250kt under 10k restriction. Any RW controllers out there?

[Fatback 84]

I'm having a problem with my PMDG 747 busting the 250kt speed restriction. The AP is reducing thrust and raising the pitch in an attempt to meet it but many times seems to bust it by a few kts before settling back to 250kts. My question for controllers is whether this is acceptable or common in the RW. Thanks!

[bic 44]

Not a problem.

 

Several years ago they were actually testing something like 280 under 10k.  And from what I remember one controller said he really didn't care and would as needed tell you a speed to maintain.  Granted intercepting a localiser becomes much more difficult, so you'd probably want a better speed by then. 

[Ponk 51]

No big deal if it´s only a few kts.  Maybe you just have to plan your descent a little earlier, or put some restriction in before 10´000ft to be sure.  In real world, at least in Europe, the speed restriction is much higher under 10´000ft unless the airspace is very busy, same for the departure phase.

[Fatback 84]

This on departure. I know that if a 747 if fully loaded you can get clearance many times to exceed 250kts because your minimum clean manouvering speed is higher than 250kts. Otherwise you'd have to keep some flaps engaged until you reached 10k. But in a relatively light 747 that doesn't "need" to exceed 250kts is it ok and/or common to exceed it by just a few knots when ascending? 

[FLEX1978 373]

Yes, perfectly normal and acceptable.

[ryanbatc 12,836]

In busy airspaces they might care but it's hard to notice a deviation of your IAS.  What we see on the radar is ground speed (essentially your true air speed with wind correction)..

 

There's no way they'd really notice a few kts here and there...

 

Where I work (not busy airspace), pilots bust the 250 kt rule all the time.  We don't mind, get's them in faster.

[Fatback 84]

What would the airline itself think? All airline aircraft now have data recorders that the airline monitors and an overspeed below 10k would surely trigger an alert of some kind. Would the airline worry about a small overspeed? However small, it is still a breach of regulation. 

[FLEX1978 373]

Yes the data is recorded however it is not going to be flagged because it is not a big deal. Airlines come down hard on altitude busts, not meeting stable approach criteria, reasons for a missed approach, things that are actually dangerous, not going over 250kts indicated by a few kts whilst on the SID or STAR.

 

As mentioned above, ATC normally want you out of there airspace as quickly as possible and will often give you high speed if available. If they want you at 250kts IAS 220kts or whatever speed just do your best to keep within that range.

 

Next time you are flying the STAR at exactly 250kts Indicated take a look at your ground speed and TAS on the ND, you are not actually flying 250kts

[jerry allen 3]

Contrary to a very widely held opinion, ATC in the United States is not authorized to waive the 250-knot limit below 10,000 feet. Apart from special conditions, flights that wish to exceed this limit (as for airshows) must obtain a waiver directly from the FAA for the flight, the event, or the facility. The military has a standing waiver from the FAA for certain flights under certain conditions.

 

What you hear of may be the deleting of a Departure speed restriction, or even a STAR restriction when traffic is light.  IF ATC in the US is allowing non authorized aircraft to violate the 250 kt rule, then they too are in violation.

 

The ATC facility and pilot may find themselves explaining "why". 

 

[FLEX1978 373]

Yeah this gets discussed to death all over the Internet. Simple fact is thousands of heavy commercial aircraft depart US airfields with a gross weight that gives them a minimum clean speed above 250kts, they are not keeping slats and flaps out all the way up to 10k.

[ryanbatc 12,836]

Contrary to a very widely held opinion, ATC in the United States is not authorized to waive the 250-knot limit below 10,000 feet. Apart from special conditions, flights that wish to exceed this limit (as for airshows) must obtain a waiver directly from the FAA for the flight, the event, or the facility. The military has a standing waiver from the FAA for certain flights under certain conditions.

 

What you hear of may be the deleting of a Departure speed restriction, or even a STAR restriction when traffic is light. IF ATC in the US is allowing non authorized aircraft to violate the 250 kt rule, then they too are in violation.

 

The ATC facility and pilot may find themselves explaining "why".

 

 

This is all good theory and I agree with you... But the practical side and what really happens is different to your post here.

[Airbus Commander 563]

All I can say is that there's plenty of aircraft that break that limit out there. Most of the time you can just fly either "free speed" or "280 knots" depending on the day, if they want you slower they'll tell you, and no pilot is going to keep the flaps and slats out to 10,000' just because of the 250 below 10 rule.

 

Regards,

Ró.

[jerry allen 3]

Well, it's not theory, it's an FAA rule.  You must maintain your assigned, or obligatory speed within 10 kts or face a possible violation.

[Airbus Commander 563]

Well all I'll say is practically every pilot who's flown a heavy jet out of the states has a violation then, those  of us who've been flying out of there for years will have hundreds.

 

The phrase: "It's the spirit of the rule, not the rule itself that counts" comes to mind here.

 

Regards,
Ró.

[FLEX1978 373]

Well, it's not theory, it's an FAA rule. You must maintain your assigned, or obligatory speed within 10 kts or face a possible violation.

Hey Jerry, we get what your saying regarding the rule. Do you think the bulk of all these heavy jets departing US airfields as we type are not flying their clean speed? Do you think they keep their slats out to maintain 250kts? Just curious.