why is it that planes have to fly below 250 kts airspeed when under 10,000 ft MSL?

MSL is Mean Sea Level... i am asking this because i have found a program that allows you to take virtual passengers on your flights for Microsoft Flight Simulator 2004 and it pits the rules of passenger flying into Flight Simulator 2004 and i never fully understood it

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  • 1 decade ago
    Best Answer

    FAA FAR § 91.117 Aircraft speed.

    (a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).

    (b) Unless otherwise authorized or required by ATC, no person may operate an aircraft at or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D airspace area at an indicated airspeed of more than 200 knots (230 mph.). This paragraph (b) does not apply to any operations within a Class B airspace area. Such operations shall comply with paragraph (a) of this section.

    (c) No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport or in a VFR corridor designated through such a Class B airspace area, at an indicated airspeed of more than 200 knots (230 mph).

    (d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

  • 1 decade ago

    A couple of reasons

    Firstly for safety, below 10000 feet there is a higher concentration of air traffic, and in uncontrolled airspace it is up to the pilots to see each other and avoid unless they have a TCAS system on board (Traffic Collision Awareness System) and even then the primary means is looking out the window. 250 knots was decided to be a reasonable speed where it gives enough time for pilots to see and avoid, in fact in control zones in certain parts of the world this drops to 200 knots for jets.

    Secondly the risk of bird strike increases greatly and at 250 knots a significant amount of damage can occur, so typically large passenger aircraft windshields are designed to take a direct hit from a large bird at that speed without it entering the cabin. It has been known for direct hits from birds to seriously injure pilots after making it all the way through the aircraft structure, the amount of energy involved is huge.

    agoodair is actually incorrect, the 250 knot speed limit also apples in European and Canadian airspace, with some exceptions (Class A and B, IFR Class C and as authorised by ATC, test flights, air displays etc)

    Hope this helps

    Source(s): Here are a couple of sites showing what damage can occur http://www.airsafe.com/events/birdhit.htm This one is particularily gross http://www.militaryphotos.net/forums/showthread.ph...
  • shula
    Lv 4
    3 years ago

    I comprehend that they have got been given caught up interior the thrill of the 2nd and did no longer intend any style of threat, yet i could surely no longer have had to be on that airplane. i think of the Harlem Shake is various exciting, yet that replaced into no longer the situation for it. if that they had carried out an identical element in a park or a great open area, no difficulty. They went too far. rather everyone isn't over-reacting. the factor now's to be certain rather everyone gets the message that it is not okay to do something like this in flight.

  • Anonymous
    1 decade ago

    Below that altitude aircraft make turns more often (to line up for runways, to join airways, etc). Requiring them to go slowly makes it easier for the air traffic controllers who have to time these turns for just the right moment. It also means the planes are quieter when heard from the ground so they don't affect residential areas with noise.

    It isn't always a requirement. Outside of controlled airspace aircraft can go as fast as they like (I think). Also outside of the USA controllers will often tell aircraft that 'high-speed is approved', even below FL100, so they can get to their destination quicker.

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  • 1 decade ago

    This is purely a US FAA requirement. The problem is that FS2004 is obviously a game made by an American company so, due to the limitations of the game engine, this rule is applied globally.

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