I think we are all basically talking about the same thing.
Nowhere have I said that V1 is a "decision" speed, it is (as others have said) a "must have decided by" speed. So, for example, my takeoff briefs have always, for the last twenty years, been "... at or after V1 we will continue the takeoff..." Note the "at or after".
Now, having said that...
Chimbu Chuckles
If you decide to reject AT V1 by the time you react, slam the thrust levers closed, autobrakes kicks in (or you stand on them) and the reversers deploy and spool up you'll be significantly above V1 by the time you stop accelerating and start to slow down.
Firstly, the certification requirements of the aircraft allow for that (2 second recognition time). Secondly, what is the difference between an abort at V1 minus say, 1/4 second, and V1? Figure it out - if your V1 is 120 kts, we are talking about an additional 15m. Thirdly, deceleration starts as soon as you close the thrust levers - it just isn't at it's maximum until spoilers are out, brakes are applied and reverse is at full noise. If you do exceed V1, it will be by very little. I've never seen anyone take two seconds to figure out it was time to stop with a failure, most folk have the thrust levers retarded within half a second. So figure another 30m or so if your failure happens ever so slightly under V1.
I'm not saying that your point about V1 is wrong, simply that the performance of the aircraft already allows for your scenario.
JT
I fear that you have the cart before the horse. If a yaw departure has occurred then there is no option for acceleration to get out of the situation for Vmcg
If Vmcg is controlling, you are on the ground, right? That is what Vmcg means. So in that situation, you control the yaw with asymmetric brake.
and only descent for Vmca ... the very thrust upon which you place your salvation's reliance is the same thrust which is taking you to your accident .... the thrust must be reduced to regain control. Like it or not ... we can't overcome the realities of the physics involved.
Whatever happened to lowering the nose to, at the worst, maintain level flight while you accelerate? It doesn't have to be a descent, not even in the F27 which is marginal at the best of times. The only time I can see that you would be correct is if you had an unfeathered prop or a similar failure. Of course, if you are talking about GA aircraft at high weights, then sure.
A multi can be so limited IF the thrust/speed mix is appropriate.
Not quite sure what you mean by that...
they all allow you to maintain an achieved speed ..
I'm afraid you have quite lost me here .. perhaps you might elaborate on your point ?
With the 146 (and the F27 too I think), under JAA-approved manuals, it was permissible to fly the engine-out departure profile at a speed higher than V2 if that speed had been achieved and the minimum climb gradient was being complied with. So, for example, if you were at training weights, it is actually pretty hard to stop the speed running away a bit while still maintaining a reasonable rate of climb (probably initially around 2000'/min at training weights in the 146). The point was that, rather than trying to chase a low V2, allow the aircraft to accelerate a little to aid controllability.
This is not at all a theoretical exercise. Many aircraft schedule takeoff speeds at low weight which put you right in this sort of harm's way if you mishandle the failure during a continued takeoff. I think that it will be useful for the newchums if we continue with this discussion ?
OK, but I can't think of any transport-category aircraft that wouldn't either accelerate quickly through the danger zone you are describing, or allow a power or pitch reduction to regain control while still climbing away quite happily. The reason I say that it is theoretical, is that you never need to get into that position in the first place. Again, using the 146 as an example, if you take off using flex thrust (as you normally would at training weights), there is no requirement to increase thrust to N1ref if you suffer an engine failure. You can if you want, but you don't have to as the flex thrust performance allows for the engine failure case. So for the 146, you have even less of an issue with controllability as the assymetric thrust is lower than it would be with full thrust.
I would be interested to know what aircraft you are thinking of when you mention these difficulties.
The point is that, under the present paradigm, reaching V1 confirms that you are going to continue keeping on going
Yep been saying that from the beginning...
Obie2
Err!...could I just humbly suggest that you all read the Ops Manual of the airline that you currently work for?
If you do what I say, you will find that it doesn't differ from the airline that you previously worked for!
Maybe not in Oz, but I have flown for three 146 operators in Europe with markedly different Ops Manuals and SOPs. One was radically different to the others.
I don't think any of us are fundamentally in disagreement, but we are seeing the problem from our own experience and the instruction that we have had. One's views may well be different if one has operated a type with marginal performance, etc...