Failure of T-Bar Control Column in Cherokee on Approach

[countryman]

CADOR: 2016C0338.

Not withstanding the fact that this incident which is classified by the Transportation Safety Board as an accident, which is still under investigation to determine a cause, I could not in good conscience belay advising my fellow aviators, aviator friends, instructor cadre, ex-instructor cadre and current flights instructors of the events of Feb 13th, 2016. Moreover, since cracks around the weld a T-Bar assembly of another Cherokee have post incident been revealed through Non-Destructive Testing, (NDT) the statistical odds of a repeat occurrence are increasing.

Succinctly put on approach to Runway 13 with a student at CYAV, when the aircraft was rounded out to begin it's descent to land, and audible noise of something breaking could be heard through my ANR headset at which they the control immediately became unresponsive. The aircraft landed without incident and we taxied back to the hangar and advised the CFI and AMO. Immediate inspection revealed a catastrophic failure at the top of the T-bar assembly with the horizontal control bar completely separating from the vertical post (pitch control). Transport Canada and TSB were advised. The subsequent NDT inspection of the T-bar control assembly of a decommissioned Cherokee revealed cracks around the weld joint attaching they horizontal control bar to the vertical post. Visual inspection did not reveal any anomaly respecting the T-bar assembly. The defect was only detectable through an NDT inspection. TSB is still investigating the cause of the failure but it is suffice to say that it has occurred, which apparently is unprecidented, and cracks have been found in a second. I will update this post when TSB publishes there findings. As an instructor with 2600 instructing hours, I can state with all assurance that I will no longer be instructing in any Cherokee where they T-bar assembly has not been subject to NDT inspection. Spins are an unusual attitude enough without worrying if the T-Bar assembly is going to fail when attempting to pull out of a dive. Submitted for your information.