On September 22, a trim motor failure resulted in erratic movements of the trim wheel on a Hawaiian Air A330 that was performing flight HA3 from Los Angeles to Honolulu. Aviation Herald and others reported the incident. In total, this makes 14 recent Hawaii-related flight diversions since mid-summer.
Let’s revisit that first sentence again and what it means. We invite the pilots who follow Beat Of Hawaii to add their comments too. On some planes, the trim wheel is moved manually and can raise the nose of the plane up or down. Once that’s set, it will hold the yoke in place, which is helpful at times like when the aircraft is climbing.
On the Airbus A330, there is an auto-trim setting. As soon as the weights and center of gravity position are inserted into the flight management computer, a motor causes the trim wheel to turn automatically to the correct settings for takeoff and during flight.
“Trim Systems are considered to be a secondary flight control system. Aircraft “trim” is the adjustment of aerodynamic forces on the control surfaces so that the aircraft maintains the set attitude without any control input.”
Following take off from LAX, the trim wheel began to move erratically, which could cause the nose to be unstable. To resolve the situation, the flight crew disengaged the autopilot, worked through the appropriate checklists, and then decided to divert back to LAX. The plane departed LAX at 9:58 am and returned back to the same airport at 11:43 am. The plane was out of service at LAX for two days following the incident.
There is an NTSB report on this that said that the primary trim motor failure was the cause of the erratic trim wheel movements. There were no other indications of issues as reported by the plane’s Electronic Centralized Aircraft Monitor (ECAM). That is the system on Airbus planes that monitors and displays both engine and aircraft information for the flight crew. When there is a malfunction, ECAM is designed to display the fault and may also indicate the remediation steps needed.
Thanks to the great work of the flight crew, this issue was resolved without a dangerous situation. Trim motor failures have previously created serious pitch issues with airliners and, in 2019, caused a nosedive on a Boeing 737-800.
14 recent Hawaii flight diversions.
We’ve covered Hawaii flight diversions for years but can’t recall a period of time when there have been as many as is the case since mid-summer. Here’s the list of issues that occurred recently:
Hawaii Southwest 737MAX Smoke In Cockpit Diversion. A scary incident ended well when a Southwest Hawaii flight diverted over the Pacific Ocean.
Another Southwest Hawaii Mid-Pacific Diversion. For the second time in a three-week period, a Southwest Hawaii flight has had an over-water diversion.
Within 48-Hours, 3 Alaska Air Hawaii Flights Divert Over the Pacific. When three Hawaii flights to/from San Diego all experienced flight diversions crossing the Pacific.
Hawaiian Joins Mid-Air Diversions | Now 7 In Three Weeks. Lucky 7: 3 airlines, 5 diversions in 1 week, 7 diversions in 3 weeks.
What Are Fumes In Aircraft Events? | Hawaiian Diverts Again. Aborted flight, flight crew oxygen masks, fast return. Fumes onboard are always concerning on long Hawaii flights without diversion points.
Hawaiian Air A330 Diversion Results In 15-Hr Phoenix Delay. This latest Hawaii flight diversion brings the total to 9 in recent weeks.
UAL Hawaii Flight Diversion Today | Medical Emergency Reminder. So many recent flight diversions; this one ended up in Hawaii due to a life-threatening situation.
4 More Hawaii Flight Diversions Include Hawaiian & United. Twelve Hawaii flight diversions in 60 days.
We found a short video on what it means to trim an airplane. While this is on a Cessna that requires a manual setting, it seems to do a great job explaining the concept.
Image courtesy of Flightaware.