High speed departing heavies.

[stormcloud]

Just wondering...

Do ATC require prior notice before start every time a heavy has a min clean speed above 250 kts on departure or is it generally accepted that they will be @ 260-270 kts?

If notice is required, would a company visit/chat with ATC management be ok to cover an operators schedlue?

Cheers.:ok:

[ZRH]

The pilot usually asks on freq if high speed is ok and it allways is.
Often you'll hear one of the ATC's clearing the aircraft for climb and approving high speed without it being asked for by the pilot.
It never is a problem and no high level meetings required. If you need it, just ask.
Happy flying

[055166k]

Many SIDs contain a speed limit of 250 knots; if you cannot accept such a clearance then tell ATC as you suggest. At a busy airport the departure sequence and spacing may need to be altered to accommodate the higher speed, particularly in a dense terminal environment. If this is a common operating characteristic of your aircraft then a chat to ATC ops would enable an advisory to be published internally to highlight and anticipate any request........possibly a special clearance or procedure protocol. ATC are here to help and not to hinder.

[FWA NATCA]

Storm,

The only time I haven't seen a departure exceeding 250 kts is when they aren't capable of going that fast. Lets see last week I had a departure doing 380 kts at 6000 ft.

Mike
NATCA FWA

[stormcloud]

Sounds good to me,
Bet he was'nt going for 12 hours & 300+ tonnes, but I like the idea!:cool:
Reason I ask is because there has been much discussion due to new type posing the problem for the first time in present company. :confused:
I seem to remember from my previous that we did'nt have to say anything, it had all been cleared before ( I think).
Any particular thoughts from Oz/USA on this one?
Cheers.:ok:

[Scott Voigt]

Stormcloud;

We expect that the pilot would tell us that he can not comply with the 250 knot rule. There is no automatic approval. As to Mike not seeing many heavies. Ya have to understand that where he works, there aren't many <G>...

regards

Scott

[MAKWALA]

Another solution consists of maintaining a slats config permitting 250KTs up to 10000ft

[West Coast]

Scott
As far as automatic approval, the crew of a heavy need not ask permission to exceed 250 KTS, they must simply advise ATC of such. No matter what ATC/DP or appropriate regs say, if the min manuevering speed is in excess of 250 as may be the case on some of the larger heavies, thats what they are going to fly.

[APP Radar]

Here (Lisbon, Portugal) is common to hear requests for "high speed climb" even for lighter aircrafts, mainly A320 family from Portuguese carrier but some times also from other companies but this has nothing to do with aircraft performance ...

However TAAG (DTA) B747's often request higher speed due height limitation.

When the request is due aircraft performance limitations ATC due expect that pilot normally advise tower before take-off clearance. This is also true when aircraft is unable to comply with any other SID restriction ...

Principle is "if unnable to comply advise ATC"

Eduardo Ascensão
Air Traffic Controller

[055166k]

In the UK there is a speed limit of 250knots below 10,000 when outside Controlled Airspace ; neither the pilot nor ATC have authority to lift or vary the restriction........military aircraft are exempt. In the last decade there has been a huge increase in the use of regional airports, and in the UK all the Controlled and regulated airspace is based around the major airport hubs of a quarter of a century ago. This leaves many airports [that have become quite busy] with little or no protected airspace and no linking structure into a less than ideal controlled airspace system. That is why in the UK a heavy can be restricted to 250 knots....it's not ATC, it's the regulations that are the problem.

[West Coast]

I should have said in the US. I am a bit surprised however. Aerodynamics are the same on both sides of the pond. If a 747 needs 280Kts for min manuevering over here, then it needs it over there also. Unless its weight restricted to make sure it complies, that however means lost revenue. The reg over here reads 250 below 10K. A bit further down an exemption exists that says if a speed in excess of 250Kts (or other airspeed restrictions) is required that the aircraft may be operated at that airspeed. Are you sure an exemption doesn't exist within your regulations?

[DFC]

The B747 and similar aircraft all have lift augmentation devices...flaps, slats etc.

Consequently, there is absolutely no normal reason why they can not fly and manoeuvere at speeds below 250Kt IAS.

Even holding speeds for such aircraft up to 20,000ft are below 250Kt except in turbulent conditions.

So, the B747 and similar aircraft are well capable of coping with a 250Kt restriction below 10,000 or FL100 as appropriate.

However, in the event of a failure/malfunction, there may be a requirement to fly clean (obstacle clearance requirements etc) which could require a speed above 250. This situation is allowed for in the regulations regardless of airspace.

That said, we all know that operating all the way to FL100 with flap/slats deployed is not very efficient.....so we try to avoid it and would like for ATC to help us operate as efficiently as possible. So we ask sooner rather than later so that ATC can make the appropriate arrangements.

250Kt is the limit for:

All flights in Class E,F and G airspace below FL100 and for all US aircraft (N regstered) below 10,000 where ever they are.

What must also be remembered is that SID and STAR speed limitations are mandatory to ensure that the aircraft remains within the protected airspace...........as an example, if the turn after departure is placarded max 220Kt, that is the maximum speed at which a rate 1 turn/ 25deg of bank will turn the aircraft while remaining within the procedure........if ATC say "no speed restriction" and one accelerates to 280Kt, will the turn at 280Kt and 25 deg bank remain within the protected airspace?.....I don't think so.

Regards,

DFC

[Scott Voigt]

West Coast;

What DFS said... There isn't an aircraft out there in civil service that can not fly below 250 KIAS. Now, that said, we can neither approve or disaprove the greater than 250knots. We do however need to know that they are going to do it... If they tell us that they are going to do it, we may inform them of the traffic ahead and that we are not able to approve the manuver. But then again it isn't that we are approving or disapproving. If the pilot sets the bell off with inappropriate separation then there will be a pilot deviation filed. Wheather or not Flight Standards does anything with it is another story.

regards

Scott

[Dan Winterland]

Yes, any aircraft should be able to cope with 250 knots or less under 10,000'. But the fuel penalty of climbing with flap to that height doesn't bear thinking about.

As a pilot of freighter 747's there is rarely an instance of when our V2+100 knts (clean minimum safety speed) is less than 250. But in my company, we always ask and a polite request rerely meets with an answer in the negative.

[Odlix]

Hi




My 2c.

Please bear in mind that the Wing Anti Ice systems in the 747-400 only work when the flaps are fully retracted, which may require by default a speed above 250 as discussed. The speed the 744 flies by default below 10´ is Vref30 plus 100 or 250 kt whichever is lower. However it is well possible to fly Vref30 plus 80 (equal to flap up maneuvering speed or Vmax angle) safely. Vref30 plus 80 will almost never exceed 250 kt (except near MTOW). Hope this is of some use.

Best regards

Sander van Bergen

[email protected]

[West Coast]

Scott
As described above some aircraft DO need a speed in excess of 250 Kts. It may not be often, but there are times its required. There is a reason that para D offers relief, not only for the other restrictions but for the 250Kt rule also. I am getting outside of my aircraft knowledge area as I am on the other end of the Boeing spectrum but some commenters who have flown it say there is on occaision a reason to exceed 250 blow 10. I will go with what the experts say.

[DFC]

My reading of the Para (c) of the relevant FAR is that there is an allowance for aircraft which are unable to fly safely at the required maximum speeds.

Retracting the flap and then saying that one is unable to fly at 250 Knots may indeed be common practice but looking at the question when at the opposite end of the flight;

We all know that we can expect speeds like 230, 210, 180 and 160 to 4nm from ATC when being vectored.

Now using the same principle as we used to get above 250Kt in the departure (we can't fly that slow clean and flying dirty wastes fuel) all we have to do is tell ATC well in advance that we require to maintain 280Kt to 20nm and then 250Kt to 15 and 210 to10 regardless of who is in front..........same logic but I bet no rational person would try it............and why not.....it has the exact same justification as the departure scenario!! :E ......Oh and we can never hold because with a min clean of 280Kt, we can't fit into the holding pattern so we just have to go straight in number 1 Horray :E :E

The UK has heavies operating to/from places like Teesside where they are in Class G shortly after departure.........no posibility of ging above 250Kt there so what do people do.........Ignore the airspace restriction most likely or more likely.....not be aware of what class they are in anyway.

I am off the design and aircraft that operates with the same cost base as a B737 but has a big placard on the pannel......minimum 260Kt in climbout!!........no need to worry aboput those speeds then!! :D

Regards,

DFC