The Walkup family has a long history in aviation. Johns father has a bronze statue of his likeness adorning Wiley field in OK, for his achievements and accomplishments in aviation. That type of commitment is well imbedded in John Walkup.
John & Diana Walkup operate Chander Air Service. I'll agree with the recent poster, John's operation is top notch. Their longevity on field, since 1976, speaks for itself.
As far as the incident with the cowling. If it was an Archer, as FlyinBrian mentions, there is an inspection door located on the top of the cowling for the purpose of the pre-flight. Unlike the Warrior, the Archer cowling does not have a hindged cowling for inspection. It would take two people to remove the cowling correctly for inspection, revealing the entire engine compartment, which is not nessecary for pre-flight per POH. The mechanic would have questioned that procedure for a pre-flight on an Archer. I've had some problems with the Warriors cowling latches and they were look into and corrected promptly. The training aircraft are well used and although not the best looking, they are safe and well maintained. There has been and never will be any short cuts taken at CAS. I would highly recommend CAS for any of their services.
Additionally, I have not had the pleasure to use Sunbirds services, although I have shared the field and airspace with their instructors and students. My assessment of their pilots would be one of professional aviators with safety being their upmost concerns. Their pilots do a great job in Chandlers Class D airspace as well as the surrounding Class B.
As far as the OLS incident, regardless of who maybe at fault, lives were lost, and that should not have happened. Justice will prevail, hopefully sooner than later, for those still in harms way.
Regards........8sm