaces on an aircraft are flaps!
Flaps are on the inner half of the trailing edge of wing. They are controlled by a hydraulic or electrical (rarely manual) system. Their purpose is to increase the area of the wing and the drag on the aircraft to allow it to fly slower without stalling.
Ailerons are on the outer half of the trailing edge of the wing. They are controlled by the yoke, and control the roll of the aircraft. They operate differentially, and cause the plane to turn.
Elevators are on the straight part of the tail. They are controlled by the yoke. They control the pitch of the aircraft, and cause it to climb or descend.
Rudder is on the airplane's vertical stabilizer, a part of the tail. It is controlled by the foot pedals, and mediates the yaw of the aircraft, or its side-to-side orientation in the air.
Ruddervaters are found in V-tailed aircraft.
Trim tabs are used to trim out control forces, and can be found on the rudder, the elevators, or the ailerons.
Spoilers or speed brakes are on the main body of the wings. They allow the plane to slow down rapidly.
muse
Not once, but three times, the author made reference to the pilot 'pulling back on the flaps' to land. This is an example of something that bothers me about aviation in fiction--most authors don't actually spend the TIME to learn what the control surfaces of an aircraft ARE, or what they DO.
'Flaps' is not a generic term that refers to any of the control surfaces on the aircraft. It's an easy mistake to make, but still fundamentally incorrect.
The flaps, for those who aren't in the know about aircraft, are a part of the trailing edge of the wing on fixed-wing aircraft. They begin at the wingroot (where the wing joins the fusillage) and usually extend about half the length of the wing. Their primary purpose is to slow the plane down, but they also allow for more lift when the plane is flying very slowly (i.e., just prior to landing). They do this by increasing both the cord (width) of the wing, providing more flight surface, and the camber ('bend') of the wing.
The flaps operate on a hydraulic or electrical system; when the pilot flips a switch in the cockpit, the flaps extend/lower. They are NOT controlled from the yoke (the 'steering wheel', though it rarely resembles one, but is in an analogous position to that of a car's steering wheel) of the aircraft, so you can't 'pull back on them'.
Presumably, what this author--and many authors--are thinking of when they say 'flaps' are the ailerons, which begin midway through the wing (where the flaps END) and extend nearly to the wingtips. The ailerons are used for steering the aircraft, and operate differentially--when you turn the yoke one way, the aileron on that side of the aircraft goes up, and the opposite aileron goes down. This changes the conformation of the wings--and therefore the airflow over them--such that the plane turns in the direction you turn the yoke. However, you do not 'pull back on the flaps [ailerons]' when landing, so this description is ALSO inaccurate. The ailerons control roll, or movement rotationally around the centerline of the aircraft.
The third flight surface on the plane are the elevators. On most straight-tail aircraft, the elevators are at the base of the vertical stabilizer (the up and down part of the tail). In T-tail aircraft, the elevators are on the crosspiece of the tail. In V-tail aircraft like the V-class Bonanza, the elevators are combined with the rudder to form 'ruddervators'. (I'll discuss these and rudders in a bit.) The elevators control the pitch of the aircraft, or its orientation vertically.
When you push forward on the yoke, the elevators go down. The flow of air over the tail changes so that the tail pitches up, and the nose pitches down. The angle of attack of the entire plane changes, so that the plane begins to descend. When you pull back on the yoke, the elevators go up, and the tail pitches down. The plane ascends.
When landing, you flare using the elevators to slow the plane down to a touch-down speed. You do this by pulling back on the yoke once the plane is near stall speed, dropping the tail and inducing it to land on the main gear (in tricycle-gear aircraft, e.g., not taildraggers), as well as causing the aircraft to begin to stall (and NOT FLY). I can only think that this is what was meant by 'pulling back on the flaps', since flaring is the only reason to pull back on the yoke while landing the plane.
As an aside, in some old aircraft--old Cessna 182's and 185's, old Pipers--the flaps WERE controlled by a lever, but you pulled up on the lever to lower the flaps. So there is no way that 'pulling back on the flaps' is a reference to the control surfaces actually know as flaps by pilots and others involved with aircraft.
The other tail control surface is the rudder. On most aircraft, it is found on the back of the vertical stabilizer, or straight up and down part of the tail. The rudder controls yaw, or the side-to-side orientation of the aircraft's nose (and therefore the aircraft). In most aircraft, the rudder is controlled by foot pedals on the floor of the aircraft, not by the yoke. The foot pedals are also used for steering while taxiing the plane on the ground, as opposed to the yoke.
The rudder on a plane operates much like the rudder of a ship; turn it, and the flow of a fluid (water with a ship, air with a plane) around the plane changes, causing the plane to yaw in one direction or the other.
Ruddervators are a variant on V-tailed aircraft that combines the rudder and elevators of straight-tailed aircraft. They operate partially differentially; when they are functioning to control the pitch as elevators, they move together. When operating like the rudder to control the aircraft's yaw, they move separately. The largest problem V-tails have is they can't control the plane's yaw as well as straight-tailed aircraft can, and so tend to be somewhat more sensitive to turbulence.
There are two other control surfaces you can find on aircraft: trim tabs and spoilers.
Trim tabs are used to trim out control forces, or the tendancy of an aircraft to pitch, yaw, or roll when the controls are in a neutral position. Some varieties can be adjusted while in flight; others need to be trimmed manually prior to take off.
Spoilers, also known as speed brakes, are not common to all aircraft, though if you've sat over the wing of a jet plane and watched during the landing roll-out, you've probably seen spoilers in action. Spoilers are panels on the wing itself that spring up from the wing when activated, and serve to 'spoil' the lift over the plane's wing, thus helping faster aircraft slow down during landing and roll-out. Many smaller aircraft do not have spoilers, but you can get speed brakes/spoilers installed.
In summary:
Not all control surfaces on an aircraft are flaps!
Flaps are on the inner half of the trailing edge of wing. They are controlled by a hydraulic or electrical (rarely manual) system. Their purpose is to increase the area of the wing and the drag on the aircraft to allow it to fly slower without stalling.
Ailerons are on the outer half of the trailing edge of the wing. They are controlled by the yoke, and control the roll of the aircraft. They operate differentially, and cause the plane to turn.
Elevators are on the straight part of the tail. They are controlled by the yoke. They control the pitch of the aircraft, and cause it to climb or descend.
Rudder is on the airplane's vertical stabilizer, a part of the tail. It is controlled by the foot pedals, and mediates the yaw of the aircraft, or its side-to-side orientation in the air.
Ruddervaters are found in V-tailed aircraft.
Trim tabs are used to trim out control forces, and can be found on the rudder, the elevators, or the ailerons.
Spoilers or speed brakes are on the main body of the wings. They allow the plane to slow down rapidly.
muse