Pilot of Lao plane was 'told to change course'

[peecee]

I do not want to put a lid on the wild speculations and the first conspiracy theories, but as a retired air traffic controller, certified ICAO PANSOPS procedure designer and former holder of a multi engine instrument rating I feel inclined to add my few cents.

1. Pakse Airport VLPS is located on the banks of the Mekong River with a runway direction of 33/15 (327°/147°) nearly parallel to the river. It has the following restrictions: Landing RWY 15, takeoff RWY 33, meaning that all landings have to come in from the NNW and all departures have to leave in opposite direction to the NNW, irrespective of the prevailing wind direction. Reason seems to be (according to the terrain map) that there is mountainous terrain in the departure sector of RWY 15, SSE of the airport.

2. Pakse Airport does neither have radar, nor an Instrument Landing System (ILS) which would provide the pilot with an electronic glide slope on the last miles of the approach. The airport has an on-field NDB (non-directional radio bacon) and a VOR/DME (VHF omnidirectional radio range/distance measuring equipment) at 4.7 nautical miles on a magnetic bearing of 327° from the airport, on the final approach track for RWY 15. For details on the two radio navigational aids see wiki.

3. There are two instrument approaches for Pakse Airport, a VOR/DME RWY 15 and an NDB RWY 15. Both approaches require a minimum weather condition for landing. These are defined by ground visibility at the airport and the lowest layer of clouds covering more than half of the sky. Based on their accuracy (VOR/DME offers a higher one) the pilot may only descend to a procedure-specified MDA (minimum descent altitude) unless he has the ground or airport in sight and can continue by terrestrial navigation until touchdown on the runway. These instrument approaches are specifically designed for each airport and prescribe mandatory flight paths and minimum altitudes during any phase of the approach. Pilots may not deviate from these procedures unless authorized by air traffic control under exactly defined circumstances ("visual approach" - the pilot has visual contact to ground or airport and wishes to shorten the approach while observing obstacle clearance on his own).

4. As there are no actual approach charts for Pakse Airport to be found on the net I have to speculate a bit on the layout of the VOR/DME approach. The pilot will have to cross the VOR/DME station at an altitude (either "not below" or "at") and fly on the 147° radial with a predetermined descent rate or calculated "not below" altitudes for each mile outbound from the VOR/DME station, levelling off at the MDA - unless he has ground/airport in sight - and continue until passing the MAPt, the Missed Approach Point, when he would start a climb or climbing turn (depending on procedure layout) that would take him back to the beginning of the approach - the IAF (Initial Approach Fix), from where he could either safely proceed to his alternate aerodrome or try a second approach.

As the reporting by press and authorities is extremely shoddy I have to interpret the bits and pieces flung around:

1. Pakse Airport weather was below the minima required for landing. The pilot was made aware of that

2. The airplane crash was a CFIT - Controlled flight Into Terrain - meaning that a probably fully operational aircraft was flown into the ground.

3. The crash happened at a position where the aircraft should have been at least 500 meters/1500 feet above ground - 5 nautical miles from the airport

4. The pilot was obviously advised by ATC to proceed to his alternate destination - distorted to "change course", which is BS as the Control tower never saw the aircraft and most probably was not aware what the pilot was actually doing. Towers do not advise pilots "to change course", Radar Control Units do that, and only if the aircraft is at a certain minimum altitude above ground/obstacles. Aircraft in the final stages of an approach are usually in a procedure sector below the Minimum Radar Vectoring Altitude, so even Radar would not have given a "change course" order to the pilot.

5. In a clear deviation from the Instrument Approach Procedure the aircraft was apparently flying low level along the Mekong river in poor visibility. This was most probably done by using the onboard RNAV (Area Navigation) - GPS with detailed moving map display. I can only speculate whether that island was displayed on that map. It seems that the pilot used this approach to avoid obstacles. This indicates that the plane at least occasionally flew below 30 meters/100 feet above ground in an attempt not to lose visual reference and in consequence lead to a crash into the suddenly appearing island.

The facts that the plane had just recently be purchased from the manufacturer, that the pilots did not report any irregularities or emergencies, that the crash happened at a location where the aircraft should have been at least 500 meters/1500 feet above ground level, that the weather was most probably below the minima for this approach, make it highly probable that the pilot decided to resort to a non standard, illegal and irresponsible low level approach to enforce a landing, thus wiping out 44 lives.

I think to speculate it's pilot error in this case is quite feasible.

[Mudcrab]

It will be interesting to see the final outcome of this tragedy. I just read in the Oz news that they had recovered a passengers body....30k form the crash site, presumably due to the flow of the Mekong. Thai Navy divers and Cambodian personnel on the scene. Good luck finding the flight recorder. Could take a while .

[Loptr]

"He followed instructions but the plane faced strong winds and it couldn't get through," Mak Sam Ol told The Phnom Penh Post.

What the hell? As a pilot, I have never the above "excuse" for an incident.

[MikeOboe57]

I found another website (Aviation Herald) with this picture showing the approximate crash site:

http://avherald.com/h?article=46a05359&opt=0

[Hedghog]

So many conspiracy theorists.

It was an aeroplane accident.

They happen.

[TallGuyJohninBKK]

The BKK Post today has a somewhat better, more informative report on the crash...

Re the Cambodian official, it says that he had been briefed on the details by Laotian officials.

Meanwhile, that news report also noted that the search for bodies and the plane's flight data recorder initially had been stalled by lack of manpower and equipment in Laos.

TV rules prohibit linking to or quoting the BKK Post report. But here's an updated version from AFP.

http://timesofindia.indiatimes.com/world/rest-of-world/14-Laos-plane-crash-victims-identified-Airline/articleshow/24371459.cms

And here is yesterday's AP report as carried by the Washington Post, which includes a lot of direct comment from Laotian officials:

http://www.washingtonpost.com/world/asia_pacific/search-for-fuselage-most-victims-after-lao-airlines-crash-lacks-manpower-equipment/2013/10/18/9a3786da-37ab-11e3-89db-8002ba99b894_story.html

Thai Transport Minister Chadchart Sittipunt said the Thai navy initially sent scuba divers but their work was complicated by strong currents, deep water of up to 10 meters (32 feet) and poor visibility in the muddy river. He said navy trawlers were being sent Friday to sweep the river with nets to try to locate the fuselage, along with a Thai forensics team to help identify bodies.

“We think the plane broke into two pieces. The tail of the plane contains the black box,” Chadchart said in a telephone interview after meeting with his Lao counterpart in Pakse. “It is believed that many bodies of the passengers are still stuck in the plane, or else they would have surfaced on the river.”

Edited October 19, 2013 by TallGuyJohninBKK

[abq2020]

The airline is reporting speculation as fact, when, if fact, it not. Need to have 'professional, competent' investigators make the call here, and only after learning what the two black boxes have to 'say.' Maybe they or we will never learn the true cause; however, it would not be unreasonable to speculate now that the cause(s) were pilot AND weather related.

[Hedghog]

Amazing how many TVers are aviation experts.

All I know is the plane stopped,when it hit the ground at the wrong angle.

Unscheduled stop.

Accident.

[dunque]

Due to the apparent severity of the weather at the time the accident occured. Me thinks that that aircraft had no business being anywhere near attempting a landing at the airfield in Pakse or even be in its airspace. We see it way to often in SEA. Pilots attempting to land when they should not be due to extreme weather condition at the destination.

Just a couple of bad weather related examples off the top of my head.

Thai Flight 261 carrying 146 people on board took off from Don Mueang International Airport at 11:40 UST on a two hour flight to Surat Thani. When the aircraft began to descend to Surat Thani Airport, the weather was bad with heavy rain and poor visibility, and the pilot executed a missed approach two times. On a third attempt to land, the aircraft stalled and crashed two miles southwest of the airport, killing 101 people and injuring 45 people. 90 passengers and 11 crew members died.^[1]

One-Two-GO Airlines Flight 269 (OG269), a McDonnell Douglas MD-82, crashed into a non-frangible embankment beside runway 27 at Phuket International Airport (HKT) bursting into flames upon impact on September 16, 2007, at about 15:41 ICT during an attempted go-around after an aborted landing, killing 89 of the 130 persons on board.

Here's another - off the top of my head - fog related

1977: 583 people died after two Boeing 747s (KLM and Pan Am) collided on a runway in Tenerife in the worst accident in the history of commercial aviation.

[fish fingers]

Air France don't have the best safety record and they cover up the true causes.

Back to the topic, the skid marks suggest that the angle of impact was shallow, so it cd well be that he was flying low for visability reasons - there was no mayday was there?

Edited October 19, 2013 by fish fingers

[bangon04]

Thanks for that Mike. If true, I find it amazing that a pilot with 30 years experience pulled a stunt like that.

" after having trained in Russia"

[Bpuumike]

There is too much speculation here.

Personally I am thinking hostile weather.

That would beg the question why the pilot was there?

Commercial pressure? Guess we shall never know.

RIP

[Asiantravel]

Good to see that the conspiracy fans don't limit themselves to Thailand

<deleted>?

I was referring to some of the posts stating that the black box would never be found or it would be "damaged" and rendered unusable. As far as I know, a manufacturer's rep will be on the scene prettty quickly as they have a vested interest in finding out what happened.

" Investigators say they have picked up signals from the black box of the plane that crashed in southern Laos last week but the raging torrent and murky waters of the Mekong River have prevented them finding it."

http://www.smh.com.au/world/laos-plane-crash-black-box-signals-detected-20131021-2vvvk.html#ixzz2iJyj6PFG

[Cheapcharly]

What could be?

Windshear, water contamination? How far was the plane from runway?

[yingyo]

the control tower at the Pakse airport had issued the instruction to Cambodian-born pilot Young San

As long as everyone knows the pilot was Cambodian, and the heading hints that he disobeyed orders from the control tower, which he didn't.

Well done The Nation.

[hanno]

Good to see that the conspiracy fans don't limit themselves to Thailand

<deleted>?

I was referring to some of the posts stating that the black box would never be found or it would be "damaged" and rendered unusable. As far as I know, a manufacturer's rep will be on the scene prettty quickly as they have a vested interest in finding out what happened.

" Investigators say they have picked up signals from the black box of the plane that crashed in southern Laos last week but the raging torrent and murky waters of the Mekong River have prevented them finding it."

http://www.smh.com.au/world/laos-plane-crash-black-box-signals-detected-20131021-2vvvk.html#ixzz2iJyj6PFG

"French air crash investigators began working at the crash zone on Saturday along with a team from the aircraft manufacturers, bringing much-needed technical expertise to the operation in one of Asia's poorest countries. Navy divers from Thailand are also helping the search."

http://abcnews.go.com/International/wireStory/lao-airlines-crash-probe-hones-black-box-20625722

[ableguy]

Perhaps the air traffic controller has been instructed to lie in an attempt to brush off any accusations that he might have been negligent, and at the same time shift the blame to the pilot who is unable to defend himself. Also he has offered an explanation that "saves the pilot's face" by saying that he obeyed the instructions but the plane was caught up in the winds and it was too late. The Lao government and airline is off the hook, the black box will never be found, air traffic control recordings disappear and the families of the innocent victims are screwed as always. What else would you expect from a communist regime?

All you none pilots on this thread have not got a bloody clue and no nothing about this incident, wannabe pilot drivel.

[Chao Lao Beach]

They are getting a signal from the box. It will be found, it is an ATR, there will be huge Intl interest in this crash, if nothing else to put it down to human error to keep ATR's name good.

[davehowden]

Perhaps the air traffic controller has been instructed to lie in an attempt to brush off any accusations that he might have been negligent, and at the same time shift the blame to the pilot who is unable to defend himself. Also he has offered an explanation that "saves the pilot's face" by saying that he obeyed the instructions but the plane was caught up in the winds and it was too late. The Lao government and airline is off the hook, the black box will never be found, air traffic control recordings disappear and the families of the innocent victims are screwed as always. What else would you expect from a communist regime?

All you none pilots on this thread have not got a bloody clue and no nothing about this incident, wannabe pilot drivel.

I think everybody has the right to make themselves look stupid?

[VMOMMO]

While we are speculating here, Mike has pretty much explained it. The only plausible reason for the aircraft to have been where it was when it crashed was that the pilot was scud running (flying underneath a low cloud layer) to try and get into the airport when it was below landing minimums. The logical way to scud run to the airport that is located along the river is to get down low and follow the river. Maybe somewhat dangerous and risky at 65 mph in a Supercub but downright stupid at 200mph in an airliner. Passengers don't pay for stupid risk taking behaviour. That is why you carry fuel to divert to an alternate airport. An error on the instrument approach would have wound up with an accident site underneath the final approach course. Scud running along the river at low altitude would put him exactly where he wound up. Flying low along a river at low altitudes it only takes a moment of inattention and you can hit the ground. I am not sure of the altitude of the island but he also could have been low enough to hit that.

There is no radar at either the approach control or tower so they will not be giving headings to the pilot (change course) or even know where he is actually flying unless he tells them.

Somebody else thought that ATRs ice up and maybe the tail stalled, not much icing over SE ASia at 100' or even at 10,000 feet and the ATR crash was in severe icing conditions.

Why would the pilot have tried this? He was experienced, but at what? Flying regionally in Cambodia. Probably had been doing things like this most of his career as I doubt the state of the navigation aids and other such things was any better than most of the other infrastructure in Cambodia. He had probably done this before and gotten away with it. You can only get away with it for so long.

I would wonder about the safety culture that might condone or tolerate this sort of flying. Where was the first officer (co-pilot) during this stunt? He obviously let this happen. He let the Captain kill him and the other passengers.

They will recover the flight data recorder and the voice recorder. This will get investigated and the results will eventually be published. Maybe my suspicions will be proved wrong, but I doubt it. 23 years of flying and 17,000 hours, gives me a pretty good idea how they came to crash where they did.

[VMOMMO]

There is no Glideslope, only non-precision approaches at that airport. He was not on the approach course to the airport but rather was over the river instead. At 5 miles from the airport he should have been at least 1500 feet above the ground, the minimums for the approach are around 650 feet above the ground so he should not have been below that without having the runway in sight and being in a position to make a safe landing on it.