Loss of all Generators
 

What is the procedure that you'll follow in case you had a loss of all generators on the T/O roll before V1?

Stop :ok: :D :D :D

That was a hard one! Ask another.

I'll ask a hard one!

How well would a jet transport stop from anywhere near V1 with no antiskid on alternate brakes, no reversers and no steering?

Er, by using the alternate brakes (without antiskid) and using differential braking for directional control.

Can we have a harder one please.

(PS - this question is a bit type specific. Did you have a type in mind? The situation which you describe wouldn't happen in the three civilian types I have flown.)

Er sorry Dan I'll spell it out.

Years ago a mate had this in the sim and of course when all the screens go blank nearly everyone shouts Stop!

Only problem is that a whole bunch of nice stopping stuff probably isn't working.

Reversers are not usually included in take-off performance, so no problem there- they are usually just a plus. Alternate brakes should be just as effective as normal brakes. No anti-skid requires carefully brake application- probably multiple applications and affects the efficiency of the brakes. Steering- absolutely no problem- rudder control and diff brakes slowing down. Might have smokey wheels, but not much increase in stopping distance.

Come on- we want a harder one!

Well there's not much point in taking off, as that same stuff isn't going to slow you down when you land either!

3 Greens

Fine do what you like but personally I really don't see it as a simple decision near V1 because IMHO there's a very good chance you won't be on the runway when you eventually stop. :ooh:

Multiple failures before V1 = stop without question, imho.

I'd personally rather go off the end at low speed (unless it's over a large cliff, for example), than get airborne well above max landing weight with limited electrical life and instrument capacity from the battery(ies) and have to reland in that condition.

No brainer for me ..... as said before, ask a difficult one.

Mike , why making it easy, make it slippery wet runway,Imc night and the failure happenned just before V1,with max T/O weight taking Off from Quito or SANAA.

It's not a question of what i like, more like what Boeing recommends!! And as for the comment regarding leaving the paved surface...well there are so many variables there that i find it quite a statement to make. As mentioned above there is still plenty of braking available. It's a no-brainer if there are multiple failures prior to V1 - STOP!!
Granted, take each case on ti's merits and if one encountered such a scenario then important decisions have to be made quickly, But (as a TRE), if you elected to continue in a sim check with me with this scenario i'm afraid, in all probability, you'd be retested!

I am with the stops, undoubtedly. You are below V1 remember. There is only one thing to do with multiple failures like that, and dragging it into the air not knowing exactly what you have and haven't got? Not for me.

3Greens,If you think Boeing recommends the Stop at or near V1 with this particular failure , then I would suggest writing to them before you start retesting pilots for there decisions after this failure. Why don't you try both decisions in the Sim as you have the chance and come back with your findings.

Reevaluate your statement here 3Greens , your chances at the begining of the R/W to stop thats when you land is way much better than trying to stop with the failure at or near V1.Thats assuming as well that you were unable to reset any of the Generators.

A TRE, wow I'm unimpressed!

For starters TRE's shouldn't make assumptions about it being a Boeing though, should they?:ugh:

I know it will fly but I'm really not sure about it being able to stop.

BTW I'm not saying I would always go and yes it's an extremely unlikely event. (Like a mid air in the middle of Brazil with the TCAS U/s maybe)

This thread reminds me of an old Avsig thread where all the experts were busy buttering each other up with how easy it is in the sim to control an uncommanded reverser deployment on takeoff. Right up until a very experienced test pilot from Boeing came on and said basically '...if it happens for real your pretty much screwed !'

Hmm. This thread reminds me of an Old Pilot/Bold Pilot thing.

The Young Pilot seeks to aviate. The Old Pilot seeks reasons not to aviate. The Young seek the wisdom to become the Old.

Our SOPs are to only stop between 80kts and V1 for engine fire, engine failure, winsheer warning or a condition which meant the aircraft was not flyable, like jammed controls. And that is on a Boeing. Johnman makes a very valid point that a circuit and (possibly) overweight landing gives you the full runway length to stop on and not just what you have remaining if you reject at high speed. What would be wrong with getting airborne and starting the APU? From the phrasing of the question 'all' generators would imply those that were running at the time of take-off, which in our operation wouldn't include the APU?:ok:

PP

Indeed, but you'll dispose of an extra 110% tape length to do it.

Sorry Stan, I will explain a bit for you.

For a start, in my experience this is a very unlikely scenario. The type your friend was flying may have this as a possibility, but a modern transport aircraft would not get certified if there was a fault which could lead to the simultaneous failure of all power generation on the take off roll. Maybe this was a 'what if' scenaio.

On my current type, I would consider it so unlikely as to be inconsiderable (if you follow my drift). But if it were to happen, there would be a gap of up to about seven seconds before the hydraullic powered emergency generator kicks in and then you will be in the emergency electrical configuration in which you can continue flying so long as you have fuel - albeit with with much reduced services. Flight on batteries would only happen until you lowered the gear and then on only some of the older airfarmes. Now if this were to happen on the take off roll, I would consider that a proabale cause for stopping. It's a major failure. I would have braking from the emergency accumulator to a maximum of 1000psi, which is fine for stopping in most circumstances. Rudder and assymetric braking would keep me straight. But if it was a VMC day on a very short runway I would consider getting airborne and relying on the emergency generator. (You did specify a double generator failure rather than an even more unlikely scenario of complete electrical failure).

All my other types have been 4 engine aircraft with paralleled genarators split into 2 systems. A failure of all generators is even more unlikely. A tie bus fault could lead to the loss of two generators if the protection doesn't work and un-parrallel them before serious damage occurs. But loosing four? Very unlikely.

Hi Dan

I agree that it's an unlikely scenario and quite type dependent, my pal was on the A320 at the time and the trainer considered it worth demonstrating.I seem to remember that trying to stop led to quite high speed departures off the end.

Either way it's very difficult to know exactly what the problem is when it happens near V1 but the engines aren't affected. I agree with the standard parameters Pilot Pete put forward for stopping between 80kts and V1, they are pretty much what I have seen everywhere I've worked.

What I do disagree with is the view that even if it were to happen stopping (from V1)would be no big deal(on a limiting runway). Why does the V1 change from around 160kts to 120kts and a huge weight decrement if you depart with antiskid U/S in a 767 for example?No steering too sounds easy but how can you apply max manual braking and differential braking at the same time?

I've only had experience in the sim but antiskid u/s is a big deal in my book.Then again I'm Luton based which maybe tends to make one even more go-minded.

The point is every good pilot should think of these kind of situation,and should know what to do when this kind of failure occurs in order to reduce the element of surprise which is a killer at times.
You should know what you have when you elect to stop or continue.
Can I fly the aircraft or should I stop it , fraction of seconds counts.And every pilot needs to improve his technical knowledge to know what he has left to operate the aircraft . Remember that you are paid to make sound decisions,and you are trusted with a huge responsibilty to act at the unexpected situations.You should know the penalty for stopping with various failures, its all in the books, you should always encourage task sharing and improve your communication skills.These kind of situation has nothing to do with old or new timers,as much as it has to do with good versus poor decisions.

Distance required
 

Do you know that you need to multiply the actual distance required for landing by as much as 1.85 with loss of all generators on certain types.

Whatever the pros and cons of stopping or going are I suspect it is rather academic, when confronted by the "big clunk" of everything dropping off-line and just about every instrument on the panel going dark, 95% of pilots are going to stop anyway if V1 has not been called. Anyway, it could be a double gen. failure caused by a double engine failure.

If everything went dark, how would you know that the engines were actually functioning before you take them into the air? In the seconds (or less) you may have between the screens blanking and V1 arriving, would you have time to judge whether or not you were dealing with a gen failure or a total (dual?) engine failure?

I think we were well beyond the realms of likelihood at post #1 ;)

First the disclaimer... I've spent the better part of my adult life as ATC, so for me this is more a matter of historical perspective than it is any sort of current systems knowledge.

Two things did, however, come to mind. First is the fact that I had the pleasure of experiencing, as crew, total electrical failure on a four-engined military jet transport, mid-Pacific, in the middle of the night, some 30 years ago. Sometimes it goes to hell all at once.

Second, when this thread first started I had a flashback about the United 727 out of LAX in 1969. In that I went on to be a controller at the LA Tracon some years later, the story was familiar to me. Of course, it never hurts to return to the primary materials when thinking about this stuff...

In short, the airframe had been operating for three days (42 hours) with the number 3 generator inop and placarded. Just after takeoff, the crew got a fire warning on the number 1 engine, told the departure controller that they had shut down number 1, and requested a return to the airport. Five seconds later they lost power from the number 2 generator. Count 'em--that's all three generators gone. The standby electrical system either failed or was not activated. By my math, total electrical failure occurred 90 seconds after VR. Of course, it was dark out and the weather sucked--low ceiling and vis with rain and apparently a fog bank just waiting for them. It took six weeks for the NTSB to recover the CVR. It was on the bottom with the rest of the aircraft in 1,000 feet of water. Nobody survived.

Now, I'll be the first to point out that this is NOT the situation originally set out in this thread... this happened a hundred years ago in a type of aircraft that almost nobody in this discussion still flies, this situation didn't require a decision before V1, etc. But consider that this was a new aircraft in 1969 (16 months old with less than 1100 hours total time), properly equipped with things like a battery/standby electrical system which was supposed to give the crew enough juice to get back to the airport in IMC, and a third guy sitting sideways in front of a panel in the cockpit babysitting the whole mess. What's more, the accident happened on departure from what was probably one of the best-equipped airports in the world (navaids, ATC, etc) in an area where terrain wasn't an immediate concern.

I'm not advocating for stopping or not stopping--I don't really have a dog in this fight. I'm just sticking my nose in this thread to suggest that such a scenario today is still not "well beyond the realms of likelihood." And Mike--bless you man, you tend to write some of the most sensible things I read--you've got to entertain the idea that there remains the possibility that them big, beautiful MFDs are going to be dark. Yeah, I know, systems evolve and airframes today are tremendously more reliable than a new 727 was in '69. Still, I'm sure that Capt. in '69 also had confidence in the standby system powering his steam gauges. The confidence in this case just doesn't sit well with me.

Sorry about the lengthy babble... Oddly, I'm still not certain I made the point I was trying to make. Perhaps someone will give me a hand. And again, I do understand that the 1969 scenerio simply doesn't fit the "total elecrical failure before V1" question, even if you move the engine fire indication to a point before V1. That's not why I brought it up.

Am I making sense?:ugh:

Dave

IIRC, when I did my initial training with DanAir in the 80's, the advice was that it was not a 'recommended' necessary stop (737), subject to weather, runway length, speed at the time etc. and the stock answer to the next question was - "that is why the Captain is paid to be Captain and has 4 stripes on his shoulders".:)

My decision would depend on several factors. It is an unlikely event and again comes into the 'double emergency' category - triple, in fact, assuming a serviceable APU/generator.

And that makes me feel better, Mike, honestly. Not so much the fact that the backup for the "guaranteed 77 minute MFDs" exists (which I already assumed), but rather, that you're now mentioning that backup. My quarrel was with the statements (from more than one person) which sounded like, "this won't happen to me because system failures in the aircraft I fly will not cascade beyond a certain point," or, "this scenario is so remote that even mentioning it is laughable." In my experience at least, if you're not considering the prospect of holding the flashlight between your teeth, you're not thinking about how bad it could get!

On your final note... in that my military experience was like yours--flying--I've never provided a PAR. I have, however, had the pleasure of working at a civilian approach control where we provided ASRs (and no, it wasn't during my tenure at LA approach!). So I can play the "no-gyro-make-half-standard-rate-turns-do-not-acknowledge-further-transmissions" game as well as most! Did them at least once per quarter to stay current, but in my career only had one actual. It was an A6 who had the nerve to complain that, when he broke out, his left wing was over the left side runway lights. This in the first 1/4 of a 10,000+ runway. Hmpf. No pleasing some folks! :)

Dave

Oddly enough, I've actually had this happen, all three generators tripped off just prior to V1...one quickly restored due to quick action of the Flight Engineer.
What to do if at/near V1, if heavy/WAT limited?
Continue, absolutely, using the standby instruments, which is what they are there for.
Sliding off the end is NOT on my list of available options.
Period.
PS: I've also had both attitude indicators go TU just at rotation...just what the standby is installed for, but you sure don't want to depart with a depleted ships battery, otherwise, up the creek without a paddle...on a dark night/IMC.

av8boy ... and all the experienced aviation people, Thank you very much for your valued inputs and for sharing your experiences. I know for a fact that complacency is an enemy to all of us.

Talk about pre-empting fate - I was given this very emergency in the A320 sim a couple of days ago! At 120kts, it all went dark and I elected to stop. It wasn't pretty and I did go off the runway - but we stopped without hitting anything. A mate got the same at 130kts and continued. Getting airborne hoping the RAT is going to kick in 7 seconds after take off takes balls, but it worked for him and he managed to land in the electrical emergency configuration.

Still pretty unlikely in real life though.

Sometimes the dog of fate simply lifts its leg and pi55e5 on the leg of science. :uhoh:

I have some difficulty with those posters who see this as a black and white exercise. Apart from the obvious stop if well below V1 scenario, there are just too many causes for the posed situation to pick it at/near V1 unless the ASDR is very much less than the ASDA .. in which case one can consider stopping ...

If MELs are not being carried then I think the situation is not likely from a basic systems viewpoint for the typical aircraft .. however, something out of left field certainly can do mischief. For instance, we had a cargo L188 years ago went dark on rotate due to water or whatever in the electrical bits and pieces from previous flights. If I recall it was a case of external water coming in through the main freight door during a turnaround and the cabin sealing not quite being up to it on the day .. very much a case of sometimes the dog of fate simply lifts its leg ...

If the reasonable assessment (that typical collect data, evaluate, decide in 0.3519 seconds sort of thing) is that the bird isn't going to fly .. then it might be better to takes one's chances in the overrun regardless .. if the bird goes in vertically half a mile off the runway head, the outcome is a foregone conclusion .. all comes back to playing the numbers and rolling the die.

However .. unless the overrun is very attractive and I knew that for a fact .. think I'd opt for taking my chances on continuing ...

This sort of thing probably is going to be in the Sioux City league of incidents/accidents, I guess ..

Sorry. I should have mentioned that it wasn't an overrun, we went off the side. We stopped before the end and would probably have stayed on the runway if it wasn't for the crosswind. In the 320 in this situation, you have some braking but hardly any directional control. Also, the weather was on CAT 1 limits, so this was also a factor.