Philadelphia

The pilot reported getting an unsafe indication on the right main landing gear when the landing gear was lowered. The crew recycled the landing gear and got the same unsafe indication. The crew retracted the gear and diverted to Detroit. On arrival, the crew performed the 'landing gear abnormal extension checklist,' but the unsafe indication remained. The air traffic control tower reported that the gear appeared normal. During the landing, the right main landing gear retracted. The airplane slid sideways, striking a runway marker as it departed the runway, and came to rest in a field. Examination revealed that the right landing gear downlock mechanism could be overcome with physical force. Examination of the right landing gear actuator revealed that one of the six shims which separate the spacers and help guide the safety lock switch was out of position and lying on top of the lock assembly.

N458J was landing during a rain shower. As the airplane started to flare for landing, the wind caused it to drift to the right. The pilot started to correct this drift, as the rain became heavier. During the touchdown, the pilot lost visual reference with the runway, yet he continued with the landing roll. The airplane drifted off the left side of the runway and ran into soft terrain. Both pilots escaped uninjured and the aircraft was damaged beyond repair.

Piper Aerostar 601, N3645D, was arriving as Bell 412 (helicopter), N78S, was departing. N3645D reported the aircraft's nose gear indicator light did not illuminate to verify the nose gear was down and locked. Crew of N78S heard the communication and saw N3645D as they crossed beneath N3645D's approach path. They reported N3546D's nose gear appeared to be extended. N3645D flew past the tower and tower personnel also reported the nose gear appeared to be extended. As N3645D was cleared to turn downwind, N78S offered to join for a closer look. Captain of N3645D accepted the offer. During joinup, N78S converged from left rear, then reported they would pass around the right side and look at everything as they went by. They reported that everything looked ok. Moments later, the two aircrafts collided and crashed to the ground. No mechanical reason was found that would have resulted in the accident. None of the pilots had training for flight in close proximity to another aircraft. There were indications the captain of N3645D lacked training in aircraft systems and that his employer (the operator) lacked surveillance by the FAA. The emergency procedure section of the Aerostar flight manual lacked info on emergency gear extension. All three occupants were killed as well as both pilots on board the helicopter. Four other people on the ground were injured, one seriously.

At 0938, while climbing thru 9,000 feet, the pilot was cleared to climb to FL210. Approximately 10 minutes later, the ATC controller noted the aircraft's mode C return wasn't being displayed on his scope. He tried to advise the pilot, but couldn't establish radio contact. The aircraft broke up in flight and the wreckage was found submerged in a creek and on marshland. A large piece of the right outboard wing panel was found about 2 miles east of the main wreckage. The right engine was found approximately 800 feet to 1,200 feet northeast of the main wreckage in 4 feet of water. There was evidence the right outboard wing had failed from upward and aft overload. No pre-accident mechanical failure or malfunction was found that would have resulted in an in-flight break-up. Radar data showed the aircraft was climbing at 115 knots and 1,100 feet/minute; at approximately 16,000 feet msl, rate of climb slowed to approximately 750 feet/minute, then increased to 1,200 feet/minute. Peak altitude was approximately 18,200 feet. Aircraft then entered a steep descent and crashed. At the approximately time and place of peak altitude, primary targets appeared on radar and remained for several minutes. Organic material was found on left engine inlet screen, but source was not determined. Accident occurred along bird flyway. Both occupants were killed.

At 2232 edt, the aircraft was climbing to 15,000 feet when the pilot reported a low oil pressure light. ATC advised Jimmy Stewart Field is about eleven thirty and 15 miles. After the pilot asked, 'is that a Tower Field?', ATC advised he did not know, Westmoreland County is at two o'clock and about 15 miles, turn right 180°, descend and maintain 4,000 feet. At 2233 edt, ATC said that they believe Westmoreland County Tower is closed down. The pilot said that he was thinking of where he should go and ATC advised Pittsburgh's 35 miles away if you can make that. At 2234:35 edt, the aircraft was returning to Pittsburgh when the pilot reported zero oil pressure and an oil light. At 2237:27 edt, the pilot reported an emergency. Flight was cleared to Allegheny County Airport and advised Monroeville Airport 230 heading and 5 miles. The aircraft crashed at 2247 edt. The investigation showed a loose flange nut on left turbocharger feed line finger tight. Test produced a steady leak. At site oil covered bottom of fuselage and empennage. Two passengers were killed while two other occupants were injured.

After landing, the aircraft was parked on the ramp for approximately 39 minutes to load cargo. During that time, light freezing drizzle was falling, intermittently mixed with ice pellets and snow. The crew checked the aircraft surfaces from the cockpit and entry door, but observed no ice or snow adhering to the tops of the wings, nose section, windshield or above the door. The captain declined an offer to de-ice, two other aircraft were being de-iced. The takeoff was normal (18° nose up attitude) until just after lift-off, then the aircraft entered an uncommanded left roll and both engines compressor stalled. The captain corrected with left aileron and rudder, then began aborting the takeoff. The aircraft touched down left of the runway on the tail skid and right wing tip, approximately 5,600 feet from the threshold and on a 070° heading. It then traveled another 2,025 feet in a sweeping right arc, hitting 2 runway signs and came to rest heading west with the right pylon bent down. Investigations revealed a thin layer of ice (est 0.15 inch thick) would have been on the wings, raising the aircraft's stall speed. When DC-9-15 aircraft stall, engines are susceptible to compressor stalls.

During gear retraction after takeoff, the right main gear became jammed in a partially retracted position and the respective in-transit gear light would not extinguish. Attempts to recycle the gear were unsuccessful. The flight crew diverted to Atlanta, GA; then decided to land at Dobbins AFB, where there was a long, wide runway that could be foamed. Foam was applied to approximately 300 feet of runway 29. The aircraft was landed with the nose and left main gear extended and the right main gear partially retracted. Subsequently, the aircraft veered to the right and stopped with the nose gear approximately 70 feet off the runway. Fire erupted in the area of the right main gear; however, the fire was quickly extinguished by fire dept personnel. An investigation revealed the clearance between the main landing gear door hook, pn 803845-1, and the strut roller was excessive. The reason for the improper clearance was not determined. Lockheed service bulletin 88/sb-558 warned that excessive clearance combined with a drop in hydraulic pressure, gust or maneuver could result in the gear jamming. All three crew members were uninjured.

While en route, the pilot encountered icing conditions, then reported he was unable to maintain altitude and was having engine problems. He diverted toward Allentown, PA, then advised he had lost power in the left engine. Approach control began issuing vectors for a VOR approach; however, the pilot advised he was unable to open his approach plates and requested a surveillance radar approach. Radar vectors and advisories were provided until the pilot reported he had the airport in sight. Several witnesses observed that the left prop was feathered as the aircraft approached the airport. The pilot maneuvered the aircraft to a left downwind for runway 24 at about 400 feet agl with the landing gear extended. Witnesses reported the aircraft's nose pitch up, then down, then the aircraft rolled to the left and crashed. In a trailer court it hit a mobile home and a propane tank and burned. A person in the mobile home was fatally injured. An exam of the wreckage revealed the left prop blades were at the low pitch stops. No preimpact failures were found.

On approach to Toronto-Lester Bowles Pearson Airport following an uneventful flight from Philadelphia, the airplane rolled left and right then lost altitude and crashed in a field, bursting into flames. The wreckage was found 13 km from runway 24R threshold. The aircraft was destroyed by impact forces and a post crash fire and all five occupants were killed, among them Ross Henningar, President and CEO of Sun Oil Company (Sunoco).

The aircraft crashed while making a visual approach to runway 27R at Philadelphia International Airport. The aircraft, a scheduled commuter flight from Reading, Pennsylvania, arrived in the Philadelphia Approach Control area as a VFR 'pop up' flight and was sequenced to land behind United flight 555, a Boeing 727 IFR arrival, on runway 27R. Witnesses stated that, when flight 501 was about 1/2 mile on final approach, it rolled from side to side, pitched up, rolled inverted to the left, and flew into the ground nose first. All three persons aboard the aircraft were killed and the aircraft was destroyed.