Small plane crashes in Chachoengsao

[PeteC]

https://www.bangkokpost.com/thailand/ge ... achoengsao. (Photos)

......"The nine people onboard were reported to be five Chinese and two Thai passengers, and a Thai pilot and co-pilot"...... "Nine onboard Cessna Caravan flying from Bangkok to Trat still unaccounted for."

[PeteC]

More detail and video. No bodies or survivors found yet as of this morning.

https://www.khaosodenglish.com/news/202 ... ared-dead/

[PeteC]

Some human remains now found. Wreckage and remains were 10 + meters deep in the mud. Apparently the plane went in at high speed, nose first.

Chachoengsao plane crash: All 9 aboard feared dead

https://www.bangkokpost.com/thailand/ge ... eared-dead


....."The wreckage of the plane was found in the mud in a mangrove forest near the temple. Women's clothes and a photograph of three foreign women were also found at the site.

Rescuers used pumps to drain water and backhoe trucks to excavate mud about 10 metres deep and eight metres wide. During their search, they located several human body parts.".........

[Nereus]

Apparently the plane went in at high speed, nose first.

Yes, they don't do crashes lightly, do they! Cessna Caravan, a well proven GA aircraft, although there have been a lot lost over the years, but then they do get used a lot in 3rd World countries.

No mention of any Mayday calls, or not reported if there was. I have to wonder if airframe icing caught them out? Those aircraft are not pressurized, so would not be above 10,000ft. To crash like that indicates an aerodynamic stall, which even if an engine failure, it should not have gone in at high speed.

[VincentD]

The HS registration goes back a long way, they are now HS1, indications that this aircraft is quite old. Possibly around 40 years vintage. Maintenance of something of this vintage could be a constraint.

[STEVE G]

The HS registration goes back a long way, they are now HS1, indications that this aircraft is quite old. Possibly around 40 years vintage. Maintenance of something of this vintage could be a constraint.

Apparently it was first registered in 2007, so it was quite old but not excessive for an aircraft like that.
Of course it depends how aircraft are maintained, they'll practically fly forever if they're looked after.

[PeteC]

The plane was not equipped with a black box. Doubt if anyone will now ever know the full story of what happened.

https://tna.mcot.net/english-news-1409747

[PeteC]

Probe begins into plane crash that killed 9

https://www.bangkokpost.com/thailand/ge ... t-killed-9

This articles indicates that this particular plane had permission to fly at 5,000 feet maximum.

[Nereus]

The HS registration goes back a long way, they are now HS1, indications that this aircraft is quite old. Possibly around 40 years vintage. Maintenance of something of this vintage could be a constraint.

Age has nothing to do with it.

https://asn.flightsafety.org/wikibase/155569

Owner/operator: Siam General Aviation
Registration: HS-SKR
MSN: 208B1241
Year of manufacture: 2007

Cessna 208B HS-SKR, named "Soneva Kiri", suffered a prop strike and nose wheel collapse following overrun on landing on 10/12/2012 at Ko Mai Si, Thailand. Later repaired & returned to Don Mueang 13/7/13

[Nereus]

Probe begins into plane crash that killed 9

https://www.bangkokpost.com/thailand/ge ... t-killed-9

This articles indicates that this particular plane had permission to fly at 5,000 feet maximum.

It may just mean that it was flight planned at 5,000ft. The aircraft was certified to 25,000ft originally.

[Nereus]

It appears that the aircraft was part of the "Soneva Kiri" resort, a place where it costs around 45,000 Baht a night. The resort also owns the small island called "Ko Mai Si", which has the airport / landing strip for the bigger island where there are several other expensive resorts. (Koh Kood)

The flight was being operated under a charter / air taxi license, but it is not clear if all of the passengers were going to the Soneva Kiri resort, or that the two Thai girls may have been resort staff, rather than flight hostesses.
Under Thai regulations the aircraft probably did not require any flight recorders.

A copy of the weather forecast at the time does not show any expected bad weather and does not mention any icing areas.

[PeteC]

If they recover enough bodies, I would look at the 61 year old pilot perhaps having a heart attack or similar. At 5,000 ft or less it wouldn't take much for him to fall onto the controls and send the aircraft into a dive. Perhaps not enough time for the co-pilot to regain control. Speculation of course, but reasonable.

One of the articles said villagers noted the engine running full open (sound) as it came down.

[PeteC]

Police to identify all plane crash victims by Monday

https://www.bangkokpost.com/thailand/ge ... -by-monday


The Police Forensic Science Office will on Monday complete the identification of the nine people who died when their small plane crashed in Chachoengsao province.

Typically, the data will be released after it is complete.................

[Nereus]

Slow news day. What may have happened:

Run away trim:

I has been reported that the aircraft crashed in a nose down near vertical dive, hence how it came to be buried in the mud. There are not many ways that can happen. In an aerodynamic stall a fixed wing aircraft tends to rotate about its vertical axis, with the wings either level, or one wing down a bit. That is called a “spin”, and the aircraft can usually be recovered, providing it has enough altitude, and that the pilot takes the correct action with the controls. So, in this case it is unlikely that it stalled for whatever reason.

The next likely cause could be a catastrophic failure of the elevator controls at the tail of the aircraft which control the longitudinal pitch: nose up or nose down. A structural failure, or something like a bird strike could be the cause. Apart from a bird strike, a structural failure is unlikely with a proven type of aircraft such as this one. Even gross mis-handling by a pilot would be an unlikely cause.

It has been reported on another forum that there have been past accidents with this aircraft type suffering what is called a “runaway trim”. The elevator, and on most aircraft the rudder, have a small “tab” as part of the control system fitted in addition to the primary control surface. Its purpose is to keep the main control surface “trimmed”, or moved in very small amounts, so that the airflow over the control surface is maintained in a smooth aerodynamic flow and in turn, balanced in such a way that there is no unnecessary load on the overall control system. With most aircraft the pilot is able to “feel” out of trim as feedback on the primary controls, and or, the relevant instruments in the cockpit.

Also, in most aircraft, including this one, the trim control is electrically powered. In this case probably a small “trim switch” is mounted on the control yoke which the pilot can use without having to take his hands from the control yoke. Usually, the rudder trim control is a separate control not mounted on the yoke, as once set it does not require constant corrections.

A “run away trim” condition occurs when there is some form of electrical failure in the control system. The control switch may stick closed, a relay may also do the same thing, damaged wiring could also be a cause, water ingress may also be a cause.

The point is; such a condition will rapidly cause an uncontrolled pitch either up or down, of the longitudinal state of the aircraft. A pitch of nose up will rapidly lead to an aerodynamic stall, where as a pitch of nose down will put the aircraft into an uncontrolled dive.

The circuit for the trim system will have its own circuit breaker, and that is the only way to stop the run away on most aircraft. However: first the pilot has to immediately recognise the problem, and THEN, find and pop the circuit breaker. Unlikely to happen, more so if only at 5,000ft and pointing straight down!

In addition, the investigation into a previous accident led investigators to the conclusion that the aerodynamic force on the control system meant that they could not recover from the dive, no matter how hard the pilot(s) tried to push or pull on the controls. I could not find the reason for the run away, except that it was widely reported at the time.

There are conflicting reports of which direction the aircraft was travelling; one saying that it departed Swampy, another saying it departed from the island. I believe that it departed from Swampy, and taking into account of where it crashed, it may well have just arrived at 5,000ft, whereby the pilot would have been leveling off and using the trim.

[Dannie Boy]

I read this report about the plane direction,

The plane, a Thai Flying Service Cessna Caravan C208, took off from Suvarnabhumi Airport at 2:46 p.m., bound for Ko Mai Si Airport in Trat province. Around 3:00 p.m., the aircraft lost contact with the Suvarnabhumi control tower and crashed at 3:18 p.m. in a mangrove forest in Bang Pakong district, Chachoengsao province.