NTSB


At least one manufacturer


announced at HAI HELI-EXPO 2020 that it’s close to approval for


installation of a


protective cage for floor-mounted


controls in missions where the public


might be seated near those controls. (The helicopter shown is not the accident aircraft.)


captured “a ‘click’ sound followed by noise associated with float deployment.” After a brief cyclic flare, the helicopter touched down


in a somewhat shallow attitude into the East River and immediately began to roll right. Within 11 seconds, it had rolled inverted with the cabin completely submerged. The pilot was unable to free the front-seat passenger


and was himself under water before he could release his four-point harness, but he managed to escape. Unable to extricate themselves from their harnesses, all five pas- sengers drowned. At least two never removed the cut- ters from their pouches. (One harness and part of another weren’t recovered, presumably having been lost during extrication efforts by first responders, and one cutter was found loose in the cabin.) The pilot was rescued by a tugboat crew; divers


reached the scene and began recovery efforts about 18 minutes after touchdown.


What Went Wrong Footage captured by a camera mounted inside the cabin showed that several times during the six minutes before the power loss, the front-seat passenger leaned back- ward over the center console with the tail of his tether hanging down by the helicopter’s floor-mounted controls. At 7:06:08, as he pulled himself upright, the tail of the tether pulled taut and then popped loose; the engine noise began to diminish two seconds later. The pilot told


74 ROTOR 2020 Q2


investigators that the tether had gotten snagged on the FSOL and pulled it up, breaking the safety wire intended to prevent unintended activation. Photographs of the sub- merged wreckage showed the left skid’s floats more fully inflated than those on the right. Subsequent examination found that only the left air reservoir had discharged, and the cross- over hose included for that pur- pose hadn’t fully balanced inflation pressures on both sides. (Follow-up testing showed that even with balanced pressures, one reservoir’s sup- ply didn’t provide enough buoy- ancy to keep the helicopter upright on its floats.) The right reservoir’s failure to discharge was traced to a kink in


its activation cable. The manufacturer’s instructions for continued airworthiness only require checking the rig- ging every 18 months. The 36-month inspection includes a full inflation test; it had last been completed on the helicopter 15 months earlier.


The Takeaway


At first glance, this accident sequence might seem like a constellation of individually unlikely events: an accidental fuel shutoff that initially went unnoticed in the darkness; an autorotation from an altitude too low to allow a restart after fuel flow was restored; and a malfunction of the emergency floats that left the passengers without time to escape their harnesses.


But a closer look confirms the NTSB’s view that this


tragedy was entirely foreseeable. On a low-altitude flight over an urban area offering few emergency landing sites, preventing inadvertent passenger interference with the floor-mounted engine controls should have been an urgent priority, and any passenger-carrying operation should anticipate that the cabin might have to be evacu- ated quickly. Overlooking or ignoring those concerns created vul-


nerability to a single-point failure almost guaranteed to cascade out of control in the abbreviated time available to respond—particularly in an operation serving “off-the- street” customers with little training regarding the flight’s risks and how to mitigate them.


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