Republic E-175 Runaway Trim/FBW Failure Event
 

An American Eagle Republic E-175 had a runaway trim (or possible Capt FBW failure). Could not reduce pitch of the airplane for abot five minutes after takeoff. :eek:

Kudos to the crew.

https://www.avgeekery.com/american-e...rim-situation/

Good job on the part of the crew. It sounded like it got a little dicey for a while there.

There are four pages (and growing) on this in the "Major Tool of the Day" thread in the "Majors" section. Very little discussion of the actual incident, though; just lots of Delta-bashing.:rolleyes:

So this crew was really in a bad situation... :eek:

https://www.avweb.com/uncategorized/...pitch-control/

Wire Chafing Checks Recommended After EMB 175 Crew Briefly Loses Pitch Control

Russ Niles
February 2, 2020

https://s30121.pcdn.co/wp-content/up...1.30.42-PM.jpgThe NTSB has issued recommendations to the FAA and National Civil Aviation Agency of Brazil to order checks for wire chafing on the pitch trim controls of Embraer E-series aircraft after an incident in Atlanta in November. The crew of a Republic Airlines EMB-175 lost pitch trim control shortly after takeoff Nov. 9. As the aircraft, which had six passengers aboard, went through 2200 feet, the captain, who was flying, tried to engage the autopilot but it wouldn’t activate. He quickly diagnosed the problem but the autopilot/pitch trim wouldn’t disconnect. Both pilots had to use both hands to keep the nose down before the first officer’s switch finally worked and they were able to retrim the plane.
Investigators found a chafed wire in the captain’s control column caused by contact with an untucked safety wire pigtail. Republic inspected its other EMB-170/175s and found nine other aircraft with similar chafing. At least one other airplane at another airline had similar damage. The NTSB says all aircraft in the series, including 190/195 models and Lineage business jets, should be inspected. The investigators of the Atlanta incident also discovered the disconnect switch had been installed upside down. There are 667 U.S.-registered aircraft and more than 1,500 worldwide. The issue does not affect the new E2 generation of the aircraft, none of which are registered in the U.S.

Wow!

Glad the problem was found and not “could not duplicate.”

Looks like the root cause of the runaway was that MX was troubleshooting the messages caused by the chaffing, decided to defer the CA's split trim switch, and re-installed it upside down. They didn't op test it since it was deferred.

Technically the CA should have been able to use the good trim switch, but both switches were in the same assembly, so both were upside down.

The wire chaffing caused the EICAS message which led to the MX troubleshooting and error.

https://www.youtube.com/watch?v=iMMQ6-OfnL0

As it turns out... DL dude was more right than wrong.

The ERJ crew had their hands full and didn't run the QRC. If they had, they would have disabled the trim via cutout switches.

The CA initially solved the problem by transferring control to the FO, but then brought the problem back again by taking control back. Trim cutout would have prevented that.

Backtrim is inferior trim /s