I flew on UA 924 from IAD to LHR on 4/12. While starting the push back the pilot said they received some kind of problem indicator on the battery. After a while of trying to clear the error, the pilots and mechanics decided to "reboot" the airplane (my term, not theirs) by powering everything off and powering it on again. The flight attendants positioned themselves at each exit with flashlights and all the lights went out momentarily, then emergency lighting activated. After a few minutes the lights came back on, the IFE started powering up, and the pilot said that everything was looking good, but that it would take them a while to reprogram the FMS. We then pushed back again and taxied to 19L.

We paused at the top of 19L and waited, and waited, we then started to roll, but it was back to the gate. The pilots said they were having trouble setting the trim and that because we had been taxing so long we had busted the fuel reserve budget and needed 4000lb more fuel. Back at the gate, the attendants gave us the opportunity to deplane because we had been on about 3 hours at that point. They were still having trouble with the computers, though, so we went through one more reboot cycle and onboarded the additional fuel. The flight departed 4 hours late (2:20AM) and arrived late as well. We were nervous the whole way across because we had lost some confidence in the aircraft.

I was SO excited for this trip because this was my first flight on the 787. I was a bit disappointed with the experience. I hope this was a rare occurrence and that we were just unlucky

Error 404? Thanks God they didn't have to do it mid-flight...

Rebooting or powering-down or darkening the aircraft or ctrl-alt-delete is a time honored way to "fix" or reset a balky computer, system and/or aircraft...in the case or more modern aircraft.

It's analogous to rebooting your phone or computer when it glitches.

Kikko19 wrote:

Error 404? Thanks God they didn't have to do it mid-flight...

They wouldn't.

airplanecrazy wrote:

I was a bit disappointed with the experience. I hope this was a rare occurrence and that we were just unlucky

I'm surprised they were so honest in their communications about the issue. Would've expected far more generic explanations than that.

Had exactly that on Air Canada flying daylight YYZ-LHR last year. Taxied out in the rain and joined the long queue for departure, unbeknownst to us, flight deck were troubleshooting a similar issue. Nea the front of the queue, they admitted defeat and headed back to the gate. Re-booted (twice) to no avail. Aircraft swap and 12 hour delay as LHR said no to a late arrival.

airplanecrazy wrote:

The flight departed 4 hours late (2:20AM) and arrived late as well.

I am not a native speaker but I had to smile when reading this sentence. What did you expect? The Dreamliner going supersonic?

LAX772LR wrote:

airplanecrazy wrote:

I was a bit disappointed with the experience. I hope this was a rare occurrence and that we were just unlucky

I'm surprised they were so honest in their communications about the issue. Would've expected far more generic explanations than that.

That’s in deed noteworthy. I regularly fly CA and VN. Such airlines would never ever provide you with such details. I would appreciate if they would work with „generic explanations“, instead of this they tell you a lot of BS or even lie when something goes wrong...

So great that the UA pilots shared so many details.

Kikko19 wrote:

Error 404? Thanks God they didn't have to do it mid-flight...

No. That would be Error 500.

Onboarded???

fr8mech wrote:

Rebooting or powering-down or darkening the aircraft or ctrl-alt-delete is a time honored way to "fix" or reset a balky computer, system and/or aircraft...in the case or more modern aircraft.

It's analogous to rebooting your phone or computer when it glitches.

Thank you for that explanation.

I've seen E175's having to be rebooted quite often too. It is just more common on today's newer aircraft as is the same with your own computer or phone.

The 787 is VERY sensitive regarding power switches.
If after the engine start you turn off the APU too soon (and the aircraft has not properly switched to engine generators) it can mean a three hour delay!

A while back I actually had the ground power fail at an outstation, that resulted in a serious delay (on a 787) and coincidentally a week later the same scenario on the 777 and no problems at all.

Done it on a Brazilia, DC-10, MD-80, 737, 757 and 767. It’s amazing what powering down an aircraft can fix.

Unfortunately this can happen and does from time to time. The 787 has many more ways to clear faults with it electronic circuit breakers and myriad of ground tests, but older planes like the 747 were commonly powered down and powered back up to clear all the faults. For those who have not done it before, it is important to precisely follow the maintenance manual when uploading software on a 787. One little mistake can lead to hours of trouble. With so much software talking to each other, mechanics have to be careful when replacing parts to ensure the configuration is correct.

I will say that once the engines are running the airplane is very reliable. It is what happens when maintenance is going on and the process before the airplane is configured for takeoff that leads to problems. The airplane is very good at diagnosing problems itself. Sometimes too good. All these checks that the airplane does when powering up should give passengers confidence that the plane is safe when it gets in the air. It can be a hassle on the ground and lead to delays, but once in the air the airplane is very easy to fly.

PHBVF wrote:

The 787 is VERY sensitive regarding power switches.
If after the engine start you turn off the APU too soon (and the aircraft has not properly switched to engine generators) it can mean a three hour delay!

A while back I actually had the ground power fail at an outstation, that resulted in a serious delay (on a 787) and coincidentally a week later the same scenario on the 777 and no problems at all.

It seems like newer airplanes have more and more problems with power transfers. Once the airplane has the engines running, everything is fine. Switching from ground power to APU power to Engine power can cause problems. One flight control computer or flight management computer resetting can lead to quite a lot of Fault messages and require data to be entered again. Dispatching an airplane with an inoperative APU certainly can lead to delays if everyone isn’t very careful with the power at the gate.

Rebooting, or powering down then powering up a 787 is not a recommended way of clearing faults. This is quite common on a 777. In the early years, this would cause a lot of fault messages, that would take while to clear. With software updates, things have improved. I've done several power ups on a 787 and never had any problems, it takes a while though. The Key is to do it correctly, by the checklist. An error many people make is to start the APU right after turning on the battery switch. You have to wait until the displays come up.

Same thing happened to me on a Jetstar 787 a couple of years ago. The pilots were having trouble with trim and navigation systems. They announced that they would restart the aircraft. Let's just say 787s are not fun after they restart. We were on board at the gate for 5 hours after....

airplanecrazy wrote:

I was SO excited for this trip because this was my first flight on the 787. I was a bit disappointed with the experience. I hope this was a rare occurrence and that we were just unlucky

For those of you who do not remember other aircraft introductions into service, the "teething" problems on the 787 and 350 are nothing new. I was on the 757 as a FO back when it was introduced in 84. It did the exact same thing. It was not unusual to end up de-powering the entire plane. Let is sit completely unpowered for a couple of minutes, then gradually rebuild the power to the aircraft.

After what seemed like many, many years, the eventual root of the problem appeared to be power supply. Back in those days, it was very common to have a GPU attached to the aircraft supplying power. It turns out, that power supply was too erratic (think volts and frequency) and the 757 didn't like that. So, the solution was to leave the APU on while the aircraft was on the ground and vast sums of money was invested to get cleaner GPUs and gate power units. That seemed to make a great difference in reliability. The 787 is exactly the same.

It seems that every new generation tends to get more and more sensitive to power fluctuations and the 787 is no different. Trying to remember, but I seem to remember an issue on the 320 where it had to be completely de-powered at least once every 24 hours. I can't find anything about that so it might have been an operator issue. But, the problem will get worked out and the next generation of aircraft will come with the associated problems.

Common line call out on a 737. Something electronic gets locked up. "Did you try rebooting the aircraft?" This phrase is not liked. They know it will likely fix the problem and will have to retype the FMS info for their flight plan.

I worked on the A320 from 1988 until last year when I retired. (and many others B777 A330 etc), but my knowledge of the B787 is limited.
When I started on the A320, repowering the aircraft was common, but as we learned the systems, it became less common, and when I finished it happened very rarely, and never with pax on board. I found that it wasn't as helpful. All the important computors have battery back up, and the very important ones have hot battery connection. One or two have their own capacitance system that keeps them powered for 20 minutes. Crews tried resetting the power on their own, and were surprised when all the nav data was still loaded.
I believe that ramp technicians should try and learn how to reset individual systems without plunging the pax into the dark. And pilots should only touch CBs that are listed in the QRH. (good reference for techs as well!)

Yeah, but completely power down and power up an 737 including inserting all FMS data can be done in less than 10min. Probably less than 5min if the company has company routes in the FMS.

No 787 experience, but on the ATR it's not uncommon to have issues with avionics or electrical when getting ready to depart in the morning. We usually tell the pilots we'll be down there shortly to have a look but in the mean time turn everything off so the cockpit is 100% dark, have a sip or two of coffee, then turn it on again and see what it does. In my experience probably 6 or 7 out of 10 times the problem goes away and the airplane proceeds to fly around all day long with no further issues.

The MD11 gets the reboot a whole lot. Unfortunately, it is also a little temperamental if you don't power it down/up just right. The other aircraft we have (B757/B767/A300) we can keep down for 30-60 seconds and bring them back OK. The MD11...sometimes we'll shut it down for 5-10 minutes to really let the electrons drain out of the masts...along with fuel.

Not sure about our -400's & -8's.

airplanecrazy wrote:

I was SO excited for this trip because this was my first flight on the 787. I was a bit disappointed with the experience.

Seems to me you got an authentic 787 experience!

Martijn

CanadianNorth wrote:

No 787 experience, but on the ATR it's not uncommon to have issues with avionics or electrical when getting ready to depart in the morning. We usually tell the pilots we'll be down there shortly to have a look but in the mean time turn everything off so the cockpit is 100% dark, have a sip or two of coffee, then turn it on again and see what it does. In my experience probably 6 or 7 out of 10 times the problem goes away and the airplane proceeds to fly around all day long with no further issues.

ATR = Always Try Reset

Dalmd88 wrote:

Common line call out on a 73all computer7. Something electronic gets locked up. "Did you try rebooting the aircraft?" This phrase is not liked. They know it will likely fix the problem and will have to retype the FMS info for their flight plan.

on a 737 you can reset many things by a circuit breaker reset. the later computer controlled airplanes require more detailed computer resets.
The B787 has many more computer interfaces, and it might be more economical to have the airplane go dark and relax all the interface relays than to find the faulty relay and depower it alone.