Cessna over DC, supersonic boom

[basilosaurus]

Jun 5, 2023 14:07:10 GMT -5 pixy0stix said:

I read about this yesterday, and I'm amused at how many people don't know what a sonic boom sounds like. I grew up in the buttcrack of nowhere NE, which is perfect for training flights for numerous western Air Force bases. I can't tell you how frequently they occurred, but it was enough that they never phased me or I wondered what they were.

I've lived on/near fighter bases and still never heard it. They really try hard to make sure it's far from people.

I'm pretty sure I would have thought it was a transformer explosion. Probably at my metro stop. Because that's happened to me in DMV before.

[Deleted]

Jun 6, 2023 8:22:18 GMT -5 litebright said:

Jun 6, 2023 7:55:08 GMT -5 Velar Fricative said:

Hearing that boom would have freaked me the fuck out, as I've never heard a sonic boom before. My mind would have gone to some sort of 9/11-esque thought immediately too.

The path the flight ended up taking was also eerily remiscent of the Flight 93 path (in terms of that sharp turn backwards, not the actual locations), and obviously we know that path was intentional. From what I read, this pilot somehow made (intentionally or not) a very sharp turn backwards. Not knowing anything about where various flight controls are, I suppose he could have collapsed onto the mechanism used to turn the plane but then it straightened out as if they were heading back towards their departure site. Because they were seen as unresponsive I don't believe there was intention behind it, but I guess my expectation would have been that the plane would have just been meandering past Long Island towards perhaps New England or Canada (land or waters).

Huh. I swear I read in early versions of this story that the turnaround at NY was actually one of the things that led investigators to think that the plane was already on autopilot at that point. Like it would automatically head back toward its originating point if it was not landed? 

Now there's an updated WaPo story that says that would be unexpected behavior even if the plane was on autopilot. 

www.washingtonpost.com/transportation/2023/06/05/dc-sonic-boom-cessna-ntsb-investigation/

From the story: Hassan Shahidi, president and CEO of the nonprofit Flight Safety Foundation, said the route was perplexing and will be a focus for investigators. He said it would not be normal for a plane to set out for a destination, then make a U-turn and head toward where it started, even if autopilot capabilities were guiding the plane.

“It’s very unclear why it made this maneuver so close to its intended destination,” Shahidi said. “The aircraft, especially the Cessna airplane, it has to be directed by the pilot to take a certain flight path and altitude.”

It would be pretty weird for the plane to just turn around, but not unthinkable. When you program the navigational route, you enter in a start location, the waypoints, and an end point. In many systems you can program a “second” route. Many pilots like to program their starting location as the “end point” in a second route in case they need to suddenly return to the departure airport (like a bird strike on takeoff a la Miracle on the Hudson).

Normally the system wouldn’t switch from the “primary” route to the “secondary” route, but I suppose it’s possible that if the system didn’t offer a “secondary route” option, the pilot could program an extra waypoint at the end that was the departure airport, so if they needed to return suddenly he could just skip ahead through by points.

[fortnightlily]

I was sitting in a friend's backyard in a Maryland suburb outside of DC and heard what sounded like a thunderclap even though the sky was pretty clear. I just kind of shrugged it off and assumed it was a heavy truck or whatnot because the property behind hers had some workers doing something.

Such a sad story.

[dcrunnergirl52]

We live in Alexandria, VA, about 15 miles from Andrews. We had just arrived at the pool when we heard it. I had simultaneous thoughts of 1) OMG, we're under attack/there are bombs going off in the distance and 2) OMG, that's a lot of thunder and we just got to the pool and the 5 year old is going to freak out if we have to go home.

I'm so sorry to hear what happened to the plane and the people aboard. We had a death in our family in a small plane crash about 2 years ago, and it's just devastating.