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Each commercial flight in the US is required to file a flight plan before takeoff. This flight plan is created and approved by an FAA licensed dispatcher, who t
by imadethis 5y ago
Each commercial flight in the US is required to file a flight plan before takeoff. This flight plan is created and approved by an FAA licensed dispatcher, who then tracks the progress of the flight and develops alternative routing as necessary.
An important part of the flight plan is weather conditions along the route. There are obvious safety concerns, but weather conditions are also responsible for the route chosen, the amount of fuel onboard the plane, and passenger comfort. Without weather information, the flight plan cannot be filed and the plane cannot fly. Keep in mind that there are specific regulatory standards that must be met with any information included in the flight plan. A pilot cannot simply open up the weather app on their phone for instance. The weather info needs to come from an approved source.
I have no specific information about Southwest's current issue, but my guess is the third party service they use for weather in the flight plan is out of service. If they can't transmit this info to aircraft in the air or on the ground, then nobody gets to fly today. I'm also guessing that an incident like this will result in backup solutions being put into place, and that there is an IT or systems engineer somewhere who is trying to hide their "I told you so" expression.
Edit: an example flight plan can be found here: https://www.simbrief.com/system/guide.php#ofpsample https://www.simbrief.com/system/guide.php#ofpsample. This is from a site for sim pilots, but the format of the brief is the same as what a commercial airline would file for a flight.
- AnimalMuppet 5y agoSo if a plane is in flight (and I'm sure some were), and the weather system goes down, then what? Stick with the previous plan? Divert?
- bombcar 5y agoIn-flight weather by radio is an option but it’s a manual thing. And the airline may not be set up to use that except an emergency situation.
- _s 5y agoIt is a requirement - AWIS/ATIS and ATC/Tower (all via radio) can provide weather information at airfields, and a lot of instrument approaches do require certain readings before an approach can be commenced.
- imadethis 5y agoI don't think the equipment to receive weather updates is on the Minimum Equipment List, but if dispatch couldn't even update over the radio then I would imagine they would start diverting flights. This is just a guess, hopefully someone with more knowledge can jump in here.
- _s 5y agoIt depends on the airframe - but I believe for Airline Transport category aircraft a storm scope and a few others are required.
- kayfox 5y agoIn flight weather can be observed (most airliners have weather radar onboard) and the pilots can check on weather along their route with controllers and at the destination or in specific places by electronic inquiry.
- Wistar 5y agoThere is also the PIREPS (Pilot Reports) system where pilots report actual weather conditions as encountered by an aircraft in flight. Some aircraft have automated weather reporting systems (AMDAR). https://www.skybrary.aero/index.php/Pilot_Report_(PIREP) https://www.skybrary.aero/index.php/Pilot_Report_(PIREP)
- mrandish 5y agoThanks, that is certainly a plausible explanation - basically not being able to sufficiently guarantee compliance with some approved process that had a single point of failure somewhere. I also agree that, much like when the Space Shuttle blew up, there were engineers somewhere who immediately suspected exactly how and why.
- landemva 5y agoLike the space shuttle o-ring, I at first thought this was announcing 737MAX crashes. That new Boeing design to fit the larger engines should have a new type certification, instead of software which creates a pretend appearance of older 737s.
- _s 5y agoI'll add to this (as a private pilot) - there are also a lot of requirements of weather at your destination; in terms of wind, visibility, temperatures and how long those forecasts are valid for and so forth. In order to dispatch a flight you need to ensure that the weather at the arrival airport meets certain minima at that point in the future (hence the need for forecasts), and so does that at suitable alternative airports, and enough fuel is carried to be able to divert (depending on a heap of other factors such as aircraft load, capacity, prevailing winds enroute, at destination, time of day and so forth). Aircraft are then also required to check the AWIS/ATIS or the Tower (usually the most reliable source of weather at an airfield) to ensure that the weather at the destination is within their safe margins. There's the FAA requirements, and then airlines and aircraft and airports then also have their own established minimum requirements that all need to be within the safe range. You can certainly dispatch a flight with potential updates and diversions as they progress / get closer to the destination, but with an outage and no means to update the enroute aircraft - there's usually no easy safe or legal way to dispatch them.
- jeffrallen 5y agoI agree with everything you wrote except "trying to hide". In these situations, it's impossible to hide "I told you so". :) Also, the nice thing about wfh is the possibility of screaming about the stupidity of your organization more conveniently...