Landing gear retracted during ground demonstration in Blackshape aircraft

Casualties unknown • Runway 22 at Oudtshoorn Airport, Western Cape, ZA

A Blackshape/Rossouw JJ V.B-560 experienced landing gear retraction while backtracking on a runway, resulting in substantial aircraft damage.

What happened

On 27 October 2023, a Blackshape/Rossouw JJ V.B-560, registration ZU-TFA, was conducting a conversion flight from Oudtshoorn Airport (FAOH) in the Western Cape. The flight, operated under visual flight rules, included an instructor and a pilot performing maneuvers in the local general flying area before returning to the airport.

After completing three circuits and a full-stop landing, the aircraft was backtracking on Runway 22. During this time, the instructor, seated in the rear cockpit, attempted to demonstrate the difference in flap indications between the front and rear control panels. To do this, the instructor turned the key to activate the rear cockpit control panel. This action inadvertently triggered the retraction of the landing gear. As the gear retracted, the propeller blades struck the ground, causing one blade to separate from the hub. The aircraft skidded approximately five meters before coming to a halt. There were no injuries to the two occupants, though the aircraft sustained substantial damage.

The investigation

SACAA AIID examined the aircraft's control systems and the procedures followed during the flight. The investigation established that the aircraft lacked squat switches—electrical sensors on the landing gear struts that prevent retraction while the aircraft is on the ground. Consequently, the system allowed the gear to be retracted even while the aircraft was taxiing.

Furthermore, the investigation looked into the cockpit configuration. The rear cockpit features a mode selector key with three settings: OFF, PASSable, and TRAINING. The investigation found that when the key is turned to the TRAINING position, the rear cockpit controls can override the front cockpit's settings. In this instance, while the front cockpit gear lever was set to the DOWN position, the rear cockpit gear lever was set to the UP position.

Findings

  • The inadvertent retraction of the landing gear occurred while the aircraft was backtracking on the runway during a demonstration of flap indications.
  • The instructor rotated the mode selector key during the landing roll, which violated the manufacturer's procedures, which state the mode should be set on the ground and the key removed immediately.
  • The aircraft's design allowed for gear retraction on the ground because it lacked a landing gear micro switch (squat switch).
  • The rear cockpit control system was able to override the front cockpit's gear selection because the mode selector had been activated.

Probable cause

The landing gear was accidentally retracted while the aircraft was backtracking on the runway during a demonstration of flap indications, made possible by the lack of a ground-detection squat switch.

Frequently asked questions

What happened in the 2023-10-27 Blackshape/Rossouw JJ V.B-560 accident near Runway 22 at Oudtshoorn Airport, Western Cape, ZA?

A Blackshape/Rossouw JJ V.B-560 experienced landing gear retraction while backtracking on a runway, resulting in substantial aircraft damage.

What aircraft was involved and where did it happen?

The accident on 2023-10-27 involved a Blackshape/Rossouw JJ V.B-560, registration ZU-TFA, at Runway 22 at Oudtshoorn Airport, Western Cape, ZA.

What was the probable cause of the accident?

The landing gear was accidentally retracted while the aircraft was backtracking on the runway during a demonstration of flap indications, made possible by the lack of a ground-detection squat switch.

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