Summary
- Alaska Airlines E175 diverted to Portland, where it made a safe emergency landing due to hydraulics failure.
- It is possible that Portland was chosen as the diversion airport due to its longer runways and the safety advantages it offers.
- Most aircraft, including the E175, have multiple hydraulic systems for redundancy.
An Alaska Airlines Embraer E175 aircraft, on Monday, en route from Seattle to Redmond, declared an emergency due to hydraulics failure and diverted to Portland, where the aircraft landed safely. While the passengers were flown to their destination after an equipment swap, the aircraft involved has been re-positioned to Seattle, and its first commercial flight since the incident is scheduled for later today.
The diversion
Alaska Airlines flight AS2020 is a scheduled service between Seattle Tacoma International Airport (SEA) and Redmond Municipal Airport (RDM). It utilizes a fleet of Embraer E175s that operate under Alaska Airlines’ regional subsidiary, Alaska Horizon.
As per a post on X, the diversion happened due to the aircraft suffering a loss of the aircraft’s number two hydraulic system midflight, which resulted in the flight crew taking the precautionary decision to declare an emergency and divert to Portland International Airport (PDX). The aircraft landed safely at PDX, although the aircraft has been reported to have experienced ‘wobbly nose gear’ upon landing.
As seen in the video shared on social media, the nose wheel appears to be shimmying as the aircraft rolls down the runway. Though it is not entirely sure if the nose gear’s characteristics were linked to the failure of the number two hydraulics system, the hydraulics are responsible for various movements of the aircraft’s flight controls and nose wheel steering.
Simple Flying has contacted Alaska Airlines to learn more about the incident. Any response received will be included in the article.
Why Portland?
A look at the flight path of the aircraft during the flight, as per the data from FlightRadar24.com, shows that the E175 had flown well past Portland and had reached close to its destination before turning around and flying to PDX.
Considering that Portland is one of the airline’s bases and offers longer runways than those available at Redmond, it is possible that the flight crew nominated Portland as their diversion airport due to the safety and operational advantages it offers.
While the E175 (and, for that matter, most modern aircraft) has multiple hydraulic systems, the failure of one system does not mean it is critical; it does bring into question the aircraft’s capability in terms of control in the air or ground and even aircraft braking, which necessitates a longer runway in such scenarios for safety reasons.
In the event of a hydraulic failure, the ability of the aircraft to use tire brakes or deploy spoilers upon landing might be degraded; thus, having a longer runway can be helpful in the event the aircraft has to come to a stop with natural deceleration.
Hydraulic systems
Modern aircraft flight surfaces and steering systems are actuated by hydraulic systems by pilots from the flight deck. The powering up of the system prior to taking off is what passengers generally hear as “dogs barking” or “back and forth scrubbing.”
Related
Hydraulics, Chimes & Everything In Between: The Various Sounds Heard On The Ground & Inflight
Insights into the sounds you hear on every flight.
Most jet aircraft have multiple hydraulic systems for redundancy purposes. While the Embraer E175 has three separate hydraulic systems, larger aircraft, such as the Boeing 747, have four systems.
Interestingly enough, the Airbus A380, despite being larger than the Boeing 747, only has 2 hydraulic systems.
