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-   -   Twin Otter (N153QS) ditches into Pacific Ocean (https://www.pprune.org/pacific-general-aviation-questions/652827-twin-otter-n153qs-ditches-into-pacific-ocean.html)

Petropavlovsk 21st May 2023 08:45

Twin Otter (N153QS) ditches into Pacific Ocean
 
Twin Otter (Viking 400 series) N153QS,


https://cimg6.ibsrv.net/gimg/pprune....c33335dfe6.jpg


has ditched into Pacific Ocean during ferry flight from USA to Honolulu.

The aircraft at times has believed to be, but unconfirmed, part of the fleet of twin Otters operated by a Resort company in Fiji. and may also be part of the Google fleet. (both unconfirmed.)

The aircraft was last in Australia for major maintenance in 2019 during which time the aircraft was on amphibious floats.

lucille 22nd May 2023 04:37

Not too long after takeoff and thus presumably still too heavy to maintain height on one?


Bosi72 22nd May 2023 07:05

What is the Vbg and what RoD would that give ?
Very sad :(

Petropavlovsk 22nd May 2023 07:44

The aircraft made a mid crossing return to West Coast after problems became apparent with the fuel system.

The crew put out a mayday call suggesting they had no fuel left. The aircraft is floating in the ocean and the NTSB are mounting a recovery exercise to examine the wreckage. With empty fuel tanks, ferry tanks and airtight floats the aircraft should float until recovered.

lucille 22nd May 2023 10:36

https://www.cbsnews.com/sacramento/n...20a20statement

If you can believe this news article, no one survived, aircraft sunk and it occurred shortly after takeoff. But as they say in the USA… YMMV.

gsfromc 22nd May 2023 12:22


Originally Posted by Petropavlovsk (Post 11438374)
The aircraft made a mid crossing return to West Coast after problems became apparent with the fuel system.

The crew put out a mayday call suggesting they had no fuel left. The aircraft is floating in the ocean and the NTSB are mounting a recovery exercise to examine the wreckage. With empty fuel tanks, ferry tanks and airtight floats the aircraft should float until recovered.

>>> The aircraft was is a wheels configuration for ferry flight.

MechEngr 22nd May 2023 13:57

https://www.pressdemocrat.com/articl...iles-off-half/

This says a fuel transfer problem - seems like there was fuel, but some difficulty in accessing it.
It was reported to be inverted on the floats.

There must have been a wind towards the west - it took around an extra hour to get back and even that without making it all the way: https://globe.adsbexchange.com/?icao...20&trackLabels


lucille 22nd May 2023 15:16


Originally Posted by lucille (Post 11438464)
https://www.cbsnews.com/sacramento/n...20a20statement

If you can believe this news article, no one survived, aircraft sunk and it occurred shortly after takeoff. But as they say in the USA… YMMV.


Just goes to show, you can’t believe the media.

MechEngr 22nd May 2023 17:35

Who believes the media for detailed crash information? However, no one survived and that's the important message for the general public and is correct.

caseydubose 22nd May 2023 19:49


Originally Posted by gsfromc (Post 11438512)
>>> The aircraft was is a wheels configuration for ferry flight.

Curious how you know this? I thought it was on floats. That could explain why it flipped over.

Petropavlovsk 22nd May 2023 23:57

.
The date of the aircraft photograph is uncertain and therefore it is unconfirmed if the amphibious floats had been removed. A Twin Otter is capable of ferrying with float.

The owner believed to be "Google" is recovering the wreckage.


The pilot and co-pilot reported they knew they were not going to make it to shore due to a fuel line malfunction, the U.S. Coast Guard said.
https://imengine.prod.srp.navigaclou...=72&width=1024
https://imengine.prod.srp.navigaclou...=72&width=1024
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SLIDE 1 OF 3
The plane identified in Saturday's crash off the San Mateo Coast is a Viking Air DHC-6-400 Twin Otter, tail number N153QS, shown at Atlanta Fulton County (Brown Field) on August 14, 2022. (Via planespotters.net)Gift this articleto a friend
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MADISON SMALSTIG
THE PRESS DEMOCRAT
May 21, 2023, 6:14PM

Updated 2 hours agoThe pilot and co-pilot of a small twin-engine utility plane that departed Santa Rosa Saturday morning for Hawaii radioed authorities they were nearly out of fuel shortly before their aircraft crashed into the ocean off the San Mateo County coast, killing both men.

Authorities received a distress call from the Viking Air DHC-6-400 Twin Otter when it was about 70 nautical miles west of Pacifica — when the men realized they weren’t going to make it to shore, said U.S. Coast Guard Lt.j.g. Jillian Stuckey.

The pilot and co-pilot were the lone people aboard and reported their plane had only about 15 minutes of fuel left, Stuckey said. They were preparing to ditch into the water.

The men told authorities to look out for a yellow life raft which they had stored in their aircraft, according to the Coast Guard.

Around 2:30 p.m. a Coast Guard search crew spotted the plane in the Pacific Ocean about 40 nautical miles southwest of San Francisco.

It was upside down and no life raft was in sight.



A rescue swimmer looked into the plane and saw the pilot and co-pilot still strapped in.

The swimmer shook one of the men’s legs. He didn’t move, Stuckey said.

The men were pronounced dead at the scene, said National Transportation Safety Board spokesperson Sarah Taylor Sulick. Their names were not immediately available.

A call Sunday to the spokesperson for the San Mateo County Sheriff’s Office, which is in charge of releasing the identities of the victims, was not returned.

National Transportation Safety Board investigators are working to recover the plane and
.

The plane is registered to a trust managed by the Bank of Utah, according to FAA records.

The men took off in the Twin Otter about 8:20 a.m. Saturday from the Charles M. Schulz-Sonoma County Airport on a flight path to Honolulu, Hawaii, according to preliminary flight data.

The STOL turboprop plane was originally designed to travel about 700 nautical miles. However, the aircraft had been refitted with an auxiliary fuel system to allow for longer flights, according to FAA records.

The plane flew southwest for about two hours before turning around about 10:40 a.m., according to tracking by Flightradar.

They were running low on fuel and later would report “a fuel transfer system malfunction,” according to Stuckey.

The pilots radioed that they were heading back to Santa Rosa. Eventually, they changed course and directed the plane to Half Moon Bay.

At 1:30 p.m., the Coast Guard received a report from the Oakland Air Route Traffic Control Center about the aircraft. The guard issued an urgent marine information broadcast asking for boaters southwest of the Farallon Islands to look for a potentially downed plane.

A Coast Guard helicopter crew was the first to spot the aircraft, which had gone into the water about 2:15 p.m. and had significant damage, Stuckey said.

In addition to the aircrew, the Coast Guard deployed two of its boats to assist with the search.

“We needed as many eyes as we could get to find this plane,” Stuckey said.

She said the plane’s owner had hired a salvage company to recover the aircraft.

You can reach Staff Writer Madison Smalstig at [email protected]. On Twitter @madi.smals.

thunderbird five 23rd May 2023 04:31

..................has ditched into Pacific Ocean during ferry flight from USA to Honolulu.

Ummmmm... err..... 'scuse me....... yeah, ahhh, you know about Honolulu, yeah?

Bosi72 23rd May 2023 12:17

Sadly they crashed ~12nm from Farallon island (~400m long).
If they tracked directly from 10.000ft to Farallon island instead of Half Moon Bay, they would ended ~6nm away from Farallon.

I am seeing various speeds/rate od descents, I wonder whether they would be able to reach the island if they had different rate of descent?

Mach E Avelli 23rd May 2023 13:06


Originally Posted by thunderbird five (Post 11438901)
..................has ditched into Pacific Ocean during ferry flight from USA to Honolulu.

Ummmmm... err..... 'scuse me....... yeah, ahhh, you know about Honolulu, yeah?

Well spotted, that man.

Desert Flower 23rd May 2023 13:37


Originally Posted by Petropavlovsk (Post 11438818)
.

A rescue swimmer looked into the plane and saw the pilot and co-pilot still strapped in.

The swimmer shook one of the men’s legs. He didn’t move, Stuckey said.

Talk about stating the bleeding obvious!

DF.

Mach E Avelli 23rd May 2023 22:21


Originally Posted by Bosi72 (Post 11439093)
Sadly they crashed ~12nm from Farallon island (~400m long).
If they tracked directly from 10.000ft to Farallon island instead of Half Moon Bay, they would ended ~6nm away from Farallon.

I am seeing various speeds/rate od descents, I wonder whether they would be able to reach the island if they had different rate of descent?

Sure, a descent rate of , say , 50 feet a minute, and they probably could have also flown three legs of a circuit. GT move over, we have an expert analyst here.
Most ferry installations don’t have fuel dump, so despite media reports that they were short of fuel, they still may have been heavy and therefore faster than normal. Systems typically require take-off and climb on the aircraft’s main tanks, consuming a certain amount of fuel, before changing over to the ferry tanks, thus preserving enough in the main tanks for an approach at destination. If the aircraft also has auxiliary tanks, fuel system management can sometimes be quite complex.
85 knots just prior to touchdown may seem high for a Twotter, but bear in mind it could have been nearly 50% over normal gross weight. Ferry pilots are often working well outside certification values. Extrapolating charts for takeoff distances, engine inoperative, best glide, stall speeds etc does not work, so ferry pilots faced with emergencies may suddenly become test pilots.
Fixed gear, (or floats), high approach speed, no power, open sea….it’s not going to end well.

compressor stall 23rd May 2023 22:31

Yes, it’s a long time since I’ve done any ferry flights but I can’t imagine the ROD being low when OEI with fuel for 2100nm in a twotter, no matter how skilled the pilot, the skills and decision making of whom Bosi appears to be trying to impugn.

LTC8K6 24th May 2023 00:24

Looks like the floats would make the ferry impossible due to drag. So it was likely ferried without the floats.

Blancolirio has a good video.

Fris B. Fairing 24th May 2023 02:31


Originally Posted by LTC8K6 (Post 11439374)
Looks like the floats would make the ferry impossible due to drag. So it was likely ferried without the floats.

Blancolirio has a good video.


Mach E Avelli 24th May 2023 03:27

Frisbee, thanks for the link to that Youtube video. The presenter explains it well.
In my experience the FAA approved 40% ferry overload is often exceeded, as tools & spares seem to find their way onto such flights when nobody is looking...


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