AD 2010-18-01 75 FR 53861

We are adopting a new airworthiness directive (AD) for all Robert E. Rust, Jr. Models DeHavilland DH.C1 Chipmunk 21, DH.C1 Chipmunk 22, and DH.C1 Chipmunk 22A airplanes. This AD requires you to do a one-time inspection of the flap operating system for an unapproved latch plate design installation, with replacement as necessary. This AD results from a report of a latch plate failing in service that was not made in accordance with the applicable de Havilland drawing. We are issuing this AD to detect and correct an unauthorized latch plate design installation which could result in an un-commanded retraction of the flaps. This failure could lead to a stall during a landing approach.