v1 min vs balanced field lengh

ruhroa

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so guys n gals here is the question............... which is the prefered assuming a 5000' plus runway normal conditions..........
with the current feelings about the disadvantages of high speed aborts what are your thoughts on using either vi min or balanced field v1 speeds.... my initial idea is this if i reach v1 quicker then except for the fire,loss of control,loss of engine i have now taken the abort consideration out of the equation........however my coleague just went thru giv recurrent in dallas and they say no............. use balanced field v1 etc................. what says you?
 

caseyd

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so guys n gals here is the question............... which is the prefered assuming a 5000' plus runway normal conditions..........
with the current feelings about the disadvantages of high speed aborts what are your thoughts on using either vi min or balanced field v1 speeds.... my initial idea is this if i reach v1 quicker then except for the fire,loss of control,loss of engine i have now taken the abort consideration out of the equation........however my coleague just went thru giv recurrent in dallas and they say no............. use balanced field v1 etc................. what says you?

Hi ruhroa,

I don't know what they told your friend at recurrent and I've never flown a GIV/V. But after many takeoffs and landings in other planes I do know this: the liklehood of a fire, failure, configuration warning or sense the ship won't fly after 80 knots (or other subjective number) is so remote as to be statistically insignificant. But the certainty of an overrun after an ill-advised high speed abort is well documented. So the question is this: Do you want to create a culture which says "abort" when a problem (regardless of it's severity) presents itself or do you want to create a culture which says "continue unless". The "unless" is obviously one of the four conditions (maybe others) I previously identified. The benefit of the "continue" culture is that it ingrains the statistically safest choice (continue) by training pilots to allow for the most likely problems (minor) on the most likely runways ( >5000' ) while simultanously training them to stop if appropriate, even if it is a max effort reject. Most modern jet airplanes flown from less than critical runways can continue to a safe takeoff even with an engine failure 15 knots below V1. Continuing allows the poor slob who experienced the loss a long runway to stop on when s/he returns rather than what little remains if s/he chooses to abort at high speed.

caseyd
 

MauleSkinner

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Depends what you're trying to do...

If you use the balanced field V1, your A-stop and A-go distances are the same. If you're trying to haul the most weight out of a runway, this is the number.

If you reduce V1, your A-stop distance decreases, but your A-go distance increases. You're either reducing the weight you can carry out of that runway, or you're not going to have A-go distance (assuming, again, a critical runway length).

I guess it depends on which is more likely to kill me...If I'm going to run off a cliff in an abort, I'll reduce V1. If I'm going to hit the fence on the go, I'll use the balanced field number.

Fly safe!

David
 
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