Question about airspeed in class B?

[Sir Humpalot]

I understand that if one is below 10000ft, the limiting airspeed is not greater than 250knots. If a class B airspace extends over 10000ft (ie DEN), does the airspeed still have to be 250 or less?

The logic states that it is still in class Bravo and so the airspeed has to be less than 250 but i just wanted someones input on this one.

Any help appreciated.

 

[igneousy2]

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.

No special speed restrictions in Class B.

 

[liv'n_on_credit]

Class B

.....

 

[regionalcap]

Are you talking about being beneath Class B or inside Class B? He just quoted you an FAR.

 

[Lead Sled]

The last post is incorrect. Everyone knows that there is a 250 knot speed restriction inside class B. Yes, even though it is above 10,000 you are still in class B airspace (like at DEN), therefore you still limited to 250KIAS.

That's not quite correct. There are exceptions...

This very issue was discussed on one of the NBAA forums that I participate in awhile back. (It's only been that last few years that this has even come up for us bizjet types, we haven't had any aircraft where this was even an issue.) Several airline pilots chimed in and contributed to the discussion. The following quote was typical of what they all said: "...If your weight nets a required clean min speed above 250 kts below 10,000' you can accelerate to that speed, period. There is no requirement that you fly with flaps/slats out so you can stay below 250 or 200 kts below the lateral limits of Class B, etc." The bottom line is that the intent of 14 CFR 91.117 is not to force heavy jets to leave flaps/slats out to climb. They are expected to clean up and fly at clean MMS until 10000'.

For us, the issue was what about when we operate out of one of the airports that are underneath the lateral limits of CBA? There is a 200 KIAS limit in that airspace. The Gulfstream G-200, at higher takeoff weights, requires airspeeds of around 220 KIAS to retract the slats and Krueger flaps. Although I believed what the airline pilots were telling us, I also wanted to avoid the opportunity of having to spend "quality time" at the local FSDO so I contacted a good friend of mine who is an FAA inspector. I asked him the following specific question: "...is it necessary to maintain a configuration (slats and Kruger flaps deployed) that will allow the aircraft to comply with the 200 KIAS speed limit when operating beneath the lateral limits of Class B airspace or is it acceptable to fly the aircraft in the "clean" configuration even though the minimum safe airspeed in the clean configuration is above the 200 KIAS limit?" He refered the question to another inspector at another office, who sent me the following reply:

"...The FAR's do not prohibit that operation. Now that I have said that let me explain the finer points about working with ATC and the FAA.
1. If you are at a low altitude and exceed 200 or 250 there is a record made by ATC and ATC may question you. However your flight in question will end up as an
investigation at the FSDO. When you are contacted regarding the "possible fracture" of 91.117 and you tell them what you told me it will probably be closed with no action.

2. You have 2 choices (1) configure the airplane to maintain the speed limits or (2) fly clean at the higher speed.

3. If you maintain speed limits and configure the airplane to do so, no problem end of subject.

4. If you clean the airplane up and accelerate to the speed required be absolutely positive you tell ATC on each frequency you operate on the reasons for exceeding the speed limits while in the airspace discussed in 91.117. Remember ATC spaces aircraft distances based on speed. This should preclude a FSDO investigation.

If you read 91.117(d) it does not specify the aircraft configuration. All it says is "...any particular operation..."

The decision is yours. Hope this helps."

There are those who think that 91.117 (a) authorizes individual air traffic controllers to authorize deviations from the rule. NOT! ATC is NOT the "Administrator" and controllers can not authorize deviations. There is an ongoing "test" at IAH where the Administrator has authorized increased speed operations and controllers can and do ask you to pick up the speed.

There are some other exemptions, such as operational necessity & emergencies that allow you to deviate. Personally, I've deviated from the rule many times, back when I was a Life Flight pilot flying Citations and MU-2 air ambulances. When the flight nurse or physician told us to "step on it" that's exactly what we did. We just told ATC that we needed to keep our speed up. We'd keep the speed at the barber pole until it was necessary to start slowing down for landing. All the FSDO guys wanted from us was the usual deviation letter. I bet I filled a couple of dozen of those forms over a 3-year period.

Hope this helps clarify things.

Lead Sled

 

[NewBlue]

The last post is incorrect. Everyone knows that there is a 250 knot speed restriction inside class B.

Yes, even though it is above 10,000 you are still in class B airspace (like at DEN), therefore you still limited to 250KIAS.

Do you have the reference for this? I have tried unsuccessfully to find a regulatory reference for this. There used to be a restriction but I haven't seen it for a couple of years.

 

[prpjt]

Everyone knows that there is a 250 knot speed restriction inside class B.

I did not know that, please explain.

 

[minitour]

igneous guy has it right...

250 below 10k...no special restrictions for class b...

Class B is (supposed to be) set up for large traffic volume airports and is (supposed to be) from the surface up to 10k msl... obviously some are not...it just depends on the instrument approach procedures associated with the particular Class B airspace regarding how the airspace is set up...

for example...PIT is Class B from SFC up to 8,000...the airport elevatipon is 1204 so would it make sense to have another 9,000' of airspace for them? No 7,000' does just fine for the instrument procedures that are set up into PIT...

now for DEN...the elevation is 5431' so for them to go to 10,000' MSL wouldn't make sense either as that would only be another 4569' AGL...not very much space to set up instrument approaches with that much traffic coming in...so the set up their airspace to go higher for them (not sure on their cieling)

Its all in 91.117 (which was quoted already)...just like it says Class B airspace doesn't apply and aircraft are to abide by paragraph (a) [250 below 10,000 unless otherwise authorized by the administrator]...*edit* I'm assuming its in there like this so a big ol heavy doesn't have to stay at 200KIAS on departure until clear of that initial "surface area' of the airspace...thats just my assumption though

-mini

 

[liv'n_on_credit]

Correction

There used to be a restriction but I haven't seen it for a couple of years.

I stand corrected. I guess I need to update my books!

When I took my ATP written, there was a question in there about being in class B airspace and what the speed restriction was, and the answer was 250 knots. But on second thought, I think the airplane in the question was also below 10,000 feet.

After reading through the current FAR's, I agree with the last post.

 

[501261]

Wrong

The last post is incorrect. Everyone knows that there is a 250 knot speed restriction inside class B.

Yes, even though it is above 10,000 you are still in class B airspace (like at DEN), therefore you still limited to 250KIAS.

FAR 91.117 states 10,000' not Class B! Lots of people incorrectly assume that since most Class B's go up to 10,000' that's the reason for the speed limit.

In places like Denver and Atlanta it is common practice to accelerate to above 250 once above 10,000 and still within the Class B.

Here's an excerpt from a legal opinion dated 10/3/1993: "On September 16, 1993, the Airspace Reclassification Final Rule became effective. Under the provisions of this rule, TCA's are reclassified as Class B airspace areas. FAR Sec. 91.117(a) now states, "unless otherwise authorized by the Administrator (or by ATC in the case of operations in Class A or Class B airspace), no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 mph)." FAR Sec. 91.117(b) now states, "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 the primary airport of a Class C or Class D airport at an indicated airspeed of more than 200 knots (230 mph)." Under this regulatory scheme, it is now clear that the pilot operating in a Class B airspace area at and above 10,000 feet MSL is not subject to a 250 knot speed limitation."

 

[minitour]

I stand corrected. I guess I need to update my books!

When I took my ATP written, there was a question in there about being in class B airspace and what the speed restriction was, and the answer was 250 knots. But on second thought, I think the airplane in the question was also below 10,000 feet.

After reading through the current FAR's, I agree with the last post.

I'll admit that even I thought there was a 250KIAS limitation in Class B during my PVT stuff...

Then I started getting really close to the FAR/AIM in this Instrument crap and I've been probably reading too much of to much in this....

...oh well, at least the pages aren't sticking together like some people I know...

-mini

 

[English]

FAR 91.117 states 10,000' not Class B! Lots of people incorrectly assume that since most Class B's go up to 10,000' that's the reason for the speed limit.

In places like Denver and Atlanta it is common practice to accelerate to above 250 once above 10,000 and still within the Class B.

Here's an excerpt from a legal opinion dated 10/3/1993: "On September 16, 1993, the Airspace Reclassification Final Rule became effective. Under the provisions of this rule, TCA's are reclassified as Class B airspace areas. FAR Sec. 91.117(a) now states, "unless otherwise authorized by the Administrator (or by ATC in the case of operations in Class A or Class B airspace), no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 mph)." FAR Sec. 91.117(b) now states, "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 the primary airport of a Class C or Class D airport at an indicated airspeed of more than 200 knots (230 mph)." Under this regulatory scheme, it is now clear that the pilot operating in a Class B airspace area at and above 10,000 feet MSL is not subject to a 250 knot speed limitation."

So, let's make this a little more complicated (but not a lot).

Let's say you have class b airspace in Hawaii, where the 250 kts below 10,000 feet does not apply more than 12 miles offshore. So, inside the class b, from 20 miles until reaching 12 miles, below 10,000 feet, 350 knots all the way?

 

[Freight Dog]

So, let's make this a little more complicated (but not a lot).

Let's say you have class b airspace in Hawaii, where the 250 kts below 10,000 feet does not apply more than 12 miles offshore. So, inside the class b, from 20 miles until reaching 12 miles, below 10,000 feet, 350 knots all the way?

Gotta love cargo...

 

[igneousy2]

So, let's make this a little more complicated (but not a lot).

Let's say you have class b airspace in Hawaii, where the 250 kts below 10,000 feet does not apply more than 12 miles offshore. So, inside the class b, from 20 miles until reaching 12 miles, below 10,000 feet, 350 knots all the way?

I would say it's true, unfortunatelly you wouldn't get to do it very often unless you were going out of your way just to go fast. Most of the routes don't go that far offshore. You may be more than 12 miles from HNL but you aren't usually 12 miles off shore unless you are coming from directly south, but there is nothing directly south. I've heard that Hawaiian and Aloha have an exemption but I don't know that for sure. I do know that they routinely do 300knots indicated while being vectored for the 8L channel. When I'm doing 240 and the controller is telling Aloha that the traffic they are following (me) is 50 knots slower then I'm guessing they aren't following the 250 rule. Legaly or not...I don't know.



Later

 

[Vector4fun]

When I'm doing 240 and the controller is telling Aloha that the traffic they are following (me) is 50 knots slower then I'm guessing they aren't following the 250 rule.

Heck, you don't have to be in HNL to see that happen.....

 

[islandhopper]

I would say it's true, unfortunatelly you wouldn't get to do it very often unless you were going out of your way just to go fast. Most of the routes don't go that far offshore. You may be more than 12 miles from HNL but you aren't usually 12 miles off shore unless you are coming from directly south, but there is nothing directly south. I've heard that Hawaiian and Aloha have an exemption but I don't know that for sure. I do know that they routinely do 300knots indicated while being vectored for the 8L channel. When I'm doing 240 and the controller is telling Aloha that the traffic they are following (me) is 50 knots slower then I'm guessing they aren't following the 250 rule. Legaly or not...I don't know.

Later

There is no exemption. it is legal, when you're 12 miles off shore, you are in international airspace. Or outside the ADIZ, that might be it. One or the other or both. Throw your radar on next time you get the JULLE arrival and stick a 20 mile ring on it. If you do a JULLE arrival you are not 12 miles until just before coming abeam Diamond Head. If you get roped into the Koko Head arrival then your going for a drive.

On our International runs.. Straight south of Honolulu may only be the arrivals and departures for the few South Pacific runs. But don't forget we do many more arrivals into Maui from California every day. Those are straight out of the North. It is legal fly a descent profile at say 290 until 8K that works out to about 240 @ 12 miles.

On our inter-island runs.. Going into places like Kona and Lihue you can adjust your descent profile to take advantage of the rule and slow down later as you approach both airports from the deep blue.

We slow it down coming from Lihue to Honolulu as Kaena Point sticks out into our flight path and puts us in the 12 mile deal way out over the water still. Going into Maui you are over 10K while still over Lanai so we slow it down from Lanai into OGG. Coming into HNL from the East you need to slow down when the controller asks you to, or abeam Diamond Head. (12 miles) The controllers kind of expect you to keep a certain pace and if you slow at 10K way out closer to Lanai than Oahu they will often ask you to speed it up.

Remember, the airspace between HNL and OGG is traditionally the busyest, most congested run in the USA. Not any of the NE or SO Cal corridors. But PHX into So Cal was impossible some days. 250 the whole friggin way some days!

All in all I like the way things are in Hawaii. Go fast, keep it safe.

 

[English]

islandhopper,


Our ops manual has a statement restricting us to 250 knots within the class B. Not sure why, since it is not a FAR. So that's about 20 NM out of HNL.

 

[islandhopper]

islandhopper,


Our ops manual has a statement restricting us to 250 knots within the class B. Not sure why, since it is not a FAR. So that's about 20 NM out of HNL.

I dont have mine with me, does it say anything about the controllers authority?

 

[English]

Nope.

 

[Guitar Guy]

Here's the applicable FAR, 91.117 (from the FAA's own website):

§ 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.


Operations in Class B airspace are specifically addressed in para. (b) which states very clearly that Class B ops are governed by para. (a) - isn't that a nice bit of misdirection. That means that in Class B and below 10,000 ft. MSL, an aircraft is restricted to 250 KIAS. In Class B but at or above 10,000 ft. MSL, there is no 250 KIAS restriction. Of course, the caveat continued in para. (d) allows for speeds over 250 KIAS in Class B when operating below 10,000 ft. MSL.

I know that this question is sometimes asked in interviews, so it's a good one to know.