SWA 737 Max-8 "Dutch Roll" Incident

The fact that voice recorders are constantly getting overwritten in all these incidents lately, in the age of NAND in the TBs taking up virtually minuscule amounts of mass and volume, is absolutely ridiculous.

Saw the headline but decided to just wait until Juan talked about it instead of looking then.

I love aviation and I know just enough to be dangerous to humanity. However, I am an engineer and spent my entire career in nuclear power, which which is complex . I watch your channel frequently. You do ask for input on occasion, but this video was very much different. You did something that is rare on YouTube. I am extremely impressed. I don’t know how many people noticed. You stated when you did not have details of the max rotor system and asked for help from the professionals that watch your channel. You did not bloviate. You’re confident enough that you knew your limits and asked for data. That requires maturity, common sense, and confidence. I salute you, sir. I got to add a dig. Go Navy.

I only flew the 737 100/200 (guppy series) for PEOPLExpress in the early 80s. I was dispatched once from Florida to Newark with a YAW DAMPER INOP MEL. Holy shit! Even though we were restricted to a lower altitude by the MEL, the passengers in the back sure knew it was not a normal flight by the tail swishing around. I couldn’t feel it up front at cruise altitude, but I REALLY noticed the difference when I was hand flying and we went skidding right through the final approach course… and I realized that because of inop Yaw Damper I had to use the rudder pedals just like in a Cessna , which 737 pilots never do. It was an eye opening experience.

Was at the Columbus Airshow today and I thought that voice sounded familiar. You and all the announcers did a great job today.

Thanks Juan. As a retired 30k hour heavy jet captain, I find it absolutely bizarre that cockpit voice recorders have not been able to record literally many tens of hours, and should have been able to do this for many years. 30 mins, or in this case just two hours is ridiculous. Even my phone can do that- it’s inexcusable.

I had some incredible instructors in the USAF. When you do these breakdowns it really reminds me of the quality airmanship passed down to us and expected by us. I have immense respect for instructors like yourself. I always enjoy the nostalgia.

"On Jun 13th 2024 The Aviation Herald learned that two ribs, that the stand by PCU is being mounted to, were damaged as well as the mounts of the stand by actuator. A temporary repair was done in Oakland replacing the damaged PCU, the aircraft was then ferried to Everett to replace the damaged ribs."

As a flight attendant of 28 years, responsible for the 737 in all of its iterations, thank you for this . I guarantee we will hear nothing of this in our annual training . I will share it with my co hearts . A very well done presentation.

I experienced a total loss of the PCU in a SWA 737-200 on a flight from SAN to PHX. At touch down we lost all hydraulics of the A,B, and Stby system. They claimed that it was not possible to loose all hydraulics through the PCU, but it did occur. This occurred around the time of the crash of the United 737 that crashed in Colorado Springs from a PCU fault.

One of the things we do in simulator training is a Dutch Roll demo at high altitude. We disarm the Yaw Damper and turn off the autopilot. The results of displacing the rudder in this condition causes a Dutch Roll that can be really dramatic in swept wing jets and hard to recover. Props to the pilots in this case who managed to recover from this incident.

For all you fellow aviation geeks out there, according to William Cook in his book The Road to the 707, the yaw damper was invented by Ed Pfafman, an engineer at Boeing during the flight testing of the XB-47 - the USAF's first swept wing jet bomber. The test pilots noted a continuing Dutch Roll in '47 and Ed came up with a solution. Brilliant guy. A yaw damper has been standard equipment on swept wing jets ever since.

Electrical engineer here. Great explanation, of an unstable system, with phase shift contribution !

Watching this, I realized what a great FAA Administrator Juan would be. Knowledgeable, committed, and truly focused on getting things right. Juan wouldn't need to fire the incompetent ones, they would just quit out of fear.

Never have I seen modified charades so expertly explain the physics of a Dutch roll. Well done, Juan!⚡👊🏼⚡

Hey Juan. I thoroughly enjoy your videos and all the in-depth research you do. I just watched the video about the 737rudder issue that happened recently. I am a tech instructor for both the A-320 and B737 Max for an airline. To answer your question, the Max uses the same rudder control system as the NG. Incidentally, after the RSEP (Rudder System Enhancement Program) which was mandated in the early 2000's, a new main PCU was installed (I did a few of them while I was turning wrenches). That said, the classics then had the same type of rudder system as the NG and the Max after the modification was incorporated (RSEP). The Force Fight Monitor was a big part of this upgrade. The Force Fight Monitor is installed in the main rudder PCU and once it detects a difference of 3600 psi for a minimum of 5 seconds (one system pulling one way while the other system pulls the other way), it will automatically turn on the standby hydraulic pump and activate the standby PCU which will control the rudder. One disclaimer is that I DO NOT work for the airline that had the problem but am aware of it via the news and your channel. Hope this helps and keep your awesome content coming!

I just had to look it up: "Dutch Roll was the term used for skating repetitively to right and left on the outer edge of one's skates. By 1916, the term had been imported from skating to aeronautical engineering."

Total "Hull Loss" is a phrase you never want to hear :/

Back when the 707 was fairly new, Brannif was taking delivery of a new aircraft . It was a test flight with Boeing test pilots, and Brannif pilots. The pilot flying the plane induced a Dutch roll which ended up tearing off the engines, and resulted in a catastrophic crash. Luckily only a few people died.

Juan, 11k hour NG/MAX driver here, unfortunately or fortunately depending on your perspective, I’m inclined to posit human error on this one. One of the pilots “stuffed” a rudder accidentally and either the YD was overwhelmed or they (the pilot) tried to override the YD to correct his/her misstep. Similar to loss of control of Lantam 787, with inadvertent seat movement. FWIW.