No sign of mechanical problems in midair collision between plane and police helicopter

Sean Simmers/The Patriot-News/AP

No evidence of mechanical problems was found in either of the two aircraft involved in last month’s deadly midair collision between a small private plane and a Pennsylvania State Police helicopter, according to the National Transportation Safety Board.

The finding is part of a new preliminary report on the August 19 collision at the Carlisle, Pennsylvania, airport, about 30 miles west of Harrisburg.

Examinations of both the Cessna 150 private plane and the Bell 407 helicopter revealed “no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation,” NTSB investigators wrote.

The helicopter was on a training mission and hovering just feet above the grass next to the runway when the plane slammed into it. The Cessna pilot, 57-year-old emergency room doctor Paul Sokoloski, was killed. The two Pennsylvania State Police pilots aboard the helicopter were seriously injured.

The NTSB report reveals for the first time what the pilots said to each other before the crash. The airport does not have a control tower, so aircraft must coordinate using on a shared radio frequency.

The Cessna pilot asked by radio whether he should extend his “downwind” leg, the portion of the airport traffic pattern flown parallel to the runway, the helicopter instructor pilot told investigators. The move would essentially expand the space between the aircraft.

“Yes, extend your downwind,” the instructor replied.

The Cessna pilot acknowledged and said he was number two for landing, according to the report.

Thirty seconds after the helicopter flew over the end of the runway, the plane followed it, according to the report.

The moment a small plane collided with a state police helicopter was captured by security camera. The pilot of the small plane was killed in the crash, and two state troopers were injured, according to police. NTSB investigators said the pilots of the two aircraft were in communication and were aware of each other prior to the collision.

The Cessna’s wings rocked from side to side as it flew low over the runway without touching down. It pitched up and down, turned right and hit the helicopter hovering beside the runway.

Only about eight seconds passed between the helicopter moving off the runway and the collision, the NTSB said.

The preliminary report does not determine a probable cause for the crash, which will come at the conclusion of the investigation, usually within one to two years.

Investigators said last month they were studying whether rotor wash – wind created by the helicopter’s blades – could have affected the Cessna, while cautioning it was too early to say whether it played any role. The preliminary report does not address the issue.

肖恩·西默斯/《爱国者新闻报》/美联社

据美国国家运输安全委员会称，上个月一架小型私人飞机与一架宾夕法尼亚州警用直升机发生致命空中相撞事故，事故涉及的两架飞机均未发现机械故障的证据。

这一发现是关于 8 月 19 日发生在宾夕法尼亚州卡莱尔机场（位于哈里斯堡以西约 30 英里处）的碰撞事故的最新初步报告的一部分。

美国国家运输安全委员会 (NTSB) 的调查人员写道，对塞斯纳 150 私人飞机和贝尔 407 直升机的检查显示，“没有任何证据表明撞击前存在任何机械故障或失效，这些故障或失效会妨碍正常运行”。

当时直升机正在执行训练任务，在跑道旁的草地上空几英尺处盘旋时，与一架飞机相撞。塞斯纳飞机的飞行员，57岁的急诊室医生保罗·索科洛斯基不幸遇难。机上两名宾夕法尼亚州警飞行员身受重伤。

美国国家运输安全委员会的报告首次披露了飞行员在坠机前彼此的通话内容。该机场没有塔台，因此飞机必须使用共享的无线电频率进行协调。

据直升机教练飞行员向调查人员透露，塞斯纳飞机飞行员通过无线电询问是否应该延长其“顺风”航段，即机场飞行航线中与跑道平行的那段航程。此举实际上会扩大两架飞机之间的距离。

“是的，延长你的下风距离，”教练回答道。

据报道，塞斯纳飞机飞行员承认了这一点，并表示他是第二个着陆的。

报道称，直升机飞过跑道尽头 30 秒后，飞机也跟了过去。

监控摄像头拍下了小型飞机与州警直升机相撞的瞬间。据警方称，小型飞机的飞行员在事故中丧生，两名州警受伤。美国国家运输安全委员会（NTSB）的调查人员表示，两架飞机的飞行员在碰撞前曾保持联系，并且彼此都了解对方的位置。

这架塞斯纳飞机低空掠过跑道，没有着陆，机翼左右摇晃。它上下俯仰，向右转弯，撞上了盘旋在跑道旁的直升机。

美国国家运输安全委员会表示，从直升机离开跑道到发生碰撞，仅仅过去了大约八秒钟。

初步报告并未确定事故的可能原因，该原因将在调查结束后得出，通常在一到两年内。

调查人员上个月表示，他们正在研究旋翼气流（直升机旋翼产生的风）是否可能对塞斯纳飞机造成影响，但同时谨慎地指出，现在断定旋翼气流是否起作用还为时过早。初步报告并未涉及此问题。