Call V1 3 to 5kts prior

[eight16kreug]

Call Outs

Old Airbus callouts: Flaps One. Speed Check, flaps one, selected. Indicating.

Current callouts. Flaps one. Speed Check, Flaps one.

I think the trend is towards less callouts.

[Basil]

I surely wish the airlines would stop mucking about with the manufacturers' operational procedures.

You're certainly preaching to the converted with me
Re verbosity; flew for an outfit which Called: "Set thrust 1.nn EPR!"
I always felt that I should be looking outside at that moment rather than glancing at the card or the EPR bugs.

[UL975]

I may be wrong, (have been in the past) but I thought that very simply put.....


FAA performance V1 has no fudge factor bult in.

JAA adds a 2sec fudge factor to the V1 speed.


So the operators calling V1 before V1 are probably FAA airlines adding their own fudge factor.

[safetypee]

See
UK AIC information on RTO. This is based on JAR/CS 25 certification requirements which have (as far as possible) been harmonized with FAR.

The decision speed (V1) is the highest speed by which the pilot should have made the mental decision to reject the take-off in the event of a relevant failure.

A recognition period (distance) is included in the certificated data – Vef is prior to V1; crews need not be concerned with the technicalities, just respect V1.
A period (distance) after V1 is provided in the calculations to enable completion of the RTO drills, again crews need not be concerned with these values; perhaps more so with the accuracy of the speed setting and total distance required to stop.

It might be of greater importance to understand what failure or condition determines the need for a RTO as opposed to time periods, and then preparedness for timely and correct action if the decision is to stop, e.g. apply maximum braking. Beware the human limitation from time dilation in judgments made in stressful conditions.
Does anyone have procedures that require manual braking even if auto brake is selected – mitigates any error in setting autobrake?

Note new UK AIS web site.

Also, see ‘accelerate-stop time delays’ AC 25-7A Flight test guide for certification of transport category airplanes. Chapt 2, a good diagram on page 80/9.

[mutt]

AFAIK, there are 5 versions of FAR25.109.... so a blanket statement regarding reaction times and engine failure point, may not apply to YOUR specific aircraft.

For example, the B777 has the VEF 1 second prior to V1, with continued acceleration until complete stopping congfiguration is achieved.

Mutt

[oldfella]

I may be out of date on my definitions and understanding so apologies if I am wrong. I thought that a rejected take-off before V1 was guaranteed to stop within the ASDA i.e. TORA and Stopway, not guaranteed to stop on the runway, however, with no stopway, e.g.Gibraltar, ASDA = TORA and, in theory, you would not get your feet wet. A lot of assumptions are made that you will stop on the runway.

[Pugilistic Animus]

I'm one of those who responds with a thank you or precedes with a please. I don't see that as extraneous or out of line, but I've sure met a few who had a fit because those "extra words" were apparently just too much to handle.

Guppy,

Yeah, today people in aviation get excited over immaterial things and yet blissfully ignore very important operational concepts if they're not explicitly written as sops---the answer--- longer more confusing procedures---to create higher risk of RWY incursions



OldFella,

the geometric definitions haven't changed, just the perfermence requirements along the length of the defined 'sectors', so you're absolutely correct

Thanks,

PA

[john_tullamarine]

Post A/L 42 aircraft are in a more comfortable situation .. pre amendment aircraft represent a VERY critical accel-stop in limiting conditions.

[Pugilistic Animus]

John T,

How would you characterize the accelerate-GO?--in a limiting situations---but I guess this may have biased one toward non-BF calculations and where possible a lower V1?

PA

[john_tullamarine]

(a) considerations of BFL, unbalancing, overspeed schedules, etc., are all made before the takeoff as part of the performance assessment. This is done either in the preparation of RTOW tables/charts by the ops engineering folk, or by the pilot in those operations which impose that task on the crew.

(b) if the takeoff is accel-stop-limited then, in the GO situation, if the sums have been done acceptably, aircraft and pilot performance and weather are reasonably similar to the certification expectations ... then it should be a matter of just flying the aircraft through the exercise.

(c) if the riders attached to (b) don't apply then, just perhaps, the crew and operator have their collective necks on the line ?

[Pugilistic Animus]

a) considerations of BFL, unbalancing, overspeed schedules, etc., are all made before the takeoff as part of the performance assessment. This is done either in the preparation of RTOW tables/charts by the ops engineering folk, or by the pilot in those operations which impose that task on the crew.

As usual JT ---wise and knowledgeable words--- but I was referering to the engineering side--not the end user---i.e if on an earlier type of older certification do you tend to unbalance according to the limiting cert scenario in the RTOW assumptions? is it such that unbalancing occurs mainly in the ASD--but leave the BF for the GO--just wondering how a pro would handle it?---I have looked at the preammendment requirements, but would like to know how such things affect the performance calculations

PA

[PantLoad]

Mutt is correct....

Mutt is correct.....it depends on the standards under which the aircraft was certified. His B-777 was, I believe, certified, after certification standards underwent major changes (subtle on the surface, but quite significant).

FAA/JAA and manufacturers have been for years aware of the shortcomings of this stop/go dilemma. The accident I cited in my above post brought to light the issue of inadequate certification standards in this reagard.

Of course, your company's SOP takes priority over everything...as this is one of the predicates upon which the airline operating certificate is granted. (I know, this is a controversial statement.... But, you need to follow your SOP. If you find a problem with anything in your company's SOP, you should bring this to the attention of management.)

And, as always, be careful out there....



PantLoad

[Pugilistic Animus]

PF: SET POWER
PNF:SETTING POWER

PF: AIRSPEED ALIVE
PNF:CROSSCHECK
PNF: CONFIRMED POWER SET 1.06epr UNITS

PF: 60 KNOTS
PNF: CHECK
PF: 80 KNOTS--ENGINES STABILIZED
PNF: CHECK --ENGINES STABILIZED
PF: ONE HUNDRED KNOTS
PNF: CHECK ONE HUNDRED KNOTS
PNF: V1 FIVE TO GO
PF: CHECK

PF:VEE ONE

PNF: CHECK VEE ONE
PNF: VEE ARE ---ROTATE

PNF: VEE TWO


PF: CLEAR OF GROUND POSITIVE RATE GEAR UP

PNF: GEAR UP--AND LOCKED
PF: CROSS CHECKED

PNF: APRROACHING ACCELERATION ALTITUDE

PF: SET CLIMB POWER

PNF: CLIMB POWER SET

PF: ACCELLERATING --FLAPS SCHEDULE

PNF: FLAPS UP

PF: CHECK FLAPS UP

ummm....where the hell are we going????

Sorry, couldn't resist---everyone gets the joke

[mutt]

Look dude, if you are going to keep coming in here using different user names... please learn to spell OBSTACLES correctly, otherwise you are just making things too easy!!!!!!!

Mutt

[john_tullamarine]

but I was referering to the engineering side--not the end user

If I read your question correctly ...

(a) the takeoff calcs are for one set of runway data ... you can't make one bit BFL and another bit unbalanced, etc.

(b) nothing secret about the process .. for those aircraft whose AFM permits unbalancing, one just iterates the calculation with different levels of unbalancing until the RTOW for that given data set is maximised.

(c) this is constrained a bit if the output is graphical but, for the normal tabulated RTOW tables, it is a doddle and each point can be optimised without consideration of others .. at the end of the day the pilot needs the speed schedule and the unbalancing extent is buried within this output.

(d) there is no reason why the data cannot tell you the extent of unbalancing but that is not normally done

If I have missed your point, do try again and I shall endeavour to be a more diligent reader.



Mutt .. that's a tad cruel ....

[Mach E Avelli]

With reference to the Gear Up call I once had to endure the response 'selected, 3 reds' followed by 'gear is up, lights out'.
No one ever told me what to do between then and until after final clean-up if there were only 2 reds. Hold the checks, maybe?
At the risk of thread drift, other useless classics include during takeoff 'temps and pressures checked' , 'on finals, no flags' and in response to the 500ft rad alt call 'for the threshold'.

[Brian Abraham]

Mutt .. that's a tad cruel

I thought mutt showed considerable restraint, a measure of delicacy and tact. Quite unlike some.

[TheChitterneFlyer]

V1 or V1 minus 3-5, what's the difference... you're still likely to be eating dirt if you stop. Plus an interview that doesn't include tea and biscuits... hat on!

TCF

[Pugilistic Animus]

JT---the prior post was helpful in removing some confusion I had---although, and I blame my own phrasing,---but what I'm really getting at id

when you do the RTOW charts---is it's a good decision to use --let's say for example---I'm on an ASD RWY for a given set of condition, so I use unbalanced data iteration for that limiting case---for another set of conditions my ASD is adequate, but I'm climb limited so--I use the BF UBF data[whichever will allow the higher weight---but the end user is unaware--or am I jus' makin' up stuff?
but does 'mixing the two' on a RTOW--allow higher weights if the RTOW--is produced from different sets of data--of course the end user will have no clue

Thanks,
PA

[mutt]

PA, its called optimized v-speeds and is available from all your favourite manufacturers.................

you're still likely to be eating dirt if you stop

not always true... but hey this is pprune!!!!

Mutt