Just get the ITVV Virgin 747 DVD and watch that. At about 3000 ft they clean up and accelerate to 290 kts. You don't hear them requesting it - ATC just accept they need to do it.

 

Best regards,

Robin.

Just get the ITVV Virgin 747 DVD and watch that. At about 3000 ft they clean up and accelerate to 290 kts. You don't hear them requesting it - ATC just accept they need to do it.

 

Best regards,

Robin.

 

No because they get it on first contact, 46:50 in.

"VIR19 squawk ident there is no atc speed restriction".

Just get the ITVV Virgin 747 DVD and watch that. At about 3000 ft they clean up and accelerate to 290 kts. You don't hear them requesting it - ATC just accept they need to do it.

 

Best regards,

Robin.

No. ATC doesn't accept that aircraft can fly at any speed a pilot chooses in controlled airspace. That would negate the whole concept of controlled airspace - why not let aircraft fly at any altitude as well?

FAR 91.117, it states:

 

"(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.

 

The whole deal is that FAR 91.117(a) says it all.  It is a speed limit to which may not be exceeded unless authorization is obtained from the Administrator (ATC).....there is no question or individual interpertation of this, it is black and white. 

 

If this speed is exceeded without authorization, then the FAA can and has in the past issued fines for it.  But seeing as this is flight sim and no one really cares, then the speed is more often than not exceeded.

 

The authorization is the phraseology "No ATC speed restriction" or like verbage and as stated in 91.117(b ), (c ), (d) 

 

The only exception to this is for military training routes, where the FAA has authorized speeds up to but not including MACH 1 over land and within 12 miles of the coast.

Harry, reread the whole thread..

Rob,

 

As 91.117(a) states "no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.)". 

 

This may be exceeded by 91.117(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."

 

91.117(b ) and (c ) are talking about indicated airspeeds below 250kts.

Tell me something I don't know, again read the whole thread, this has been covered..

No. ATC doesn't accept that aircraft can fly at any speed a pilot chooses in controlled airspace. That would negate the whole concept of controlled airspace - why not let aircraft fly at any altitude as well?

This is not true Gerry. You're misapplying the concepts.

 

ATC does accept that the aircraft will fly at the speed it needs to fly, and this does not negate the concept of controlled airspace. Controlled airspace simply means that the flight is subject to the commands of ATC as directed. A clearance can be left completely ambiguous, and the pilot left at his or her discretion for altitude, speed, and route. The only real requirement in controlled airspace is the controller's ability to:

Communicate with the pilot to issue command instructions (restrictions to that discretion); and

Be able to positively identify that aircraft on the scope (the reason for the discrete squawk, though non-radar means may be used via position reports), or visually (for towers).

 

Again, ATC absolutely does accept the fact that the aircraft will fly at whatever speed is necessary. Note that in a route clearance, there is no explicit speed information (except that which is stated on charted SID/STARs.) Because the speeds of various aircraft are so diverse anyway, the controller is constantly adapting to the speed scenario that presents itself. Since the need to exceed 250/10 for heavies is primarily on departure, I'm isolating my discussion to that.

 

The three tools controllers have to separate aircraft are heading (to affect lateral separation), altitude (to affect vertical separation), and speed (to affect lateral separation - specifically related to compression along the same route). In your clearance you get only two of these listed:

"United 734, cleared to the Chicago O'Hare airport via the BUNZZ2 departure, RAMAY transition, as filed. [Maintain 3000. Expect FL380, 10 minutes after departure. Departure frequency 126.65.]* Squawk 5642."

*This information may or may not be stated in the clearance - depending on the controller - as this is stated on the chart.

 

From this clearance, we have two of those tools covered. The pilot has been assigned specific heading instructions: runway heading to 820 feet, then direct to a fix, then headings to various fixes on the SID (and their filed route thereafter). Altitude is also covered in the BUNZZ2 as 3000 initial, and the expectation of the filed altitude 10 min after departure. Nowhere in that clearance was speed addressed. As such, it is left at the discretion of the pilot to utilize the appropriate speed according to the AFM, while in compliance with the regs. Controllers will then issue vectors to establish a sequence, or maintain separation. Note that the BUNZZ2 SID actually states that it is turbojets only, which helps to minimize speed diversity.

 

The issue at hand here is that controllers are taught not to inhibit the speed of aircraft in critical phases of flight. Speed being the very thing that keeps the craft airborne, in addition to the fact that the departure profile is very much a speed-based procedure, the controller is taught to utilize all other means available before interfering with that.

 

While this means that ATC is not controlling the aircraft's speed, the controller is still capable of issuing a speed restriction, and is therefore still in positive control of the flight. Also note that, in many cases controllers will state "if able, maintain [speed, with "or greater/less" as appropriate]."

 

 

 

 

To everyone in opposition:

I'm not trying to taunt, insult, or take shots at anyone, but do you really want to throw down on this?

-The regs have been quoted - noting the 91.117d exemption, with the grey area

-Stated how the grey area is handled operationally (if you don't believe me, listen to MEMphis push heavies in the morning*)

-And addressed all of the other fringe issues raised in attempts to prove this idea wrong

 

*Listen for FDX1413 Heavy (first contact at 05:00 on that recording). If you look at the FlightAware data, it has the aircraft at 6,400 at 296 knots. While, yes, this is groundspeed, wind at that altitude this morning was calm, and the TAS to IAS conversion would have the indicated at about 264. Note that in the entire recording, FDX1413 - or any other heavy for that matter - request a speed higher than 250 a grand total of zero times. If you listen for a FDX5124 (304 GS at 5000 - TAS to IAS is about 276), you'll hear no request or approval for greater than 250.

 

I know you've grown up in the sim, and the sim and sim community have raised you under the idea that busting 250 under 10 would make you instantly burst into flame from the long arm of the law, but this is not true.

 

It's time you take the red pill. The blue pill only leads to blissful ignorance of reality.

 

Honestly Kyle, it is impossible to get this through to these guy's. Or at least get it into there heads about how it is done in the 'REAL' world... Standby for repeat postings of regulations, documents and how to do things 100% by the book

Honestly Kyle, it is impossible to get this through to these guy's. Or at least get it into there heads about how it is done in the 'REAL' world... Standby for repeat postings of regulations, documents and how to do things 100% by the book

 

haha - it's Friday.  My telcons are over, and most people aren't going to hit me up for much from now until the end of the day at work.

 

Game on.

This is not true Gerry. You're misapplying the concepts.

 

As you are by arguing from the particular to the general.

 

There are two types of speed limit - airspace and procedural.

 

Airspace Speed Limit

 

In the UK the law requires aircraft flying below FL100 to observe a speed limit of 250 KIAS. This  limit is an essential component of the 'see and avoid' principle when separation is not established by ATC. This 250KIAS speed limit does not apply to:

 

a) flights in Class A and B airspace;

 

B) IFR flights in Class C airspace; etc

 

Heathrow CTR is Class A airspace as is the LTMA above it, so the airspace speed limit of 250KIAS/FL100 doesn't apply.

 

Procedural Speed Control

 

Speed limits are published for specific ATC procedures for a number of reasons. For example:

 

a) A speed limit of 250KIAS is applied to published SID procedures to assist in the initial provision of separation between successive departing aircraft;

 

B) A speed limit of 250KIAS is applied to some STAR procedures to assist ATC in the integration of traffic flows; etc

 

All Heathrow SIDS have a procedural speed limit - Maximum Speed 250KIAS below FL100 - and departing aircraft may not exceed this unless it's explicitly relaxed by ATC. Controllers are advised to be very careful about relaxing speed limits because the controllers then become responsible for providing separation, controlled airspace containment, and obstacle clearance, which the carefully designed procedures are intended to provide.

 

 

 

 

As you are by arguing from the particular to the general.

 

Your earlier post left it up to interpretation as to where this was being applied.  I answered to the FAA angle just to clarify.  You may well be right for that side of the pond, but not on this side.

Are there no clearances/procedures with speed limits in the USA?

Are there no clearances/procedures with speed limits in the USA?

 

You'll see the occasional SID, which you'd comply with, or advise unable.  STARs for sure, but by that point even heavies are primarily able to comply with those restrictions.

 

To my knowledge, I don't know of a single facility that would issue a speed restriction in a clearance.  Again, issuing a restriction to departing traffic is highly frowned upon as it's predominantly unnecessary - vectors are more effective.

 

Heck, even in the most complex airspace in the world (the NY Area), they manage to avoid departure speed restrictions.  The fleet mix there is pretty diverse, too.

You'll see the occasional SID, which you'd comply with, or advise unable. STARs for sure, but by that point even heavies are primarily able to comply with those restrictions.

 

To my knowledge, I don't know of a single facility that would issue a speed restriction in a clearance

Not even when the clearance includes a SID with a speed limit?