RTO Question
 

My airline has only 4 valid reason's to reject a takeoff above 80kts:

• Fire or fire warning
• Engine failure
• Predictive windshear warning
• Airplane is unsafe or unable to fly.

However I fly with one Captain who also includes if ATC tells us to stop. Is he correct? I suppose it could be include in the airplane is unsafe or unable to fly part, because the tower might see something that we might not. A good example would be on a runway with a hump in the middle where you might not see a vehicle until it was too late...

What do you all think?

In my opinion ATC should not be commanding a stop esp at high speed, they should pass information instead. In your example of a vehicle on the runway, ATC wont know how close you are to flying it could be that a continue and fly over the vehicle would avoid an accident than an attempt to stop in insufficient distance and hit the vehicle. Only the flight crew are in a position to make this very difficult judgement. Don't expect the scenario to black and white.

This is in our SOP.

There may be an occasion where ATC may call “ABC XXXX STOP IMMEDIATELY, ABC XXXX STOP IMMEDIATELY”. Clearly the ATC unit may have very good reason for this call, i.e. runway incursion or obstructed runway but ultimate responsibility for the stop/go decision remains with the aircraft Commander.

There was some work done in the UK on this topic, maybe 10 years ago. I think it followed some poor calls by ATC to stop/canx take-off clearance. The option for ATC to cancel a take-off clearance has been in the books for many years and originates from ICAO.

There was some guidance produced as a result of discussions involving ATC and flight operations people from the CAA and aircraft operators. The guidance appears to have disappeared from the CAA website (ATSIN 27 for the ATC people) but I don't know of anywhere else it has been published.

In simple terms, as I recall the guidance, it explained typical SOPs for operators of large aircraft (and, I think, a bit about smaller aircraft ops) and asked for ATC unit managers to identify typical points along the runway after which it would be a bad idea to cancel the take-off clearance. There was also some guidance about what sort of things were justifiable/sensible reasons for cancelling the clearance. There was a similar document for pilots, I think - giving a bit of background about when ATC might cancel a take-off clearance.

From what I can remember, all of the guidance recognised that when an aircraft is rolling there is probably little time to explain things in detail and so only brief info would normally be provided by the controller. It also clearly recognised that it's the commander's decision and that even if the controller calls 'STOP' the commander may decide to continue the take-off.

Not expressing a view on the original question ...

it could be that a continue and fly over the vehicle would avoid an accident than an attempt to stop in insufficient distance and hit the vehicle

In general stopping will take less distance than going until the aircraft is at the high speed end of the takeoff.

A well known mishap incident relating to the stop/go question occurred at Sydney many years ago.

Good heavens .. that's 42 years ago nearly ... how time flies when one is having fun .. can recall it like it was yesterday.

Point taken John,It all depends on when the crew become aware of the obstruction, they could be nearer Vmu and decide to continue. As I say nothing is black and white when it comes these things.

If ATC ask you to stop it will be for a good reason, like an aircraft on the runway, which I would class as aircraft unsafe to fly, just like incapacitation.

Not sure I agree with you on that one Nick. A former colleague of mine was told to stop in BCN at 100 kts by ATC simply because they had issued the wrong SID in the ATC clearance. :ugh:

Please don't assume that ATC in these 3rd world countries are actually competent.

I brief "an instruction from ATC to stop, with which I choose to comply". Necessarily, this will sometimes be a pressured decision. I have a think about the go/stop decision for each takeoff, so I'm more likely to reject at LHR than at ABZ, say.

I am personally very "GO" oriented, especially at higher speeds.
However one should leave room for some common sense.
Take for instance tire failure... My personal opinion is I would not reject a takeoff for tire failure when within 20 kts of v1. That could be argued as well but considering ATC doesn't generally ask you to stop without a very good reason and I was at least 20 kts below v1, I personally would feel that to be a legitimate reject decision.

Your generally not advised to reject for tire failure above 80 knots because of the reduced braking efficiency etc.

Now incorporated into the body of MATS Part 1.

Cancelling a take-off clearance often comes up as a verbal question on ATCOs annual competency checks and a few years ago it was one of the CAA's hot topics during ATS Inspectors visits. 80KT (roughly 300m for most usual jets) is known by ATCOs as the 'critical point' beyond which, you are unlikely to attempt to stop and we have the approximate 300m position on the runway listed in our local instructions.

From the UK MATS Part 1:
Cancelling Take-off Clearance
13.1 If take-off clearance has to be cancelled before the take-off run has commenced, the pilot shall be instructed to hold position and to acknowledge the instruction.

13.2 In certain circumstances the aerodrome controller may consider that it is necessary to cancel take-off clearance after the aircraft has commenced the take-off run. In this event the pilot shall be instructed to stop immediately and to acknowledge the instruction.

13.3 The cancellation of a take-off clearance after an aircraft has commenced its take-off roll should only occur when the aircraft will be in serious and imminent danger should it continue. Controllers should be aware of the potential for an aircraft to overrun the end of the runway if the take-off is abandoned at a late stage; this is particularly so with large aircraft or those operating close to their performance limit, such as at maximum take-off mass, in high ambient temperatures or when the runway braking action may be adversely affected. Because of this risk, even if a take-off clearance is cancelled, the commander of the aircraft may consider it safer to continue the takeoff than to attempt to stop the aircraft.

13.4 As the aircraft accelerates, the risks associated with abandoning the take-off increase significantly. For modern jet aircraft, at speeds above 80kt flight deck procedures balance the seriousness of a failure with the increased risk associated with rejecting the takeoff. For example, many system warnings and cautions on the flight deck may be inhibited during the take-off roll, and between 80kt and V1 most aircraft operators define a limited number of emergency conditions in which the take-off will be rejected. Consequently, at speeds above 80kt, the take-off clearance should normally only be cancelled if there is a serious risk of collision should the aircraft continue its take-off, or if substantial debris is observed or reported on the runway in a location
likely to result in damage to the aircraft. The critical speed will be dependent on the aircraft type and configuration, environmental conditions and a range of other factors but, as a general rule, for modern jet aircraft, it will be in the region of 80kt airspeed. The typical distance at which a jet aircraft reaches 80kt is approximately 300m from the point at which the take-off roll is commenced. The unit MATS Part 2 shall contain further guidance on the likely position on the runway at which those aircraft types commonly using the aerodrome typically reach 80kt.

13.5 Controllers should also be aware of the possibility that an aircraft that abandons its take-off may suffer overheated brakes or another abnormal situation and should be prepared to declare the appropriate category of emergency or to provide other suitable assistance.

A good topic... and discussed in our airline.

Firsly, it is "interesting" but irrelevant what the ATC rules are. The key here is the message has arrived, and in fact you do not have time to verify if it is ATC, another aircraft, or Johnny F*rtpants wiht a handheld in the car park.

Secondly most TO Briefs have a "cutoff" speed (not V1). Below stop for anything (within reason), above stop for serious stuff. I'd put an "RT Stop" in the first category only.

Thirdly you stated "Airplane is unsafe or unable to fly." - this might cover it.

To me, above the cutoff, I would not stop based on an RT call alone. Hopefully the RT call, or it's context, would give some indication of "why" and that might draw one's attention to it and asses on that.

Finally:I would say no as a "compulsory stop".
Disagree strongly!

NoD

Hey guys, check out the US AIRWAYS vs AER LINGUS event at Boston. It's on YouTube.

A real close call and quite applicable to this thread:
-Stopping the AER LINGUS only could have been disastrous.
-Stopping the US AIRWAYS only could have been safer.
-Stopping both could of again been disastrous, you choose!

Apparently the US AIRWAYS First Officer saw it unfold and held the nose down well after VR, master stroke.

I hope this challenges your thought processes, hoss

Andy, the information that you quote did come from the ATSIN but there was substantially more guidance and advice in the original ATSIN. From what I recall it included good and useful information about how large aircraft are operated and the typical flight deck SOPs about which many controllers may not be familiar these days.

I'm not sure exactly what point you are trying to make hoss. Cancelling a take off clearance when an aircraft is well into the take off roll is a big deal for a controller and not something that is usually done without very good reason. If it becomes necessary we are entering uncharted territory where normal procedures are not going to cover every eventuality and the pilots and controllers will have to make decisions based on professional judgement - this is where everyone earns their respective money! Almost by definition, if this situation occurs it is because someone has made an error - it doesn't really matter who or why at that moment, what matters is doing anything and everything possible to achieve a safe outcome. Whilst I don't know the detail of the BOS incident, if what you say is true (and I'm not suggesting that it isn't) then the FO took a decision/action which resulted in a safe outcome. Another day it might be a CPT or controller's actions that avoid a catastrophic outcome. Each abnormal situation is different.

Hi, I feel as if I must state the obvious, that it all depends upon runway length vs. type of aircraft.
For a large aircraft operating from a 1000m runway, it might be impossible to reject a take-off, at any stage once rolling.
But for a light aircraft on a 4000m runway, you could abort the take-off even if the wheels had left the ground.

Pete

In summary of the original question, if the Captain in question feels the need to include this in the brief good on him! Personally, I wouldn't. Be thankful that you fly with someone who is a thinker and has probably thought this scenario through. Believe me some haven't and would die procedurally.

Safe flying.

ps. type runway incursion into YouTube, scary stuff.

1. ATC does make mistakes, and they might be wrong in shouting at you to reject the takeoff.

2. it is always up to the PIC whether he/she decides to follow instructions by the controllers.

3. ATC has used ''reject'' for very dumb things.

4. ATC has cleared me for takeoff with a fuel truck on the runway ahead of me. When I queried the clearance, they (atc) shouted at me that I should get the ear wax out of my ears and that I should takeoff...when I said...there is a fuel truck on the runway...they cancelled takeoff clearance.

so...be careful out there. I personally know a guy, then a copilot, cleared for takeoff in a DC9 at KORD...and there was a 727 crossing and stopping on the runway...he managed to takeoff considerably below V1 and kept everyone safe.

so...think NOW what you might do and remember you can fly considerably below V1/Vr...you might even want to know what VMU is for your plane/weight.

always know YOU have to know what is going on.

seven, I'm really not interested in us and them point-scorring. Anyone with a professional approach to their work will recognise that ATC can make errors, just as vehicle drivers can and, believe it or not, so can pilots.

After a few years in this business everyone can come up with a bar-room tale that actually happened to them. I'll raise your fuel truck with a 767 that rolled without a clearance while I had cleared a vehicle to cross the upwind end of the runway. If it's of any interest I decided not to try and stop the aircraft because I considered the situation and judged that it would not make it any safer to do so. But even so if you ask me, it's a pretty dumb thing to take off without a clearance.

I'm never going to suggest that ATC is always correct and it is true that sometimes cancellation of take off clearances has been done for poor and unjustifiable reasons. But I'll make a point that I have raised in response to your comments before - ATC often has a bigger picture of what's going on than each pilot. It's not a good or bad thing, just a simple fact - what they do with that information is at issue.

Nor am I ever going to suggest that the commander of an aircraft doesn't have the ultimate and absolute responsibility for the operation of his/her aircraft. But that doesn't mean that he/she is always right or always has all of the information that might be available to help decisions to be made. Making each flight end safely relies on teamwork....and the team is not just the people on the aircraft. Having had a little involvement in some airline CRM training, it was fascinating to see the range of attitudes that could be found on the flightdeck - and the one's that frightened me most were the pilots who thought that they were infallible and weren't looking for their own errors (although everyone else's was fair game). Just as the controllers with a similar outlook scare me.

so...think NOW what you might do and remember you can fly considerably below V1/Vr...you might even want to know what VMU is for your plane/weight.


.. but do keep in mind that, in general, stopping takes less distance than going and may well be the better option on most occasions.