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Thread: V1 question.
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Old 23rd Aug 2011, 05:28
  #73 (permalink)  
john_tullamarine
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I have very rarely seen a runway limited case.

Depends on Type and runway. I have worked with operators where the limitation on RTOW was just about invariably runway length.

Most of the times second segment or obstacles is the limitation.

Often the case but cannot be relied to be so. A problem is that the RTOW chart may not explicitly state the limiting case on the day.

Can that be the reason for the high V1 VR values, that the optimum speeds are sort of an improved climb?

Certainly, one wouldn't normally be looking to exploit improved climb by pushing the V1 down.

It is better to stop a wreck and overrun the runway than become airborne and crash.

All a risk management exercise. If the overrun is benign, of course. If tiger country (eg have a look at Nauru) perhaps not so clearcut. However, what is clear is that SOPs cover the reasonably routine - a well trained and educated captain gets to handle the hard ones .. presents a problem if the captain is a bit underdone.

But the good thing is that chances of choosing the correct action are much better than in the instinctive reaction.

That's the one. Run with the numbers and keep your fingers crossed that today you are not at the wrong end of the distribution curve.

It is, however, necessary to understand that there are occasions where the normal gameplan(s) won't work and, if you get it right (or at least get away with it), you get the bouquets (Sioux City, the Hudson, and a few others come to mind). If things don't work out so well (we don't need to cite instances) then folks tend to look down their noses.

The captain is called on to make a decision and implement it. The important thing is that a rational decision be made .. longterm fence sitting generally doesn't cut it. The outcome often involves a bit of planning, a bit of skill, and a LOT of luck.

ssg to follow

... that's a bit cruel ?
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