250 kts below 10000?

[NARVAL]

Reading the comments on this subject, I realise that many captains are now very decided to save some pounds of fuel at all costs. Accelerating like a slingshot...sent a shudder through my old spine. Reminds me of gung-ho captains in my company who kept more than 300 knots until interceepting the localizer, when the controller agreed, "to save time for the company"...then would wait twenty minutes for the stairs to reach the aircraft because they were early at the block...
More important...Va is 250 knots on the A320 (or was in my days) and above VA...you do not have full deflection of the ailerons and spoilers...you have a reduced rate of roll to protect the airframe...if any strong avoidance tactics should be needed, you might hit the intruder...45 or 60 pouds of fuel lighter.But managers talk about saving fuel, so let us forget it...

[737Jock]

Narval, that is only valid for:

If alternate or direct law is active, full ailerons and rudder application should be confined to speeds below VA. If alternate or direct law is active manoeuvres involving angle of attack near stall should be confined to speeds below VA.

And

(Applies in alternate or direct flight control laws only).

The speed you quote is also incorrect!

FCOM LIM-13

[sudden Winds]

it's 25 kg in a 737NG. A bird strike at 300 kts is a bit more expensive than 25 kg of fuel. Having to pull 3 g to avoid a lost piper cub at 3000 ft and 300 kts is not good either.

Want to save fuel?

-ask your dispatcher to make sure CG is not too far forward.
-takeoff with less flaps, conditions permitting.
-keep airplane's takeoff config for early turns after takeoff, or flaps up speed for big turns after accel ht.
-do not use reduced climb.
-ask for off airway direct routings, if possible and safe.
-use a-p
-keep airplane properly trimmed, especially rudder.
-make good use of engine anti ice.
-use fmc computed speeds for the majority of the time.
-give the fmc as much info as you can, regarding temp and winds.
-make sure you've entered the correct CRUISE CG, so that your speed tapes display correct maneuver margins AND MAX ALT is not erroneously low, we've got ex Easy Jet 737NGs and it seems CAA requires a default value of 8% CG in perf init. I keep changing that, but some pilots disregard that completely.
-During cruise, use the recirc fan even if itīs noisier (I do not comply with this one in the older ex Virgin Blue planes that donīt have the vortex generators).
-try to stay within +/- 1000 ft from optimum alt.
-Use delayed flap approach whenever possible.
-Use flaps 30 for landing.
-Make a correct use of thrust reversers.
-shut down one engine for long taxiing after cooling, conditions permitting.
-make a good use of apu.

[exeng]

Sudden winds

Please don't post the obvious.

Apart from the rediculous such as

do not use reduced climb

.

Reduced climb saves engine turbines at the lessor expense of fuel - thats why all airlines do this.

As for

make good use of engine anti ice

, what do you think most Pilots do - select it because they feel like it.

And

Make a correct use of thrust reversers

Well I use idle or a reverse N1 that is comensurate with the prevailing landing conditions - that is what all Pilots are trained to do.

As for

keep airplane properly trimmed, especially rudder

. We are talking about Pilots are we not?

And [QUOTEmake a good use of apu]/QUOTE]. Good one that - delay the start on the taxi in until the last possible moment - then a distraction and I wait at the gate with an engine running till the gen is ready - been there so many times.

Keep it simple and there is just a small chance you may personally survive.


Regards
Exeng

[Sciolistes]

If you really want to be efficient you'll depart with the least flap possible and accelerate to best rate of climb as low as you can.

As expensive as fuel is, it seems engines are more so. Hence we are now using fixed derates, assumed temps and flap 1 takeoffs with non balanced calculations as much as possible which probably burns considerably more fuel for takeoff and climb.

[sudden Winds]

Exeng,

I will explain what I meant because it's OBVIOUS you didn't understand.

I was mentioning aspects that WILL help save fuel, but never said that those needed to become policies or were always the best courses of action.

1) reduced climb. If for some reason your estimated fuel on board on arrival is too close to reserve+alternate, that's one thing you can do, especially if flying with a tailwind.

2) you and probably everyone else in the airline you work for are perfect (except for forgetting to start the apu on time, according to your confession) but here in imperfectland I've seen improper use of engine (and wing) anti ice repeatedly.

Examples...keeping it on when OAT is less than -40°C during climb and cruise with no thunderstorms around AND failing to enter the altitudes for TAI ON and OFF in the forecast page. That DOES increase fuel burn.

Regarding the -40°C criteria, of course I donīt just automatically turn it off when OAT says -40.0001°C but I noticed pilots still using it while riding inside harmless cirrus with OATs well below -40°C. There's a reason for NOT using engine anti ice with OATs below -40°C.

4) APUs. We fly into a few airports where taxi times can be as much as 20-30 minutes after landing. During THOSE operations what I do is I tell my first officer WHERE we will start the apu. I use a location during taxi where I am a few minutes from the gate, I can still ask for a GPU if an APU fails to start and of course the apu will be started and transferred well before engine shut down (you may want to try this yourself) From my experience, B737NG APUs are extremely reliable and after a little over a year flying the NG I can remember one time when an APU failed to start. I do not combine engine out taxi WITH an apu still off tho.

You see the company I fly for is in the process of developing fuel saving procedures, but in the meantime I use my own as nothing has been written otherwise.

Next time you contact me spare me the dos and don'ts, will ya Mr Perfect?

[Denti]

@Exeng, reduced climb thrust doesn't really save any engine wear and therefore maintenance cost. Reduced take off however does. At least thats what boeing tells us, not to mention our own 15 years of experience operating the NG. Therefore we reduce the take off thrust as much as possible using both fixed derates and assumed temperatures for the last 10 or so years, however once we get an unrestricted climb clearance or at airports where it is given on the ground we select unreduced climb thrust manually. It is nice to get a load of additional thrust at climb thrust reduction and climb out of the "dangerous" below 10.000ft environment in 2,5 minutes.

Anyway, over here there is no speed limit below FL100 if one is within a class C airspace.

[FlightPathOBN]

Anyway, over here there is no speed limit below FL100 if one is within a class C airspace.

Denti, that is being looked at as we speak. On runways where there is no ability to have diverse departures, in order to increase capacity, there will be speed restrictions on departures.
This is to prevent the aircraft from running up on each other, to maintain min separation.

[LeadSled]

Folks,
For those of you operating in US airspace, read the "250Kt" rule carefully. ATC cannot ( unless it is one of the special trial airspace areas) give you a clearance to accelerate past 250, below 10,000.
However, the rule gives the PIC the authority to exceed 250 if he has a good reason for doing so.
What might that be?? For example, most aircraft with flaps out have a negative G limit of 0/zero, and there is no shortage of types where the minimum flaps up speed and turbulence penetration speed is well above 250 kt.
Most of the rest of the world can give you clearance to exceed 250, where it is an ATC restriction, not a statutory restriction.
Tootle pip!!

[bubbers44]

I was on an FAA check ride once when the controller said expedite to 9,000 ft so said when I slowed to 250 I would descend because he had traffic crossing at 10,000 ft ahead of us. Using full speed brakes was able to descend about 5 miles later but told the FAA guy, only the administrator can authorize over 250 below 10, not ATC. Any other time I would have done it. We were in the clear so was just protecting my license. I hate it when you have to do stupid things because you have to stay legal.

[GlueBall]

only the administrator can authorize over 250 below 10, not ATC.

...How about technical necessity, like 265Kts for zero flaps speed, or do you think that I will be dragging flaps to 10,000 feet?

[bubbers44]

No, that would be minimum maneuvering speed which is authorized as covered in a previous post. I have had to use that speed in a 767 heavy a few times. You obviously don't leave flaps out to maintain 250 knots. The captain is authorized to use that higher minimum speed to operate his aircraft properly.

[aterpster]

bubbers44:

No, that would be minimum maneuvering speed which is authorized as covered in a previous post. I have had to use that speed in a 767 heavy a few times. You obviously don't leave flaps out to maintain 250 knots. The captain is authorized to use that higher minimum speed to operate his aircraft properly.

Indeed, it is done all the time, but only at a relatively small number of airports that have large airplanes and long range flights.

[NARVAL]

737Jock replied:
only in alternate direct law...
Thank you for your answer (except when you tell me the speed I quote 250 is incorrect...let us not split hairs, if it is 249 or 251, we are talking here of exceeding or not 250 knots at low altitudes)
There is something that escapes you, it seems to me. In alternate direct law ONLY, you have to respect the manoeuver speed by applying careful inputs on the stick.You are right there.
In normal law, do you believe for one moment that such a sophisticated airplane will let you violate the manoeuver speed and give you 25° deflection of ailerons at 300 knots? In normal law the plane looks after itself,, as flight control normal laws (I quote) covers "alleviation of manoeuver loads". Sorry to disagree with you on that subject, I remember au French BEA report, about a near midair where an A320 was implicated, and which said that due to its speed of 250 the pilot was able to fully deflect ailerons and spoilers. I shall try to find it, if you are interested.

[misd-agin]

767-300 at our max T.O. wt had a flap retract speed of 256kts. That was your clean min manuever speed and the speed you flew in the U.S.

Former 747 pilot told me their min man. speed was around 270 kts when heavy.

[737Jock]

Narval, the speed varies from 250 kts (10000ft) down to about 248 on a319. On A320 it comes down from 260kts to about 256kts.

No I do not think the aircraft will give full control deflections. It will give maximum flight envelope performance in normal law.

I am not disagreeing with anything just providing the correct references.

[exeng]

sudden winds

Apologies if I struck a nerve.

Your point:

1) reduced climb. If for some reason your estimated fuel on board on arrival is too close to reserve+alternate, that's one thing you can do, especially if flying with a tailwind.

Sorry but I disagree. If short in fuel then climb at max climb power and you will reduce overall burn at the expense of the engine hot end.

Your other point: [quoteyou and probably everyone else in the airline you work for are perfect ][/quote] Well thanks for the compliment but I don't believe any of us are.

Regarding the -40°C criteria, of course I donīt just automatically turn it off when OAT says -40.0001°C but I noticed pilots still using it while riding inside harmless cirrus with OATs well below -40°C.

Very good - you are correct to notice that.

Another point of yours:

AND failing to enter the altitudes for TAI ON and OFF in the forecast page. That DOES increase fuel burn.

How would you measure that? Scientifically I would doubt you have ever had the means to carry out a proper statistical study based on your assumption. Regardless of what is entered in the FMC the outside conditions are the outside conditions that exist. The FMC is just another instrument to help us manage the flight - entering this altitude or another for A/I on or off is irrelevant. Just my opinion..... We used to fly the 737-200 which had no FMC but somehow we managed.

By the way I never tell my F/O where we will start the APU because I will not insult the intelligence of my colleagues - they know what is the best option for the airfield. Occasionally they have got it wrong in and I have failed to notice.

I've tried to leave out the 'do's and don'ts' and hope that my reply leaves you feeling that I have treated you with the respect that you and everybody else deserves.


Regards
Exeng

[framer]

The FMC is just another instrument to help us manage the flight - entering this altitude or another for A/I on or off is irrelevant.

Itīs not really irrelevant and I think youīl find Sudden Winds is probably correct, that it saves fuel (although probably not much). It wouldnīt save fuel if you were in a mode other than VNAV, but lets face it, most aircraft leave their cruise altitude in VNAV.

[de facto]

Regardless of what is entered in the FMC the outside conditions are the outside conditions that exist. The FMC is just another instrument to help us manage the flight - entering this altitude or another for A/I on or off is irrelevant. Just my opinion

As Framer said,VNAV profile will be more accurate with proper data entered in the descent page of the fmc,including TAI on OFF.
EXENG,you must be aware of the N2 increase with EAI ON ,which means your idle will be higher hence adescent should be started earlier...if you delay the descent your fuel burn will increase for a fixed CI.
Same without fmc,youd have to increase your speed to to increase rate of descent if you selected tAI On,,maybe not by much,,but all counts ,even QNH setting in the descent page.

By the way I never tell my F/O where we will start the APU because I will not insult the intelligence of my colleagues - they know what is the best option for the airfield

You should have SOPS for that,no?

[ozgun]

A little break question

İ am so sorry because i couldnt search the forum and i am in the middel of my flight . İ am wondering in an ils approach you are approaching vor and the minimum altitude is 9000 feet but in fms says 9000 feet or above , some pilot says you must cross vor at 9000 feet but fms says you can cross above this altitude, in jeppesen or somewhere is it written like you can cross above ?? İf you find this i will forward to my company . Thank you and sorry for the not searching