Boeing 787 "Blacklisted" From Some Air Traffic Control Services (flightglobal.com)

An anonymous reader writes: A software glitch causes the Boeing 787 to report its position incorrectly, which has led Australia and Canada to 'blacklist' the aircraft from using ADB-S and until it is resolved the latest Boeing is treated as an aircraft without ADS-B capabilities. The practical implication is that the aircraft is not allowed to use reduced separation procedures and an maximum altitude limit of 29,000 feet was also considered. Boeing denies that the bug causes a safety hazard because existing services (radar) still allow safe operation. A bugfix is coming to restore ADS-B functionality.

Comments

Re:It's not really a blacklist then, is it?

[Anonymous Coward]

It's graceful degradation.

No, a graceful degradation would be the plane recognizing it's not operating correctly and falling back to the older service. This is a case where the plan is actually trying to use the newer/better service, failing to do so correctly, and it not aware that it is failing to do so. The humans involved are noticing the error and have had the blacklist the plan from the newer system and manually force a fallback to the old system.

I mean seriously, the second sentence in TFA even says:
Boeing says a service bulletin with instructions for operators to correct the position reporting error will be released “imminently"

Not a safety hazard? My ass!

[LordKronos]

Nav Canada first detected a problem on 1 July 2014 when controllers noticed a 787 appearing to deviate up to 38nm (70km) from its planned track. The controllers alerted the crew by radio, but the pilots insisted their instruments showed they were still on course. Suddenly, however, the 787 “was observed jumping back to the flight plan route” on the controller’s screens, according to ICAO documents.

I'm sorry, but if a plane is reporting that it is 70km from where it actually is, that's no small deviation. That deviation is more than 10 times the required flight separation. It may not pose a safety hazard once controllers already know they have to fall back to the older system. But before this was discovered? That's a HUGE safety hazard. The only reason they can get away with claiming it wasn't a safety hazard was because they lucked out and the system only screwed up when there were no other planes around

Re:So the plane tells ATC where it is...

[brambus]

I know you were trying to be snarky, but you did accidentally ask a good question where the answer isn't trivial:

• Since the dawn of radar ATC, civilian radar has been SSR - Secondary Surveillance Radar, meaning, it requires cooperation from the aircraft. SSR gives you the horizontal location of the target, but not its elevation. Instead, together with the actual radar return, the aircraft responds using a short digital code that identifies it and tells you its altitude (as read from the onboard altimeter by the SSR equipment on the aircraft). SSR has numerous advantages over PSR, mainly its not as complex, doesn't require as much power and has greater range, all of which are useful in a civilian environment. Also, it has no military application, so it carries far fewer export concerns.
• Even so, SSR is still very expensive and providing good coverage is difficult to impossible. Even modern industrialized countries such as the USA have many places where radar coverage is simply unavailable (especially at lower altitudes). In less well of places, such as large areas of Africa, radar coverage is nonexistent.
• The vast majority of all aircraft (and nearly all commercial aircraft) have some sort of navigational equipment that is completely independent of radar coverage and is reasonably accurate to provide traffic separation services. Put simply, aircraft are able to navigate without any ground assistance.

And so the natural evolution is to largely abandon SSR (except for areas of extremely high traffic density) and instead place around the country only small receiver stations that listen to aircraft position reports. Using those then, ATC can build a complete traffic picture and provide separation services without having to maintain expensive ground equipment.

The underlying problem ...

[PPH]

... is that the problem was traced back to the 787 avionics network. Information sent from the GPS (where the data originates) to the transponders (where it is sent out to air traffic control). This is the same network which attracted attention when Boeing asked for a special condition exempting the 787 from a requirement to isolate critical functions from things like the passenger entertainment system. Now, nobody has tracked down exactly what caused this communications glitch. And they may never do so. But their innovations may be coming back to bite them in the ass.

Re:at least is not tcas off

[DesertNomad]

I run a number of ADS-B receivers and feed the data into FlightAware. I have seen a number of a/c locally that are in very wrong positions (well over the 70 km mentioned in TFA) and suddenly jump into the "right" positions. Sounds like interface problems.

The ADS-B system is fairly simple, and as long as the right lat-lon string is inputted, it should transmit the right position. Maybe it's a "units" issue similar to the "units" issue that caused the Mars spacecrafts more than a decade ago to make an unexpected and unfortunate (very) hard landing...