Agreed.
For the V1 minus 5 crowd, why not V1 minus 10? Would be safer in theory. Or V1 minus 15? Even more safe. Could go on all day. V1 is indeed V1, I believe. No need to muddy the water.
Calling V1 five knots early?
- Thread starter SteveC
- Start date
Agreed.
For the V1 minus 5 crowd, why not V1 minus 10? Would be safer in theory. Or V1 minus 15? Even more safe. Could go on all day. V1 is indeed V1, I believe. No need to muddy the water.
jtrain609
Antisocial Monster
You know this is the internet, right?
dasleben
That's just, like, your opinion, man
V1-5 approximates the built-in delay between the recognition of the engine failure (or other event) and V1 itself. Calling V1-10 or V1-15 would be arbitrary, and not significant to anything in particular.
Dan208B
Well-Known Member
My company's procedure is to call V1 5 knots prior to actual V1. I think it would be very inappropriate to do anything contrary to your company procedures no matter what anyone thinks about it. However, this is a great discussion and particularly useful for anyone flying corporate or somewhere that doesn't have SOPs.
Again.....muddying the water. If one wants to do business that way, thats fine, but why not call the V1 minus 5 number simply "V1", since you're using it as such anyway. Semantics, I know; but both are being used for the same purpose, and hence should be titled as such (just known/briefed which method is being used to come up with the number........minus or no minus.)
PhilosopherPilot
Well-Known Member
Because that's what the boss says. He say call V1-5, and monkey does it.
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Again, I agree if one wants to use this metric for it. That's cool. I just think both should be called "V1", because both computing methods are being used for the same thing, even though the methods are different.
jynxyjoe
Queso King
Agreed and there's bunch of data saying V1-10 or 15 is still statistically better too, than aborting 5 knots after V1
dasleben
That's just, like, your opinion, man
We don't consider V1-5 to be V1 because it's not V1.
We simply call it 5 knots early to approximate the delay I mentioned above, and accommodate the fact that the first action to reject the takeoff must have already been made at/prior to V1. It's a bit academic, but if you're light, or the runway is contaminated, treating V1-5 as the actual V1 may put you below Vmcg.
Anyway, that's the way Boeing wants it done. Those cats are smarter than me.
We don't consider V1-5 to be V1 because it's not V1.
We simply call it 5 knots early to approximate the delay I mentioned above, and accommodate the fact that the first action to reject the takeoff must have already been made at/prior to V1. It's a bit academic, but if you're light, or the runway is contaminated, treating V1-5 as the actual V1 may put you below Vmcg.
Anyway, that's the way Boeing wants it done. Those cats are smarter than me.
Just and interesting academic, and I understand what you're saying and why it's used. It just seems that the V1 people, and the V1-5 people are using an individual number as their own refusal speed, but since both are still being used as definitive refusal speeds........whether taking into account the reaction delay or not doing so (the different metric)...both sides are using it for the same purpose. Would seem logical to (big picture) title them the same then for that reason, just realizing that the actual number at Company A means its a raw data number, and at Company B it's a number with 5 knots subtracted from it. Both used for same purpose.
I don't think that either method is wrong procedurally, they're just different techniques........different ways of doing the same thing; one slightly more conservative than the other. I agree, do what the company/manufacturer mandates, at the end of the day.
PhilosopherPilot
Well-Known Member
V1~4.7?
What's funny is these kinds of arguments especially in military aviation (where I've seen it most), where people argue instead of discuss technique vs procedure. As nearly anything can be accomplished safely/efficiently in more than just one way, you'll obviously come across different techniques people may have...........some more/less efficient than another, but whatever......because they all still conform to the overall procedure. And that's cool. The intersting things is coming across the guy.....and worse, the flight examiner.....who thinks his/her technique is the only way of doing business, and hence he considers it to be "tech-cedure." Worse, they grade to this instead of remaining big picture of "does this particular technique being used meet the overall procedure intent"?
It's nice to see that trap not being fallen into by those in this thread. Interesting discussion all around.
Not ours. The school of thought at my company is that once you reach V1, the decision to take off has been made as in the "takeoff decision speed" is somewhat mislabeled.
@PeanuckleCRJ is an instructor so please feel free to steer me if need be.
jynxyjoe
Queso King
You guys didn't rename it to "Takeoff Action Speed"?
PhilosopherPilot
Well-Known Member
It's a constant struggle to be sure to not teach YOUR way and to not debrief a perfectly valid but different technique.
Autothrust Blue
Welcome aboard the Washington State Ferries
They let me fly the sim from the left the other day, and long about V1-3 knots, I said "V1" and put my right hand from the thrust levers to my right knee. Sounds good to me.
