Exceeding 250kts below 10000

[Singlecoil]

Hmm. I spend just about all my time commuting on Alaska Airlines, and they specifically tell you that GPS units, cell phones, etc are prohibited at all times. It says so in their magazine as well. Maybe other carriers aren't so uptight about the things, I don't know.

At any rate, I still take exception with your characterization of rampant speeding below ten thousand. You are certainly allowed +- 10 knots, but I've never seen anyone willfully violate that in the U.S. The main reason being that if you speed, you are mucking up the flow of traffic. You'll be closing in on the guy ahead of you, or closing a hole in the airspace that ATC had planned for someone else. They will know immediately if you are closing in on the airplane ahead of you and they will immediately know why. Its equally bad to fly too slow in the terminal environment, ATC will then have to ask you what your deal is, then slow everybody behind you down. It literally takes only one airplane to do this, to cause enroute delays and call for release to be invoked.

 

[PeteCO]

Well, I thought they maybe were uptight about someone knowing exactly where a plane was, since I doubt there is any issue with interference. Seems like either security issues or senseless bureaucracy. Or am I being redundant?

I fly alot late at night, and it seems that this is when I hear these guys talk about 320 knots or so at 8 and 9 thousand. These are indicated speeds. Maybe it doesn't happen as often as I think, but it does happen, and there seems to be an unspoken rule that if the controller is ok with it, then no one cares.

I've never been asked to slow down in the Archer though......

 

[avbug]

Pete, I'm in and out of Denver a lot, and I've never once heard something like that. Nor in Chicago. You're probably listening to heading assignments, or confusing what you're hearing.

I'll be the first to admit that my speed may not be an exact 250 at ten grand...sometimes perhaps 260 and slowing...but it will be close.

No professional crew is going to be stupid enough to inadvertantly be carrying 70 or 100 knots over the limiting airspeed, and certainly not in a busy terminal area.

The speed restriction is nothing like failing to obey limits on the highway. 250 knots isn't just for traffic, it's also for birdsrike considerations. Many aircraft have that as a limitation as well...just for the same reason.

ATC doesn't have the authority to waive the 250 knot speed restriction, except as posted previously for the HOU area.

As for special medical authorizations to exceed 250, there's little point. I suspect the authorization that occured in the Chicago are was a heading, not knots. I've certainly never had the need to push the speed up above 250, even with a critical patient on board. In fact, a medical crew should have no interest in the patient; only in flying the airplane. A medical crew doesn't, or should not, do anything based on the condition of the patient. The crew should be kept out of the loop and should make safety of flight decisions based on the safety of flight...not on the patient.

Pushing that speed for a short time in terminal airspace and at low altitudes saves nothing, but increases risk exponentially. Further, ATC can't authorize it. If one does happen to receive such an "authorization," don't hang your hat on it when it comes to enforcement action, because ATC was never authorized to make that call. You're required to know this, and you'll be held accountable for the same. Something to think about.

 

[regionalcap]

By the way, some companies allow GPS units to be used by passengers as long as it is a receiver only.

 

[501261]

Pete I think your way off base here. Everybody does 250 or close to it below 10. Listen to the other people on the board here; we're not going to risk a violation by exceeding 250kts below 10,000.

Here's what I think is happening on your flights. You stated you do a lot of Chicago to Denver flights. Well coming into Denver you'll be on the Sayge (or Landr) arrival. There is a speed restriction of "Expect to cross" Sagye at 250. Well guess what, expect to cross is just that, they can give you no speed limit, 310, 280 or anything else. You will have to cross Sayge at FL190 though. Sayge is where Denver approach takes control from Denver Center, so this is where you might hear guys on the radio being told slow to 280 or so. But guess what no FAR has been broken here since all the traffic is still above 10,000MSL (remember, thats only 4000 AGl in the Denver area). Coming into Denver you don't generally get below 10 until they put you on that wide base, which is generally when you start slowing down and configuring the airplane.

Pete, remember 1, there is no speed limit within Class B (its 250 below 10). 2, at 10,000' an indicated airspeed of 250kts will give you a TAS of about 300kts. 3, in Denver you don't go below 10,000 until you're about a 10 mile final.

 

[501261]

Uh, I am aware of the altitude of the planes in question, and when I say I am in the Class B I mean that I am flying in the Class B, and hear these radio calls, which I am quite sure I am not misinterpreting. I am relying more on my experience in the Denver Class B than by my GPS observations on commercial flights, and I am aware of the difference between TAS and IAS.

Just to reemphasize, there is no speed limit within Class B! Here’s where I think you are being confused, you’re following the flight on your GPS and it shows you squarely inside the Class B! Well guess what unless they’re below 10,000MSL there’s no violation.

Another thing, if you’re getting your perceived altitude from the GPS unit, its way off! Remember the GPS unit will show True Altitude. Well, that can be as very much off the indicated altitude which incorporates altimeter setting and static error.

 

[JungleJetFO]

questions

First, I fly military out of San Diego and they allow us to fly greater than 250 KIAS below 10K almost every time we ask. We fly by the same rules pretty much as civilian when it comes to IFR. Is Socal violating rules when they do this?

Second, do you notice that ATC has to ask what our airspeed is when they are trying to manage flow? If that's the case, can I assume they can't tell how fast we are going? And thus, cannot violate you for speeding? Not that I plan to blow through anywhere at 350 KIAS but why does everyone act like they are going to get violated if they are still going 265 KIAS when they descend out of 10K?

 

[varicam]

Re: questions

First, I fly military out of San Diego and they allow us to fly greater than 250 KIAS below 10K almost every time we ask. We fly by the same rules pretty much as civilian when it comes to IFR. Is Socal violating rules when they do this?

Second, do you notice that ATC has to ask what our airspeed is when they are trying to manage flow? If that's the case, can I assume they can't tell how fast we are going? And thus, cannot violate you for speeding? Not that I plan to blow through anywhere at 350 KIAS but why does everyone act like they are going to get violated if they are still going 265 KIAS when they descend out of 10K?

There's a clause in the regulations that allows 250 to be exceeded if required for the safe operation of the aircraft in question. Since the controller isn't going to second-guess the pilot unless he/she is certain safety isn't involved, a request for higher speed will probably not raise an objection. (Unless you're in Houston, it won't be approved, as the controller doesn't have approval authority).

Controllers have a read out of ground speed. When they ask for IAS they're usually giving you a hint that they suspect you're not at the required or assigned speed. But, they might be trying to determine the IAS that produces the indicated groundspeed. 265 knots probably won't get you a violation. However, if you cause a screw up in sequencing, all bets are off. It's pretty easy to reconstruct a flight from radar data and come up with an accurate IAS.

 

[501261]

Re: questions

First, I fly military out of San Diego and they allow us to fly greater than 250 KIAS below 10K almost every time we ask. We fly by the same rules pretty much as civilian when it comes to IFR. Is Socal violating rules when they do this?

First, if your out over the water you can go whatever speed you want.

Secondly the DoD has an exception to FAR 91.117 that is used pretty frequently:

The Department of Defense's (DoD's) Flight Information Publication General Planning GP, Section E-Supplementary Information, Para 5-35, "Aircraft Speed Below 10,000 Feet Mean Sea Level" states:

"(Exemption to Federal Air Regulations 91.177 issued to DOD, May 18, 1978)-Operations below 10,000 feet Mean Sea Level at Indicated Air Speed in excess of 250 knots, in noncompliance with Federal Air Regulations 91.117 (a), are authorized for military aircraft, including Reserve and Air National Guard components, only under the following conditions:...

"g. If the airspeed required or recommended in the airplane flight manual to maintain safe maneuverability is greater than the maximum speed described in Federal Air regulations 91.117, the airplane may be operated at that speed."

The F-16C/D flight manual, in Section VI, "Flight Characteristics," recommends "a minimum of 300 knots during normal cruise operation below 10,000 MSL." The Air Force Instruction 11-2f-16, F-16 Operations Procedures states in Chapter 5, "Air to Air Weapons Employment," Para 5.3.2, that the "minimum airspeed during low altitude offensive or defensive maneuvering is 350 KIAS."

 

[JungleJetFO]

Re: Re: questions

First, if your out over the water you can go whatever speed you want.

Secondly the DoD has an exception to FAR 91.117 that is used pretty frequently:

The Department of Defense's (DoD's) Flight Information Publication General Planning GP, Section E-Supplementary Information, Para 5-35, "Aircraft Speed Below 10,000 Feet Mean Sea Level" states:

"(Exemption to Federal Air Regulations 91.177 issued to DOD, May 18, 1978)-Operations below 10,000 feet Mean Sea Level at Indicated Air Speed in excess of 250 knots, in noncompliance with Federal Air Regulations 91.117 (a), are authorized for military aircraft, including Reserve and Air National Guard components, only under the following conditions:...

"g. If the airspeed required or recommended in the airplane flight manual to maintain safe maneuverability is greater than the maximum speed described in Federal Air regulations 91.117, the airplane may be operated at that speed."

Thanks for the responses. As far as over water, I believe that is outside of 12 miles but I'm flying back from over water into Class B where airspeed rules for below 10K apply. So it seems to be, Socal is inadvertently breaking the rules when allowing us to stay fast.
And for aircraft type, I fly in the S-3B and the only speed waiver we have is being allowed to come into the overhead break at greater than 250. Usually we accelerate to whatever airspeed we can achieve in the 5 miles from the initial point to the numbers of the runway.