In what circumstances will the trial judge be found guilty of error in the exclusion of evidence concerning custom in the making of a pilot?

In view of our rulings it is unnecessary for us to rule on the other allegations of error by the trial judge. In regard to the exclusion of evidence concerning custom, Tors himself testified concerning custom in the industry in the making of pilots to show to prospective purchasers. Other evidentiary rulings were within the discretion of the trial judge. As to the claim that the judge on several occasions took over the examination of the witnesses, 'The trial judge has a wide discretion in the control and ultimate scope of cross-examination of a witness * * *' (People v. Stone, 239 Cal.App.2d 14, 20, 48 Cal.Rptr. 469, 473.) It is sufficient to say that there was no indication in the record of intentional unfairness or hostility by the trial judge against either appellant or his cause of action. The trial judge's extensive participation in the examination of witnesses may have been disconcerting to counsel but it was hardly prejudicial. Colloquy between counsel and the court, however disconcerting to counsel, was no more than a socratic pursuit of truth concerning points of law.