250 Kts limit

[angels355]

Corrected:

No speed limit above 10,000 feet, 250 knots below 10,000 feet, underneath the Class B shelf 200 knots, or a VFR corridor through Class B airspace 200 knots, 4 nm from Class C or D airspace at or below 2,500 feet 200 knots. I could swear I've seen a 210 knot speed limit also, can't remember where. Hmmmm, I think it is on approach plates, at a certain altitude on approach they expect a lower airspeed like 210 knots, I think that is it. Every approach plate to an airport is different, often they want you to descend in steps and have specific airspeeds as you go at specific locations on the approach, that's why you have to look at each airport plate and know it before landing there (or taking off also).

At those low speeds heavy metal planes need quite a lot of flaps to avoid stalling. You can watch this on your fs, fly straight and level at for example FL50 (5,000 feet) and maintain 200 knots with your airliner. Start out with no flaps, it will fly nose high, like it could be in stall territory. Now add one notch of flaps and watch the nose, it will level out a little, add another notch, and another, eventually the nose nose will be flying nice and level.

The two speed limits, 250 knots and 200 knots are as loki mentions for better separation of aircraft and better safety, especially in B, C, D, controlled airspace where the traffic can get really congested with all varieties of aircraft.

In Class A airspace, FL180 to FL600, you can fly as fast as you want, however you must be on an IFR flight plan no matter what the weather conditions are, this again is due to separtation control by ATC.

BTW, the reason you want to avoid clouds when flying VFR is because if for example a 747 pops out of the clouds heading straight for you, you want to be far enough away to have time to get out of the way. If you're flying VFR and are just singing "I gotta me meee! I gotta be freee!" (Sammy Davis Jr) and flying through one cloud after another as if you're doing a Hollywood video production, you could smack into an IFR plane. So when flying VFR, practice actually avoiding clouds at a safe distance, and stay 20 miles away from thunderstorms.

[Adam24]

Okay, tanks for the replies.

[mgh]

In the UK the Rules of the Air state;

Speed limitations

21 (1) Subject to paragraph (2), an aircraft shall not fly below flight level 100 at a speed
which, according to its air speed indicator, is more than 250 knots.

(2) Paragraph (1) shall not apply to:
(a) flights in Class A airspace;
(b) VFR flights or IFR flights in Class B airspace;
(c) IFR flights in Class C airspace;
(d) VFR flights in Class C airspace or VFR flights or IFR flights in Class D airspace
when authorised by the appropriate air traffic control unit;
(e) an aircraft taking part in an exhibition of flying for which a permission is required
by article 80(1) of the Order, if the flight is made in accordance with the terms of
the permission granted to the organiser of the exhibition of flying and in
accordance with the conditions of the display authorisation granted to the pilot
under article 80(6)(a) of the Order;
(f) the flight of an aircraft flying in accordance with the A Conditions or the B
Conditions; or
(g) an aircraft flying in accordance with a written permission granted by the CAA
authorising the aircraft to exceed the speed limit in paragraph (1).