91.117 question. Aircraft speed below class B

DE727UPS

DE727UPS

Well-Known Member
Came up today in a brief before a 757 sim about speed limits below class B airspace. The example was westbound out of Long Beach with an altitude clearance that is below the floor of LAX B airspace. Was told you have to stay at flaps 5 and no more than 200 knots until entering B airspace vertically or leaving it laterally. I had heard about the 200 knot limit within D airspace but this was a new one.

Came up with a paragraph in 91.117 that seems to support the agrument that you must stay below 200 knots but it seems funny the way they word it:

(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).

"No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport..."

Why would there be class B designated for something other than an airport? I guess it's just the way they are saying it that makes me wondering if I'm understanding fully. Not sure if this speed limit applies to all aircraft or just aircraft operating into the primary airport?

Also, if the weather is less than 800 and 2, is it ATC's responsibility to have you hold short of the ILS critical area? or your responsibility to know the weather and know you have to stop short of it? I heard a crew got yelled at by ATC for not holding short of the critical area with less than 800 and 2 when they were told "taxi to the runway". ATC didn't say "hold short of the ILS critical area". I think that is an ATC mistake.
 
Here is another wrench to throw in...from the ATP written

Large turbine-powered airplanes operating to or from a primary airport in Class B airspace must operate above the floor of the Class B airspace when within the lateral limits of the Class B airspace.
 
I think that one only applies when you are operating into the primary airport of that B airspace.

I've been doing a lot of research and, to everyone else, it seems to be pretty common knowledge that you can't exceed 200 below a class B. Guess I just missed this one somewhere along the line. It still seems a little wierd to me the way 91.117 (c) says "class B designated for an airport"....why not just say "class B" in that sentence and I wouldn't have questioned it.

I'm going to go have a beer now.....
 
Im havent seen class Bs, but i have seen Class E's that have no airport that they are classifying, maybe thats what theyre getting at. Who knows!? Dern Lawyers.
 
As stated above...

From the regs.

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).
 
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It still seems a little wierd to me the way 91.117 (c) says "class B designated for an airport"....why not just say "class B"


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Because this is the FAA we're talking about. They're not about to make it easy on us. We've got to think until it hurts or it dosn't count.
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Makes it nice to be exempt from 14 CFR 91.117, which is what we are allowed to do under 117(d), since our aircraft ops manuals (Dash-1) have limitations imposed.

DE727, I would think that in an airplane where you have to begin lowering lift devices, like flaps, in order to comply with this part, why wouldn't you then have an exemption under (d)?
 
I'm not a 757 pilot, but I believe normal takeoff settings are at least flaps 5 if not greater (for some reason I'm thinking 15 or 20 is normal, but it has been a long time since I rode in the pointy end of one). So you're not really "lowering" high lift devices, you're just delaying cleaning up the airplane. No different really than a speed restriction on a SID that limits you to speed "X" until a certain position or altitude (generally to protect airspace). So, I'm not sure a 117(d) exception would apply in this case.

DE, will the 757 do 200 or less clean or do you need flaps 5 for an acceptable margin over stall?
 
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I'm not a 757 pilot, but I believe normal takeoff settings are at least flaps 5 if not greater (for some reason I'm thinking 15 or 20 is normal, but it has been a long time since I rode in the pointy end of one). So you're not really "lowering" high lift devices, you're just delaying cleaning up the airplane. No different really than a speed restriction on a SID that limits you to speed "X" until a certain position or altitude (generally to protect airspace). So, I'm not sure a 117(d) exception would apply in this case.

DE, will the 757 do 200 or less clean or do you need flaps 5 for an acceptable margin over stall?

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Yeah. I wasn't considering takeoff portion of flight, I was thinking more of transitioning under the "wedding cake". Something I do, something I doubt airliners would.

Wonder why 200 anyway?
 
You'd have to be pretty light for clean manueuvering speed to be 200 knots. We could fly around all day at flaps 5 and keep the speed down, so I guess that's what you have to do. I think the feds would say that if you have the capability to use flaps and fly slow...then you have to comply with the reg. No, it wouldn't be safe to fly clean at 200 knots but we can always put the flaps down.
 
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(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).

"No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport..."

Why would there be class B designated for something other than an airport? I guess it's just the way they are saying it that makes me wondering if I'm understanding fully.

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I'm not sure that's the correct interpretation of that sentence (not that the legalese it's written in helps matters). To my reading, the phrase "designated for an airport" is a property of "the airspace underlying", not of "a Class B airspace area". Which is to say, my read is that you may not exceed 200 kts within airspace designated for an airport (i.,e., Class C, D or E) that also happens to underlie Class B airspace.
 
Well, I'm studying for the Comm written, and this is pretty much a question straight out of the Gleim. 200 kts below class B, UNLESS your minumum safe airspeed is higher. Then operate at that speed.
 
I think this is a great example of a pilot who has been flying professionally for 10+ years, and still learning something new everyday!

I think the FAA just have a funny way of wording things to make them more complicated then they need to be! If you look too much deeper for a reason, it will start to get even more confusing!

Are you getting command on the 757? Could you bid it? Are you going to be based out of ONT? If so mate, we have to hang out before I leave again!
 
"I think this is a great example of a pilot who has been flying professionally for 10+ years, and still learning something new everyday!"

Amen to that. What's weird is that it was a pretty common practice while I was doing the YVR-BFI trips to come screaming in to the outer marker on the 13R localizer at the GSIA....800 feet below the floor of class B. Never had another crewmember or ATC say a thing about it.

I'm going for the F/O seat cause it's a new airplane to me and I want to get it down before I upgrade....having never flown high tech autopilots, FMC's, or real glass. I'll be very senior in my seat and should be able to do day trips out of my home town to Dallas and back....if I'm lucky, I might be able to get away with working 9 days out of 28...doesn't get any better than that at UPS.
 
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Quote:
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(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).

"No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport..."

Why would there be class B designated for something other than an airport? I guess it's just the way they are saying it that makes me wondering if I'm understanding fully.


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I'm not sure that's the correct interpretation of that sentence (not that the legalese it's written in helps matters). To my reading, the phrase "designated for an airport" is a property of "the airspace underlying", not of "a Class B airspace area". Which is to say, my read is that you may not exceed 200 kts within airspace designated for an airport (i.,e., Class C, D or E) that also happens to underlie Class B airspace.



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Exactly!
 
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Also, if the weather is less than 800 and 2, is it ATC's responsibility to have you hold short of the ILS critical area? or your responsibility to know the weather and know you have to stop short of it? I heard a crew got yelled at by ATC for not holding short of the critical area with less than 800 and 2 when they were told "taxi to the runway". ATC didn't say "hold short of the ILS critical area". I think that is an ATC mistake.

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It seems to be ATC's responsibility from this AC, but I've seen it argued both ways.

REFERENCE-
AC150/5340-1, Standards for Airport Markings.

3-7-5. PRECISION APPROACH CRITICAL AREA

a. ILS critical area dimensions are described in FAAO 6750.16, Siting Criteria for Instrument Landing Systems. Aircraft and vehicle access to the ILS/MLS critical area must be controlled to ensure the integrity of ILS/MLS course signals whenever conditions are less than reported ceiling 800 feet or visibility less than 2 miles. Do not authorize vehicles/aircraft to operate in or over the critical area, except as specified in subpara a1, whenever an arriving aircraft is inside the ILS outer marker (OM) or the fix used in lieu of the OM unless the arriving aircraft has reported the runway in sight or is circling to land on another runway.

PHRASEOLOGY-
HOLD SHORT OF (runway) ILS/MLS CRITICAL AREA.

1. LOCALIZER CRITICAL AREA

(a) Do not authorize vehicle or aircraft operations in or over the area when an arriving aircraft is inside the ILS OM or the fix used in lieu of the OM when conditions are less than reported ceiling 800 feet or visibility less than
2 miles, except:

(1) A preceding arriving aircraft on the same or another runway that passes over or through the area while landing or exiting the runway.

(2) A preceding departing aircraft or missed approach on the same or another runway that passes through or over the area.

(b) In addition to subpara a1(a), do not authorize vehicles or aircraft operations in or over the area when an arriving aircraft is inside the middle marker when conditions are less than reported ceiling 200 feet or RVR 2,000 feet.

2. GLIDESLOPE CRITICAL AREA. Do not authorize vehicles or aircraft operations in or over the area when an arriving aircraft is inside the ILS OM or the fix used in lieu of the OM unless the arriving aircraft has reported the runway in sight or is circling to land on another runway when conditions are less than reported ceiling 800 feet or visibility less than 2 miles.

b. Air carriers commonly conduct "coupled" or "autoland" operations to satisfy maintenance, training, or reliability program requirements. Promptly issue an advisory if the critical area will not be protected when an arriving aircraft advises that a "coupled," "CATIII," "autoland," or similar type approach will be conducted and the weather is reported ceiling of 800 feet or more, and the visibility is 2 miles or more.

PHRASEOLOGY-
ILS/MLS CRITICAL AREA NOT PROTECTED.

c. The Department of Defense (DOD) is authorized to define criteria for protection of precision approach critical areas at military controlled airports. This protection is provided to all aircraft operating at that military controlled airport. Waiver authority for DOD precision approach critical area criteria rests with the appropriate military authority.

NOTE-
Signs and markings are installed by the airport operator to define the ILS/MLS critical area. No point along the longitudinal axis of the aircraft is permitted past the hold line for holding purposes. The operator is responsible to properly position the aircraft, vehicle, or equipment at the appropriate hold line/sign or designated point. The requirements in para 3-1-12, Visually Scanning Runways, remain valid as appropriate.
 
Yeah...this is word for word out of the 7110.65. This is what I used to defend my position that it's ATC's responsibility. Other than the usual "the pilot is just responsible for everything", I'd like to see what would back up a warning letter given to a crew who was not told to hold short of the critical area.
 
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