Quoting Deanger (Reply 250): Interesting that people have different impressions. For what it is worth, my understanding was MAYDAY was for loss, or imminent loss of aircraft control for any number of different reasons... Whereas PAN PAN PAN would be more appropriate for an engine loss in a twin (without the imminent loss of control)

The call is related to the situation directly, based on what is occurring. There is no specific guidelines on the usage of the phrases. From ICAO standards, mayday is a distress call (situation where the aircraft requires immediate assistance) and pan-pan is a urgency message (situation where an aircraft is in difficulties which compel it to land, but the pilot considers that he does not need immediate assistance).

It is the pilots call. In this case, the aircraft should be able to maintain an approx climb rate of 400fpm SE (With auto/manual feathering and uptrim on standard ISA). I do not know the drag penalty if such systems fail and whether that would result in severely degraded climb performance.

Quoting rcair1 (Reply 124): If the pilot were trying for the river - would have turned right, not left.

If the pilot had turned to the right, there would have been some very tall office buildings in the way (depending on when the right turn was initiated), a different road bridge over the river, a very large parking lot, and the terminus of the Taipei Metro system. Oh, and a very, very large tent full of school children -- think Cirque du Soleil tents.

Bascially the aircraft managed to crash between two bridges in about the only area that didn't (for all intents and purposes) guarantee 100% fatality on the aircraft and multiple fatalities on the ground.

There are no two ways about this: We were very, very fortunate yesterday that there were not many more casualties.

Quoting spacecadet (Reply 246): Only if you've only got one. "Mayday" means the airplane is in urgent distress and in need of immediate assistance. In a two-engine plane, that is just not the case after an engine failure. It would be true in a single-engine Cessna.

Mayday = emergency. Losing an engine on a twin-engined aircraft is an emergency.

Quoting spacecadet (Reply 246): Plenty of US pilots use "Mayday" in an emergency - it's standard ICAO and FAA terminology: https://www.faa.gov/air_traffic/publications/ATpubs/FSS/fss0501.html#Section 1. General

Yes, I'm aware mayday is standard terminology, but "delcaring an emergency" is not, yet is often used in the US. Gets the point across though, so I'm not really complaining.

Quoting Deanger (Reply 250): Interesting that people have different impressions. For what it is worth, my understanding was MAYDAY was for loss, or imminent loss of aircraft control for any number of different reasons... Whereas PAN PAN PAN would be more appropriate for an engine loss in a twin (without the imminent loss of control)

http://www.youtube.com/watch?v=9KhZwsYtNDE

http://www.youtube.com/watch?v=fdHfYONgOAA

http://www.youtube.com/watch?v=ZR3IQSjbzJg

http://www.youtube.com/watch?v=ScLVhDSKquQ

http://www.youtube.com/watch?v=TNJOJCvNg88

Several ATC recordings there. 2 European crews with engine failures, declaring mayday. 3 American crews "declaring an emergency" which is the same thing.

Being down to one engine is an emergency. As rara said, if you have an engine failure, especially during a critical phase of flight and don't declare an emergency, people (i.e the chief pilot) may well be asking you why. What's the point in playing the hero when you're in a sticky situation? Obviously the crew on the day makes the decision, but at most airlines, if you lose 50% of your powerplants, it's an emergency.

[Edited 2015-02-04 16:51:15]

Does anyone know what SID they were flying. If you interpolate the SID with the FR24 data (post 209) and correct the ground speed with the METARS data, you can get a pretty good idea of what the aircraft was doing aerodynamically. Why is another story.

Quoting PW100 (Reply 239): The important question is: why was the aircraft (even with engine failure) not able to maintain a positive energy state? From the data and video available at this time, there is not a single shred of evidence to suggest that cause of a pilot error. Of course, at the same time there is no single shred of evidence that it wasn't a pilot problem. It bothers me that some have already decided that it must be poor airmanship that put them in this situation.

  

Exactly. There are some on here who attribute every accident / incident to pilot incompetence and then disappear when the causes become known through the investigation Final Report - without even the decency of an apology to the families of the pilots they've accused and denigrated.

Has anyone noticed that few knowledgeable transport pilots (Zeke honourably excepted) bother to participate in these threads any more? I have time on C130s (but not ATRs), so I wait for the DFDR and CVR and refrain from speculating in order not to demonstrate what I don't know. Others, apparently, have no qualms about displaying their complete ignorance of aerodynamics, aircraft systems, CRM, MX, WX, etc.

I would like to add some further information to this accident, I am based in Taiwan.

1. There are three flight crews at the cockpit - the third was an observer according to local press - may be on training.
2. Once again, local press states that the aircraft, on its delivery flight to Taiwan from France(?), had a new engine installed at Macao where it apparently made a stop - now, this is according to local press and the truth of that, may be questionable. Aircraft in question was actually less than 1 year old.
3. TransAsia has a terrible record on their ATR72 fleet. Let me give a quick summary, they lost one over at MaKong island due to icing build up on wing - this one was opearting as a freighter. TransAsia lost another one while flying empty (ferr flight) from KinMen (the same destination as this flight was heading) to Taipei over Taoyuan due to navigation mistake. All four crews were killed. They lost one last year while attempting to land in bad weather at MaKong island. And now, this one.
4. It is understandable to question the quality of their air-crew flight training as evidence of their accidents point to this. Ironically, I think, they appoint someone who just retired from EVA as their VP or something on flight safety - very ironic indeed. I also recall, from previous readings, of numerous mistake in their maintenance, and poor handling. Overall, I do believe this is not a very safe airline and now they are acquiring newer A330 to their fleet. Last year, when the Taiwan government receive additional landing slots to China, most of them went to China Airlines and EVA AIR. TransAsia made a big deal, citing inequality treatment. Well, prove to me otherwise.
5. Before the highspeed railway opens in Taiwan, we have many smaller airlines aside from CI and BR. A round of consolidation left with only 4 I think. The other time bomb in my opinion is Far Eastern. They went bankrupt for some time and now resume flying with very old, hopefully well maintained - Mad Dogs (MD series).

It is ironic that country like China, have a decidedly better safety record than a much smaller country like Taiwan. Although we complaint so much on delays in China, in the name of flight safety, they are really doing well, at least on the record.

Quoting Kaiarahi (Reply 259):

Do you or anyone know if this is accurate? SIDs start on page 4

http://www.ivaocn.org/cn_events/20090101/event-Dateien/RCSS-N.pdf

Quoting macc (Reply 97): It always puzzles me how people just move on. It would have been my first to stop in front the debris to avoid others run over them, check with the taxi driver and see what became of the plane.

Why? People have lives to get on to. We pay taxes for things like emergency services.

At time of accident:

METAR RCSS 040230Z 10008KT 9999 FEW013 BKN028 BKN040 16/13 Q1024 NOSIG RMK A3025=
METAR RCSS 040300Z 10010KT 9999 FEW015 BKN028 BKN040 16/13 Q1024 NOSIG RMK A3025=

Quoting AIRWALK (Reply 261): Do you or anyone know if this is accurate? SIDs start on page 4

At the time. But they're 10 years old (March 2005). Thank you for finding them and taking the time to ask - this is the kind of basic info that's needed to decipher what may have happened. Zeke may have access to current charts.

My quick cull of the ATC comms didn't turn up the SID they were flying, but I may be wrong.

Quoting Kaiarahi (Reply 259): Has anyone noticed that few knowledgeable transport pilots (Zeke honourably excepted) bother to participate in these threads any more?

Indeed. I have some thoughts but will refrain from most of them.

I will say that Vs and Vmca were probably so close together that it was more than likely a combination of both that contributed to the end result. A multi-engine airplane with only one engine operating acts considerably different than one with two engines operating. The jury is still out about what brought the airplane to the unrecoverable low and slow situation that it was in.

Quoting Kaiarahi (Reply 259): There are some on here who attribute every accident / incident to pilot incompetence

That's because most accidents have such cause, after a point it becomes infuriating.

It's true that any number of mechanical problems could ultimately explain the accident, jammed controls for example, but it's not likely.

Quoting N766UA (Reply 196): I've had it with this shit.

So then wouldn't the smart thing be to stop posting if you're so done? I'd think you'd just want to save yourself the trouble of dealing with this forum if it bothers you so much.

May those that have lost their lives R.I.P.

My condolences to the family & friends of the victims  

The footgae of the final 5 or so seconds captured on the vehicle dash cams is quite sad. Nonetheless, at least investigators have some pretty clear / good footage of the end of the flight and can see how the plane was configured / looked from the outside and how it was flying at the end.

Quoting Kaiarahi (Reply 264): At the time. But they're 10 years old (March 2005). Thank you for finding them and taking the time to ask - this is the kind of basic info that's needed to decipher what may have happened. Zeke may have access to current charts. My quick cull of the ATC comms didn't turn up the SID they were flying, but I may be wrong.

My company doesn't fly there so we don't have any Jepps or Lido access.

However, most countries do post their charts services online.

The ones relevant to this discussion can be found here:

http://eaip.caa.gov.tw:10000/search/...query=rcss&results=50&filter=false

Songshan:

http://eaip.caa.gov.tw/eaip/history/.../html/eAIP/RC-AD-2.RCSS-en-TW.html

The likely relevant SID chart:

http://eaip.caa.gov.tw/eaip/history/2015-01-22/graphics/86118.pdf

Obstacle chart A:

http://eaip.caa.gov.tw/eaip/history/2015-01-22/graphics/81416.pdf

Obstacle chart B:

http://eaip.caa.gov.tw/eaip/history/2015-01-22/graphics/81418.pdf

Due to length, this thread has been closed for further posts. Please continue the discussion in part 2 here: Transasia ATR-72 Crashes In Taipei - Part 2 (by bnatraveler Feb 4 2015 in Civil Aviation)

Any posts after this notice will be removed as part of housekeeping activities.