The helicopter was leased by the Allentown Sacred Heart Hospital. At 2236 EDT, the pilot, who was standing by for duty, obtained a weather briefing. Later, at 2312, there was a request for a med-evac helicopter to respond to a car accident. The helicopter departed 10 minutes later and landed at the site at 2343 EDT. A short time later, the helicopter lifted off with a patient, two nurses, and a pilot on board. At that time, the weather conditions were very rainy with a mild breeze. Reportedly, the helicopter departed toward the southeast with the searchlight on. A short time later, it impacted on rising terrain in a steep nose down attitude and in a right bank. A witness reported seeing the helicopter cross over trees with the searchlight on, pointing down, before impact. The aircraft was destroyed by impact and fire. Rotational damage was found in both engines. An FAA Form 337, dated 4/27/82, revealed that a Nightsun searchlight had been installed and the weight and balance had been adjusted for the installation.