What Happened
On 6 February 2024, a student pilot and flight instructor conducted a dual training flight from Gold Coast Airport, Queensland, in a Cessna 172R aircraft, registered VH-EWW. Upon return, the student received an initial air traffic control clearance to track direct to runway 32. Approximately 40 seconds later, the flight crew accepted an amended clearance to track to the shorter runway 35 at 'best speed'. When VH-EWW was at 1,000 ft and 1.9 NM from the runway 35 threshold, the flight crew were cleared to conduct an approach and maintain 'best speed all the way in to crossing the runway'. Unsure how to comply with that instruction, the instructor directed the student to reduce the throttle to idle and lower the aircraft's nose.
The aircraft subsequently passed about 100 ft above the runway threshold at approximately 25 kt faster than the normal approach speed. As a result, the aircraft floated along the runway before touching down and bouncing once. During the landing roll, as the aircraft approached the end of the runway, the instructor took over control. They attempted to brake and turn the aircraft onto a taxiway beyond the end of the runway. During the turn, the aircraft veered off the taxiway towards a ditch. In response, the instructor applied back pressure on the control column and full power to commence a go-around, during which the rear fuselage and tail struck the ground. A right circuit and landing to runway 32 was then conducted.
ATSB Findings
The ATSB found that the air traffic controller's request to maintain best speed to the runway, combined with the instructor's interpretation of the instruction, resulted in an excessively fast approach. Although the aircraft exceeded both the manufacturer’s approach speed and the operator’s stabilised approach speed, the instructor did not conduct a go-around prior to landing or while on the runway. This resulted in the aircraft landing long and fast. The excessive landing speed also resulted in reduced braking effectiveness and a loss of control during the turn onto the taxiway. Following the loss of control, a go-around was initiated to avoid a drainage ditch, resulting in a ground strike and near collision with hangars located on the eastern boundary of the airport.
The ATSB also noted that the phrase 'best speed' used by the controller was not included in the standard air traffic control phraseology published in Airservices Australia’s Aeronautical Information Publication (AIP). However, controllers could use clear and concise plain language when a standard phrase did not exist. The controller's emphasis to maintain best speed until within the vicinity of the runway contributed to the aircraft’s excessive airspeed. Based on published landing data, runway 35 was long enough for the aircraft to land at maximum weight, even using a normal landing technique with flaps retracted. However, VH-EWW’s 90 kt airspeed when it crossed the runway threshold was 15 kt higher than the upper limit of the flapless approach speed specified in the POH. Additionally, the aircraft’s approach speed exceeded the operator’s stabilised approach criteria, which should have prompted a go-around.
Safety Actions
The aircraft operator reviewed the company’s standard operating procedures for stabilised and unstable approaches. They also reviewed training material and sequences for instructors and students, including human factors aspects regarding communication, decision making, and assertiveness. The operator and their instructor team discussed training challenges at Gold Coast Airport with a focus on non-standard air traffic control requests and clearances, including the refusal of clearances considered operationally unacceptable.
Safety Message
The ATSB emphasized that although not standard phraseology, air traffic controllers may ask pilots to maintain 'best speed'. It is up to the pilot to determine what is best in this context and more generally to advise if an instruction is unclear or cannot be complied with. An approach must be flown in accordance with the aircraft flight manual and operator’s procedures. Landing with excessive speed is likely to result in floating, landing long, bouncing, or ballooning, all of which increase the risk of a mishap. When operating in visual meteorological conditions, if an approach is not stabilised by the height specified by the operator (or generally by about 500 ft above ground), or becomes unstable after that point, a go-around should be conducted.