Helicopter down in East River, NYC
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An excerpt from the NTSB preliminary report detailing a fatal foot selfie scenario:
The NTSB preliminary report is here: https://t.co/gjQX7xl8Dw
...As the helicopter neared the eastern boundary of Central Park, the pilot slowed the helicopter to between 20 and 30 knots groundspeed so the passengers could take photographs. At this point, he noticed that the front passenger's restraint was hanging from the seat. He picked it up, tapped the passenger, and told him to put it back on, which he did. During the interview the pilot also recalled that other passengers had inadvertently released their seatbelts during previous flights.
As they were flying along the eastern side of Central Park, the front seat passenger turned sideways, slid across the double bench seat toward the pilot, leaned back, and extended his feet to take a photograph of his feet outside the helicopter. As the pilot initiated a right pedal turn to begin to head south, the nose of the helicopter began to turn right faster than he expected, and he heard a low rotor rpm alert in his headset. He then observed engine pressure and fuel pressure warning lights and believed he had experienced an engine failure. He lowered the collective pitch control to maintain rotor rpm and let the nose continue to turn to the right. Central Park came into view and he briefly considered landing there but thought there were "too many people." He continued the turn back toward the East River and made his first distress call to air traffic control. He yelled to the passengers to get back in their seats. Due to the helicopter's airspeed, he was not sure he could make it to the East River and reduced rotor rpm so he could "glide better." Once he was in an established autorotative glide, he attempted to restart the engine but was unsuccessful. He waited 1 or 2 seconds and tried the starter again, but there were no positive indications of a successful engine restart on the instrumentation. He checked the fuel control lever and found that it was still in its detent for normal operation. When he was sure he could clear the buildings and make it to the river, he activated the floats at an altitude of about 800 ft agl.
At this point he was "committed to impact," and, when he reached down for the emergency fuel shutoff lever, he realized that it was in the off position. He also noted that a portion of the front seat passenger's tether was underneath the lever.
As the helicopter continued to descend through 600 ft agl, he positioned the fuel shutoff lever to the "on" position and attempted to restart the engine. He observed positive indications on the engine instruments immediately. As the helicopter descended through 300 ft, he realized that the engine "wasn't spooling up fast enough," and, given the helicopter's proximity to the surface, he had to continue the autorotation. He again reached for the fuel shutoff lever and positioned it back to "off." Passing through between 100 and 50 ft, he began the cyclic flare in an extended glide configuration, but he "did not get a lot of rpm back." He performed a flare reduction at 10 to 15 ft. He pulled the collective pitch control up "as far as it would go." The helicopter then impacted the water at 5° to 10° nose-up attitude.
After impacting the water, the chin bubble on the pilot's side began to fill with water, which quickly covered the floor. He kept his restraint on and reached down for the front seat passenger's carabiner attachment to the helicopter. He turned the knurled screw "two or three rotations"; by that time, the helicopter was "listing past a 45° roll." He then decided to egress the helicopter, and by the time he unbuckled his restraint, he was fully under water. He used two hands to grab the door frame and pull himself out. He surfaced about 4 ft away from the nose of the helicopter and crawled up onto the belly. He stood up and waved for help but could not see anything.
As they were flying along the eastern side of Central Park, the front seat passenger turned sideways, slid across the double bench seat toward the pilot, leaned back, and extended his feet to take a photograph of his feet outside the helicopter. As the pilot initiated a right pedal turn to begin to head south, the nose of the helicopter began to turn right faster than he expected, and he heard a low rotor rpm alert in his headset. He then observed engine pressure and fuel pressure warning lights and believed he had experienced an engine failure. He lowered the collective pitch control to maintain rotor rpm and let the nose continue to turn to the right. Central Park came into view and he briefly considered landing there but thought there were "too many people." He continued the turn back toward the East River and made his first distress call to air traffic control. He yelled to the passengers to get back in their seats. Due to the helicopter's airspeed, he was not sure he could make it to the East River and reduced rotor rpm so he could "glide better." Once he was in an established autorotative glide, he attempted to restart the engine but was unsuccessful. He waited 1 or 2 seconds and tried the starter again, but there were no positive indications of a successful engine restart on the instrumentation. He checked the fuel control lever and found that it was still in its detent for normal operation. When he was sure he could clear the buildings and make it to the river, he activated the floats at an altitude of about 800 ft agl.
At this point he was "committed to impact," and, when he reached down for the emergency fuel shutoff lever, he realized that it was in the off position. He also noted that a portion of the front seat passenger's tether was underneath the lever.
As the helicopter continued to descend through 600 ft agl, he positioned the fuel shutoff lever to the "on" position and attempted to restart the engine. He observed positive indications on the engine instruments immediately. As the helicopter descended through 300 ft, he realized that the engine "wasn't spooling up fast enough," and, given the helicopter's proximity to the surface, he had to continue the autorotation. He again reached for the fuel shutoff lever and positioned it back to "off." Passing through between 100 and 50 ft, he began the cyclic flare in an extended glide configuration, but he "did not get a lot of rpm back." He performed a flare reduction at 10 to 15 ft. He pulled the collective pitch control up "as far as it would go." The helicopter then impacted the water at 5° to 10° nose-up attitude.
After impacting the water, the chin bubble on the pilot's side began to fill with water, which quickly covered the floor. He kept his restraint on and reached down for the front seat passenger's carabiner attachment to the helicopter. He turned the knurled screw "two or three rotations"; by that time, the helicopter was "listing past a 45° roll." He then decided to egress the helicopter, and by the time he unbuckled his restraint, he was fully under water. He used two hands to grab the door frame and pull himself out. He surfaced about 4 ft away from the nose of the helicopter and crawled up onto the belly. He stood up and waved for help but could not see anything.
Originally posted by Hot and Hi
...and by trying to restart the engine. Three times.
Originally Posted by Thomas coupling
Yes, maybe with making Mayday calls, and trying to inflate the floats.
I accept the pilot was 'busy' during the engine off ...
Not sure I understand what's going on here: pax unstrapping from the front seat during flight?
Is this normal? (I don't do these kinds of flights so I ask anyone who does).
Is this normal? (I don't do these kinds of flights so I ask anyone who does).
If I am reading it correctly, the front pax unbuckled his seat belt in order to scoot closer to the pilot, as in the middle front seat, to get a better angle on his feet hanging out the door.
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About to land in the biggest fire extinguisher around, why turn the fuel off again on an engine spooling up? It just might give you the extra RRPM to cushion the touchdown or even Droop NR and fly away if it played catchup? A lot of faffing about rather then flying...
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Anything unusual or concerning about this?
I ask because if a pax had noticed a strap (or whatever) under the emergency fuel shutoff lever, or even realized he'd just pulled on the strap and something had moved, would that person be able to convey that information to the pilot? Or (if applicable) to tell a fellow passenger your strap is in the wrong place?
Albeit enabling each pax to talk over the headset potentially could be a distraction for a pilot unless the pax were equipped with hand-activated microphones and instructed to use them only in an emergency or other limited scenario (ie, no jabbering).
He . . . did a communications check through the headsets. The passengers could hear him and radio traffic, but they did not have microphones and could not speak to the pilot or each other.
I ask because if a pax had noticed a strap (or whatever) under the emergency fuel shutoff lever, or even realized he'd just pulled on the strap and something had moved, would that person be able to convey that information to the pilot? Or (if applicable) to tell a fellow passenger your strap is in the wrong place?
Albeit enabling each pax to talk over the headset potentially could be a distraction for a pilot unless the pax were equipped with hand-activated microphones and instructed to use them only in an emergency or other limited scenario (ie, no jabbering).
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The rest of the problem space is obvious.
To me, this is far more interesting:
"Examination of the emergency float system revealed that the three floats installed on the left landing gear skid appeared to be more inflated than the floats on the right landing gear skid. The emergency floats' left pressurized gas cylinder gauge indicated about 0 psi, while the right pressurized gas cylinder gauge indicated about 4,000 psi."
To me, this is far more interesting:
"Examination of the emergency float system revealed that the three floats installed on the left landing gear skid appeared to be more inflated than the floats on the right landing gear skid. The emergency floats' left pressurized gas cylinder gauge indicated about 0 psi, while the right pressurized gas cylinder gauge indicated about 4,000 psi."
Surely if there are 2 gas bottles in the emergency floatation system, each bottle would pressurize a separate partition of each float bag? Or at the very least, via a manifold to each float bag so the system had some redundancy? Surely not one bottle pressurize per side?
NRDK:
From the Preliminary:
That seems to indicate that the mishap pilot lost control of his RRPM during his autorotation from 2,000 ft AGL, and allowed the RRPM to decay.
A lot of faffing about rather then flying...
Passing through between 100 and 50 ft, he began the cyclic flare in an extended glide configuration, but he "did not get a lot of rpm back."
In this situation, it seems that there was enough height for a restart if it had simply been the FFL that was pulled or it had been identified that the it was the cut off that was pulled before the first attempt.
One bottle for each side is standard for the 350
In that case it's the most stupid design point of any helicopter I have ever seen in my 26 years of flying. I bet that one bottle had enough gas in it to partially inflate both sides sufficient for the helicopter to have floated upright after landing.
If the floats only inflated on one side of the helicopter in flight, I imagine the asymmetric drag wouldn't have been helpful for directional control.
If the floats only inflated on one side of the helicopter in flight, I imagine the asymmetric drag wouldn't have been helpful for directional control.
Last edited by gulliBell; 27th Mar 2018 at 11:12.
And as for the comment about not recovering much RRPM in the flare, it looked to me like he still had enough forward airspeed at splashdown to recover at least a couple more RRPM at the bottom.
What I'm finding difficult to comprehend is, the pilot must have known prior to 500' that the floats on one side of the aircraft had failed to inflate, so why continue to a water landing? Those passengers were all doomed from the moment the decision was made to continue with the water landing after the floats had failed to inflate properly.
What I'm finding difficult to comprehend is, the pilot must have known prior to 500' that the floats on one side of the aircraft had failed to inflate, so why continue to a water landing? Those passengers were all doomed from the moment the decision was made to continue with the water landing after the floats had failed to inflate properly.
skadi
At the risk of being an armchair judge......
Hate to break it to him but the only way to improve your glide range in auto is to increase your speed and NOT decay Nr. But it seems he didn't have the height for that.
Bleeding off Nr with a duff engine is going to place you behind the drag curve when the time comes to recover it.
Looking at the vid again, suggests to me that the last 100 to 50 feet brought home to the pilot the realisation that his Nr was not high enough to arrest the RoD enough to minimise impact.
That very (early stage) action (drooping Nr) may have been the last straw for determining the submersion of the cabin immediately after impact.
Lots of Nr is your ONLY friend during an EOL. And a zero/zero may well have resulted in a stable and upright cabin platform on a relatively calm surface (Notwithstanding assymetric float deployment). Giving time for an evacuation by the odd pax?
Fuel: ON.
Ignition: ON.
START button.
Due to the helicopter's airspeed, he was not sure he could make it to the East River and reduced rotor rpm so he could "glide better."
he began the cyclic flare in an extended glide configuration, but he "did not get a lot of rpm back.
Bleeding off Nr with a duff engine is going to place you behind the drag curve when the time comes to recover it.
Looking at the vid again, suggests to me that the last 100 to 50 feet brought home to the pilot the realisation that his Nr was not high enough to arrest the RoD enough to minimise impact.
That very (early stage) action (drooping Nr) may have been the last straw for determining the submersion of the cabin immediately after impact.
Lots of Nr is your ONLY friend during an EOL. And a zero/zero may well have resulted in a stable and upright cabin platform on a relatively calm surface (Notwithstanding assymetric float deployment). Giving time for an evacuation by the odd pax?
Fuel: ON.
Ignition: ON.
START button.
If the pilot was looking outside, which is where you tend to look when looking for an emergency landing spot, a pilot sitting in the right seat should see that the floats on the right side were not inflated. And the flight asymmetry I should think would be a pretty good clue.
And as for ditching in freezing cold water with only one side inflated, or none inflated, particularly with all passengers basically tied to the aircraft, and if there was 500' altitude to come up with an alternative, then the option chosen resulted in the inevitable outcome.
And as for ditching in freezing cold water with only one side inflated, or none inflated, particularly with all passengers basically tied to the aircraft, and if there was 500' altitude to come up with an alternative, then the option chosen resulted in the inevitable outcome.
Last edited by gulliBell; 27th Mar 2018 at 11:53.