FA Calls on short final..

[Bumblebee]

thanks for the data Steve.

I have always considered that V1 is more about going than aborting....that once @ V1 you have guaranteed performance you are now at a safer point than you were at high speed approaching V1 and in the precarious position of a high speed abort. That being said, 5 knots before V1 you do not have guaranteed performance.

 

[Autothrust Blue]

thanks for the data Steve.

I have always considered that V1 is more about going than aborting....that once @ V1 you have guaranteed performance you are now at a safer point than you were at high speed approaching V1 and in the precarious position of a high speed abort. That being said, 5 knots before V1 you do not have guaranteed performance.

Vmcg limited V1...I've seen it.

 

[dasleben]

Do you guys really think the plane won't stop? If so, why call v1 if you won't reject above 80 knots?

Reduced safety margin, and stuff like this can happen:

If CFR is slow to respond, the above is an evac and potential hull loss.

 

[jtrain609]

Reduced safety margin, and stuff like this can happen:

If CFR is slow to respond, the above is an evac and potential hull loss.

I don't reject the idea that high speed aborts are serious business. I've done two in my life, and thankfully things didn't get interesting.

But when people advocate positions like calling V1 5 knots early, or never rejecting above X arbitrary speed because they don't want to run off the end of the runway but have no guarantee that they'll get into the air (and at a point, 80 knots IS that arbitrary speed to many people), or whatever other concept that gets espoused in threads like this, it makes me concerned that folks don't understand the concepts that they're discussing. Or maybe said another way, the nature of the answers makes me think that there is a lack of knowledge. It's not the answer per se, it's the thought process surrounding it that makes me wonder if people really grasp what they're discussing.

And this should be stuff that we can all discuss. This stuff has been standardized for a reason.

Finally, great examples of things going wrong on takeoff if you abort AFTER V1:

 

[dasleben]

I agree with all of the above, though calling "V1" at V1-5 is approved Boeing procedure. Being that V1 is the maximum speed at which the first action must be taken, a call by the PM at the actual V1 will allow the aircraft to accelerate through V1 before the first action is taken.

I'll also add, Part 25 allows for a short single-engine acceleration from Vef to V1. For our performance planning, that interval between Vef and V1 is 1 second.

 

[jtrain609]

I agree with all of the above, though calling "V1" at V1-5 is approved Boeing procedure. Being that V1 is the maximum speed at which the first action must be taken, a call by the PM at the actual V1 will allow the aircraft to accelerate through V1 before the first action is taken.

I'll also add, Part 25 allows for a short single-engine acceleration from Vef to V1.

See post 98, it gives the details of why WE don't need to over think this. If you are below V1, you abort. If you are AT or ABOVE, you go. The nitty gritty is already calculated and we don't need to reinvent the wheel with this stuff.

Again, it was standardized and made simple in order for this to be bright line.

 

[dasleben]

See post 98, it gives the details of why WE don't need to over think this. If you are below V1, you abort. If you are AT or ABOVE, you go. The nitty gritty is already calculated and we don't need to reinvent the wheel with this stuff.

Again, it was standardized and made simple in order for this to be bright line.

Post 98 affirms my post.

 

[Dugie8]

The "80 knot" thing, drives me crazy, short drive, I know.

Calling V1 early is inviting a problem (save those that have it figured in to performance already, ala Boeing/McD). If I don't say anything until actually passing V1, the chance of trying to accelerate go before V1 is reduced. IMO running out of runway at or near Vr is worse than running out of runway while trying to slow down, all things being equal.

Rolling down the runway and the dude in the other seat hasn't said anything (other than A/S alive, etc) and all of a sudden my confidence in the ability of the aircraft to fly comes into question, a new set of breaks are going to be needed.

 

[jtrain609]

I agree with all of the above, though calling "V1" at V1-5 is approved Boeing procedure. Being that V1 is the maximum speed at which the first action must be taken

Everything above this is affirmed by post 98.

a call by the PM at the actual V1 will allow the aircraft to accelerate through V1 before the first action is taken.

Where what is above this is NOT.

The calculations are formulated so that you WILL go above V1 before you make the first move to abort the takeoff. If you call engine failure at V1 minus 1 knot, you will go over V1 and that is known. If you call engine failure at V1, you wouldn't be calling for an engine failure, you'd be calling V1.

If your aircraft states that V1 should be called at V1 minus 5, that's great. Mine does not. Our books tells us to call V1 AT V1.

 

[jtrain609]

Also, if it's not clear to everybody, we're really picking nits here. The aircraft is likely accelerating so quickly that the exact millisecond in time where you open your mouth to say "V1" isn't ever going fall exactly at V1, or V1 minus 5, or V1 plus 10, or whatever it eneds up being.

 

[dasleben]

The calculations are formulated so that you WILL go above V1 before you make the first move to abort the takeoff.

Not correct. V1 is the maximum speed at which the first action must be taken, typically brake application. The 2 second buffer used in accelerate-stop calculations are for the remainder of the actions required, such as thrust reduction and spoiler deployment.

If your aircraft states that V1 should be called at V1 minus 5, that's great. Mine does not. Our books tells us to call V1 AT V1.

In other words, do what your book tells you to do.

 

[jtrain609]

Not correct. V1 is the maximum speed at which the first action must be taken, typically brake application. The 2 second buffer used in accelerate-stop calculations are for the remainder of the actions required, such as thrust reduction and spoiler deployment.



In other words, do what your book tells you to do.

If what you are saying is correct, then ALL books that say calling V1 at V1 are wrong, and you will slide off the end of the runway every time.

Do you believe this to be the case?

 

[dasleben]

If what you are saying is correct, then ALL books that say calling V1 at V1 are wrong, and you will slide off the end of the runway every time.

Do you believe this to be the case?

Not at all, though because V1 is itself the speed at which the decision to reject must have already been made (and brakes applied), calling V1-5 isn't inherently bad procedure. Calling "V1" at V1 isn't bad procedure either, but rather requires better speed awareness (i.e., if you've already heard "V1," you've already missed the window to decide/execute the RTO).

For those keeping score, the V1-5 callout is roughly the same as calling "V1" at Vef.

 

[jtrain609]

I think there's a disconnect here in how this discussion is being formulated. I think you believe that the PNF will either call "Engine failure, abort" or call "V1." I see this going more like this: The engine grenades prior to V1, and before the PNF can say anything, the PF is already stomping on the brakes and pulling the power back. If the PNF were to call V1 at V1 minus 5 in an aircraft where that is not the designated procedure, then you're jumping the gun.

Does that make sense?

Also, I think the more important discussion here isn't the exact moment you call V1, but what happens at companies where the captain always does the abort. I can see getting into a situation where you'd do a rejection above V1 if the captain has to call, "ABORT ABORT ABORT MY AIRCRAFT," take control of the aircraft, pull the power back and apply braking if you're close to V1.

I've never understood why this is done. I figure the guy that's actually operating the aircraft is going to have a much better idea of something going wrong than the PNF. I.E. You're going to know the engine just lost power long (albeit, seconds) before the PNF does, verifies it on the EICAS and makes the power loss call.

 

[dasleben]

I think there's a disconnect here in how this discussion is being formulated. I think you believe that the PNF will either call "Engine failure, abort" or call "V1." I see this going more like this: The engine grenades prior to V1, and before the PNF can say anything, the PF is already stomping on the brakes and pulling the power back. If the PNF were to call V1 at V1 minus 5 in an aircraft where that is not the designated procedure, then you're jumping the gun.

I'm not sure where you feel there's a disconnect. The following assumes an engine failure at Vef:

For certification and operational performance planning, V1 is the end of the decision window, and the maximum speed at which the brakes must have already been applied. Just to nip this whole thing in the bud: I don't care if you call "V1" at V1, 5 knots before, or 50 knots before. It doesn't matter as long as the first action to stop is taken at or before V1.

The Feds have built in two buffers:

The first buffer is the time between Vef (engine failure speed), and V1. In the worst case scenario for a reject (engine failure at Vef), you have a small window of single-engine acceleration (1 second per Boeing manuals) in which to make a decision and apply braking at/before reaching V1. Calling V1-5 does indeed guarantee performance, as accelerate-stop/accelerate-go distances are predicated on an engine failure before V1 (at Vef).

The second buffer is a distance added to the end of the deceleration phase, equal to 2 seconds of travel at V1. Per the AC SteveC posted, that 2 seconds is built in as a buffer for bringing the thrust levers to idle and extending the speedbrakes (second and third actions required during an RTO). This is not a buffer designed to allow the PIC to make a decision as V1 is reached; this buffer has a specific purpose, and the reject decision must have already been made.

Some manuals say that a call should be made at V1. That's fine. As I've already said however, the decision must have already been made prior to that call, and speed awareness is paramount. Contrary to popular belief, there is not a built-in buffer for pilot hesitation at V1.

As always, measure with a micrometer, mark with a crayon, cut with a chainsaw.

 

[ppragman]

Some manuals say that a call should be made at V1. That's fine. As I've already said however, the decision must have already been made prior to that call, and speed awareness is paramount. Contrary to popular belief, there is not a built-in buffer for pilot hesitation at V1.

From 23.51

VEFis the calibrated airspeed at which the critical engine is assumed to fail. VEFmust be selected by the applicant but must not be less than 1.05 VMCdetermined under §23.149(b) or, at the option of the applicant, not less than VMCGdetermined under §23.149(f).



(ii) The takeoff decision speed, V1, is the calibrated airspeed on the ground at which, as a result of engine failure or other reasons, the pilot is assumed to have made a decision to continue or discontinue the takeoff. The takeoff decision speed, V1, must be selected by the applicant but must not be less than VEFplus the speed gained with the critical engine inoperative during the time interval between the instant at which the critical engine is failed and the instant at which the pilot recognizes and reacts to the engine failure, as indicated by the pilot's application of the first retarding means during the accelerate-stop determination of §23.55.

You are correct. The hesitation comes before V1 at VEF exactly as you posted. This is a pretty critical distinction that I am not sure if a lot of people are aware of, though in practice I think the first definition given in part 1 is more appropriate for operations, whereas the part 23 definition is more appropriate for flight test and design:

From Part 1

V 1 means the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF , at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance.

So, to put it a little bit more succinctly if my understanding is correct for part 23 airplanes (don't have any experience with the bigger stuff) You will be able to successfully abort at V1 and get the airplane stopped in the published accelerate-stop distance, however if you lose an engine in that tiny window between Vef and V1 and attempt to takeoff you're in uncharted territory.

When I was flying airplanes where that sort of thing mattered, it was pretty obvious to me, you'd better be trying to get the thing stopped at or below V1 if you have an engine failure, after V1 you have the book performance to go flying.

 

[ppragman]

Oh, and relevant website:
http://www.boeing.com/commercial/aeromagazine/aero_11/takeoff_story.html

BACKGROUND
The RTO maneuver has been a fact of a pilot’s life since the beginning of aviation. Each takeoff includes the possibility of an RTO and a subsequent series of problems resulting from the actions taken during the reject. Historically, the RTO maneuver occurs approximately once each 3,000 takeoffs. Because the industry now acknowledges that many RTOs are not reported, however, the actual number may be estimated at 1 in 2,000 takeoffs. For example, an unreported RTO may occur when a takeoff is stopped very early in the takeoff roll because the flight crew hears a takeoff warning horn, stops to reset trim, then taxis back to the runway and continues takeoff.
According to these statistics, a pilot who flies primarily long-haul routes, such as in our Boeing 747 fleet, may be faced with an RTO decision only once in 20 years. In contrast, a pilot in our DC-9 short-haul fleet who makes 30 takeoffs per month may see an RTO every 7 years. Unfortunately, the pilot in each of these fleets must be prepared to make an RTO decision during every takeoff.

Boeing studies indicate that approximately 75 percent of RTOs are initiated at speeds less than 80 kt and rarely result in an accident. About 2 percent occur at speeds in excess of 120 kt. The overruns and incidents that occur invariably stem from these high-speed events.
A takeoff may be rejected for a variety of reasons, including engine failure, activation of the takeoff warning horn, direction from air traffic control (ATC), blown tires, or system warnings. In contrast, the large number of takeoffs that continue successfully with indications of airplane system problems, such as master caution lights or blown tires, are rarely reported outside the airline’s own information system. These takeoffs may result in diversions or delays, but the landings are usually uneventful. In fact, in about 55 percent of RTOs the result might have been an uneventful landing if the take-off had been continued, as stated in the Takeoff Safety Training Aid published in 1992 with the endorsement of the U.S. Federal Aviation Administration (FAA).
Some of the lessons learned from studying RTO accidents and incidents include the following:

• More than half the RTO accidents and incidents reported in the past 30 years were initiated from a speed in excess of V1.
• About one-third were reported as occurring on runways that were wet or contaminated with snow or ice.
• Only slightly more than one-fourth of the accidents and incidents actually involved any loss of engine thrust.
• Nearly one-fourth of the accidents and incidents were the result of wheel or tire failures.
• Approximately 80 percent of the overrun events were potentially avoidable by following appropriate operational practices.

HISTORY OF RTO OPERATIONS AT EVERGREEN
Evergreen International Airlines began a study of the RTO maneuver in 1991. Resources included information from the FAA and industry studies, notably RTO data produced by Boeing.
Our standard procedure was to use the V speeds generated from Boeing airplane flight manuals (AFM) in the form of speed cards. These cards list the appropriate speeds for a given weight and flap configuration. However, the speeds given provide only the FAA minimum recognition interval. In addition, a definition of V1 was in use that referred to "decision speed." This term implied that the airplane could accelerate to that speed, that the decision to reject or continue could then be made, and that the resulting maneuver would have a successful outcome.

All the data we collected pointed toward some weaknesses in this philosophy. In addition, the FAA-approved takeoff data is based on performance demonstrated on a clean, dry runway. Separate adjustments for a wet or contaminated runway are published in operational documents. The takeoff accelerate-stop distance shown in the AFM is based on a specified amount of time allocated to accomplish an RTO from V1 speed. Time delays in addition to those demonstrated in actual flight tests are included in the AFM computations. Simulator studies conducted in the 1970s showed that a flight crew requires anywhere from 3 to 7 seconds to recognize and perform an RTO, especially when the cause is other than a power plant fire or failure. More recent studies with higher fidelity simulations, such as those conducted in conjunction with the development of the Takeoff Safety Training Aid, indicate that the times for the pilot to recognize and perform the RTO procedure are within the time allotted in the AFM.

INITIAL PROPOSALS
Although we did not have a history of high-speed RTOs to use for our data, we determined that a better method must be designed to improve the flight crew’s chances for an uneventful RTO. Using the Boeing data, quoted below from FAA Advisory Circular 120-62, we first changed the definition of V1. We used the definition of V1 as:
The speed selected for each takeoff, based upon approved performance data and specified conditions, which represents:

1. The maximum speed by which a rejected takeoff must be initiated to assure that a safe stop can be completed within the remaining runway, or runway and stopway;
2. The minimum speed which assures that a takeoff can be safely completed within the remaining runway, or runway and clearway, after failure of the most critical engine at a designated speed; and
3. The single speed which permits a successful stop or continued takeoff when operating at the minimum allowable field length for a particular weight.

Note 1: Safe completion of the takeoff includes both attainment of the designated screen height at the end of the runway or clearway and safe obstacle clearance along the designated takeoff flight path.
Note 2: Reference performance conditions for determining V1 may not necessarily account for all variables possibly affecting a takeoff, such as runway surface friction, failures other than a critical power plant, etc. ​

The "go/no-go" decision must be made prior to reaching the published V1 (fig. 1). As the speed approaches V1 the "go" decision becomes more appealing. Our goal became to identify a reduced "decision speed" to provide increased flight crew recognition time in case of a catastrophic situation. Using the Boeing data, we initially approached the FAA with a proposal to call a reduced V1 the "decision speed" and treat it as a V1 speed. The flight crew would remove their hands from the thrust levers, and the takeoff would continue. The initial proposed speed was 10 kt less than published V1.
We presented this proposal to our principal operations inspector (POI) in 1991. After several months of dialogue and deliberation, it was disapproved because it was too different from certification criteria.

APPROVED PROCEDURES
In late 1992, after we received the Boeing Takeoff Safety Training Aid in draft form, we decided to again seek approval of the "decision speed" concept. This time we chose a speed of 8 kt for a reduction, which added approximately 2 seconds of recognition time. In the worst case the screen height was degraded to approximately 15 to 20 ft. We also expanded our efforts to include a revised airspeed call. We had been using an airspeed call of 80 kt, both for airspeed verification and for power setting completion in the 747. A 100-kt call was added, which indicates entry to a high-speed regime where an RTO would be more difficult and dangerous. We also refined the guidelines for an RTO as follows:

• Although V1 will be obtained from the appropriate speed cards, 8 kt will be subtracted from this value and the airspeed bug will be set at that point. In no case will this speed be less than ground minimum control speed.
• The call at this new speed will be V1 and the takeoff will be continued.
• If an adjustment is required for contamination, the 8-kt reduction will not be made.
• Above 100 kt the takeoff should be rejected only for engine failure or other catastrophic failure.
• Improved climb procedures will use the 8-kt reduction.

Again with the help of our POI, the revised procedure was presented to the FAA in early 1993 and approved after much discussion. It was implemented throughout our fleet in June 1993.
We believe that this reduced V1 procedure provides a valuable increase in the safety margin over that provided in the AFM in the event of an RTO. At V1, the decision to initiate an RTO must already have been made and the RTO must already have begun. If there is any hesitation, the remaining time may be insufficient to allow a successful high-speed RTO (see information on simulator studies in the previous section, History of RTO Operations at Evergreen). With our reduced V1, we increase the stopping margins on every takeoff. If an engine failure did occur just before V1, screen height is reduced. However, engine failure was not involved in nearly 75 percent of all RTO accidents. In addition, because we fly earlier generation airplanes that lack the automatic inhibit of lower level warnings after 80 kt, the use of 100 kt as a notification of entry to high-speed operations provides the pilots with more incentive to continue a takeoff if a nuisance warning occurs.

During training, our instructors traditionally used simple engine failures to teach the RTO maneuver. This technique, however, may condition pilots to think an engine failure is the only cause of all rejects. After the new procedures were implemented, the check airmen were instructed to use other failures, such as tires, warning lights, or system failures, to force pilots to make an RTO decision. In the high-speed regime above 100 kt, rejects should be performed only for engine failure or other catastrophic failure. The takeoff should be continued if noncritical alerts, tire failures, or system problems not related to the safe completion of the takeoff occur. Introduction of these problems requires a decision by the pilots and makes the RTO maneuver more realistic.
The reject itself is now taught as an emergency maneuver, with emphasis on full braking and correct use of spoilers and reverse as essential to the successful outcome of the maneuver.

RESULTS
Since the introduction of our RTO procedures, we have had only one related incident. This incident, however, proves the point of the procedure.
A DC-9 was departing Portland International Airport on runway 10L. Conditions included a crosswind, wet runway, and the airplane at balanced-field maximum weight. Near 100 kt during the takeoff roll, the captain felt something strange occur in the nose area. Because he was not sure if a tire had blown or failed in another manner, he elected to continue takeoff. A noise similar to a deflated tire thump was heard as the airplane accelerated. The takeoff continued uneventfully, however, and the airplane diverted to Seattle-Tacoma International Airport. After landing, it was discovered that the left nose tire had come apart and deflated.
This incident could have had other consequences had the captain attempted an RTO from high speed. Given the conditions of the runway, and the fact that the tire was deflated, the airplane could have been very difficult to stop on the available runway.

The captain reported that, when he first heard the noise from the nose tire area, he remembered our training and cautions regarding a high-speed reject for any reason other than a catastrophic failure.
SUMMARY
Although we sacrifice about 15 to 20 ft of screen height on the DC-9 and less on the 747 if an engine actually fails at V1, the airplane is flying when it reaches the end of the runway. We believe that the procedures and training we have developed, using flight operations data and other information from Boeing and other sources, have helped give our pilots an edge in takeoff safety.
(All references to Boeing studies are from the Boeing Takeoff Safety Training Aid as endorsed by the FAA in 1992, in draft and final form, and other documents produced by Boeing, the Air Transport Association, the FAA, and the U.S. National Transportation Safety Board. Statistics noted in this article appeared in either the draft or final version of the training aid. Doug Smuin, then director of flight training at Evergreen and currently DC-9 captain, assisted in the preparation of this article and initial approval of the RTO studies project.)

ROBERT A. MACKINNON
CAPTAIN, BOEING 747
EVERGREEN INTERNATIONAL AIRLINES

 

[SrFnFly227]

Everybody seems to be overlooking the fact that there is more than one reason to abort a takeoff. Catastrophic engine failure is, in my opinion, the easiest scenario when it comes to aborting. It really doesn't take any decision making as you will know what is going on. It is also directly addressed in the definition of V1, "minimum speed in the takeoff, following a failure of the critical engine at VEF , at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance." Because of this definition, we all associate V1 with engine failure and we know how we would react. Engine fails before V1 and we stop, after and we abort. Easy! Well, easy in discussion.

There are also a handful of other reasons that may require you to stop. The decision to abort for these other reasons may not be as cut and dry and it is that decision making process that was taken in to account while deciding to call V1 at V1-5 knots. I didn't come up with that policy, but as a pilot at that particular company, I did agree with it. That company operated a plane that was very overpowered. Acceleration was insanely quick.

Let's say at a few knots before V1, there is suddenly a flashing light in your face. Do you abort? I would assume that many people reading this would say "I have no idea." Why? Because the light alone doesn't tell you much other than something out of the normal is going. So now you have to look down (or listen for PNF). So you look down and read the message. Your brain then has to comprehend what that little bit of information actually means and you have to react to it. Let's say that you make the decision to abort. How far above V1 do you think you are after that little scenario played out? I'd be willing to bet that you are at least a few knots above by the time you pull power or apply brakes.

My point is that, this isn't as cut and dry as some people would like to think. Every takeoff is different and things like weight, runway length, what is past the runway, etc should all come in to play every time you line up.

 

[SteveC]

...

Let's say at a few knots before V1, there is suddenly a flashing light in your face. Do you abort? I would assume that many people reading this would say "I have no idea." Why? Because the light alone doesn't tell you much other than something out of the normal is going. So now you have to look down (or listen for PNF). So you look down and read the message. Your brain then has to comprehend what that little bit of information actually means and you have to react to it. Let's say that you make the decision to abort. How far above V1 do you think you are after that little scenario played out? I'd be willing to bet that you are at least a few knots above by the time you pull power or apply brakes.

This is why our company policy is to brief that we will abort for any abnormality up to V1. We don't try to differentiate between what flashing lights mean what while accelerating down the runway, we keep it simple. Anything wrong, abort. (Remember that we are in small corporate jets, typically operating on runways with PLENTY of room to stop in case of a high speed abort. We stress to our captains that they retain the PIC authority to modify the abort criteria if the runway is *short*, and in those cases many will choose to add the "after 80 knots we'll abort only for engine failure, fire, loss of directional control" or similar kind of caveats. I'm sure airliners are a different kettle of fish entirely.)

 

[dasleben]

Everybody seems to be overlooking the fact that there is more than one reason to abort a takeoff. Catastrophic engine failure is, in my opinion, the easiest scenario when it comes to aborting. It really doesn't take any decision making as you will know what is going on. It is also directly addressed in the definition of V1, "minimum speed in the takeoff, following a failure of the critical engine at VEF , at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance." Because of this definition, we all associate V1 with engine failure and we know how we would react. Engine fails before V1 and we stop, after and we abort. Easy! Well, easy in discussion.

There are also a handful of other reasons that may require you to stop. The decision to abort for these other reasons may not be as cut and dry and it is that decision making process that was taken in to account while deciding to call V1 at V1-5 knots. I didn't come up with that policy, but as a pilot at that particular company, I did agree with it. That company operated a plane that was very overpowered. Acceleration was insanely quick.

Let's say at a few knots before V1, there is suddenly a flashing light in your face. Do you abort? I would assume that many people reading this would say "I have no idea." Why? Because the light alone doesn't tell you much other than something out of the normal is going. So now you have to look down (or listen for PNF). So you look down and read the message. Your brain then has to comprehend what that little bit of information actually means and you have to react to it. Let's say that you make the decision to abort. How far above V1 do you think you are after that little scenario played out? I'd be willing to bet that you are at least a few knots above by the time you pull power or apply brakes.

My point is that, this isn't as cut and dry as some people would like to think. Every takeoff is different and things like weight, runway length, what is past the runway, etc should all come in to play every time you line up.

Not overlooking; the discussion using engine failures was simply convenient. The data for us also assumes an "event" 1 second prior to V1, first action to reject the takeoff at V1, and a two-engine deceleration (plus the 2 seconds at V1, etc. etc.). The legal accelerate-stop distance, per Part 25, is the greater of the engine-out scenario, or the two-engine scenario.

Like you said, with a light aircraft, by the time you even hear the fire bell 1 second before V1, you're past V1. The reality of flying airplanes can be quite different from the black and white on the speed card, but it's important to understand just how the V1 speed is calculated, and particularly to get rid of the myth that there's a delay built in at V1. All this technical information aside, the latter belief may very well cause an overrun one day.