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Guest monsterzero_jr

Question about 250 KTS speed limit

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Below 10,000 feet maximum speed limit (air traffic rules) is 250 knots. Whenever I descend below 10,000 feet I pay attention to that but does the rule apply to takeoffs as well? My Boeing 727 has a normal climb speed of 300 knots. Obviously I would like to establish 300 knots as soon as I get off the ground so I have an efficient climb...Would that violate the rule?

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They differ but as a rule staying below 250kts under 10'000 feet is the way to do it.Some airspace areas require you to stay at or below 210kts, like at Heathrow. Unless of course you are cleared to a higher speed. Some instances would be say a fully loaded 747 may need more speed to stay airborne so they would be cleared to a higher speed.On VATSIM I get clearence to only 180kts during takeoff on a busy day until they hand me off...

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In a word, yes.250kts below FL100 (or 10,000ft) means exactly that. It's to allow for the fact that there are lots more (slower) aircraft (read GA) operating down there. It applies when climbing and descending.In the US I believe it's law so you always do it, pretty much everywhere else on the planet it's recommended but can be (and often is) not applied. I think this is something to do with the airspace rules below 10,000ft in the US. I know in the UK we can have class A airspace (airways and TMAs) down low so the controllers have a better idea of who's where and what they're doing so it's easier for them to decide if greater than 250kts will be OK. Out of Heathrow, on first contact to London they always used to say "ident, no speed" but just over a year ago it changed and they started keeping us at 250kts. Every so often you get it but it's much less likely now, I've never been restricted to anything less than 250.In some places they have different restrictions, e.g. in Russia it's 270kts below 3000m.If you're in a heavy and your minimum clean speed is higher than 250 then you can get alleviation from this rule.As an aside the 300kt climb gives you a good rate, 250kts gives you a better angle (usually) so climbing at 250kts can be quite a good idea if there's high ground around.Hope this helps,Ian

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That is not correct. Actually, the rule applies to inbound aircraft only. For airspace efficiency reasons, it is most desireable to have departing aircraft leave the terminal area asap, and so the 250kts rule does not apply to departing aircraft. To avoid any arguement, here is a link to the canadian AIM, explaining this regulations. (note, because it is canadian does not mean it varies very much, as this is an ICAO goverened system)http://www.tc.gc.ca/CivilAviation/publicat...C/2-1.htm#2-5-2

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Hmmm. Looks like even real world aviators who responded to my thread are not certain. Perhaps we could talk to a real life ATC controller.

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In US Airspace, yes, 250 kias below 10K unless specified or approved by a controller.Retired ARTCC Controller (28 years).Bob

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0-250kts below and up to 10,000ft. 0-200kts below 2500ft with in 4NM of airport. (Class B,C,D Airspace)Doesn't matter whether you're going or coming.

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Yes, it would violate the rule and you'd be getting a call from FSDO. FARs are clear that the speed limit is 250kts IAS below 10,000 feet period. All commerical jet aircaft have a normal climb rate above 250kts, and that can be established above 10,000 feet as you see fit.Terminal airspace (class B, C, etc) speed limits that mandate speeds below 250kts are for approaching aircraft only and don't usually apply to departing aircraft or aircraft flying through the airspace. Of course, there are always exceptions due to congestion where the approach controller may slow you down but that is seldom the case. If you are not approaching the terminal the controllers want you out of their airspace as quickly as possible.Also, you are not flying your 727 correctly. You do not establish 300 kts as soon as you get off the ground. You should be targeting ~v2+20 through 1,500 feet AGL and then set climb thrust (and leave it there) as you begin to accelerate to 250kts and get the aircraft cleaned up and pitch to maintain that speed. At 10,000ft reduce pitch to increase your speed to 300kts and then pitch to maintain 300kts (and then the appropriate Mach #) in your climb (at climb thrust).With noise abatement rules at most airports now-a-days you need to be shooting for Vx which means you have to use a steeper rate of climb to achieve a higher altitude in a shorter period of time. What you are doing is attempting to fly Vy which does not minimize your horizontal distance. Flying Vy will allow you to accellerate faster but will also have people complaining that some genius in a 727 just flew 20' over their roof at 300kts! :-lolHTHMike T.

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Like most aviation safety rules - this one is written in blood, not ink.There was an aircraft collision over New York City in December 1960 when a United DC-8 and a TWA Lockheed Constellation went down after the DC-8 flying at close to 500mph flew past it's hold point and struck the Connie.Though the DC-8 pilot was cited as responsible for flying past his clearance point - the speed of the DC-8, it's relative speed difference with the Connie, and the difficulty of the controllers in determining the two aircraft speeds, or that they were even flying a different speeds was noted and discussed heavily.The 250 kts under 10,000 rule was a result of the best thinking at the time - keeping aircraft at similar speeds to make traffic flow easier to monitor and control.Do understand that like almost any rule in aviation - there are exceptions and modifications for various reasons.http://dotlibrary1.specialcollection.net/Go to Historical Aircraft Accident Reports (1934-1965)1960United Airlines and Trans World AirlinesThe Board notes that during the course of this investigation the Federal Aviation Agency took various steps to improve and strengthen the efficiency and effectiveness of its Air Traffic Control System, including the following:1. A special regulation (SR-445) was issued which requires pilots operating under instrument flight rules to report in-flight malfunctions of navigation or communication equipment. 2. A program has been established for all turbine-powered aircraft to be equipped with distance-measuring equipment (DME) by January 1, 1963. One year later all aircraft of over 12,500 pounds maximum takeoff weight must be so equipped. 3. Radar handoff service for arriving and departing aircraft in the New York area is being performed to a much greater extent than was practiced before the accident. On a national basis, full-time radar handoff service has increased to a great extent. 4. Controllers have been instructed to issue an advisory to arriving jet aircraft to "slow to holding pattern airspeed at least 3 minutes before reaching holding fix." 5. The Stroudsburg, Pennsylvania, VOR name and identification signal (SSB) have been changed to Taunersville (TVE) because of potential confusion with Solberg VOR (SBJ). 6. The Agency has issued a speed rule which prohibits aircraft from exceeding 250 knots when within 30 nautical miles of a destination airport and below 10,000, except where the safety requirement of tactical military jets dictates a higher minimum speed, which Then applies to these aircraft.

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Naw, Mike.Who in the world would fly their 727 20' over someones house at 300kts? No one I know, ROTFLMAO. However I've never seen that particular rule enforced in the 'Southern' part of this hemisphere. The monkeys and birds in the jungle next to those 'God awful' grass and gravel strips I use to fly in and out of use to get our numbers all the time, they just arn't very good at dialing a phone to turn us in LOL.Best my friend, Clayhttp://www.dreamfleet2000.com/gfx/images/F...ers/Dopke01.jpgClayton T. Dopke (Clay)Major, USAF (retired)"Drac"

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Yeah, Yeah, Yeah, for some reason you black ops types believe that flying a 727 off of grass and gravel strips in unnamed countries is good. I would imagine that the monkeys at treetop level didn't mind you diving in and out of those airports, but I'm not sure about the indigenous people liking you blowing the roofs off of their homes!I wonder: If a flight never officially took off, and never officially landed, does it break any offical laws? :-lol

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Just curious, Was Concorde one of those few exemptions to the 250kts rule? I'm sure they needed clearance for that.:-wave

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Nope, same restrictions for Concorde. As long as Concorde maintained a speed of no less than 170kts she was fine.

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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.).(:( 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 m.p.h.). This paragraph (:( does not apply to any operations within a Class B airspace area. Such operations shall comply with paragraph (a) of this section.© No person may operate an aircraft in the airspace underlying 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.

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