A continued unstable approach by a Fokker 100 into Perth earlier this year highlights the importance of flight crews ensuring they follow stabilised approach procedures.
On 29 April 2025, an Alliance Airlines Fokker 100 received an air traffic control clearance to conduct a visual approach following a standard instrument arrival to Perth Airport's runway 03. The approach required a 90° turn onto final that resulted in the aircraft being aligned with the runway, and on the correct approach profile about 4 NM from the runway threshold.
Passing about 1,000 ft radio altitude, the aircraft was above the operator's permitted airspeed‑related stabilised approach criteria. However, a go‑around was not initiated.
"An ATSB investigation found that the captain, who was pilot flying, incorrectly assessed that the applicable stabilisation height was 500 ft, and therefore did not manage the aircraft's energy state to ensure the stabilised approach speed was achieved by 1,000 ft," said ATSB Director Transport Safety Stuart Macleod
"In addition, the first officer, as pilot monitoring, did not announce the approach was unstable, possibly due to their workload, the required check being completed slightly late, and an assessment that the airspeed was reducing."
The aircraft, which was carrying four crew and 15 passengers, landed uneventfully.
Mr Macleod said the incident highlights the importance of flight crew having a common understanding of the approach requirements.
"Best practice advises flight crews to be aware of the relevant stable approach criteria, comply with the standard operating procedures, and advise air traffic control when unable to comply with a clearance that would result in the aircraft being too high or fast for that criterion," he said.
While it did not contribute to the occurrence, the ATSB's investigation also identified that the captain had inadvertently not changed the altimeter setting from standard pressure to QNH during the descent.
This resulted in the left altimeter indicating 300 ft lower than the right altimeter. Neither flight crewmember detected this incorrect setting during two subsequent checks prior to landing.
"This incident also illustrates the need for effective flight crew monitoring, which can be improved through the use of standard operating procedures, increased emphasis and practice," Mr Macleod concluded.
You can find here the final report: Unstable approach involving Fokker 100, VH-FKF, near Perth Airport, Western Australia, on 29 April 2025
