View Full Version : JMC 250Kts Below FL100

Major Cong
24th Jun 2001, 13:49
Why do JMC insist on 250Kts below FL100? The rest of us are prevented from flying high speed descents because of the JMC log jam ahead. Yesterday an ATC request to maintain 280Kts for sequencing was politely refused causing ATC problems. I know SOP’s Are SOP’s but I think this one needs changing.

24th Jun 2001, 13:59
At easyJet we also have a SOP for 250kts below FL100. However, we can exceed it at ATC's request.

24th Jun 2001, 14:08
Major Cong, did this occur outside of controlled airspace? I'm sure you are aware that 250 below 10 is mandatory outside of CAS. Although there is always the temptation to wind it up when someone is behind us. Some ATC units will waive the speed restriction when they do not have the right to.

In my company, the descent profile is normally designed with 250/100 but if circumstances require it, there is nothing to stop us exceeding it legally (although the little birdies hitting the windscreen at 314kts are reckoned to a bit more dangerous than their slower friends).

November Kilo
24th Jun 2001, 14:27
Major Cong

JMC seem to have the same SOP as easyJet. You were probably just unlucky to get stuck behind a training flight or something. Most/all of us would comply with an ATC request for high speed when we can although a "no speed control" is insufficient reason to ignore SOPs.

24th Jun 2001, 15:05
Bono Vax, you are talking rubbish, it has nothing to do with the airfield, on passing 10,000' you will probably be nowhere near the airfield's control area, as long as your are still inside controlled airspace (nearly always) and descending you can do greater than 250 below 10.

If you need to do 320 kts to get the height off and the a/c ahead of you is doing 250 can soon catch him up. Why do you think that London ATC often ask one a/c to maintain 280 or greater and another to maintain 280 or less. If it made no difference they wouldn't bother!

I often find that JMC often lack consideration of what is going on around them and who is doing what in front and behind them. I am not advocating doing things that will make the crew uncomforatble but a bit of consideration, please?

24th Jun 2001, 15:15
It has everything to do with which airfield, as (outside the London TMA) the airspace classification varies considerably between airports.

By way of an example, descending in the Scottish TMA below 6000 feet inbound to Edinburgh, you are in class E airspace until 10dme - that means 250kts or less; ATC have no authority to waive the 250kts rule.

Inbound to Glasgow, it's class D for most profiles, so ATC can let you do whatever speed you like.

24th Jun 2001, 15:24
OK fair enough, but Class E is not all that common.

Hung start
24th Jun 2001, 15:29
shlittlenellie and Bono Vox,

If ATC requested the guy to do 280, then why all your usual talk of uncontrolled airspace and minimal time gain?? They ask him for a reason. And there could easily be many many trackmiles to go, when descending below level 100.
I see this behavior often with BA and Air France when they approach my home port. Irritates me, not because I might arrive 2 min. later if getting stuck behind one of them, but because of the situation they sometimes unnecessarily put the controller in.

24th Jun 2001, 16:41
EMB145 has a structural speed limit of 250 knots below 10,000.

24th Jun 2001, 17:26
The JMC SOP is 250kts below FL100, However if ATC instruct you to go faster than 250Kts you can. The important thing to remember is it is only if ATC ask you to. Personaly think its quite a good SOP, leaves less room for rushed approaches etc.

24th Jun 2001, 18:16
I personally think that it is a very poor SOP. It removes a very useful tool for energy management in ones descent profile. Sadly in the JMC SOP’s there is a very ‘fly by numbers’ approach which hopefully with some senior retirements next year will change.

24th Jun 2001, 19:06
Man do I agree with youm Mcrit.

It certainly took the fun away from the flying for me as well...

Lets see, burns more gas, reduces options, and is generally a miserable idea. Lets go for it...

Right about the time that the policy was instituted life as I knew from Airworld ceased being fun. The wrong management team survived the first shakeup!


24th Jun 2001, 20:13
Why all this JMC bashing??

From an ATCO's perspective, I've never had a problem with them. If anything, I'd say when it comes to R/T discipline and complying with ATC instructions, they are one of the better operators.

Only one thing that DOES bug me about them.....the God-awful climb performance of those bloody 300s.....makes a 146 look like a home-sick angel :-(

flite idol
24th Jun 2001, 20:28
Not quite sure but off the top of my head I think in the EMB145/135 you can do about 280 @10,000 derceasing to 250 by 8,000 or the soothing high speed alarms will remind you of your error, making comms with ATC all but impossible. If on autos the aircraft will pitch up to try and mantain the limit.

24th Jun 2001, 20:59
Might birdstrike impact be a consideration?

24th Jun 2001, 21:38
No parkfell that's 313 Kts below 8000 ft.

shake rattle n roll
24th Jun 2001, 23:09
It seems to me that most of you have forgotten one thing, none of you were present on the JMC flight deck at the time and it was that Captains decision to accept or reject the speed. It is very arrogant of some of you to question his decision without all the relevant information?

Few Cloudy
24th Jun 2001, 23:48
ATC saying "no ATC speed restriction" does not constitute a request so the company limit remains binding. If ATC requires more speed the wording would have to be different - "request 290kts (until clear of Bovingdon zone)-(as long as possible)" etc.

Hint - hint.......

Hung start
24th Jun 2001, 23:55
Didnīt Major Congīs post say exactly that. ATC requested 280 to maintain separation. Well, as shake rattle and roll said, it is a decision made entirely by the crew/captain but please, some (most often British and French operators) make it sound like 250+ is getting dangerous. Come on!

25th Jun 2001, 00:18
For all you guys who like high speed at low levels, consider this---
One ten pound bird (estimated size) thru:
forward pressure bulkhead,
cockpit door and,
splatered all over the F/C lounge.
Oh yes, it broke the F/O's left leg in the process.
Viewed the aircraft, NOT a pretty sight.
Imagine if it had hit the windscreen.

25th Jun 2001, 00:21
Seems a daft SOP to have a blanket 250 below 10. As someone said, it is essential to keep the speed up sometimes to dive the height off with the speedbrake. On the 737 the speedbrake does nothing below 250kts. Surely its best to exceed 250 below 10 than to end up 'hot and high' with a subsequent rushed and un-stable approach?

At LHR i've done 310kts downnwind at 6000', when it was quiet! I don't keep the speed up to save time generally, as it doesn't and it just means things happen quicker. But, if ATC ask for high speed it's a good opportunity to get the height off, and help out the ATCO.

411A - isn't that what the windscreen wipers are for? :)

[This message has been edited by BmPilot21 (edited 24 June 2001).]

25th Jun 2001, 00:54
Think you are very young.....and/or an idoit!
How would you like to be in hospital with a broken leg, or worse, no head (hello coroner). Maybe in your case, it would be an improvement. Typical British arrogance. With your attitude, you can't be anything else.

25th Jun 2001, 01:01

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I often find that JMC often lack consideration of what is going on around them and who is doing what in front and behind them.

What a bloody ridiculous comment!

Do you reckon it is an SOP to be inconsiderate ?

You werent there !

25th Jun 2001, 01:05
I'm a Yank. Who or what is JMC?

Most carriers' SOPs in the U.S. specify 250 below 10 "unless otherwise authorized by the Administrator", which allows high speed below 10 whenever and wherever legal.

25th Jun 2001, 01:31
411A, typical British humour actually.
Mate, it was a JOKE!
I take the matter of bird strikes very seriously indeed. Apparantly the new generation of TCAS will be bird compatible, although only for birds large enough carry the transponder / aerial / digital processer and EFIS display, but i guess they're the ones we're all worried about anyway - a sparrow never hurt anybody.

JMC are a large UK charter airline with mostly 757 and Airbus. They were the result of a merger between Caledonian and Flying Colours. I believe JMC stands for John Michael Cook, son / grandson of Thomas Cook which is a large travel agency etc. (Braced for corrections from JMC pilots / spotters).

[This message has been edited by BmPilot21 (edited 24 June 2001).]

Hung start
25th Jun 2001, 01:43

We know about the birdstrikes at higher speeds, although a good oleī Heathrow canada goose would also do some pretty extensive damage at 250kts, if hitting the wrong spot.
But does it then mean, that youīll never ever fly more than 250 below FL100?
Itīs not so much to do with catching up on lost time, this was, one more time, an ATC request!

25th Jun 2001, 01:50
Expedite; Not an SOP but more of an attitude!

Going into MAH the other day we brought the speed back to 250 at about 20,000 knowing that he was in front of us, and he knew that we were behind him, and that nobosy was infront of him, but would he increase his speed? Well what do you think? Guess who ends up having to go around the hold!

I was there!

Captain Spud
25th Jun 2001, 01:58
Hi big guys - just a confused wannabe here.

When I took & passed my ATPL nav group exams last November the rules were quite clear.

The speed limit is 250kts IAS below FL 100 in ALL clases of airspace except Class A(no speed limit).

Anyone disagee with that?


25th Jun 2001, 02:56
I was there, you weren't there etc etc

My dad is bigger than your dad etc etc.

Ladies and Gents, why dont we act with some dignity for Gods sake.

I am a JMCite and I guess ultimately that the decision rests with the Commander.

We aren't selfish and we do listen out on the R/T. Oh, and there are some very accommodating crews in JMC too. We would always try and help...not hinder I like to believe.

On a couple of other points:

1) I believe JMC stands for John MASON Cook, not Michael.


2) We have quite a lot of FEMALE Commanders now, so why don't you mysogonist dinosaurs out there refer to that? It could well have been a lady Captain making the decisions in this instance. Oh and of course they would want to go slower wouldn't they? In order not to get scared or bump into a shopping trolley or something like that........that is of course what you would like to think!

So, stop bashing JMC for no reason. If the SOP of 250 below 10 isnt one of yours you dont need to worry about it.

25th Jun 2001, 03:19
There's nothing wrong with 250 &lt;10 - unless you wish to break (US Pitch up) into the circuit at 400.
You don't save significant time by doing 350 and you have more flexibility.
If ATC ask for higher then do it - if lower, do it.
Final decision is from the LHS - wassa big deal??

Compliant One
25th Jun 2001, 04:41
767 ex CDG (http://www.fmcguide.com/media/birdstrike/Mvc-003f.jpg)

Edited because the image was too wide for the screen. Please make sure that images are reduced in size before posting them.

[This message has been edited by Capt PPRuNe (edited 25 June 2001).]

25th Jun 2001, 11:16
Captain Spud, I believe there is no mandatory speed limit below 10000' in A, B, and IFR in class C airspace. Therefore, it only applies to VFR in C, plus all flights in D to G. Of course, most TMA's have speed limit points, usually approaching the holding fixes (12nm before lambourne etc). However, these are flexible depending on the traffic, whether you'll be holding etc. ATC can waive the speed restriction at there discretion on departure and arrival.

On departure, if we are heading in the right direction, it's not turbulent, and we get no speed, I will normally wind the speed up to the FMS speed (sometimes up to 300kts).

737's have heated windscreens for added bird protection. The manual says that if the window heat stops working, limit speed to 250 below 10000'. This implies that Boeing are happy that the windscreen will survive SOME birdstrikes above 250kts. (Not a 50lb Teredactyl, obviously).

What height do flocks of birds NORMALLY fly up to (I know some geese have been up to 30000'), but is 5000' any more dangerous than 15000'? Most birdstrikes occur near the ground on T/O and Landing below about a thousand feet. In Western Europe, do that many birds fly above this?

25th Jun 2001, 11:51
I too have on occasion been a little frustrated by JMC and the 250 below Fl00
SOP. You know the situation, its been a
frustrating day, you are trying to make up
a bit of time to keep the programme in some
sort of order and here is matey wombling in
at 250 when ATC would in all probability be
happy to let him keep high-speed. Yes - I
know its probably does not make a great deal
of difference but it just seems so annoying
at the time.

Now before the legal beagles have a go, a
couple of riders need to be added to the above. In crappy weather, areas of difficult
terrain, busy GA situations etc - there is no
point in risking anything by going balls-out
but in a correctly controlled ATCenvironment application of a higher speed descent
profile should be an option at the commanders
discretion - and I do not mean high speed
downwind or 250 to the marker - I've seen them all over the years.

Not a problem in the winter however - JMC
aircraft seem to be parked up most of the time - oops only joking !

25th Jun 2001, 12:05
As a member of the green tail brigade, I think the 250kts below 10 is a very good SOP. Esp going into some of the Greek Islands, it alows more time on preventing the ATC Controller from killing you, and a bird met at 250kts is a lot kinder to the aircraft than one met at 300+kts.

Just one thing to bare in mind is that the 250kts below 10 is not rigid, if ATC ask for a higher speed then the SOP can be ignored, as long as the captain feels that its safe.

As far as this incident, MC, either the captain felt the request was unsafe or you were stuck behind a training flight, and the captain felt that someone new to the aircraft hurtling around the sky at 280Kts at 6000ft was unsafe. I tend to agree with him.

If it makes you feel any better is happens to us also. Stuck behind a British world 737 into Faro, the GIT decended at M0.70 from FL330!! No complaints, just spent alot of time laughing at the poor b@stard

25th Jun 2001, 12:14
Jonty, I totally agree there's no point bombing down towards high ground, at night, with dodgy ATC and an unfamiliar airfield.

If you can break the SOP, then sounds ok. If you can break it, then what's the point in having it?

You can laugh at us poor 737 drivers with our 0.7 descents. We get our own back when you're stuck behind us at FL370 all the way through France at 0.74!!

25th Jun 2001, 12:50
I can live with 250 below 10,000.
Being stuck behind a JMC 757, and having to reduce to 170, 25 miles out (of AGP) was ridiculous.
This is the third time in as many days.
Is there something else going on, perhaps related to your pay claim?

25th Jun 2001, 12:50
At last, BM, you make a decent point... I'm also a JMCer and from my point of view it is a reasonably good SOP. It does frustrate us also when we are coming back into the UK at some silly hour of the morning when there is no traffic around but I believe it is a more safe procedure.


In controlled A/S ATC are responsible for the separation between aircraft and so either they control the speeds and profiles to fit in OR the published procedure does.

I agree totally that slowing up early does frustrate but if some one in front brings it back to 250 below 10 (Talking from the perspective of previous SOP's) it never worried me, however, what really does piss me off is someone doing 150- 160 kts from 18 miles out. This happens on many approaches into Spain and Portugal, usually on NPA, and usually by GB Airways. WHATS THAT ALL ABOUT? Recently we were flying normal "JMC" speeds into FARO and the aforementioned airline was back at 160 kts from around 20 miles out. Needless to say we had to fly around in circles too make space. NOW THAT IS FRUSTRATING. Before anyone says it was probably a training flight... I have it on good authority from an ex- airbus GB'er that they seemed to do this as a matter of course.


25th Jun 2001, 13:01

Agreed, however I have 3 pts on AGP

1. Lots of high ground

2. On Rw14 you need to slow up early as the speed runs away on the approach. I can't speak from the 757 perspective as I fly an Airbus, but we usually have to take the gear out of sequence just to hold the speed back.

3. Rw32 usually means you get vectored in on a shortened approach.. as we all know slow down OR go down NOT BOTH! Its one way to lose the height (Maybe not the most favourable). It could have been training!

25th Jun 2001, 17:24

1)Yes there are lots of hills at AGP, but if you fly the STAR you won’t hit them, especially in good VMC.
Avoid high rate of descent and high speed as you approach MAR (not below 6000ft) and you won’t set the GPWS off either.

We were in descent .78/290 and catching the JMC 757 up, put on a delaying vector, whilst he was on short cut vector, and still closing. Voluntarily reduced to 240 at about 50 miles, way above 10,000ft then to 170 at 25 miles. I wounded if I was following a Cessna!

2) RWY 14. Try 250/6000 at MAR, decel to 190 descending to 5000, then go down with the glide in Flap 2.
Works a treat. Similar profile in slightly more slippery (but better speedbrakes) 757. No problem either.

3) RWY 32 If anticipating visual, arrange speed to be 190 @ 5000 right downwind, once past the high ground descend to circuit altitude for visual. No problem at all, saves about 15 track miles.

Maybe JMC don’t do visual approaches, as I had to follow one onto a 14 mile final at FUE (or LPA), could have been on the stand before he turned final!

Other one was PMI, again following a 757 at PMI published speeds, had to reduce to min approach for last 12 miles.

Me thinks you guys are on a go-slow!

Yes, they may be training, but if so there’s something wrong with the training if you have to go that slow.

F_A are you in the spare parts buisness?.
If I keep having to follow you, I'm going to wear my flaps out!

25th Jun 2001, 18:29
I work for JMC, It's an SOP that you get used to, in fact it can be quite fun to see how close you can get to the 250/ &lt;10, it makes for a much safer app. and after all it safety thats the name of the game, I seem to remember a gulf air A320 coming to grief not so long ago, after he came hurtling into the circuit fast & high, whilst i'm not saying that this was the prime cause for the accident , it may have been a contibuting factor, the more time you have the better you think and so on.
Weren't Emiates thinking of having the same Sop?
From what I gather most airlines have this rule in some form.
Another point to remember Bigrab, is that we're doing a lot of training at the moment (cause the line guys are doing all the night flts)so if you cast your mind back to when you were training i'll bet you wanted time to think!!!

Pilot Pete
25th Jun 2001, 19:18
Big Rab,

I think I have to put my hand up to being the PF on the flight in question!

Please note it was my first approach into AGP on Rwy14 and indeed only my 5th line sector. I find that doing it the way I was taught in the sim (no high speed approaches) is the only way I am going to learn how to get fully au fait with the machine before trying high speed approaches and having a working knowledge of what the 75 is capable of.

Your comments on what 'works' into AGP are noted and I am sure will be useful as my experience builds. I think it good training that the Training Captains allow us to fly what we feel comfortable with. I seem to recall one of my 'debrief' points to him was that with hindsight I could have stayed a bit cleaner/quicker for longer. Still can't get over how good it looks when I do a walk around though!

Safe flying (fast or slow)


25th Jun 2001, 19:33
Part of the training should be to fit in with the flow (safety in mind of course).

Why does it need to ba an SOP? Surely a good Captain (and I am sure that at JMC they are) is able to use his discretion when there is high ground about and the weather is **** etc! Isn't that what a Captain is paid the big bucks to do?

Brest Bonjour
25th Jun 2001, 22:04
Time out guys, maybe this was a training flight, someone new to type! we all started somewhere!!

Whipping Boy's SATCO
25th Jun 2001, 22:42
Watching this thread with interest, I today monitored a large number of aircraft arriving/departing Heathrow. My radar will give accurate groundspeed readings of any aircraft. Consequently, I allowed 50kts tailwind for aircraft leaving LAM/BIG. The following company aircraft were doing significantly more than 300kts when downwind in the pattern at altitudes/FLs of 5000'-FL80:


and an own goal


Furthermore, almost without exception, departing aircraft were in excess of 250kts on climbout way before FL100.

I don't know the specific rules but, if 250 kts below FL100 is mandatory, there are an awful lot of operators who are ignoring this rule.

Fly Safely........

25th Jun 2001, 22:43
Here here guys I agree with all your points. During training your brain doesn't work as quickly and you need the time to think.

P.S. I'm not in the spare parts business and I will certainly never try to hold you up since I have been flying large jets for many years. I still believe it to be a good SOP and as I stated earlier if you are too slow ATC can ask you to speed up.


Hung start
26th Jun 2001, 00:49
Whipping Boy,

Surprises me a great deal. Iīve been in and out of LHR regularly for years now, and have ALWAYS been at 220 kts when leaving LAM hold. And thats what everybody else is instructed to do too! NOBODY does 300 kts IAS leaving the holds at LHR!! And nobody would even dare to.

26th Jun 2001, 04:01
Whipping Boy

The 250Kts can be lifted by ATC. It's Class A airspace, where there is normally no speed limit. However the London area has a restriction of 250Kts below FL100 as an additional condition. Being a known traffic environment, ATC are quite within their rights to either cancel it, or instruct aircraft to fly faster than 250Kts if required.

10 West
[email protected]

26th Jun 2001, 14:44
Pilot Pete

Thanks for the explanation. I fully accept your reasons.
You are quire right to proceed at a pace that is commensurate with the conditions and your experience. And it was reasonable for your trainer to let you get on with it, as it was entirely safe to do so.

AGP ( Malaga – Spain) is a place were one can get into trouble under certain circumstances; and sadly ATC is sometimes not as good as it could be.

I was curious if anything odd was going on at JMC, but guess by coincidence had a run of training flights. Thanks for taking the post in the good nature that it was intended, and good luck with your training.

26th Jun 2001, 15:27
10W, maybe you clear something up for me, does the 250 below 10 in the London TMA only apply to outbouds?

The STAR plates do not state that there is a limit of 250 below 10 but there are the SLPs.

26th Jun 2001, 16:23
An interesting point autobrakemedium. As it's not actually my patch I'll leave chapter and verse to a Terminal Control ATCO. I'm sure one will be along shortly.

Having said that, your second statement is correct and there is no FL100 limit for inbounds. If you're following the STAR then the SLP could be reached at a higher level than FL100 depending on your vertical profile. To me the interesting part is what happens if you are vectored off the STAR before the SLP. As you have been given a new 'clearance' which supersedes the STAR, it might be argued that the SLP no longer applies !!

10 West
[email protected]

26th Jun 2001, 17:54
Hung Start. I've been a Heathrow Approach controller for 30 years and I have to slightly disagree with you. Especially when we're on easterlies we often have traffic coming off LAM and BIG at 300 kts and I've certainly had traffic leave LAM doing 340+, reducing gradully to 250. On westerlies it's a little more difficult but in quiet periods high speed is often OK off Bovingdon for a good 10 miles, or straight-in off BIG. I'm perfectly happy - if traffic permits - to cancel the SLP speeds and I'm sure I speak for most of my colleagues. We obviously have to slow you down sometime during the intermediate approach to enable us to keep you within "our" airspace and to give us a reasonable chance of getting you onto the ILS. With early morning straight-in approaches we often say "no ATC speed control" - then one guy goes balls out to 4DME and the next reduces to 170kts at 30 miles! Some pilots prefer to reduce speed long before I need them to... occasional 747s still downwind with 25 miles to go will say "we're still doing 220kts, London". I think this means "we'd like to slow down a bit"!

If you get a "leave LAM heading 270, speed 210kts" when there's little else about it's probably a trainee. We all have to learn sometime.

Captain Windsock
27th Jun 2001, 01:16
If you are inbound the 250kts max comes into force at the speed limit point regardless of Flight Level.

If outbound you are restricted to 250kts max until you pass FL100 unless derestricted by ATC.

ps I would love to see an outbound Virgin A340 try an go faster than 250kts during the first 20 miles or so of flight!

27th Jun 2001, 01:37
What you troups need in the UK is MAX 250 knots below FL100, period, then.....everyone marches to the same music.

27th Jun 2001, 01:51
It isn't that simple 411A as sometimes we need the high speed to get the height off.

27th Jun 2001, 01:53
If the SOP is 250 below 10 why did I get stuck behind a JMC doing 210 @ FL140, 40NM out of BHX the other night. The speed hadn't been requested by ATC either. We thought JMC had sub chartered a turbo-prop, but as we taxied in there was the 757 just ahead. Come on guys, get real!!!

27th Jun 2001, 02:03
Well, that's what spoilers are for. Works for me anyway. Granted, some aircraft may well have a problem.

Hung start
27th Jun 2001, 02:56
Heathrow Director,

Well then I stand corrected. Guess itīs just a matter of my airline (SAS) always wanting to land at Heathrow at the busiest times. :) Only highspeed Iīve ever had, was New Years eve 1999/2000. 325 kts from Logan to 15 mile final. Just great. Since then, Iīve always had the "leave LAM h.275 speed 220 kts." But hey, I get to fly fast elsewhere, at LHR I find satisfaction in just enjoying dealing with the best controllers that I get controlled by!!

27th Jun 2001, 05:20
Autobrakemedium, How do you think that pilots in N. America manage to get rid of excess height, given that they are not permitted to exceed 250kts below 10,000'? Or perhaps you thnk that getting above the profile is a purely European problem.

27th Jun 2001, 12:17
I am not a jmcer but I have to admit that I agree with there sop of 250 below 10. We have to remember that sop's are designed to cover all flights and in general jmc fly into charter destinations where atc is not always as good, high ground tends to be a major factor and the good old ILS hasn't been heard of.

Everybody has talked about birds I would prefer to avoid the odd pa28 island hopping.

Even in UK controlled airspace, how do you know that a student from oxford/cranfield hasn't strayed into controlled airspace.

250 below 10 gives you much more time to avoid others and keep an eye out. Imagine the subsequent court of enquiry - why didn't you slow down sir were you in a rush?

Think about it safety first.

27th Jun 2001, 12:44
Don't forget the beancounters - a higher speed approach (where legal, safe, etc, etc!) will use less gas than dragging in from 25 nm at slow speed.

27th Jun 2001, 14:04
HalesandPace - Have to disagree with you there. 250 kts below 10,000' is more fuel efficient, especially if ATC bring you below your ideal profile. On the B737 if you set the cost index to zero to get the best possible range, what you get is a 250kt climb and descent. On the DC-9 we used to use a 250kt descent ALL THE WAY for fuel economy - now that really did cause an ATC log jam!

Hung start
27th Jun 2001, 14:19
Thereby scr****** up profile and economy for everybody else, flying aircraft that do better with higher speeds! :) :)

Jet A1
27th Jun 2001, 14:21
While I'm all for maintaining high speed when offered there are times within my operations when during the shorter sectors ie 30 minutes the ladies down the back still havent finished the service and I would rather bring the speed back than hammer in to gain 2-3 minutes in the sector time !!!

Final 3 Greens
27th Jun 2001, 19:18

Hear, Hear and it also gives the PA28 driver more time to see and avoid you.

I've flown (legally) in the LA basin where traffic is "integrated" and sypmpathised with the jet drivers trying to pick my Arrow out amongst the clutter, whereas a 767 does tend to get my attention pretty quickly!

27th Jun 2001, 19:33
Higher speed descents do NOT save fuel - see Boeing general information for an explanation of this.

I am at a loss to understand how operators in the USA are any different to Europe, given the general rule of max 250 kts below 10,000 ft.

IMHO, increasing speed below 10,000 ft has little effect to regain profile if you are high. Increasing speed at "high levels" will bring you back on the profile because the TAS is higher and an increase in speed results in a lot more drag. (I seem to remember that if you want a steeper angle of descent then you need a lower Lift/Drag ratio!).

If you are below 10,000 ft or so and high on profile then, if anything, you need to start slowing up and getting some drag out!! (Flaps, Gear, Doors, Buckets - whatever you have got). Failing this then you can always enter the hold or do an orbit.

In the real world we have to strike a balance between a number of different factors, SOPs, weather, pilot experience, traffic, terrain etc. etc.

What worries me is when other pilots try to dictate how others should "fly" their aircraft. With safety in mind then the operation has to be based around the lowest common denominator - this may be "unpopular" at times but I would rather be unpopular than filing an MOR or crashing into the side of a mountain!

Finally, I seem to recall that high speed was a factor when Danair crashed at Tenerife many years ago. High speeds mean a bigger radius of turn when ATC comes up with a last minute instruction and, yes, I know they shouldn't but they do! That's what flying is all about!


27th Jun 2001, 19:58
Hung Start. Thank you - your comments are very much appreciated and I guess I'm mainly talking about early morning and sometimes during early afternoon when it's quiet.. I gave a Speedbird a visual approach a few days ago "Wish it was like this all the time" he said. How I agree!!

28th Jun 2001, 00:05
Bono Vox,

Leaving the original cruise level is not the problem.

It is when you are at FL180 flying over London (as directed by ATC) and you get given a left base for 26 at LTN.

I have never been to EGAA but I bet it is a bit different to going into London TMA airports.

LGW & LHR arn't nearly as much of a problem as you are far more "controlled".

As for the rest of your comments, well they are not very mature so I won't bother commenting!

28th Jun 2001, 05:06
Methinks all you aviation professionals should consult your AIC's. AIC35/1998 to be precise.
This covers most of the points raised in this thread.
Personally 250kts below 10 suits me and too bad if little boy racer throws his toys out the cot.

28th Jun 2001, 12:35

You say

"IMHO, increasing speed below 10,000 ft has little effect to regain profile if you are high. Increasing speed at "high levels" will bring you back on the profile because the TAS is higher and an increase in speed results in a lot more drag. (I seem to remember that if you want a steeper angle of descent then you need a lower Lift/Drag ratio!)."

Think about TAS/EAS and limiting mach numbers. At higher levels EAS/mach is definitely limiting. Think of it all as number of molecules of air passing over your surfaces per unit time. Higher speeds at lower levels increases drag significantly more than at higher levels. Otherwise we would all cruise round at high speed/low level to save fuel (since ,in the cruise, thrust only has to overcome drag). Now there's an idea

28th Jun 2001, 14:44
Beardy, thanks for your contribution!

I would admit that I am not 100% sure about the theory but I do know that angle of descent depends on the lift/drag ratio!

Perhaps some aerodynamics boffin out there could let us know!

I will go away and think about it but it probably depends on the exact numbers!

Essentially my point is that there is not much point getting back on the profile by increasing speed at the lower levels if you are going real fast at the bottom because you may then end up with an unstabilised approach which defeats the whole object of the exercise.


28th Jun 2001, 15:14
Beardy you beat me to it! Your responce to Fireflybob is correct, form drag is in relation to speed and high speed at low level has much more effect than at altitude due to relative air density. With regard to the policy that some have of trying to slow down early when above the profile in order to get the gear/flaps out to help recover the plot this technique simply does not work best. It might make you feel better to have low speed but in terms of losing energy from the system the most efficient method is to maintain high speed with full speedbrake and go down first ( high speed, full speedbrake, dense air = lots of drag ) then slow down second. Have a think also about the go-around situation. If you really are too hot and high and have to give it away, which would you rather, a go-around from low airspeed with high rate of descent or one from level flight with high speed. Answers on a post card! As a further thought on this, using the low speed technique how do you know if you are going to be stabilised in time by 500’ AAL? Its very difficult. However using the high speed method its simple. You descend through the profile ( below the glide ) level off with idle power and let the speed decay if you intercept the profile again before the speed is back you need to make another plan!
To sum this all up imposing a rigid ‘250 below 10’ SOP does not make things easier for the pilot. Quite the reverse it removes a useful tool which can help us efficiently manage our descent profile. It is like banning the use of speedbrake to make our lives more difficult. Thus the argument re. training/low experience does not hold up. Indeed most JMC Trainers wish to see a change to this SOP. For those who quote the USA at us, those who have operated large aircraft both there and in Europe will know that ATC environment is very different with fare less segregation of fast/slow traffic in the US hence a blanket ban on high speed makes more sence.

28th Jun 2001, 17:57

(Even though I could not have quoted the technical stuff as well!)

Does the square law not come into play as well?

28th Jun 2001, 19:09
There is, as they say, more than one way of "skinning a cat".

I am not advocating that one should never exceed 250 kts below 10,000 ft. There are occasions when this is quite appropriate.

Remember that angle of descent depends on the lift/drag ratio (and not just the drag). If you increase speed then lift AND drag will increase - what happens to the lift/drag ratio is somewhat debatable although, I agree, application of speedbrake will change this.

Perhaps we have drifted a little off the topic of this thread but nevertheless it's an interesting discussion.


28th Jun 2001, 19:47

I don't like keeping the speed on &lt;10 if high,though I guess it depends how high.You have to slow down sometime and I think 10K is a reasonable place to do so.If you have to go-around at high speed and clean you really have misjudged it!

You have lots more options at slower speed and I think its easier to judge if you're already configured.Also fast you'll be catching the guy ahead at 100+ kts which will impress the controllers.

Slowing up calms it all down and I think that helps the situation.I've seen a high speed approach turn to ratpoo because of a small problem which I don't think would have had the same effect if we had been slower.

Throw in birds/light ac/GPWS/low experience levels/manoeuvrability etc and my minds made up. 230kts/Gear + Speedbrake works 'till the controller decides to vector you for 20 more miles just in case.

250 kts we're on about- not km/hr.hehe! :)

28th Jun 2001, 20:13

I think that you may be missing the point a tad. I'm not talking about high speed for the hell of it rather as a way to correct a profile with too much energy in it. If your app. was 'ratpoo' with high speed and speedbrake then it would have been even worse at low speed. That is FACT, its phisics.

28th Jun 2001, 21:30

Bit patronising there I thought.If you read the first line of my post it says if high which I think means too much energy.

The approach was already ratpoo but a minor problem made it worse.

I got an A in physics but don't have a clue what you mean!

28th Jun 2001, 22:12
Well Flanker I apologise I did not intend to be patronising.
My point is this: If you are passing say 12,000 ft and are for example 4000 ft above profile the best chance you have of a normal, on speed, on G/S approach ( ie unhurried and safe ) is to maintain high speed say 300 Kts with speedbrake until you are BELOW profile and level and then slow down still with the speedbrake ( which of course becomes less and less effective as you slow down ). I would not advocate high speed on the glide or even planing to maintain high speed during the app. But I will say again it is a useful tool when required. And leads to a far more ‘normal’ approach in the end. When training new FO’s its those who end up with a very high rate of descent at a late stage of the approach who get into the most difficulties. Often as a result of getting high on the profile then slowing to 250 below 10 then slowing further to try and get all the flap out then with idle power, full flap, 4 whites and full fly down with no real idea of weather or not they are going to intersept the G/S before 500’ ( latest ). My aim in this is not to be a ‘Cowboy’ but rather to give the best chance of a stable and safe approach.

28th Jun 2001, 22:57
No problem.

I think that technique works if you're a bit high, but I would slow down if very high.I think aggressively getting on profile by 10000ft is the answer if possible.In the example you gave thats quite a lot to get off,are you 757 or 320? Headwind only IMHO.

Anyway I normally prefer slowing down,certainly by 20 track miles.We have the same rule, I remember it being a bit unpopular at FLC,at least initially.

28th Jun 2001, 23:40
MCRIT, valuable information for us ATCOs.
I see you are a 757 pilot, would the 'high speed with speedbrake' approach be as benificial on other types or is it more appropriate for 'slippy' A/C like the 757 ?
In my experience most of the big heavies (747,MD11,A340) prefer to slow down first.

29th Jun 2001, 04:35
Nice way to wake up the pax by going fast and shaking them with speed brakes!!
you guys are a engineers nightmare.
If you are a few steps ahead of the game you can plan and always be on profile!!!

29th Jun 2001, 10:28
So many posts on the same subject and people will think that I am obsessed with flying fast at low level which isn’t so.
Vertigo I have never flown a super heavy so can’t comment on them however in my experience which includes 737 –200/300 , A320 , 757 , 767 – 200/300 up to about 180 Tonnes the technique works well. It works particularly well on the 757 as the speedbrakes are relatively good and excellent at high speed in dense air. Flanker however makes the best point, which is to try to correct the profile as early as possible and preferably before 10,000 ft. However this can often be difficult and there is much more scope after 10,000 as the FMC will be programmed to slow down thus even without speedbrakes just by maintaining your normal descent speed you can begin to recover profile. All this is of course dependant on ATC allowing a continuous descent profile. I would like to stress that we are not talking about late stages of the approach here but say between 10 and 5 thousand ft when there is little else one can do to help. In any event one must start to reduce speed by say 20 track miles or it isn’t going to happen anyway and we will need to talk nicely to ATC about some more miles!
FogMeister When you start to fly real aeroplanes in the real world and not just your computer you will see that it is not possible to ‘ always be on profile ‘.
Safe flying all!

Marko Ramius
30th Jun 2001, 02:21
If ATC keep you high there is not a lot you can do about it.

1st Jul 2001, 03:11
Seeing as you have decided to become personal thought i would address your comments.Yes our colleague is absoluteley right and you are an engineers nightmare, and probably to all the road users around you as well, and anybody else who happens to get into the boundary layer of your ego.
I am a subscriber to 250 &lt;FL100 and have never once had to ask ATC for extra miles..EVER. Why for 2 reasons, firstly i plan my descents carefully, with allowances for the unexpected (as any sensible airman would), and as we all know vs go down and slowdown, if you are already slowed down then the speedbrake will then make you go down. No doubt your sterling effort to arrive that 2 min earlier, is completeley lost by downtime in maintenance because you drive the machine like a company car. But of course you wouldnt be privy to that statistic or I doubt give a toss.
Am i qualified to make these comments? well 20 years as engineer Licensed on 1-11, 727, 737, 747, 757, 767, 777, 320, DC10. A,C&E,I
Flt Eng , and now demoted to ATPL on one of the types you operate, gives me a far better all round view than you..I would love to hazard a guess at your background.
I suggest you show a little more respect for the guys who your life depends on !!!
By the way just how many G/A's have you done from screwed up approaches?
Chill and respect !

1st Jul 2001, 11:10

Well balanced post.Why did you 'demote' yourself and how many weeks have you been a pilot?


See - you're a nightmare . I was right! :)
By the way your types are exactly the same as my own,variants too.

1st Jul 2001, 12:26
One thing is for certain, lowflyer is a CRM nightmare! I'll bet every sentence begins with "When I....."


1st Jul 2001, 14:18

You can not always plan your desent to the nth degree as you suggest unless you are of course always flying to airports that do not have any other traffic or other airports near them. Or are you flying around at FL190 with 25 degs of flap out and the gear down!

[This message has been edited by autobrakemedium (edited 01 July 2001).]

[This message has been edited by PPRuNe Towers (edited 01 July 2001).]

1st Jul 2001, 17:24
Much talk of "Time saving" and "Dragging it in at 250 knots".Assuming an idle descent from TOD to say 1000'agl with no speedbrake the difference between a 2 stage deceleration (ie,back to 250 at 10) and a single level deceleration at say 3000' is most certainly not several minutes as many seem to think.It is realy very marginal.You have a set amount of kinetic energy at TOD and while high speed sure does get the hieght of and increase drag you will need longer to lose the speed.
I would like to see some hard figures but "Keeping the speed up" on an idle no speedbrake approach does NOT save much time at all.

2nd Jul 2001, 02:09
I don't think that people are arguing about time saving but about separation and being able to lose height.

2nd Jul 2001, 12:38
Just a quick question, it has been mentioned on this thred about using speed to correct the profile (too high). Good idea above 10,000ft. Below 10,000ft options are suddenly running out, someone commented on using speed to correct the proflile in a low alt (below 10K) situation because if your high you have to much energy, ok so far. Now your back on profile but about 70kts too fast, havent you just changed to type of energy you have? you are still in a situation of too much energy, but now a few thousand feet lower. If you are fast what are your options? Speedbrake, more track miles to run. If you are high? flap, gear, speedbrake and more track miles to run are all options to help the situation.

Its best to be on speed and on profile, but as we all know ATC get in the way. In our company the managment have decided that it is best to be high on the profile but slow, with plenty of options at correction, than fast but at the correct alt with limited options at corrections and with the constant threat of "direct centre fix" coming over the airwaves.

What Im trying to say is if your fast, you cannot get gear and flap down, and to slow down your going to have to go high on the profile. Is it not best to do this early, say around the 10K mark, than just before you capture the glide slope?

B757, gear down, flap 30 = Six degree glide slope, this will get you out of most high on the profile situations at low altitude.

Dont mean to be patronising, sorry!!!!

[This message has been edited by Jonty (edited 02 July 2001).]

2nd Jul 2001, 17:59
What you say makes perfectly good sense and is of course, correct.
I have found over the years that it is the junior F/O types who like the high speed at low levels. These guys are relatively new to the profession (and jets) and therefore many times have little experience at ANTICIPATING possible problems with high speed and short vectors to the FAF.
I tend to let them make these mistakes on their own rather than correcting the situation earlier.
Once bitten, twice shy seems to work well at their experience level. After many years in line training, seems the best method to me.
Others may disagree, of course.

3rd Jul 2001, 01:22
Jonty, you seem to have missed the point. You say
"In our company the managment have decided that it is best to be high on the profile but slow, with plenty of options at correction, than fast but at the correct alt with limited options at corrections and with the constant threat of "direct centre fix" coming over the airwaves.

"What Im trying to say is if your fast, you cannot get gear and flap down, and to slow down your going to have to go high on the profile. Is it not best to do this early, say around the 10K mark, than just before you capture the glide slope?"

Energy management has to be part of an overall package within profile and sequencing management. Kinetic and potential energy can be transferred from one to the other. Flap and gear should be viewed as "irreversible" of course they are reversible, you can retract them, however try treating them as one shot operations. Should you be unlucky enough to be caught out hauling it in in high drag, the fuel penalty is significant. However should you have had the foresight and opportunity to use the speed (the drag/squared law) to reduce energy to the point wher you can haul it in clean (under the profile) the fuel penalty is much reduced. Higher speeds produce more drag and therefore disperse energy more efficiently especially at lower levels.
You may misunderstand, our company has a defined policy in writing to maintain 250 kts below 10000ft with certain noteable exceptions. None of these exceptions preclude sensibe use of the laws of aerodynamics and the characteristics of your aircraft type to integrate SAFELY into traffic patterns.

I did try hard to say nothing derogatory and something positive about 411a's comments.

[This message has been edited by beardy (edited 02 July 2001).]

Hung start
3rd Jul 2001, 12:43
Excuse me for returning to a point that the subscribers of high speed gave up on a while ago.
Peoples arguments that 250 below FL100 doesnīt take much longer than 300, hang their hats on a 30-35 mile straight in. I agree, in that case the savings are negligable. But I do an awful lot of approaches where we have to be at FL 100 with more than 60 trackmiles. Sometimes much more! So I havenīt quite given up on the good sense in keeping speed high if allowed.
People are talking rushed approaches and being high, with unnecessary go arounds to follow. Sure, donīt get pulled into something that youīre not comfortable with. But Iīm talking well planned and excecuted highspeed approaches. They can give our pax and my conx times, just those extra few minutes that they need. Sometimes it doesnīt matter, sometimes it helps a lot. And with our company 1000-1100 flights a day, a few minutes here and there, CAN count.

3rd Jul 2001, 19:28
2 aircraft arrive at a holding fix at about the same time. At FL60 was an ATP (215kt flat out). JMC 757, 1000 feet above and just ahead of said ATP. By asking for 280kt for 2 minutes, in an area where wide heading splits would have been difficult, JMC pulled far enough ahead of the ATP to allow a descent through its level, then reduced speed in a normal manner and completed a thoroughly unrushed and safe approach. Otherwise it would have been into the hold for JMC or 210kt or slower and a wider circuit to follow the ATP.

There is nothing wrong with a bit of extra speed if it is used wisely and for the good of all airspace users.

Thanks for the information in this thread.

[This message has been edited by cossack (edited 03 July 2001).]