I'm going to disagree with you. To your first point about not landing but opening yourself up to liability, that liability is implicit as soon as you take your seat on the flight deck. While you're correct that your liability and potential to have to answer for your actions increases as a result of not landing, it doesn't mean that you suddenly have liability where you once did not.

 

To your next point about continuing the flight, you're assuming that something else is going to go wrong. While that may be valid, if the correct action is to land the aircraft under the assumption that something else is going to go wrong, then why would we take off in the first place? I'd also be very, very hesitant to claim what someone would be accused of, by the agency or a court. What happens after you decide to continue to your destination, if not linked to the failure of the AUX PITOT HEAT, could very well be seen as not the fault of the crew. I will, however, agree with your later point that blame is often placed on the pilot(s). Not looking at the details to find cases similar to this one, however, it would not be a fair assumption to compare those to this case.

 

If you land early and all goes fine, there are most certainly a downsides:

-Your passengers just took a huge delay for something that, weighing the risks, could be negligible. What if there's someone there who planned that flight to make a wedding, or jumped on the flight in a last minute decision to hopefully spend a few last hours with a dying relative?

-Your airline probably just got smacked with a host of fees and charges. That's also not mentioning that the aircraft now likely has to be serviced wherever you landed it, which the airline will also have to pay for at whatever external rate exists where you landed. Your actions also got the airline some negative reactions from the passengers. If there's one thing you'll find out about passengers, it's that very few are very understanding when you mess up their day, particularly when it's maintenance-related. While, sure, the airline has no retribution against you as the QRH said land at the nearest suitable airport, that negative publicity could affect you indirectly.

 

The comment on how it would be stupid is one that leans more towards a following of notional safety. I understand everyone is entitled to an opinion, however.

 

 

You can make whatever inferences based on that rule that you wish, but the rule is rather cut and dry:

The PIC is the end authority to the operation of that aircraft. You, alone, are the final decision maker.

 

 

Again - you have to remember that it said land at the nearest suitable airport. There's a difference. Suitable is a subjective term, which you may offer up your own interpretations of why you continued to land at the nearest suitable airport, which happened to be your destination field. Obviously, if you bypass a listed en route alternate, they may question that, but again, the likelihood that something catastrophic happening from your AUX PITOT HEAT being inop is rather slim. As such, you're not likely to appear in court over your actions.

 

 

Everyone throws negligence around too much in today's day and age. To me, it's just a sign of how we've litigated ourselves into oblivion, but that's not really within the scope of the discussion here. The point that I need to make is that you keep bringing up that safety is the number one priority. Sure it is, but there's a huge difference between notional safety and safety. Beyond that, your opinion on what is safe may be different from mine (which it clearly is). Notional safety is the assumption that something is more safe without actually getting into the details. It's everywhere in the aviation world. I used to work for a company that stressed lighted wands at all times for aircraft marshalling for reasons of safety. That's notional safety. The lighted version seems more safe to them in the day because it is also clearly safer at night. In the day, though, it really makes no difference if I use wands or even my hands. If you ever look under the wheels of a plane, you'll see similar. Airline SOPs are often excessive with placing chocks on the wheels. On a perfectly calm day, you really only need one set of chocks on one set of wheels. I've seen both mains and the nose gear chocked on a 73' with light wind at best. Again, the notion is "if one is safe, then three is much safer." One is perfectly fine in 99% of the scenarios. Notional safety: it's not that it's actually safer - it just feels safer.

 

Same goes for your AUX PITOT HEAT. It's there as a redundant system. The backup to my main system has failed. My main system is still operational. While my margin of safety has been decreased slightly, it does not mean that safety has been wholly, or even in a major part, compromised.

 

 

 

Pick many of the other failures and I'd agree with you. The GEN BUS killing my AUX PITOT HEAT, however, doesn't compromise my safety enough to justify diverting.

Well one thing I notice from this post is that you are talking from a simulator POV and not from a real life POV. I also see some lacking knowledge in statistics and basic law.

I am not going in to comment every point because my time is more valuable but here are some thoughts though:

 

1. According to the FAA an airplane has to be 99.999% safe. That means that if your AUX system is inoperable then you won't achieve a adequate safety level. If you generator would be at fault then fine, you can just turn on the APU but in this case it was the entire bus. 1/3 systems is down. That gives you a way lower statistical chance of coming home all fine. It may still be 98% safe but then every 50th plane that decides to continue will crash. That means that 300 lives are lost because of guess what? Negligence! Via the checklist a decision has been made and it is your job to follow it.

 

2. No, you are not putting yourself out for liability every time you fly. You are though putting yourself out every time you don't follow "the book". Wouldn't be legal to fly otherwise would it?

 

3. Negligence is thrown around a lot, that means that people agree that even the slightest mistake is negligence. A court is made of the people, that means that if people agree that it was negligence, then it sure is. If you think that it isn't negligence it doesn't make a difference. The checklist (and thereby engineers who designed the plane) say that you should land at the nearest suitable airport, then guess what? Not following this tip is negligence.

 

4. You brought up the passengers being ###### at you. Now you are thinking wrong, you are letting yourself being controller by them. That is a bad mistake, it is your job to keep safety number one priority. Also, when do you think that the company will be angrier? If you make a detour, check the plane, consult a mechanic and then land 2 hours late? Or when you endangered the 100+ million USD plane and its passengers from coming home in one piece? The safer way is often way cheaper in the long run.

 

5. PIC law has nothing to do with blame. The PIC has authority over the plane, but it doesn't protect him from getting his actions sued for... Nobody can stop a pilot then and there but it says nowhere that pilot can't be sued and charged for his decisions later on. Like i posted before, nobody can stop the pilot. For example, the company can't force him to continue flying when he does want to land. But he still can get sued for it... The company won't do it but they can. Anybody can be sued for anything, it is the courts job to decide if the person is guilty.

 

6. You keep saying that most likely nothing will happen. I agree fully that this is a threshold case and in FSX I won't bother to fly to another airport. The thing is that in real life you always have to think the worst case scenario. That is why you only fly with an airplane prepared for the worst. It may seem "cool" to fly with a broken airplane but you will feel a bit different when you are flying with it. There is this quote: "A good pilot manages to save the plane in an emergency, an excellent pilot never comes in to that situation in the first place". I find it a quite good explanation on how important it is to predict the worst case situation. "What if?" is a very important question, let us say that we decrease the safety from 99,999% to just 99%. That means that a plane would crash about every second minute. Those numbers added behind the comma are still very important. Again, most likely nothing will happen but if something happens you will be questioned and you will get charged for negligence and so on...

 

I hope that you can take in this information without becoming defensive but this is the way it works, nobody is god. Not even pilots or captains.

 

Regards,

Manfred

 

Well one thing I notice from this post is that you are talking from a simulator POV and not from a real life POV. I also see some lacking knowledge in statistics and basic law.

 

I'm not at all referring to the sim in any of my posts, for the record, and if you'd really like to challenge me on my US Law from the land of my ancestors, you're welcome to do so.  Furthermore, unless you can (within a reasonable margin of error) point out my lack of statistical knowledge, I ask that you avoid taking shots at me.

1. According to the FAA an airplane has to be 99.999% safe. That means that if your AUX system is inoperable then you won't achieve a adequate safety level. If you generator would be at fault then fine, you can just turn on the APU but in this case it was the entire bus. 1/3 systems is down. That gives you a way lower statistical chance of coming home all fine. It may still be 98% safe but then every 50th plane that decides to continue will crash. That means that 300 lives are lost because of guess what? Negligence! Via the checklist a decision has been made and it is your job to follow it.

 

False.  Nowhere in the FARs does it require such a thing.  If you disagree, I kindly ask you to point out the reg, the AC, or other FAA document that specifies such a measure.  If this were indeed true, any time something gets MEL'd, the flight would get cancelled.

 

While you accuse me of not knowing law and statistics, I don't think you understand aircraft as much as you think you do.  The loss of the BUS does not mean that 1/3 of your systems are down.  The loss of the BUS means that one of your three BUSes and your AUX PITOT HEAT are inop.  The rest of your systems are fine (take a glance at your MD-11 overhead: there's a reason there are AC TIEs).  The rest of your statistical argument is a statistical (reduction of safety does not necessarily mean the aircraft will crash) and logical fallacy (fallacy of false cause).  If you disagree, I'd really like you to find me a case in which an AUX PITOT HEAT failure has brought a plane down.

 

Additionally, you can't just fire up your APU at altitude.  Even if you could figure out a way to start an APU up there to cover the loss of a GEN, you wouldn't need it , as you still have two left (not mentioning the RAT).

 

I did follow the checklist.  It said "land at the nearest suitable airport."  I determined that the nearest suitable airport was my destination.  End of story.

 

 

2. No, you are not putting yourself out for liability every time you fly. You are though putting yourself out every time you don't follow "the book". Wouldn't be legal to fly otherwise would it?

 

You really are.  Every time you get in an airplane, you are accepting new risk that you had not before.  I do not operate any vehicles that require a commercial driver's license, ergo I am not at risk of accidentally or intentionally breaking the regulations that govern that activity.  As soon as I begin that operation, that risk is added.

3. Negligence is thrown around a lot, that means that people agree that even the slightest mistake is negligence. A court is made of the people, that means that if people agree that it was negligence, then it sure is. If you think that it isn't negligence it doesn't make a difference. The checklist (and thereby engineers who designed the plane) say that you should land at the nearest suitable airport, then guess what? Not following this tip is negligence.

 

Logical fallacy again (in this case hasty/sweeping generalization).

Negligence is held to a particular standard in the legal realm.  While it is true that a jury's interpretation may be of that prevailing understanding (they'd find me negligent), the trial may not be by jury.  Furthermore, juries are also given instructions by the courts as to the legal definitions of terms, such as negligence.

 

The checklist said land at the nearest suitable airport, and I did.  I landed at the nearest suitable airport which happened to be my destination.  Like I said earlier: a failure that required more immediate attention, such as that of an engine failure, would mean I'd be looking closer, but the AUX PITOT HEAT is of little consequence.

4. You brought up the passengers being ###### at you. Now you are thinking wrong, you are letting yourself being controller by them. That is a bad mistake, it is your job to keep safety number one priority. Also, when do you think that the company will be angrier? If you make a detour, check the plane, consult a mechanic and then land 2 hours late? Or when you endangered the 100+ million USD plane and its passengers from coming home in one piece? The safer way is often way cheaper in the long run.

 

I didn't say that was part of my decision-making.  You said there is no downside, and I provided a huge downside for the passengers, and for your airline.  That is all.

 

Furthermore, you're showing a misunderstanding of airline operations here.  That's not going to be a 2 hour delay.  That will be something on the order of 6+.  You landed at an airport that wasn't expecting you, with mechanics working on their own fleets.  First, you're lucky to get a gate or stairs when you roll up, so expect to sit for a few.  Second, you're going to have to deplane everyone (20-30 min), and then have the aircraft relocated to the maintenance bays (at IAD that requires about 30-45 min, just for the relocation).  Then it will likely be seen when the personnel become available.  That's anywhere from 0-3 hours, and longer if actual work needs to be done.  Then you'll have to relocate it back to the gate/stairs (30-45min).  After that, it's 20-30 more min to get the passengers back on.  Beyond that, you're also looking at having to get on the phone to a dispatcher who will then have to get you re-planned and re-filed to your destination.  So that's two hours of only deplaning and relocating the plane.  Add on dispatch delays, ATC delays (because you're now unplanned demand) and the fact that you likely flew off of your route to get to that en route alternate, the delay increases.  Being nice: 1 hour delay for off route diversion, 0.1 hours to taxi in, 0.3 to deplane, 0.7 to relocate, 1 hour (at best) to investigate the cause, assuming 0 work needs to be done, 0.7 to relocate, 0.3 to reload, 0.1 to taxi, 1 hour to get back to your route (assumption in order to show equivalency).  That's 5.2 extra hours in the best possible situation.

 

All for the pitot heat on your backup pitot tube...

5. PIC law has nothing to do with blame. The PIC has authority over the plane, but it doesn't protect him from getting his actions sued for... Nobody can stop a pilot then and there but it says nowhere that pilot can't be sued and charged for his decisions later on. Like i posted before, nobody can stop the pilot. For example, the company can't force him to continue flying when he does want to land. But he still can get sued for it... The company won't do it but they can. Anybody can be sued for anything, it is the courts job to decide if the person is guilty.

 

I never said it had to do with blame, or protects you from getting sued.  In fact, I could just as easily get sued over my actions to divert.

 

I'm not sure how you read that into a post where I simply said the reg states the PIC is the final authority as to the operation of the aircraft.

6. You keep saying that most likely nothing will happen. I agree fully that this is a threshold case and in FSX I won't bother to fly to another airport. The thing is that in real life you always have to think the worst case scenario. That is why you only fly with an airplane prepared for the worst. It may seem "cool" to fly with a broken airplane but you will feel a bit different when you are flying with it. There is this quote: "A good pilot manages to save the plane in an emergency, an excellent pilot never comes in to that situation in the first place". I find it a quite good explanation on how important it is to predict the worst case situation. "What if?" is a very important question, let us say that we decrease the safety from 99,999% to just 99%. That means that a plane would crash about every second minute. Those numbers added behind the comma are still very important. Again, most likely nothing will happen but if something happens you will be questioned and you will get charged for negligence and so on...

 

(Again with the statistical fallacies!  A reduction in safety does not mean that the plane will crash - there are several other variables!  Perhaps this MIT Lecture could help you to avoid further statistical fallacy)

 

I am thinking of the worst possible case scenario:

My AUX PITOT HEAT is INOP, which means I'm one failure away (of the main pitot heat) from potentially getting into a situation where icing must be avoided.  So, the worst case scenario is one in which my pitot tube becomes blocked because the main pitot heat failed.  Even in that case, the plane won't magically fall out of the sky.  You're trained to recognize and handle that all the way back in private pilot training.  Heck, the planes I normally fly have pitot heat that's off by default and you only turn it on when you believe you'll need it (icing conditions - though I do understand it is normal procedure for Part 121/135 to turn it on for the entire flight).

 

I'm sure someone will go find me the couple high-profile flights where someone left tape over the static ports, or some other crash, but the difference is those guys didn't know to expect it.  If I know my pitot tube may become blocked because of the heat failure, I know that my airspeed indicator will then be unreliable. The information from the static sources and AoA vanes, however, can be used to land the plane safely.

 

That's your worst possible case scenario.  I can still talk.  I can still fly.  The plane will not spontaneously stop flying because the AUX PITOT or even the main pitot heat failed.

I hope that you can take in this information without becoming defensive but this is the way it works, nobody is god. Not even pilots or captains.

 

I understand that.  I wasn't claiming that I, or any other PIC is.  I'm simply debating the issue at hand, on the standpoint that a GEN BUS issue, causing only an AUX PITOT HEAT loss, is not a safety of flight issue.

:rolleyes:

 

Still remains the question why they did *not* link the AUX pitot to one of the remaining the sources... 

 

With only 2/3 of sources available (APU and RAT come into the game later with only main source available) the engineers might have sacrifice a consumer, but are there not less important ones? 

 

:unsure:

If I flew the type IRL I'd know the QRH as well as the ops manual, and things like recommendations for divert on loss of 1 elec sys when the thing has 3 would get me to ask why it is.

 

To put a spin on this question - does the loss of either only the #1 or #3 elec bus also call for a divert? If not, why not?

 

As for the loss of the battery charger this is a bigger deal than it appears. The batteries are ballast on the electrical system for a start, and secondly in the event of total electrical failure those batteries should be powering the HOT BATT BUS and associated critical systems. No battery charger could mean the batteries are dead just 30 mins after the loss of the chargers, meaning you have major problems on an aircraft that is heavily reliant on power should you have a total electrical failure.

 

There is more to that one solitary line in the QRH than it appears I suspect.

 

Thing is, it is a loss of the #2 bus, not a loss of the #2 generator/engine.

 

Assuming total electrical failure, what do you have left? Not much at all... Without batteries even the panels would be dead. You might have an ISIS but I wouldn't bet on that lasting more than about 10 minutes. The old gyro ADI is good for maybe 5 minutes after total loss of electrical, assuming it is in good condition.

 

Best regards,

Robin.

Thing is, it is a loss of the #2 bus, not a loss of the #2 generator/engine.

 

Assuming total electrical failure, what do you have left? Not much at all... Without batteries even the panels would be dead. You might have an ISIS but I wouldn't bet on that lasting more than about 10 minutes. The old gyro ADI is good for maybe 5 minutes after total loss of electrical, assuming it is in good condition.

I looked around a bit harder and there is a lot of info in the systems manual. Also in the QRH a bit below the "GEN BUS_fault" there are generator faults. All of them end up in "continue flying with generator inop". Looking at the systems manual it looks as if the AC bus 2 is only connected through the GEN bus 2. Even turning on APU and ADG would remove the ability to energize AC bus 2. This means that there is a fault in the system that can't be fixed and thereby a loss of redundancy. 

 

Anyway all of the GEN buses connect to respective AC bus. Looking at the QRH it makes sense now because each of the faults give a "Land at the nearest suitable airport" message. Might actually also be because the GEN buses also are the lone providers of respective cabin AC bus. I guess that this will make the passengers loose some internal electrical as well.

 

 

 

:rolleyes:

 

Still remains the question why they did *not* link the AUX pitot to one of the remaining the sources... 

 

With only 2/3 of sources available (APU and RAT come into the game later with only main source available) the engineers might have sacrifice a consumer, but are there not less important ones? 

 

:unsure:

Look at 50.3 in the systems page. There are some good diagrams showing how the system works. As it seems the GEN bus is the thing that connects the AC bus to the rest of the AC system. That means that if the GEN bus two is off the entire AC bus 2 is put out as well. My guess why they didn't build in two extra is simply because of weight and cost. It is a quite rare event and might actually be easy to exchange.

 

 

 

Regards,

 Manfred