Questions tagged [terminology]
For questions about words, phrases, and definitions that are specific to aviation or used in a different way in aviation. (Questions about standard words, phrases, and abbreviations used by pilots and ATC specifically in radio transmissions should usually use the [phraseology] tag instead.)
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What is the difference between centre of pressure, aerodynamic centre and neutral point?
I have just started learning some aerospace concepts, and I am not able to understand the difference between the three terms centre of pressure, aerodynamic centre and neutral point. What are their ...
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Is induced drag essentially nothing more than a specific type of form drag?
If I were standing outside on a windy day holding a flat rectangular object such as a food tray up in the wind, orthogonal to the direction of flow, the drag created would be classified, mostly, as ...
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What are the differences between Bearing vs Course vs Direction vs Heading vs Track?
This answer from English.SE does not focus on aviation, and does not explain 'Track'.
In basic, simple English, would you please compare and contrast all 5 terms in my question's title? The ...
user128
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What is the difference between "flight level" and "altitude"?
I have seen references to "FL180" and "FL300", and I know that they stand for Flight Level 180 and Flight Level 300. I've also seen references to "an altitude of 18000ft" or "an altitude of 30000ft".
...
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What does the term "trimming" most commonly mean in aviation?
Why does an airplane need trim, and what does it do during the flight? Does an autopilot adjust the trim automatically?
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What's the difference between FMS and FMC?
What's the difference between FMS (Flight management System), and FMC (Flight management computer)?
Can the flight management computer be thought of as what's manipulating the input information from ...
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What is a canard?
While browsing this Stack Exchange, I regularly come across mentions of canards. I am not familiar with this term, and Google only gives information about ducks when I search for "canard". So, what is ...
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What is a flat rated engine?
I've heard that a "Flat Rated Engine" is an engine where the power is reduced to keep the internal temperature within certain limits when the ambient temperature is above a certain point. Is that ...
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Why is a reduction in lift called 'drag'?
Induced drag is high pressure air 'leaking' to the upper part of the wing (low pressure zone) creating a vortex which means the area of the wing tip with the vortex can't create lift. Drag on the ...
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What is the difference between aviation "accident" and "incident"?
When I hear speaking about aviation crashes, sometimes I hear about "accidents" and other times about "incidents".
What distinguishes them? Is there an international standard that determines how ...
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Where does the term 'steam cockpit' come from?
Why are traditional style cockpits with gauges called 'steam cockpits'? Do the instruments actually run on steam?
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What are E2 and E4 airspace?
We have a number of questions here about E2 vs. E4 airspace (see summary of links in this answer) but what does that mean? As far as I can see, neither the AIM nor the ATC Orders mention E2 or E4 ...
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Does the expression "stall speed" have a definition?
I read, not only on this site, that the stall speed of an airfoil doesn't exist, and I usually make the effort to stay away from this expression.
While an airfoil can stall at any airspeed, it's ...
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What is the difference between GPS, GNSS and RNAV?
I would like to know the fundamental difference between GPS, GNSS and RNAV. How are they related each other? Are all/some of them synonyms?
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What is the difference between slice, segment and leg?
I have heard of the terms slice, segment and leg. Since I am a newbie in travel industry, I would like to know and understand the basic differences between the three.
Could someone please explain ...
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What is the difference between "sensitive" and "non-sensitive" altimeters?
In this answer reference was made to "sensitive" and "non-sensitive" altimeters.
What is the definition of each, what are the differences, and why would one be used in preference to the other?
And ...
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What is the origin of the term "pax"?
Pax in commercial transport is used as something like persons or passengers, in the context of counting people, e.g. 150 pax onboard.
(Amadeus capture, source)
I observed that in German writers tend ...
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In the United States, are ultralights legally considered aircraft?
I sometimes hear it stated that in the United States, ultralight vehicles are not legally considered to be aircraft. For example, Wikipedia used to state:
In the United States ultralights are ...
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Is there a name for the area for aircraft to back track near the runway threshold?
Some airports have an area, on the threshold, used to back track the aircraft, mainly because of the their wingspan, they look like a half wheel.
Is there any designation for this area?
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What is the difference between Cruise and Service ceilings?
I am looking at aircraft performance data. There are charts for "Cruise Ceiling" and "Service Ceiling." What is the difference? (The cruise altitude is lower.)
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How common is it in current British usage for the angle between the chord line of a wing and the flight path to be called the "angle of incidence"?
In American usage, the angle between the chord line of a wing and the flight path is called the "angle of attack". The angle of attack is also represented by the greek letter "alpha". However, some ...
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What is the difference between a flow and a checklist?
Use of checklists is a 'special emphasis area' during FAA private and commercial checkrides but there are a lot of comments in pilot forums about using flows instead, often - but not always - in the ...
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What is the difference between a fix, a waypoint and an intersection?
It seems these terms are used interchangeably. Are they the same thing? Do they all refer to the points in space that are given 5-letter names?
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What is the difference between fail-safe and fail-soft?
I have heard the following terms related to safe system design but I cannot really see a difference between fail-safe and fail-soft (graceful degradation).
To get a common understanding I will just ...
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What would be a technical or slang term for 'in the air'?
I'm writing a sci-fi story involving aircraft and space craft. I'm struggling to get the terminology right for referring to a pilot being 'in the air' either on a mission or a training exercise. I ...
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What is an airliner's "green dot speed", and how does it vary with weight, and why?
A related question told us, quoting from an Airbus performance manual,
Green dot speed (minimum gradient) is a function of weight.
Comments under the question stated that the "green dot speed" ...
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When buying airliners what is the difference between "orders", "options" and "purchase rights"?
I've often seen announcements by aircraft manufacturers or operators along these lines "Qantas announced today that they will buy 10 A380's and have taken options on another 10".
What does it mean to ...
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What is the name of the maximum altitude at which a helicopter can fly?
What is the name of the maximum altitude at which a helicopter can fly?
I recall it as "vertical limit", but I can't find a Wikipedia page for it other than a movie of the same title, which seems to ...
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From an ATC perspective, what is an "arrival gate"?
I have seen reference to ATC assigned "arrival gates".
As a passenger, an "arrival gate" is something like B12 or ...
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What exactly is a "coordinated" turn?
I am wondering what turn coordination really means and what makes a turn uncoordinated?
I know that when the turn is coordinated, there is no slip and skid, an aircraft is flying a perfect circle ...
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What is weight-climb speed?
I have a question about a document published by the Association of European Airliners. The name of the document is “Long Range Aircraft - AEA Requirements.” In the Appendix titled "Definitions and ...
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What is flight inspection, as provided by Cobham Aviation Services?
At about midnight, I saw a small plane (a Diamond Twin Star) take off from Heathrow, on flightradar24. It then proceeded to fly in irregular loops around North London, at low altitude, 1700ft. The ...
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In Raymer diagram "Take off parameter- Take off distance", what is the difference among "balanced field length", "over 50 ft", "ground roll"?
Raymer in his book suggests a method to find wing loading W/S (for example we consider jet with 2 engines) (starting from specific thrust $\frac TW$, $CL_{to}$, density/reference density etc.).
In ...
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Jettison and Dump fuel - Do they have separate meanings?
According to the definitions, is there any difference between Jettison and Dump fuel? Does one of them use a different procedure, or they are simply synonyms?
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What, exactly is "on the MEL"?
The MEL, minimum equipment list, defines whether fault of some equipment on the aircraft prevents it from being dispatched for flight or not.
However, sometimes (e.g. in comments to this question) ...
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What is a "rapid changes in gravitational force"
I've been reading an article on the BBC Website about the 21/May/2024 incident on Singapore Airlines. According to this article:
"The rapid changes in G over the 4.6 seconds duration resulted in ...
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What does "Zero for twenty" mean?
In Top Gun (1986), a flight got hit by a missile:
Pilot: I'm hit! I'm hit! We're coming apart! I can't control it! Hold on!
Zero for twenty! We're going down!
What ...
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Why does the Trent XWB have intermediate compressor stages?
I realized that the Rolls-Royce Trent XWB on the Airbus A350 has intermediate compressor stages. Why is that?
Other engines like the CFM56 or IAE V2500 that power most of the A320-family have low ...
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What is the FAA definition of solo flight?
If I'm a student pilot (for commercial), and I flew for pleasure with friends one night, do I log those hours as solo? Does solo mean, only pilot in the aircraft? Or does it literally mean only person?...
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What is the difference between Fly-By and Short-Turn?
By all definitions that my team and I have found, fly-by and short-turn (with respect to military unmanned air vehicle waypoint based flight) mean the same thing. Briefly, this allows the pilot to ...
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What does leading edge radius mean?
What does leading edge radius mean amongst these parameters of a st cyr 24 airfoil?
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Is there a standard word or phrase in the English-speaking world to describe the angle between the fuselage and the flight path / relative wind?
Is there a standard word or phrase, or several alternative commonly-used words or phrases, in the English-speaking aviation world to describe the angle between the longitudinal axis of the fuselage, ...
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What is a running rabbit?
My father used to work as an air traffic controller, and often I heard mention of a 'running rabbit'.
Obviously, vermin on the runways of airports can be a bad thing, but I don't think he was ...
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Why is the autopilot called "George?"
The autopilot of an airplane is frequently referred to as "George" (for example, in this answer). When did this nickname enter common usage, and what is its origin? Please cite sources if possible!
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What do jet pilots say during the takeoff as they are speeding down the runway?
I was watching a documentary on youtube and the pilots always say something that sounds like "B1E" when they have enough speed to take off. What exactly are they saying, and why do they say it?
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At what point does an aircraft become an airliner?
For me, the term 'airliner' conjures up an image of a passenger jet that is capable of hosting a large number of passengers¹ but I'm finding it difficult to source a reputable definition or etymology ...
user46185
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Why is the "Dutch" roll called so?
Why is the "Dutch" roll called so? When did this name enter common usage, and what is its origin? Please cite sources if possible!
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What does the term "tanker" mean when used in regards to a passenger airliner?
In a comment on this answer:
Airlines will tanker fuel if it's substantially cheaper at another airport
I've wondered what that term meant before, and now this comment leads me to think that ...
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What exactly do "captain", "pilot", "co-pilot" and "first officer" mean?
I know the co-pilot sits beside the pilot. But it's not clear for me, who is the captain and who is the first officer?
And where they are sitting during the flight? Who is in right seat and who is in ...
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What are the differences between various simulator levels?
I've heard of level A, B, C, and D simulators, (as well as FTD and AATDs) but know nothing about them.
What criteria is used to certify a sim as a particular level?
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