Question About this tricky situation..

[shyam.raman]

Flying a Multi Engine aircraft/jet.My Captain give me controls. On takeoff roll ,Suppose at 80kts my Airspeed indicator is stuck .

WHAT should i do? GO? NO GO?

Didnt know where else to post.. so dont mind it being moved as long as i get an answer..

[SUB320]

You should definately call the speed discrepancy to alert the commander. It would most probably be a STOP situation, even if runway is a short field ( below 100kts ) I would definately reject the take off at that speed
Unrelieable speed scenarios are not very easy to handle, with all the false warnings that will be generated.

[shyam.raman]

Thanks for ur immediate reply..

im one of those low time pilots in india trying to get an airline job right after my CPL..:\

Was asked this in an interview over the phone.. I said i would reject take off.. was asked the question repeatedly.. and i kept saying i would reject..
i said i was below my v1 and i would therefore abort take off. that i wouldnt fly with one of my primary flight instruments faulty.

They were clearly not satisfied with my answer.

alerting the commander is something i didnt say.. :sad::confused:

[Genghis the Engineer]

I suspect that they didn't like your answer because you proposed unilateral action.

The Captain is the Captain, and he should be making the ultimate decisions - the right answer is probably something like saying loudly and clearly "Captain, the ASI's stuck, I think that we should stop?", then follow his decision. Don't take unilateral action unless he appears to be dead/ unconscious/ unresponding.

Basically I think it's a CRM question, not an aircraft ops technical question.

G

[glawkshuter]

And what if it stuck right at V1 but never got to V2 or VR?Or if the PFDs/MFDS (with the tapes) died right at V1...I wonder how many guys would just go..plenty..and right to the scene of the accident.Prior to V1 it's an abort...the real question is after V1...

[Genghis the Engineer]

Same answer I think.

G

[Boingboingdriver]

OH MY god......no discussion...STOP!!!if you dont in sim(its a fail) online its a pack your bag and get another job..
Oh and t/o roll is not the place or time to discuss crm issues,,,pilot noticing discrepency on speed must call STOP.
After V1 is a go...unless you want to overrun the runway with a functionnable stby ASI, when airborne unreliable airspeed recall items..HENCE the necessity to know your pitch attitudes.rotation attitude,acceleration one, clean speed one.....knowing the recall items isnt enough,,read your perf manual about it and check during standard flights it will give you a precise idea of what to aim for initially.

[Genghis the Engineer]

Important point there - you said "pilot must call stop" - cockpit communication / CRM is still there, and it's a different beast to simply stopping. And then explaining what you did to the Captain afterwards. It remains a multi-crew cockpit. I still think that this was ultimately a CRM question, because the actual technical answer is relatively straightforward.

G

[BOAC]

Shyam - to reinforce the answer from G - any airline will define the items for which a F/O can call 'STOP' and they will probably differ if the F/O is handling or not. Normally this would not be one.

You did not say what a/c type - 80kts in a big jet is not fast. In a small a/c it might be, and the runway might be short too. Most airlines have a speed check between seats at around 80 kts which would bring up this error.

In general the only time the F/O will stop for this failure is if there is no response from the Captain to the alert. There are normally 3 independent airspeed indications so the loss of one is not a 'killer'. Even the loss of all three indicators at rotate will not make the a/c unflyable.

Despite what you will read on PPRune from the likes of 411A and BelArgUSA, most well run airlines not only have a failrly 'rigid' set of SOPs but expect them to be followed unless there is a very good reason. That is how your interviewers saw it, if that was the reason for your failure. The Captain will make the decision.

[Boingboingdriver]

BOAC is right.SOPS are governing and in my airline the captain says STOP.
Tricky question if you never come closer to any Standard Ops Procedures.
However if you are flying and capt calls 80..and yours is 60..he must call stop..if he doesnt (possible incapacitation/tiredness).you should do it..safety first.
Before v1,any which may make the aircraft UNSAFE to fly becomes a STOP..ater v1..its a GO unless you lose both engine...for example a windshear at V1+1knt (ie drop of speed) is a GO..stay on runway past VR till the last 2000 ft runway then rotate into the escape manoeuver..by then you may even be out of winshear condition...put in your head for the future after v1 you GO:-)
done with subject:p

[glawkshuter]

I think of the airliner in Dallas who's pitot tube froze up, everyone died..they were stable and already in flight. So how do you think a pilots of an airliner are going to do in a transistion phase just taking off into the soup, with a stuck AS indicatior? Not sure with the current airline crews how sharp thier partial panel skills are, but the 200 hour right seater is worthless...so that leaves the captain, in the cloulds...AS stuck at 100kts for instance.... And given all the SOPS junkies out there, that can't make a move unless it's written down somewhere, I have little hope that they will have a positive outcome. I have done it, when I had to, but I got the skillz... If you got the runway to stop, reqardless of the speed, don't take off with a stuck AS indicator.

[john_tullamarine]

So how do you think a pilots of an airliner are going to do in a transistion phase just taking off into the soup

FWIW, as a play time exercise during endorsements, I used to require my students to be able to handle a total pitot static failure .. and, just to emphasise the point, I would fail anything which might help .. other than the basic flight with unreliable airspeed tables ..

We would work up to the main exercise ..which was to have the failure on a min weather takeoff. The student then had to get himself back on the ground via a Cat 1 ILS without any height or speed information.

Can't recall anyone not being able to do the sequence .. including sub-200 hour airline cadets ....

However, it does require a reasonable standard of basic I/F and detailed knowledge of the pitch/thrust tables.

The workload increase if the failure occurs during the rotation flare is not significant as the students are looking for body angles anyway ... and most had a look at that case as well as the V1 style failure.

[safetypee]

I agree that the original question appears to require a CRM answer, but outright rejection for an ‘incorrect’ answer is unfair if the SOP is unknown – situation / context not defined. Thus the question would be more suitable as an interview discussion item.

The thread discussion identifies some of the difficulties of SOPs and system failures in modern aircraft.
A check and decision at a predetermined speed (80kts) involve a simple comparison more suited to older instrument systems. Most SOPs imply (not explicitly stated) that any ASI failure above the check speed is accepted, as the risk of continuing is less than that of a high speed RTO; a reasonable position for transport category aircraft.
However, modern instrument systems may have an ASI comparator system (amber alert) or a failure warning (red warning/EFIS display blanking), either of which could occur at any time during take off (some exceptions for alert limiting systems). I wonder how many operators SOPs consider this.

In modern aircraft both the probability and risk of an ASI failure during take off is lower than with older systems, thus a cross check might only be ‘a good thing to do’ or even be superfluous.
If operators do not consider this, then there could be the risk of ‘old-style’ SOPs being applied to modern systems, which might result in an RTO for any ASI alert / warning at any speed up to V1. Clearly this adds to the risk of the operation. This is even before considering the ‘CRM’ communication delays for a P2 handling event just before V1 which could result in a stop from a speed in excess of V1.

Thus while a good baseline is to follow SOPs, it assumes that that the SOPs have been well formulated and suitable for the operation. If there is doubt then clarification should be sought – internal safety report / question to Capt / Trng Capt.
However, this is probably not the discussion to have during a job interview, but if the interview questioning or SOPs are that weak then the job may not be worth it anyway.

[Boingboingdriver]

Glawkshutter,,i wrote i was done with subject..but after reading your post i really hope you are recreational pilot otherwise id be really worried.
If you are indeed flying any kind of airline...you need a serious retraining and thinking to do...just a hint start with the definition of V1 and then when you digested it...go into your performance manual and study.
:ugh:

[SNS3Guppy]

Glock shooter is a troll who previously posted and was banned under a number of other names (ssg, etc)...and is back again for his own amusement and pleasure. He's claimed to be a helicopter pilot, airline pilot, corporate pilot, and a host of other things in the past under other names...and is eventually recognized and banned.

It happens that this is his pet topic, and one he doesn't understand well at all...but can't resist commenting on every time it comes up.

As for stopping...the dangers of high speed rejects are well recognized. We consider anything over 80 knots to be a high speed reject. If one recognizes that the airspeed indicator is no longer functioning at 80 knots, or is stuck at 80 knots, then one has already passed that point and is up against a high speed reject. If one has alternate functioning sources of airspeed, rejecting the takeoff would represent a highly unwarranted risk.

Communication is certainly important. As the pilot flying, you're confirming the airspeed calls by the captain, but you're going to fly an initial pitch on rotation. The loss of airspeed isn't going to cause you nearly the threat or harm that a high speed rejected takeoff might. If you're not the captain, the decision to reject the takeoff isn't yours. The captain will make that decision.

Our company policy is that anything over 80 knots is considered a high speed reject, and it will be peformed for engine fire (in some cases, not all), engine failure, or loss of directional control, or an outward opening door...obviously in cases when flight isn't possible. In all other cases, it's going flying. Loss of a single airspeed indication doesn't represent something I'd personally feel an appropriate cause for performing a high speed rejected takeoff. Even with the loss of all indications, we have pitch and power to fall back on...but you're talking about one stuck indication.

Crew concept. Make your observation known, and if you're the F/O, continue the takeoff unless the captain elects to reject the takeoff and takes the airplane to perform that procedure. You're not going to be performing it anyway...so your actions are always to continue the takeoff unless told otherwise.

[glawkshuter]

John, Sim stuff is playtime...give them a nice brief ahead of time, tell them what is going to happen, tell them how to how handle it, then mark it off on your training sheet... In real life, you look over and your AS ind says zero, or the PFD died, or the airdata computer has crapped out...and yeah, holding 8 degrees up, with climb power should cover it...or level flight with cruise power, or some set deck angle and power setting.. But...if you consider the Dallas deal, in good weather...the Roselawn accident, where people should have been looking at deck angles and power settings like they should...but didn't show's airline guys don't handle it that well...the evidence seems to hold that only a small percentage of people are equiped to land a plane, much less fly without thier AS ind... The truth is...the AS ind will probably go when the pitot tube is iced up and the heat isn't working...hence the plane is probably icing up as well..so maybe that 8-12 degree deck angle full of ice on that go around is enough to stall the aircraft.... Guppy, not sure who you are or what your problem is, or who you think I am...but unless this is your server and your forum(is it?) best not to treat it like it's your little fiefdom to vent your personal issues... With regard to Post V1 stops...I simply adhere the concept that I go most of the time after V1 unless the plane is uncontrollable, or if I have a ton of runway to stop and evacuate vs fly a burning wreck through the air and hope it flies...pulling back the throttles and stepping on the brakes is much easier to handle then trying to climb single engine, max gross weight, flames trying to cut control cables or burn through cockpits...seems the airline boys keep flying to the scene of the accident(or the Moab deal) vs simply stopping the aircraft and skidding off the end... Do what you want...I just happen to be of the ilk, that a SOPs manual tends to not cover everything nor has it for me, and required quick thinking....still here and so are my passengers.... Besides the last time a nose baggage door opened on take off, glad the pilot stopped(old timer) and didn't try to fly it off....Wish the Concorde guys had stopped too...

[GlueBall]

If you got the runway to stop, reqardless of the speed, don't take off with a stuck AS indicator.

You may see and "think" that you have enough remaining runway, but acute brake energy limitations [especially at max gross weights, beyond V1] . . . means that braking action becomes zero at a certain point, and you have no assurance of a full stop before the pavement ends. That's how many moons ago one Chekoslovak B707-300 went off JFK's longest runway. :ooh:

[glawkshuter]

Well if we are going to get into one of those conversations...that we can't land a plane without pulling a book to get the landing distance on a 12000 ft field, or the take off distance for that matter...then taking that argument to it's logical extent, this person can't do an off landing, he can't stop a plane with with 8000 ft remaining because 'he just doesn't know'. He can't tell if his brake action is good or bad when the runway is wet...and he can't tell if he is accelerating properly on the ground run...this tool, simply looks at his books and trusts the numbers.... As far as brake energy limits and such, it's the argument for the weak. No one can determine when the brakes will give or not, or when the tires will blow for that matter...so flying a burning wreck through the air because your worried that your brakes will fail on the abort is...well...just a tad of a stretch in my book.

[SNS3Guppy]

Glock shooter is indeed ssg...and will likely find himself banned again under his current name as he did before under all his other names. The diatribe never changes...always the same uninformed rant. He just can't resist.

His involvement in a number of tech log discussions about V1 and rejected takeoffs sounds exactly like his commentary here...not a clue what he's talking about, but still determined to drive home the point. Unfortunately, here a serious poster is asking an educational question, in the case of glock boy, he's getting bad misinformation (again).

Roselawn, incidentally, was about tailplane stalls and icing, and about aileron snatch and controllability in ice; not about pitch vs. power with loss of instrument indications...it really is irrelevant and inappropriate in a discussion about an airspeed indication failure on takeoff.

Your attack on the airline industry is very familiar for a ssg post, however. Aside from your lack of understanding on emergencies, aerodynamics, and rejected takeoffs...it gives you away.

The hazards of a high speed rejected takeoff, however, are well known and documented...and known to real pilots...ranging from corporate to airline and everything in between and outside thereof...and taught at any training program and facility. Something ssg/glawkshuter wouldn't be familiar with or understand. To the original poster, I strongly encourage you to disregard what he's got to say here. He's a troll, and his advice is inappropriate and dangerous. It always has been.

As far as brake energy limits and such, it's the argument for the weak. No one can determine when the brakes will give or not, or when the tires will blow for that matter...so flying a burning wreck through the air because your worried that your brakes will fail on the abort is...well...just a tad of a stretch in my book.


That may because in your experience as a flight simulator game player you may have never dealt with brake energy charts or limits, or actually handled a performance program or manual to understand the concept. Simply becase you don't understand it or have experience with brake energy or proper training regarding high speed rejected takeoffs doesn't change the truth that they're proven to be dangerous and a significantly higher risk than continuing a takeoff...or the fact that it's not a 200 hour first officer's call.

[shyam.raman]

Are speeds like Vmbe,Vmu calculated before each flight? and are they ever displayed/marked on the ASI?

regarding BOAC's reply.. if only my ASI was inop and the other two were normal.. would the captain take controls and continue takeoff?
im assuming by the time i report and he takes controls the plane would continue acclerating..

Thank you all so much for your detailed answers/thoughts.

As a complete newbie to the forum i cant thank you all enough;it is quite big and i am little lost in all its entirity.

i think glawkshuter's precence does serve a purpose.. balance in the forum.. if everyone agreed to the same thing then a newbie like me would maybe think of alternatives as i get more experience.. i know for a fact i/my friends got cocky when i/we hit around 150 hrs.. did stupid things in the plane.took things for granted.

But i learnt lots from the new debate that sparked off cos of him too..

It is quite scary to me now that most of the first officers in india are freshers right outta cpl school. The current situation is PFT/PFJ on the A320's and 738's etc.. i know atleast 5 People who have rejected emb170s and crj200's in the last year..;)

heart wants to be instructor; brain wants super cool jet glass cockpit airconditioned airhostess in mini skirt serving ice tea job:}

[Boingboingdriver]

it is common sense that if capt wrongfully decides to continue the flight with an inop asi.(at airspeed crosschecking(80kts)hence before v1).the pilot who was taking off remains the pilot handling until aircaft is properly in control and then a change of handling pilot may be necessary,,,ie the Capt takes off..after unreliable airspeed recall items performed...the pilots realize by crosschecking the 2 speedtapes,the stby airspeed and even the irs speed display that the fo speedtape is correct..i would give control the the fo until after landing....

[SNS3Guppy]

Are speeds like Vmbe,Vmu calculated before each flight? and are they ever displayed/marked on the ASI?


Following a rejected takeoff, brake energy will be calculated (and may be seen in some systems as brake temperatures), and will have a direct impact on turn around times, the ability to taxi, any replacements or inspections that are required, etc.

Brake energy numbers aren't depicted on the airspeed indicator. The numbers you're interested in are decision and safety speeds, and flap speeds: operational numbers.

would the captain take controls and continue takeoff?
im assuming by the time i report and he takes controls the plane would continue acclerating..


As the pilot flying, you're going to continue the takeoff unless the captain elects to reject the takeoff.

[glawkshuter]

Maybe to further clarify...that the flight testers and factory determined that brake energy limits (failure of brakes) and chances of blowing tires are minimal when aborting a take off at max gross weight V1 or less...I would like to believe that if V1 is hypotheticaly 110 knots, that landing with the same wieght at a legal and specified 125kts...might tend to make the case that brake energy limits might not be problem untill well exceeding 125 kts..That said, if one can determine by having actualy flown the plane a few times on landing how much runway ahead it typicaly needed to stop a plane, being 15 knots slower at time of abort should make that descion a tad easier...So I doubt stopping an aircraft 10-15 kts slower then your landing speed will create catostrauphic brake failures....

[SNS3Guppy]

.I would like to believe that if V1 is hypotheticaly 110 knots, that landing with the same wieght at a legal and specified 125kts...


You'd like to believe that because you don't know what it is you're talking about (which includes the subject of brake energy, to say nothing of rejected takeoffs).

A rejected takeoff places much of the stopping distance behind the airplane. Continuing the takeoff to return and land places it all ahead of the airplane. Rejecting a takeoff means attempting to immediately correct the problem, rather than handling the problem and stabilizing it, then setting up a controlled return to landing at a time of one's choosing. Rejecting takeoffs provides a high probability of an overrun, departure, brake fire, control loss, or other problem. Statistically, continuing the takeoff is nearly always the best course. Brake energy is one small part of the picture. Attempting a high speed rejected takeoff for one airspeed error out of several indications and sources is certainly not worth the risk.

A company safety communique recently addressed the topic. Statistically (per Boeing and the Flight Safety Foundation), one in every three thousand takeoffs is rejected, but one third of those that reject leave the runway. 600 people have died in the last 30 years as a result of rejected takeoffs. According to the FSF, 80% of those overruns could have been avoided with better decisions. Boeing showed that approximately 1/4 of rejected takeoffs are for engine problems, while another quarter are for tire or wheel failures, and about 13% for configuration problems. Boeing and the FSF show that up to 70% of the rejected takeoff mishaps would have continued and landed safely...had they not rejected the takeoff.

Low speed rejected takeoffs don't present nearly the problem that high speed rejected takeoffs do. Whether or not the brakes can handle the event is just part of the picture. However, to suggest that because the aircraft lands faster than it rejects, it should have no problem, ignores the heat and energy already lost in taxi...which can be substantial. Taxi distance can already heat the brakes close to or well beyond what a landing may accomplish, and this before the takeoff ever begins. Compare that to a continued takeoff with an opportunity to cool the brakes with a full runway in front and all the emergency services already staged and prepared...clearly the advantage goes to continuing the takeoff.

We've been through this all before, ssg/glawkshuter. You've had it explained every which way from sunday by a number of experts here, including performance experts who do nothing but deal with this topic. You're not hear with exerience to offer, certification to offer, or anything to share. You're here to argue the same tired, ignorant banter...you're here as a troll.

With that in mind, I'll put you on my ignore list, like your other banned names, and wait for the mods to ban you again like they always do...why don't we save the rational discussion for those who have something better to do with their time than keep reappearing under a different login...until you're banned again? You've been shooting that glock just a little too much without hearing protection, again.

[BOAC]

With that in mind, I'll put you on my ignore list - you thankfully thus missed another post (now banned and 'disappeared'), SN, but you should probably add the latest Phoenix, 'Lookforshooter'?

[Pugilistic Animus]

at least he's good at coming up with creative screen names:}

well back to my {fints}:}:}

oh yeah remember in KE calculation the m is not as important as the V---if IAS=GS then at 80 KIAS 640 units, at 90 ---810 units at 100, 1000 units -----see it gets bigger very fast:\