(a) Ah now, ya can't really mean that!
I mean just that - we are talking about the wind from the same side as the failure, of course .. from the other side the situation is improved in the crosswind condition. Keep in mind that the (small) deviation we routinely see during local asy training or in the sim does not increase gradually as speed decreases .. it tends to come in a bit of a rush as the cut speed approaches Vmcg. Now add a significant additional yawing moment due to the crosswind and it all turns pear shaped.
(b) In a crosswind, the rudder will already be deflected to keep the aircraft tracking the centreline. If an engine then fails at V1 the rudder will need to be deflected further by a similar amount to the still air case. e.g.:
Still air:
Engine failure - 50% deflection required to control.
Crosswind:
Requires 40% deflection to maintain centreline.
Engine failure - 50% deflection to control.
Total 90%
Doesn't work that way ... your scenario might be the case for a "normal" cut speed well above Vmcg .. for the min V1 case, you can expect full or near full rudder deflection before you start considering the effect of wind... ergo add wind and it's all excitement
(c) If you feel that a trip to the weeds is inevitable then you are implying that the rudder will hit the stop and control will be impossible.
That's the story ...
(d) You can't honestly think that possibility has been overlooked by authorities or manufacturers.
I know so. The certification requirement looks at nil wind (or 7 kts in some older cases). There is nothing stopping you going with a min speed schedule in a strong crosswind .. you just need to understand that there is an elevated risk of control loss if you have a critical failure.
(e) At my company on the 321 there are adjustments made to V1 for crosswinds of 20 kts or greater, although this is primarily due to engine consideration which I don't understand. (Incidentally, the change is 1 knot!)
I can't speak to your company's protocol other than to suggest that the correction isn't looking at crosswind.
(f) I don't really think that you will find many manufacturers who would agree that their aircraft probably shouldn't take off at their published crosswind limit, just in case something goes wrong.
Of course not .. the OEM will refer you to the certification design standard ..
(g) Nor do I think that pilots will say "The limit is 30 knots, it's at 25 now, why don't we wait a while cos I'm worried about not having enough rudder if an engine fails"
This pilot considers the following
- if I have a longer than necessary runway, can I increase the speed schedule to make the problem go away ?
- can I delay ?
- else, is it reasonable to go and accept the (small) risk of a critical failure ?
The reason that some of us bring this topic up every now and again in PPRuNe is that the very great majority of pilots have never had the certification problem explained to them .. ignorance is bliss.
(h) What crosswind component would you sugeest we wait for?
Not a question of crosswind .. a question of speed schedule ... First consider asking your flight standards/ops eng folk to find out if the OEM has the data .. most will. Then apply that to the min V1 (ie Vmcg-limited takeoff schedule) to come up with a corrected schedule. Otherwise my thought would be to go for something not less than 0.5kt/kt for twins and 1.0kt/kt for quads
(i) ..not taking gusts into account.
Difficult to do that .. but you can make a considered assessment
(j) If your engine goes bye-bye at V1 which is limited by VMCG and at the same instant a gust that is 10 knots above your crosswind limit occurs, you may have trouble.
You don't need a gust .. you already do have a problem.
(k) You may however just simply be the most unlucky individual on the planet!
We all accept that there are days when one should not have got out of bed.