Speed Limit under Class Bravo

[PC12Cowboy]

mini...who did your spin ride??

 

[HMR]

Mini- If you're so worried about busting 200kts in the 172 during the checkride just back it off a little bit to 1700rpm or so.

 

[Lead Sled]

Mini- If you're so worried about busting 200kts in the 172 during the checkride just back it off a little bit to 1700rpm or so.

HMR...
It was his commercial checkride so it must have been a 172RG, hence the concern over busting the 200 kt speed limit.



'Sled

 

[j41driver]

The maximum airspeed underlying class B is 200 knots or clean maneuvering speed whichever is lower. In an MD-80, that can be 250 knots; 230 knots in a heavy 737. They don't expect you to keep flaps out to make this restriction.

Good call...I had forgotten about that. Mostly since I haven't flown anything that couldn't do 200 kts clean.

 

[English]

I don't think minitour is going to have to worry about speeds in an MD-80 or a 737 for a few more months...

 

[Mr. Irrelevant]

Mini,

In faster and more complex aircraft, you may very well have a MFD that depicts airspace and without going into detail on how you use it, I will say you can use the MFD to find out the floor of the class B you're in or near. PHX767 mentions PDK and the high floor out there. Yah, it's 6000 and I was at 5000 last week when ATC queried our speed and the Captain was going 215. A few guys here said they will tell you when to slow down or when you're under Class B but that is absolutely untrue. The best piece of advice besides just slowing to 200 whenever you think you may go under class B is what English and PHX767 told you, correct reponse to ATC asking is "200"!

Needless to say, every other trip to PDK last week, we were at 200 or less at least five minutes out from the class B. Better safe than sorry.

Mr. I.

 

[NJA Capt]

In faster and more complex aircraft, you may very well have a MFD that depicts airspace...

Yea, I wish! I have flown with Primus 2000 (Citation X), as well as P1000 systems, and neither depict special use airspace on MFDs. A pretty big oversight in my opinion. On the other hand, every handheld GPS these days has it, as do most small GA aircraft. Is that backwards or what?!?!

So don't get used to using those G530s while training.....the jet you move into probably won't have it. It's back to using "paper."

 

[Bandit60]

Whoa, Whoa, Whoa.

There is a very big caveat to this rule. The maximum airspeed underlying class B is 200 knots or clean maneuvering speed whichever is lower. In an MD-80, that can be 250 knots; 230 knots in a heavy 737. They don't expect you to keep flaps out to make this restriction.

I don't understand your argument. According to your statement "the max airspeed underlying class B is 200kts or clean maneuvering speed whichever is lower", then if the clean maneuvering speed is 230 or 250 then the 200kts is lower so therefore you must maintain 200.

Where did you find this because this could affect some bizjets as well? I dont remember seeing it in the regs but I could have missed it.

 

[HMR]

I don't understand your argument. According to your statement "the max airspeed underlying class B is 200kts or clean maneuvering speed whichever is lower", then if the clean maneuvering speed is 230 or 250 then the 200kts is lower so therefore you must maintain 200.

I think he meant "whichever is higher".

 

[Lead Sled]

I don't understand your argument. According to your statement "the max airspeed underlying class B is 200kts or clean maneuvering speed whichever is lower", then if the clean maneuvering speed is 230 or 250 then the 200kts is lower so therefore you must maintain 200. Where did you find this because this could affect some bizjets as well? I dont remember seeing it in the regs but I could have missed it.

Bandit60...
You are correct, it does affect certain bizjets. 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. Bottom line is this - if your weight nets a required clean minimum speed above 250 kts below 10,000' or above 200 kts when operating below the lateral limits if Class B Airspace, you can accelerate to that speed - period. The intent of 14 CFR 91.117 is not to force turbojets to leave flaps/slats out to climb. There is no requirement that you fly with flaps/slats out so you can meet the speed restrictions. You are expected to clean up and fly at clean MMS until 10000'.

I'm typed in the Gulfstream G-200 and at higher takeoff weights, it requires airspeeds of around 220 kias to retract the slats and Krueger flaps. Since I had never encountered the need to climb faster than 200 knot inorder to clean up the airplane I wanted to make sure that I avoided the need to spend some "quality, one on one time" with one of the local feds. 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 knot 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."

Here's another thing to be aware of. 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 was a "test" at IAH where the Administrator authorized increased speed operations and controllers did 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 over a 3-year period.

Hope this helps clarify things.

'Sled