Pilots said nothing as Southwest plane flew dangerously low over Tampa Bay

They didn't get a terrian warning because they were landing. Being close to the ground is what they expected. They have both radar & pressure altimeters.

What might have happened is that due to the poor weather they thought they were closer to the airport, or they weren't closely following their glide path, or the aircraft was misconfigured for the RNAV approach. Perhaps a combination of the three.

I'm not a commercial pilot but as a private pilot it looks like they were doing a manual approach .... and were lined up with the freeway bridge and attempting to land on it? The blog linked elsewhere looks like a perfect glide path for that ... which you shouldn't be doing.

In which case, the terrain warnings would be the standard "you're landing, idiot" noises which wouldn't alert them to anything, because they'd be expecting them.

It’s the sort of behaviour, and explanation, that you might expect from someone who is far too tired to function, and is operating purely on ingrained habit.

Things went well in this case, but I’ve seen the sort of schedules that are considered safe, and I can’t help but notice that if you asked me to work the same schedule then I would, at best, be exhausted at the end of every workday. If I for any reason didn’t get proper rest, if I had a subclinical cold, anything, then I’d be falling asleep at the wheel.

The reason for diverting is more about rules than simply the distance. If the weather was marginal at Tampa and the pilots were worried that another failed attempt would lead them to have less than the required fuel to reach the diversion airport (Ft Lauderdale) while still staying above their minimum reserve fuel, then they'd be required to divert without making that additional attempt. Realistically, they'd still probably have enough fuel to reach Ft Lauderdale, but there'd be more paperwork to fill out....

  "The weather in Tampa at the time was poor and getting worse. Thunderstorms were prevalent in the area and visibility was decreasing. The relevant METAR (below) indicated thunderstorms at the airfield."

Maybe something weather related?

The weather was deteriorating, and it looks like it might have been better at Fort Lauderdale from the weather map. If you're suspecting an issue with the instrument approach equipment and you're low on fuel, you might want to divert to somewhere with better weather to minimize the likelihood of having to execute a second go around and getting in a situation where you don't have enough fuel for a diversion.

For instance, if they have enough fuel to get to Fort Lauderdale and the weather there allows for a visual approach, diverting there gives them a lot more options in the case of malfunctioning instruments.

I'm just a private pilot without an instrument rating, but this diversion doesn't seem crazy to me.

Or maybe it is just over-reporting. Aviation is safe according to the data, but not according to the amount of reporting given to every minor problem. As this story pointed out one of the many backups, ATC, called out that they were low before anything bad happened. If we had even remotely close to this standard of over-reporting on any other transportation sector we would have stories multiple times a day. People are injured on busses due to rough driving all the time, no stories. 40k people die on the roads every year, barely a news story. A plane descends but is stopped before anything happens, it is a story.

When a commercial jet schedules a flight plan, they must specify alternate airports, usually two are required especially when weather is predicted to be bad. The closest airport may not be the best one to divert to due to runway restrictions, normal capacity, and it must be far enough away for the possibility of it to not be affected by the same weather conditions that the destination is (which would be a reason to divert). Ft Lauderdale is 225nm away which is not far at all for a aircraft to divert to.

Landings in which the approach is entirely over water is tricky and is done with instruments all of the time, typically ILS. This is normal for commercial flights in general, but should the localizer lose the glideslope, autopilot on the b737 defaults to the last mode it was in, which for the approach, they may have been performing a flight level change (FLC) mode down to the airports elevation which will cause a decent more rapid than the 3% guild slope, which allows the aircraft to descend into and catch the glideslope localizer.[note 1] At some point the gluideslope was lost (or was never caught to begin with) which to the pilots’ surprise, they likely encountered a “terrain, pull up” notice and recovered before the situation got worse.

So why divert? Why not go around? Well they had to make that decision because they may not be able to divert if they made the decision to go around and try again due to fuel burn. They likely did not know why they captured the glideslope and then, all of a sudden, they were getting ready for a water landing. Was it the aircraft’s ILS or guideslope localized receiver? Due to the weather, they certainly could not do a visual approach, and there may not be sufficient RNAV points in the water on that approach to land there, so they diverted to an alternate where they know they could land visually if they absolutely had to.

Making decisions while flying aircraft is a calculated process and may not be immediately obvious. It’s easy to see in hindsight how things could have turned out differently but pilots often have minutes or seconds to make a decision and they will always choose the one that results in a safe landing over a convenient one. Media that doesn’t understand how these decisions are made love to poke fun at these silly pilots and it does a huge public disservice.

Note 1: this was explained to me from a friend who flew b737 for an airline

This is the sticking point for me and somewhat feels like they did this deliberately to erase the cockpit voice recorder so they could try and limit lawsuits and negative press.

Most CVRs are overwritten in 2 hours unless it’s a brand new aircraft.

This flight incident occurred on July 14th. The Crowdstrike incident happened five days later on July 19th. They are unrelated.