A Piper 180 Arrow crashed immediately after takeoff. Heath, an employee of Swift (D), was flying the plane. The passengers were the wife and son of Heath. The executor (P) of two persons killed in that crash sued the pilot (D1) and others, alleging that the crash occurred as a result of the negligence of D1. At trial, an expert determined that D1 should have used flaps to aid in the takeoff and a reasonably prudent pilot should have made a controlled landing in the cornfield shortly after takeoff if he were experiencing difficulty attaining flight speed. The expert stated that had D1 done so the passengers would be alive. The jury was instructed that negligence is the 'failure of someone to act as a reasonable and careful and prudent person would under the same or similar circumstances .... that degree of ordinary care and caution, which an ordinary prudent pilot having the same training and experience as Fred Heath, would have used under the circumstances.' The jury returned the verdict for D. P appealed, partly on the basis that certain evidence was wrongfully excluded and the jury instructions were improper.