Occurrence
On 25 February 2025 at approximately 0935Z, a Diamond DA42 Twin Star aircraft, registration ZS-TDI, was conducting a type conversion training flight under Part 141 of the Civil Aviation Regulations. The flight, which consisted of touch-and-go landings, departed from and was intended to return to Lanseria International Airport (FALA) in Gauteng province. The aircraft was operated by an approved training organisation and carried a flight instructor and a pilot under training.
Sequence of Events
The first circuit was completed without incident. During the second circuit, while on the downwind leg approximately 2 nautical miles parallel to Runway 07 threshold, air traffic control (ATC) instructed the crew to shorten their approach due to an inbound scheduled commercial aircraft on final approach for Runway 07. The flight instructor acknowledged the instruction and initiated a short approach. He directed the pilot flying to configure the aircraft for landing and to reduce power for a steeper descent, planning for a flapless landing.
As engine power was reduced—to idle according to the pilot—the low-power audible warning horn activated. The crew anticipated this warning and disregarded it, continuing the approach without lowering the landing gear. The flight instructor later reported that they relied on each other to identify omissions during the landing checklist review.
During the flare, with the low-power warning horn still sounding, the crew realised the landing gear had not been extended. The instructor called for gear extension, but it was too late. The aircraft touched down on the runway with the gear retracted. Both propellers struck the ground, and the aircraft slid approximately 800 metres before coming to a stop on the left side of the runway centreline. The crew disembarked unassisted without injury.
Aircraft Damage
The aircraft sustained substantial damage, including damage to both propellers, engine cowlings, and the underside of the fuselage.
Crew Information
The flight instructor, aged 34, held a valid Commercial Pilot Licence with a Grade 2 instructor rating and a valid Class 1 medical certificate with restrictions (corrective lenses, hypertension protocol). He had 1130 total flying hours, including 18.1 hours on the DA42. The pilot under training, aged 23, also held a valid Commercial Pilot Licence and a Grade 2 instructor rating, with 1646.8 total flying hours but only 0.7 hours on type. His medical certificate was valid with a restriction for defective distance vision.
Aircraft Information
ZS-TDI, a Diamond DA42 Twin Star (serial number 42-200), had a valid Certificate of Airworthiness and a total of 2632.5 airframe hours at the time of the accident. The most recent mandatory periodic inspection was completed on 4 February 2025 at 2620.6 hours, with a Certificate of Release to Service issued on 14 February 2025.
Environmental Conditions
Visual meteorological conditions prevailed at the time of the flight.
Findings
The investigation found that the crew disregarded the low-power audible warning during the approach and omitted to extend the landing gear. The warning horn was functioning as specified in the Pilot's Operating Handbook. The crew, both experienced instructors, relied on each other during checklist review without clear task division or verbal confirmation, leading to an incomplete landing checklist. The landing gear was not confirmed down and locked.
Probable Cause
The pilots omitted to extend the landing gear during the landing phase.