We have an allowable 4 knots on the gauge but zero on V1, not even a conditions variant.
I have it in mind that the Standard for I/F ASI is 5 knots but won't bother to dig that out to confirm/correct just now .. certainly, there is (and must be) a tolerance.
The usual calibration will result in a lesser error .. normally, the operational application is to apply the design tolerance as a "between gauges" figure. Like many things, we can split hairs all day .. in current practice, V1 should be called marginally early so that the call is completed by the observed V1 reading. A small error will be accommodated by certification tolerances and I certainly wouldn't be losing too much sleep over this particular concern.
Now what would the call be on this famous crash be if they had Tail Cam? it happened in the "fat Zone".
As most would be aware, there were various tales about this and that with the mishap aircraft.
However, the takeoff mishap, very clearly, was way outside the certification expectations and parameters. Evidently the Commander flew the failures exceptionally well but far too many things were against him and the outcome was predictable and is well known.
Some days it doesn't pay to get out of bed .. problem is, we don't have a crystal ball to identify the days in question.
Again, the Design Standards DON'T give you any guarantees .. only reasonable probabilities based largely on historical data. Unless the situation is well and truly outside the gameplan, there is a good chance of a successful outcome, given a competent (and, where necessary, innovative) crew.
For the small percentage of folks who find themselves up that well known creek without a paddle .. life's risks sometimes catch up with us and exact a dreadful toll.
Yet when I give a scenario in which stopping action is initiated prior to or at V1, but the action fails,
I, for one, have no problem with your scenario.
However, it is well outside conventional certification expectations. Unless there be significant spare runway (hence my Edwards reference) the likely outcome is not going to be nice regardless of however the Commander might play the cards on the day. As to what is the best call .. as so often, it depends. Nothing wrong with having the discussion, though.
the decision must be to continue the take off
That will be the normal SOP. However, as a wise checkie once emphasised to me at the debrief ... "Young John, keep in mind that the manual has an admonition on the front page in invisible ink .. 'To be read with a modicum of commonsense'".
We necessarily need to keep the routine balanced against the extraordinary. SOP intentions probably will provide an acceptable outcome on the great bulk of occasions .. so we stick routinely with SOP. On those occasions when the Commander is called upon to earn his/her salary, SOPs just may not cut the mustard and the Commander may have to be a bit innovative.
Lessons learnt on B707s and early B747s may not be directly transferable to aircraft fitted with engines certified to the contemporary standard.
That may be a fair comment. However, the underlying problem is that the sorts of scenario you postulate generally have not been tested and, hence, the crew on the day probably doesn't have much to go on other than gut feel. So long as that is understood, then the folks in the sharp end just make the best play they can out of a bad hand.
What was the first aircraft in Australia to have V1 & V2 speeds, the DC-4, Electra?
Both predate my Industry involvement slightly (although I did fly and loved the Goose in the late 70s). We would need someone a bit older who was involved in the early to mid 50s (good heavens, I still had to discover girls at that stage of my life ..) to recall the precise sequence.
Prior to the PAMC changes to performance - which were around this time (as I recall the F27 was probably the first to run the recertification gauntlet) aircraft performance was scheduled to older standards.
My guess is that the DC4 wouldn't have been reworked - although I did some engineering work on the Air Express ex-QF DC4s at Essendon, I just can't recall what the cockpit procedures were. However, the turboprops certainly were redone. So the Electra and F27 (flew both) had the normal schedules. I just gave Centaurus a call (he flew Viscounts for 34SQN) and he confirms they had the normal schedules. As to which may have been the first in country, that would require some homework in the archives. Likewise for the Twin Otter question.
we were no longer required to comply with the Australian unique requirement
Actually, that wasn't a local requirement. The Australian change reflected the FAR25 design change as discussed in earlier posts.
V1 is a certification process with a perfectly serviceable aircraft with 1 failed engine and no other defect.
Not exactly the case and has varied through the years but close enough for the purposes of this discussion.
The affixation of MUST take-off at V1 or above ..
Not exactly the Industry viewpoint .. suggest a review of the video cited earlier which is still reasonably valid vice the rulebook.
but if he was not adamant he must take-off he may have elected to abort.
At the time, the crew could not have known the full story - although they certainly would have known that they had a nasty situation on their hands. I suggest that it is most unlikely that a disciplined crew would reject for the situation faced. In hindsight, knowing the details which came to light during the investigation ... perhaps ... but that's information not available to those in the front seat at the time.
Again, I can only urge folks not to read things as being hard and fast black and white. It is all based on reasonable probabilities and what might be a reasonably reliable (not necessarily the best) way to achieve an acceptable outcome on the day when only part of the story's details are to hand.