When do we announce V1 & rotate on A320

[adnanaviators]

When do we announce V1 & rotate. Some people say , announce it 5-7 kts before reaching that vspeed .

[Bula]

5-7 knots..... who is saying that?

just announce it as close to the speed as you can.

You still have the recognition/response delay from certification up your sleeve For a go or no go decision.

personally I prefer an earlier go decision 1 second prior to V1, than no go at V1 + 3 seconds. Both are certified, one gives a lot more margin.

[casablanca]

When do we announce V1 & rotate. Some people say , announce it 5-7 kts before reaching that vspeed .
that definitely gives you more margin for stopping, but if a balanced field length V1 is also minimum speed to continue, rotate and climb to 35 feet by end of runway? If you decide to continue when that much slower you may not like the results

[underfire]

When do we announce V1 & rotate. Some people say , announce it 5-7 kts before reaching that vspeed .

Before 35 feet AGL at the end of the runway.
So you know, it is assumed there is a 7 second delay, so when the ac says rotate, it assumes it takes 2 seconds for the pilot to comprehend, 2 seconds to move the controls, and 3 seconds for the ac to respond....

[piratepete]

Since around 15 years ago, and I seem to recall it came out of either a safety forum related to the rejected takeoff issue or it was from Flight Safety Foundation, it was RECOMMENDED to actually utter the word VEE- ONE at the computed V1 minus 5 knots.This is very good practice and should be applied everywhere.The reasoning is the V1 does not change at all, however the words VEE ONE will be stated by the PM just prior to V1 thus allowing the pilot in the left seat to make his go/no go decision at or before, but not later.Many many times in the simulator I have seen pilots try to reject just slightly after V1 and while most of the time with long runways you get away with this but in the most limiting cases you run the serious risk of an over run/crash.
I am aware of many airlines having this technique in their SOPs but everybody should apply this.Its safer.

[Feather44]

What about calling V1 when at V1, and Vr when at Vr???

[bigduke6]

There is no reason to call Vr early, so why would you?

[vilas]

There is no reason to call Vr early, so why would you? There is a reason to call early because V1 is the maximum speed you would take the first action for a reject takeoff. If you wait till you see V1 then that's not going to happen. There is only vague guidance on how early.

[OutsideCAS]

I agree with Feather44. Call it when it your at V1. What next, make adjustments for someone's rate of speech? Intonation? Dialect? Cant even believe it Is worthy of any other consideration. To suggest any other option is madness and lunacy and to enter the world of a test pilot.

[ACMS]

What sort of stupid second guessing question is this?

The A330 and A350 all have auto V1 callouts and they occur AT V1....not before......

Stop trying to complicate things.

just do what Airbus and your training department tells you.

[Chesty Morgan]

Personally, as PF, I keep half an eye on the ASI anyway so if anyone forgets to call V1, calls it late or early then I’ve already made my mind up what I’m going to do.

And let’s not pretend that actual performance matches exactly that which was calculated so keeping an eye on your speed and runway remaining will allow you to make a judgement call at the time.

[HGVO]

Our SOPs require us to make the call at V1-3kts

[compressor stall]

Well the Airbus opinion on the matter (refer the STOP/GO FOBN) which reflects regulatory definitions of V1 being the maximum speed at which a takeoff may be discontinued is:

V1 is considered to be the end of the STOP or GO decision-making process. Therefore, at the latest, this decision must be made at V1, so that the Captain can initiate the STOP actions as close to V1 as possible: V1 is indeed a decision/action speed.

Logic says that if the decision is to be made by or at V1, then the call can’t be made at V1.

Having said that, look at the ASI permitted discrepancies from CM1 to CM2 ...

[compressor stall]

than no go at V1 + 3 seconds. Both are certified, ...

Careful. The 2 seconds acceleration after V1 certification was amended in the early 90s to be replaced with a distance equal to 2 seconds of travel at V1 speed. Not the same.

[FlightDetent]

Why not? If you call V1 at the speed exactly, then you simply do not stop once the words are spoken.Anyways, I was trained to announce so that the callout is finished by the time we are passing the last action speed (v1). Guess about 1 sec is needed. Any captain is surely looking at his ASI at that stage, there is little practical benefit in digging deeper.

-7kt would be definitely non-compliance.

AFAIK Lufthansa uses a different call, and I admit to love their thinking. Same time, same use, yet another word. It is one syllable, so the timing becomes irrelevant. It removes ANY ambiguity about the decision/action meaning. They say ........ “go”.

Vorsprung durch Expertise, there you have it. In that light a “vee-one” call or this discussion is quite 1950s.

[Basil]

They say ........ “go”.
I like that.

[FE Hoppy]

Auto call outs do it at V1. Ive seen a lot of airlines SOPs. Probably 60 or more over the years. Most call AT v1. A couple of years ago some changed to calling x kt before but most have changed back to At. Some changed to "go" some of those have changed back to "V1".

All much of a muchness really. As PF don't reject above V1. Simple.

[FullWings]

Auto call outs do it at V1.
Hmmm. I can’t speak for all types but the Boeings I’ve flown with auto-callouts definitely start the “Vee one” phrase before the speed has got to V1, something like 2-3kts below...

[GlenQuagmire]

Might just be me but the V1 call is only part of the go-nogo for me. What defines the go-nogo is the actual indicated speed. If the PM chooses to call V1 early I will assume the ASIs are reading differently for some reason and be prepared for unreliable airspeed. If I am handling I will have the ASI in my scan and know when I am through 80kts, am passing V1, and rotate. If you are dependent on the V1 call or rotate call you will have lost an opportunity to find out that your pitot is blocked..

[Bula]

Careful. The 2 seconds acceleration after V1 certification was amended in the early 90s to be replaced with a distance equal to 2 seconds of travel at V1 speed. Not the same.


Don’t forget the 1 second of recognition time, so on a FLEX takeoff at reasonable OAT “should be good” if the aircraft is stopping by V1 + 3sec. Personally, not a chance in hell.

[Check Airman]

I remember reading somewhere (may have been on pprune) that some airline called V1 a few kts early, as had been their custom. This continued until Airbus pointed out that their published V speeds already accounted for the human factors aspect of it, and thus calling V1 early was inadvisable. Again, not entirely sure of the source. It may have been an airbus publication, or just something that was posted on a forum, but it bears consideration.

[giggitygiggity]

I remember reading somewhere (may have been on pprune) that some airline called V1 a few kts early, as had been their custom. This continued until Airbus pointed out that their published V speeds already accounted for the human factors aspect of it, and thus calling V1 early was inadvisable. Again, not entirely sure of the source. It may have been an airbus publication, or just something that was posted on a forum, but it bears consideration.
Yes, you've still calculated the perf with the 1.15 or 1.3 margin for good reason.

[pattern_is_full]

For me, the V1 call doesn't mean "Decide now!" It means "Decision time is over - we're going!" (Absent, of course, an event that makes flight impossible).

[Feather44]

I totally agree with Pattern

[Centaurus]

If it hasn’t been called, then STOPPING is still an option.

That is a very dangerous statement. IMHO, a wise pilot should never totally rely on the other pilot's speed call-out as a basis for such a critical decision as a high speed rejected takeoff. From observations in the simulator, it is rare that a high speed rejected take off on a limiting runway is conducted perfectly. In real life, that certainly is true. If there is a mistake on a limiting length runway, the chances of an over-run are high.

If a PM has not called V1 it could be for any number of reasons. That includes complacency or laziness, distraction (eg looking at an N1 reading which seems not quite right), fiddling with a thrust lever trying to get an exact N1 reading, and worst of all, momentary incapacitation. The decision to make a high speed rejected takeoff on a limiting runway length is probably the most critical life and death decision a pilot will make in his flying career. To base that decision on one man's verbal call-out rather than using your own eyes, is really stretching your luck.

There are some pilots, aware of the circumstances of previous accidents, that make the mental decision to go well below the calculated V1 even up to 15 knots below V1. They are playing the statistics i.e. the risks involved with a high speed abort versus the lesser chances of colliding with an obstacle during the lower flight path in the go situation. You have to be realistic here. The number of accidents that resulted from a high speed abort as against the number of accidents where trees and other obstacles were clipped during the second, third or fourth segment during IMC departures.

[Brain Potter]

What sort of stupid second guessing question is this?

The A330 and A350 all have auto V1 callouts and they occur AT V1....not before...



The A330 auto-callout is triggered at V1 minus 5 knots.

[john_tullamarine]

The 2 seconds acceleration after V1 certification was amended in the early 90s to be replaced with a distance equal to 2 seconds of travel at V1 speed. Not the same.

Indeed. However one needs to keep in mind that the acceleration was with the remaining operating engines, and the distance at the V1 speed. So the rundown characteristics need to be taken into consideration when considering "not the same". As the rationale was to inject a pad for those things which catch us out, the distance requirement is more readily comprehended.

Yes, you've still calculated the perf with the 1.15 or 1.3 margin for good reason.

I'm probably just having a slow day .. the factors relate to ?

[Colibris]

Here's an interesting video that covers this. (fast forward to the 14th min of the video for the V1 part)

Do what your SOPs say, there might be a reason why they ask you to do it a certain way, In doubt, email your tech pilot and he should have the answer.

https://www.youtube.com/watch?v=sDMiE4NA9IA

[Denti]

I was surprised on switching from the 737 to the airbus that the latter did not have automatic V1 calls. On the 737 the V1 call started at V1 -3 kts, but i have no idea if that was a company preset or boeing setting. With the usual 1 or 2 knot difference between V1 and Rotate there is the choice of either calling V1 a tad early, or Rotate a bit late. That said, i much prefer an automatic callout, the aircraft calls all other kind of stuff out, why not V1?

[Basil]

you will have lost an opportunity to find out that your pitot is blocked..
. . or that one of you has bugged the wrong speed :O

[VinRouge]

The 2 seconds acceleration after V1 certification was amended in the early 90s to be replaced with a distance equal to 2 seconds of travel at V1 speed. Not the same.

Indeed. However one needs to keep in mind that the acceleration was with the remaining operating engines, and the distance at the V1 speed. So the rundown characteristics need to be taken into consideration when considering "not the same". As the rationale was to inject a pad for those things which catch us out, the distance requirement is more readily comprehended.

Yes, you've still calculated the perf with the 1.15 or 1.3 margin for good reason.

I'm probably just having a slow day .. the factors relate to ?
Absolutely nada in this case as reject at V1/Go is calculated using Gross not Net performance.