USA ATC Speed below 10,000 question

[Northbeach]

I would like to draw from your wisdom. A question came up on this mornings flight. Departing KSNA talking to departure controll somewhere around 6,000 MSL (well below 10,000 with a clearance to 16,000') I was told to maintain 280 KIAS when able.

I have a copy of FAR 91.117 (Aircraft speed in front of me). For the pilots reading this, I am not interested in a discussion of (d) minimum safe airspeed for any particular operation. Again for this discussion I am not interested in the speed requirements of super heavy 747s, A380s with a clean wing-seperate discussion. Those are all interesting but that is not what I am asking about here.

When Part 91 was rewritten I believe one of the changes had to do with FAR 91.117. If I am accelerating in a Boeing 737 NG below 10,000 and ATC tells me "maintain 280 KTS when able":

1. Does this controller expect me to accelerate to 280 below 10,000 as I am certainly capable of doing so.

2. When the controller tells me to "maintain 280 KIAS" have I been (FAR 91.117 (a) "authorized by the Administrator to operate an aircraft above 250 KIAS below 10,000.

For the record we climbed at 250 KIAS untill passing 10,000 MSL then accelerated to 280 KIAS.

Seems to me that during the "educational campaing" back in the early 80s following the rewrite of FAR 91, one of the changes was that ATC could authorize more than 250 KIAS below 10,000.

For you SoCal ATC folks; if I am cleared to 16,000 and at 6,000' climbing and you tell me to maintain 280 KIAS "when able" are you slowing me down above 10,000' (as I normally climb around 300 KIAS) or are you trying to get me to go faster now? Are you authorized to assign me a speed greater than 250 KIAS below 10,000 or not?

If you are authorized to assign me a speed of greater than 250 KIAS below 10,000' what is that clearance going to sound like?

a comment from a FAA attourney would be greatly appreciated. What exactly does FAR 91.117 mean when it says "unless otherwise authorized by the Administrator." References to case history would be appreciated as well.

SoCal ATC it's a pleasure working with you.

I am off to another flight, looking forward to my further education in a few hours when I check back.

Thanks for your time!

Respectfully,

Northbeach

[Somewhere In Time]

Hi Northbeach,

"maintain 280kias when able" =
I would interpret that as increase to 280 if below 10 and to not exceed 280 if above 10.
Whatever clearance ATC gives you, if there is no condition attached, then you are expected to oblige right away.

The actual phraseology for these instructions will vary alot from unit to unit as standard phraseology is still far from reality in the US..

Icao Annex 10 is worth a read ;)

[Northbeach]

Somewhereintime,

I will look up the ICAO annex you mentioned. Thanks for your time!

Still waiting for some SoCal ATC specialist to weigh in.

How about some FAA attorney...........

PM me if you would rather.

Thanks again for contributing to my continuing education..

Northbeach; just south of the Arctic circle tonight.

[Wino]

(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.).

That's the current wording.... The only exception to this rule in the continential US I was a test that was run around Houston for a while a few years back, exploring high speed departures...

Cheers
Wino

[Northbeach]

I’ll restate the question and try to be as clear as possible. In the United States; what constitutes “being authorized by the Administrator” to exceed 250 KIAS below 10,000?

If ATC issues me the following clearance “maintain 280 KIAS when able”, and I am below 10,000, have I been “authorized by the Administrator” to exceed 250 KIAS below 10,000?

Will somebody from SoCal ATC please explain what the ATC specialists wanted me to do when being at 6,000’ climbing in a 737 NG to an assigned altitude of 14,000 or 16,000 I was told to “maintain 280 (knots-airspeed not an altitude) when able”. Do you want me to fly 280 KIAS now (below 10,000) or do you want me to fly 280 once I am above 10,000? I am certainly able to do 280 kts NOW.

In the first case it would seem you are trying to put distance between me and the aircraft following (multiple departures off KSNA following the lifting of the AM curfew). In the second case it seems you are slowing me down (above 10,000)? If the concern was my speed above 10,000’ why not say something like “Don’t exceed 280 in the/your climb”?

So specifically after having received the “maintain 280 when able” clearance, what airspeed do you want me to indicate between my current altitude of 6,000’ and 10,000’?

I have a copy of 91.117 in front of me and am familiar with the vocabulary, however what does it mean? A response from a FAA attorney with case history would be greatly appreciated!

[5milesbaby]

Northbeach - if you don't get an answer from anyone from SoCal ATC here then give them a call and find out, best to be knowledgeable than guessing. Otherwise, next time you get a similar clearance then ask whether that is approval to accelerate at your current level or wait to 10,000', you certainly can't be wrong for ensuring you are doing correct in such a safety conscious environment and may highlight to the controller concerned their need for more preciseness in future.

Here in the UK we use the addition of "unless authorised by ATC" to that speed limitation, which I think is far more clearer. I would personally expect you to accelerate to 280kts at 6000' as long as your airframe permits this at that level.

[Blockla]

My guess is if in Class E airspace, which is most likely, then the 250K IAS limit would always apply below A100. But as 5miles says, nothing like a phone call to clear it up.

[Wino]

Northbeach.

ATC is not the administrator... By the Administrator, they mean the head of the FAA.


Basically this referrs to one off events with special permits. (IE record setting flights, etc...)


Cheers
Wino

[Northbeach]

Wino, that's helpful thanks. I have a call into SoCal approach on the "land line".

[West Coast]

To amplify what Wino said...

Look elsewhere in part 91, they mention that ATC and not the administrator can waive certain speed restrictions. ATC is most definitely not the administrator.

[NuGuy]

To answer the OPs question:

In the US, a clearance to "maintain 280 kts when able" means that you must remain at 250 kts or below until 10k, then accelerate to 280 kts when above 10k.

The 250 kts below 10k speed limit is implied in all US ATC clearances. ATC cannot issue a waiver for this, and they are expecting you to maintain 250 or less below 10k. Obviously in an emergency you can do what you need to do.

On occasion, you will be issued a clearance such as "leaving 10,000, maintain 250". This simply means they want you to maintain 250 and not accelerate to your normal cruise climb airspeed.

As with all rules, there are exceptions. In this case, if you are more than 12nm off shore (outside US Territorial airspace), ATC can ask you do exceed 250 below 10k.

No need for an FAA attorney...this is the way it is, and has been in my 20+ years of flying.

Nu

[411A]

The 250 kts below 10k speed limit is implied in all US ATC clearances. ATC cannot issue a waiver for this, and they are expecting you to maintain 250 or less below 10k.

One hundred percent correct.
ATC cannot change the rules.
If SOCAL state otherwise, they are full of baloney.

[galaxy flyer]

I can't believe this is a question--it has been settled law that the controller CANNOT waive the rule since it went into effect in 1970-something. Only an aircraft limitation overrules it.

GF

[IVectorU]

This is true, we can't and won't waive the 250 knots below 10,000 limit. The reason these instructions sound like that is most likely that ATC anticipate not being able to get back to you and issue the speed when you are out of 10,000 and want to catch you before you left 10,000.

Now, I do want to mention that the clearance may sound confusing and the controller issuing it should have foreseen it. The correct way by our bible, 7110.65, would be 'Leaving 10,000, increase speed and maintain 280 knots' that way there is not a single reason to question it:8