Don S
Lv 5
Don S asked in Cars & TransportationAircraft · 8 years ago

During an approach, at what point does ATC release the pilot to take over controls?

Also, normally, at what altitude and speed and how far from touch down do pilots ensure that they are lined up for landing.

Update:

I understand that the pilot is always in control but the ATC has information which maybe useful to the pilot. If you have ten jets requesting to come in for a landing, and the pilots do whatever they wish to do claiming they are in command, I think there's going to be some conflict happening. I just thought that actions by the ATC and the pilots are coordinated for the save landing/take off of the aircraft.

13 Answers

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  • Dan B
    Lv 7
    8 years ago
    Favorite Answer

    Final approach starts about 10 nm from touchdown.

    The pilot is always in physical control of the aircraft.

    ATC is always in procedural control ( via radar and communications) of the aircraft. ATC tells the pilot where to go and how to get there, the pilot executes those instructions so that they don't conflict with other air traffic. If radar and/or communications is lost, the pilot is expected to continue as last instructed.

  • 8 years ago

    Quote "at what point does ATC release the pilot to take over controls?"

    This proves that you understand nothing about flying or the ATC system. Whether hand-flying or on autopilot, the pilots are always in complete control of the aircraft but they are always under obligation to follow instructions from ATC. If you understand this, then you do not understand the language well enough to pose a comprehensible question.

    If you meant to ask "at what point does ATC clear an aircraft to land", the answer is that at a tower-controlled airport an aircraft might be cleared to land 10 miles from the runway, or a mile from the runway, depending on traffic. At an uncontrolled airport no clearance to land is required.

    You might also wonder "at what point is an aircraft cleared for the approach while IFR?" The answer again depends upon the weather and the traffic conditions but it is always somewhere between leaving the enroute structure and entering the final approach segment. .

  • 8 years ago

    You're mistaking the meaning of "control" to "indiscretionate control". All major airports to which airlines fly are served by published arrival routes and instrument approaches, and the pilots will have reviewed the routes and altitudes to fly long before they land. They'll know the runway they're going to land (or at least the direction of landing), wind and weather conditions, what kind of visual landing aids are available, etc. Pilots know where they are supposed to be and when, and so does ATC. A little more sane than having ten jets all diving for the same white numbers at the same time, right? Here's an example of a published Standard Terminal Arrival... the Olympia Seven Arrival into Seattle Tacoma International: http://dtpp.myairplane.com/pdfs/NW-1/00582OLYMPIA....

    Your second question, "normally, at what altitude and speed and how far from touch down do pilots ensure that they are lined up for landing" is quite a bit more complicated. I suggest you read about instrument approaches here:

    http://en.wikipedia.org/wiki/Instrument_approach

    If you want to narrow the focus to commercial air traffic, all on instrument flight plans and ALL executing instrument approaches with the help of ATC and radar, the airplane could be "lined up" to the runway heading in as little as 5 miles to the runway, but much more typically 15-20 miles. A basic rule of thumb for the airplane's altitude anywhere on approach is 1000 feet AGL for every 3 miles from the landing threshold, but this will again depend on type of approach, which runway, and steepness of the particular glide slope.

    One more thing to keep in mind: IFR aircraft are separated laterally and vertically from each other from the moment they are within radar service range right down to final approach. The exact numbers depend on a bunch of factors, but absolute minimum of 2.5 miles horizontal distance from each other on final approach, with 1000 feet minimum vertical spacing. If you really want to get to the nitty gritty with radar and separation standards you can check out http://www.faa.gov/air_traffic/publications/atpubs...

    Source(s): commercial pilot since 1994
  • 8 years ago

    The pilot in command is always in control of the aircraft. ATC does not control the aircraft.

    ATC directs traffic towards the airport. Pilots follow the instructions of ATC in order to maintain safe separation from other aircraft and ensure that traffic flows smoothly. Normally, pilots are required to follow ATC instructions, but they may deviate from these instructions if they deem it necessary for safety reasons. In addition, the instructions from ATC are quite general; they do not tell the pilot how to fly the approach. ATC limits itself to providing headings and altitudes, and occasionally speed restrictions (although these are harder to impose since many aircraft have speed requirements of their own).

    So there is indeed coordination. ATC instructions are generally followed, unless there is a safety issue. The pilot is always the final authority for a flight, however. ATC provides traffic and weather information, but the rest is up to individual pilots.

    ATC clears an aircraft for an approach once it is in position for that approach. It clears an aircraft for landing once it is close to the threshold of the runway. These clearances are just for traffic coordination; the aircraft is always being controlled by the pilot. A clearance simply means that it is safe to proceed (i.e., there is no conflict with other traffic in the area).

    For airliners, a stabilized approach is established miles away from the airport. The aircraft is aligned with the runway and descends at a constant rate along a predetermined glide path. Small private aircraft have much more flexibility, although a stabilized approach is still good practice, and they must still follow ATC instructions at controlled airports (at airports without a tower, they are on their own).

    I'm not sure why other people are talking about FSX, since there was no mention of it in the question, and since ATC doesn't control aircraft in FSX, either.

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  • John R
    Lv 7
    8 years ago

    I'm not sure what you mean by "release the pilot to take over the controls" - ATC has no part in determining if the pilot is using autopilot or hand flying the plane.

    On an ILS the localizer is normally intercepted around 10 nm from the runway, typically at around 2000 AGL, the glideslope is intersected 5 to 6 nm from the airport.

    It's not uncommon for ATC to clear you for the approach as soon as you pickup the localizer and to tell you change to the tower frequency once you reach a specific fix or intersect the glideslope.

  • the "lining up for landing" is at ATC discretion and the your queue number decreases as aircraft before you land.

    pilot is at controls at all times.

    there are approaches like precision radar guided ones, where pilot does what the radar controller tells him to do (corrections in descent and heading) because the pilot needen't to have any instruments.

    in other approaches, the ATC will vector the traffic to favourable position to start the approach (may be one of the IAF OR any other position deemed favourable.

    -as an example, consider helicopter traffic. you want the helicopter shooting 10 NM approach? you better get ready for complaints from fast jocks stuck behind that helicopter (which will be flying the approach no faster than 110 knots but more likely be flying about 70 knots)

    by the rules of air, the ONLY situation where pilot is not responsible for separation from obstacles, is when being vectored by precision radar. even if vectored by surveiillance radar, you are obliged to refuse descent below radar vectoring altitude and responsible for that decision.

  • Nick
    Lv 4
    8 years ago

    ATC is just there for direction. They'll set up the pilot for an ILS but the pilot has to land the plane. Imagine how bad it would be if the guys falling asleep in the tower had control of a bunch of 747's.

  • 8 years ago

    Please tell me this is a joke? ATC has NO control of the aircraft, anything they ask me to do doesn't have to be done. As Pilot In COMMAND, I can deviate from any instruction for safety of flight.

    I line up as far out as I want to, in my T6 I fly a curvilinear approach with maybe a 1/2 mile final; in the day job I line up at least at the outer marker (even on a visual approach).

    EDIT: In the USA there are about 5100+ airports, of which only 503 offer commercial service, perhaps another 500 actually have a control tower; i.e. like Ft Lauderdale Executive or PDK in Atlanta. The rest of these airports have hundreds of planes, mostly flown by inexperienced pilots from the local flight school flying there all the time, and they manage to not need anybody to tell them when to turn, when to descend, when to takeoff, etc.

  • 8 years ago

    What are you talking about?

    ATC never control an Aeroplane.. They just tell planes what to do, to avoid collisions so that they can depart or arrive..

    The final responsibility rests with the Pilot in Command..

    Pilots will align themselves with the runway.. Wherever practical.. From 30 miles.. to 1/2 a mile...

  • 8 years ago

    The pilot is always in control. Speed depends on the aircraft. In bad weather conditions the pilot will fly IFR (Instrument Flight Rules) and use landing aids to bring the aircraft into alignment with the active runway and also to set up the proper glide slope. The pilot uses VFR (Visual Flight Rules) once he/she can visually sight the runway.

    Source(s): Licensed Pilot
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