hint.. If you answer a) I climb away clean I will refer you to your own post about having no data which you do actually but you've not noticed it
If you answer b) I take put the flaps back down and slow down and climb at V2 to V2+10....

actually.. maybe just wait for the answer...

And lets examine that a bit further. Why would you need an extended 2nd segment climb? which airfield? I think I posted regarding Geneva didn't I? is that one you will schedule an extended 2nd segment climb for? Or are you relying on a performance calculator on a laptop to give you the answer? Does the use of an extended 2nd segment climb improve or degrade your overall net take off flight path?

anyone?

all correct and mentioned earlier but mutt and cldrvr etc were busy shooting down such logic earlier in the thread because you can't prove it - there's no tables. However, final segment climb tables exist for my aircraft at least so you can prove what the climb rates clean are and thats with the power reduced to max continuous single engine - in the case of retracting flap at V2+20 (or indeed some arbitrary height should your operations require it) you would still be at max thrust so would exceed that figure.

All the other benefit - lifted off earlier, climbed better, probably going quite a bit faster, easier to fly clean than dirty - all thats a bit extra in the bank!

Mind you, still haven't actually heard back from CLDRVR with his plan from 400 feet so maybe we've missed something and are actually doomed..

Well well well, at my airplane I might (per CL) retract at 400ft & V2 +10.

V2 s are between 103 and 122 for Flaps 7° and 99 to 115 at 15°.

So I´d retract flaps with say 132 knots or 109 as the lowest figure.

Venr. is 180 KIAS.

I´d have to accelerate beteen 48 and 71 knots to get back to 'know territory'.

Flaps can be carried up to 200 Kias (15°) and 250 (7°).

We prefer 7° over 15° for much better second segment climb gradients. FSI/Cessna teach 15° for less wear and tear on the tires.

I´m not so sure that I´d stay above the required profile with an engine failing just as the flaps hit their up stops. Definitively not if I´d accelerate. Can´t gain that much height over distance up to 400ft methinks. At least there is no way to determine that easily, which is a requirement for dumb pilots such as myself...

But then the answer to the question is easy. not in the book, thus can`t happen. Done.

see..

not quite as simple as everyone thought..

No Tom, it ain´t.

http://www.pprune.org/biz-jets-ag-fl...ml#post7528407

But you can´t sell me my own question as yours !

You have changed your tune, in the beginning you were stating that you wanted to retract flaps as soon as you had the speed regardless of the height, thats what i objected to !

Now you are accepting that you will climb to the calculated acceleration height before retracting the flaps.

So i guess that we did get you to change your mind.

Mutt

Well, what an interesting thread!
As picked up by Roger Greendeck the flight techniques of FAR/JAR 25 have nothing to do with flying operation. They are the airworthiness certification rules to which manufacturers demonstrated compliance and obtained a type certificate.
Airworthiness certification flight testing establishes some limiting conditions (amongst a heap of other things) on which certain operational procedures are developed eg Vmcg, Vmc, Vs, Vso, Vdf etc.
As far a FAR 25 take-off is concerned, the manufacturer has demonstrated compliance with the Vef failure and produced some sort of WAT chart which shows if your weight is legal to go flying or not. This gives the minimum acceptable one engine inoperative performance which has been agreed to give you a high probability of not flying into the ground because of lack of performance in event of failure of the critical engine at Vef. It should never be confused with obstacle clearance - this requires a survey of all obstacles in the flight path and application of the aircraft performance data to ensure these obstacles are cleared by at least the statutory requirement.
I would be surprised if many of our bizjet operators have survey information for the airfields that they operate from. That there are so few accidents in this area is probably the result of very few critical engine failures and the high performance levels available rather than the type of pre-flight planning done by say airline performance departments.
It is not the responsibility of the airworthiness authority to rule on how a certificated aircraft is operated, other than compliance with the airworthiness limitations in the AFM. That is the responsibility of the operator and the operations section of the regulatory authority.
I have yet to see any operational requirement that stipulates that, on take off, an aircraft must fly a profile that in some way replicates the profile flown by the manufacture to demonstrate compliance with minimum climb gradient requirements. The tests have been done - if you look at your WAT chart before flight and are below the WAT limit you are compliant. If you wish to fly that profile that is fine, but that doesn't mean that you will necessarily be compliant with operational requirements.
Some have commented on the lack of material in the AFM for this sort of operation - this is not an issue for the AFM, it is operational and should be in an ops manual.
Some have no clue about scheduled performance, one even commented on 2nd segment after flap retract followed by an engine failure.
So, all engines operating, retract your flaps whenever it is appropriate, you are not required in any way to fly a profile which replicates that used to demonstrate FAR 25 minimum acceptable one engine inoperative climb gradients. In many cases obstacles make such a profile an impossibility
Whatever you do, make sure you have planned a combination of ground track and climb performance which will ensure all obstacles are cleared by at least the minimum requirements after an engine failure (or more than one engine failure if that is the requirement) at any stage of the flight. While you are at it, make sure all the ops rules are covered as well.

Oh yes it does.

I sincerely hope you are not a commercial pilot. If you are, going by your profile location, stop flying forthwith and familiarise yourself with your Part 20.

Are you for real? Or are you just helping some others here troll the thread for laughs.

At least we got Tom to agree on the 400 ft after 11 pages....

Now let's get the remaining stragglers to see sense here....

zzuf

If it is limiting then you have to fly your profile.

You might want to have a look at CAO 20.7 specifically 20.7.1b

And why does Airservices ERSA publish TODA and STODA information.

And why does the STODA provide Take Off distances for specific gradients, at 1.6%, 1.9%, 2.2% and 3.3%, look familiar?, in addition to the actual TODA gradient at each runway end.

And why cant you operate into or out of an aistrip that does not have that information available.

And why would you not use RTOWs calculated by performance engineers (we like most people including Jepp and Universal use APG) for specific airport runways as a convenient legal way of calculating an accurate weight at a given density altitude to assure that you can meet said obstacle clearance, without having to beat your calculator to death and/or get it wrong on your WAT chart.

Or maybe I'm just missing your point altogether.:hmm:

Incessant. You guys (and gals) have taken anality to a whole new level.

I feel sorry for the kid reading this thread who may now wonder if there are alternatives to V-speeds and configuration dictated by the manufacturer in the POH.

Please do, carry on.

Bingo

quick one for mutt - where, in all the posts I have made, have I accepted the 400 feet is the correct minimum platform for an all engines operating take off?

somewhere around post 220 I think clrdrvr said he thinks its ok to raise the flap at 400 feet.

I asked the question, what data does he then use for an engine failure at that point.

haven't heard anything back since then.

maybe he hit a hill..

tell you what, Bingo, if you are absolutely certain that you're up to speed with it all, why don't you post the answer for Cldrvr.

Take off, 400 feet and V2+x, engine failure, where's your proof to the authorities that you can climb away?

(I know where it is.... its in the same place that proves you can retract the flaps at V2+x and that 400 feet is a call that was dream't up by pixies and elves to annoy the ogre..)

...ps.. its 500 feet in the UK. CAP 778 applies...

http://www.caa.co.uk/docs/33/CAP778.pdf

CAP 778
Policy and Guidance for the Design and
Operation of Departure Procedures in UK
Airspace

Looks like I read your post #224 incorrectly......

Mutt

hey dudeness, have you gone from being able to retract your flaps at 400 feet to not being able to retract them to 1500 feet or are you now re-planning all your flights with the flaps at take off from the start of the ground roll to the end of the landing roll.

now we're getting somewhere.

I think we have flaps so that in the event of a double engine failure you can put them up and down really fast and the aircraft gets pushed along by the thrust from the dolphin like movement.

Is anyone certain enough to take my bet yet?

haha, yep mutt you did..

hey, dont tell the others but I had a 30 min call from Bombardier today.

email coming on monday.

and guess what.....

that dogs home is gonna get some new kennels.....

mutt, you never told me..

400 feet, v2+x, then the engine fails.

whats your plan?

where's your data?

(by the way, I think zzuf knows more than he's letting on)

His dudeness has given you figures where he has to accelerate between 48-71 kts, based on your assumption that you can clean up at V2+X regardless of height, when do you suggest he levels off to accelerate, while ensuring that he doesn't fly into a mountain?

Mutt