On January 31, 2025, at 1807 eastern standard time, a Learjet 55 airplane, Mexican registration XA-UCI (call sign MTS056) was destroyed when it was involved in an accident in Philadelphia, Pennsylvania. The two pilots, two medical crewmembers, and two passengers were fatally injured. One person on the ground was fatally injured, 4 people were seriously injured, and 20 people incurred minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 129 air ambulance flight. Preliminary ADS-B flight track data obtained from the Federal Aviation Administration revealed that the flight departed runway 24 at Northeast Philadelphia Airport (PNE), Philadelphia, Pennsylvania, about 1806, with the intended destination of Springfield-Branson National Airport (SGF), Springfield, Missouri. The airplane proceeded to the southwest before it turned right slightly and then entered a gradual left turn. The airplane continued in the left turn and reached an altitude of 1,650 ft mean sea level (airport elevation was 119 ft). The track data ended at 1807, at 1,275 ft msl, and at 242 knots ground speed. The duration of the flight was about 1 minute (see Figure 1). Figure 1. Aerial image with the airplane’s ADS-B flight track and the accident location overlaid. The flight crew was in communication with the PNE air traffic control tower at the time of the accident and there were no distress calls received from the flight crew. The airplane initially impacted a concrete sidewalk in a residential and commercial area. Security camera videos depicted a large explosion associated with the initial impact. The wreckage debris field was about 1,410 ft in length and 840 ft wide, oriented on a magnetic heading of about 150°. The airplane impacted a commercial sign during its descent, and the calculated descent angle based on the height of the observed damage to the sign was about 22°. The wreckage was highly fragmented. Wreckage and debris penetrated numerous homes, commercial buildings, and vehicles in the area, resulting in extensive fire and impact damage. The airplane was equipped with a cockpit voice recorder (CVR). The CVR was recovered from the initial impact crater under 8 ft of soil and debris and was sent to the NTSB Vehicle Recorders Laboratory, Washington, DC, for processing and readout. The recorder displayed significant impact-related damage as well as liquid ingress. After extensive repair and cleaning, the 30-minute-long tape-based recording medium was auditioned to determine its contents. The CVR did not record the accident flight and during the audition it was determined that the CVR had likely not been recording audio for several years. The airplane was also equipped with an Enhanced Ground Proximity Warning System (EGPWS). The EGPWS computer, which may contain flight data in its nonvolatile memory, was shipped to the manufacturer’s facility for evaluation and to determine whether any relevant flight data could be recovered. At the time of the writing of this report, that evaluation was ongoing. Night, instrument meteorological conditions prevailed at PNE at the time of the accident, including an overcast ceiling at 400 ft above ground level, wind from 220° at 9 knots, and 6 statute miles visibility. The pilot-in-command held an airline transport pilot certificate with ratings for airplane multiengine land and instrument airplane. He also held a medical certificate issued by Mexico’s Agencia Federal de Aviación Civil (AFAC). The operator reported that he had accumulated 9,200 total hours of flight experience. The second-in-command pilot held a commercial pilot certificate with single-engine land, multiengine land, and instrument privileges. He also held a medical certificate issued by AFAC. The operator reported that he had accumulated 2,600 total hours of flight experience. Both pilots held a type rating for the Learjet 55. The wreckage was recovered from the accident site and retained for further examination.