Lovell Field in Chattanooga, Tennessee, the student practiced maneuvers under Smith’s direction in a practice area of about 40 square miles located east of Chattanooga. The student was flying the plane approximately 1,500 feet above the ground when Smith reduced the power setting on the aircraft and asked the student to demonstrate emergency landing procedures. The student selected a grass field, located approximately 2.9 miles from the Collegedale Airport near Ooletewah, Tennessee, for the simulated emergency landing. The student began a straight-in approach to the field, and continued to a point 83 feet above the ground, where the airplane struck a ground wire which ran between towers 63 and 64 of the TVA Sequoyah — Georgia State Line transmission line. The transmission line was not marked with orange balls or contrast painting, and the student did not see it until the moment before the crash. Smith sustained critical and permanent injuries. In an action removed to federal court from a Georgia state court, Smith and his wife sought damages for the injuries resulting from the crash, contending that TVA’s failure to mark the power lines was negligent.
The question on appeal is whether there was sufficient evidence of negligence to present a jury question. In determining TVA’s alleged tort liability, the district court applied the law of Tennessee, the place of the injury. The parties have agreed that Tennessee law governs the negligence question. The elements necessary to establish a cause of action for common law negligence in Tennessee are: (1) a duty of care owed by the defendant to the plaintiff; (2) a breach of that duty; and (3) a causal relation between the injury to the plaintiff and defendant’s breach of its duty of care. Shouse v. Otis, 224 Tenn. 1, 448 S.W.2d 673, 676 (1969). To determine whether a duty exists, courts consider whether a reasonably prudent person would foresee that his or her conduct might endanger the plaintiff. See Shelton v. Russell Pipe & Foundry Co., 570 S.W.2d 861, 864 (Tenn.1978). Courts use a sliding scale in evaluating foreseeability. As the gravity of the potential harm increases, the duty to prevent the harm also increases. See Spivey v. St. Thomas Hospital, 31 Tenn.App. 12, 211 S.W.2d 450, 456 (1947). If a reasonably prudent person would foresee the possibility of injury, the particular manner in which the injury occurs need not be foreseeable. Id. at 456-57.
Whether TVA had a duty to warn pilots of the transmission line depends upon whether TVA could reasonably have foreseen the possibility of a line strike by an aircraft. In ruling on a motion for directed verdict, the court should consider all of the evidence in the case, in the light and with all reasonable inferences most favorable to the party opposed to the motion. A directed verdict is appropriate only “[i]f the facts and inferences point so strongly and overwhelmingly in favor of one party that the Court believes that reasonable men could not arrive at a contrary verdict....” Boeing Co. v. Shipman, 411 F.2d 365, 374 (5th Cir.1969) (en banc). The motion should be denied if there is “evidence of such quality and weight that reasonable and fair-minded men in the exercise of impartial judgment might reach different conclusions.... ” Id.; see Brady v. Southern Ry. Co., 320 U.S. 476, 479-80, 64 S.Ct. 232, 234-235, 88 L.Ed. 239 (1943) (directed verdict is proper only when there can be “but one reasonable conclusion” as to verdict).
The determination of negligence is -ordinarily one for the trier of fact because of the necessity that the trier of fact assess the reasonableness of defendant’s conduct under all the circumstances. Gauck v. Meleski, 346 F.2d 433, 437 (5th Cir.1965). The party seeking to have an issue of negligence withdrawn from the jury in federal court bears a heavy burden. McPherson v. Tamiami Trail Tours, Inc., 383 F.2d 527, 528 (5th Cir.1967).
The question confronting the court is not whether the court as a trier of fact would decide the injuries sustained by Smith were foreseeable under Tennessee law, but whether there was sufficient evidence of foreseeability to require the case to be sub