Blackout Threatens Hub Status Of Suvarnabhumi

[Horneytorney]

last time this happened to me was in Australia...

[kamui]

simultaneous breakdown of both the main and back-up power supplies

What are the odds? The whole point of a back up is that it's supposed to be immune from the primary system's problems. Perhaps the back up depended to the primary system's power to run?

He noted that Aerothai successfully employed radio communication

And if that'd failed, they have some flags in the desk drawer.

Passenger numbers are expected to soar further to 51 million this year.

Not after this debacle.

 

Come on, that's just a blip.Tomorrow it's forgotten - and I guess some people connected to the airport want to have it forgotten.

[Gadfly]

Whilst there is often excess cash that gets spent on projects there is rarely sufficient, or indeed any, for regular scheduled maintenance.

 

This sounds exactly like the group who managed the place where I had my old condo.

[Mekong]

simultaneous breakdown of both the main and back-up power supplies

What are the odds? The whole point of a back up is that it's supposed to be immune from the primary system's problems. Perhaps the back up depended to the primary system's power to run?

 

 

 

 

Any UPS does rely on Primary supply to function, during normal operation the Primary supply is the main feed and also feed the UPS Charger that charges the batteries, upon failure or under voltage of primary feed the UPS Kicks In and discharges the batteries via the inverter to maintain the supply.

 

In industrial applications we size our UPS for 30 Minutes for ESD Systems (Emergency Shutdown) which is enough time for a Plant to shut down safely and depressurise, we have a second UPS for Critical systems such as Fire and Gas and PA / GA systems usually sized for 4 hours back up.

 

Someone mentioned "ByPass" mode of operation, Bypass will not cause the batteries to discharge but allows for maintenance work to be done on the charger, batteries or inverter, when in By Pass mode the "Undervoltage" detection circuit which Kicks in the Inverter is isolated from main feed and as such will not detect failure of primary feed. UPS should only be put in Bypass under a Permit to Work and the Bypass alarm should keep re-initiating every 10 minutes to remind the operator that they are vulnerable, I design into my systems Automatic Shutdown of the plant if in Bypass for 72 Hours or more, this is more due to decreased SIL (Safety Integrity Level) than pure operability.

 

For ultra critical systems such as Radar for example, I am surprised that there was not an EDG back up (Emergency Diesel Generator) and the Radar was not fed from Emergency Bus.

 

I can only has as a guess one of 2 possible scenarios

 

1. UPS was Under Maintenance and in Bypass Mode When Primary Feed Failed
   
2. Inverter Failure, since most UPS systems now run continuous "Self Diagnostics" then an operator failed to act upon this alarm
   

 

I could go on for hours but I think you get the basics.

[radioman]

Any UPS does rely on Primary supply to function, during normal operation the Primary supply is the main feed and also feed the UPS Charger that charges the batteries, upon failure or under voltage of primary feed the UPS Kicks In and discharges the batteries via the inverter to maintain the supply.

 

In industrial applications we size our UPS for 30 Minutes for ESD Systems (Emergency Shutdown) which is enough time for a Plant to shut down safely and depressurise, we have a second UPS for Critical systems such as Fire and Gas and PA / GA systems usually sized for 4 hours back up.

 

Someone mentioned "ByPass" mode of operation, Bypass will not cause the batteries to discharge but allows for maintenance work to be done on the charger, batteries or inverter, when in By Pass mode the "Undervoltage" detection circuit which Kicks in the Inverter is isolated from main feed and as such will not detect failure of primary feed. UPS should only be put in Bypass under a Permit to Work and the Bypass alarm should keep re-initiating every 10 minutes to remind the operator that they are vulnerable, I design into my systems Automatic Shutdown of the plant if in Bypass for 72 Hours or more, this is more due to decreased SIL (Safety Integrity Level) than pure operability.

 

For ultra critical systems such as Radar for example, I am surprised that there was not an EDG back up (Emergency Diesel Generator) and the Radar was not fed from Emergency Bus.

 

I can only has as a guess one of 2 possible scenarios

 

1. UPS was Under Maintenance and in Bypass Mode When Primary Feed Failed
   
2. Inverter Failure, since most UPS systems now run continuous "Self Diagnostics" then an operator failed to act upon this alarm
   

 

I could go on for hours but I think you get the basics.

 

When in Bypass on the system I referred to the batteries were not being charged. After about 5 months they were sufficiently depleted that when called upon there was insufficient for them to operate. It also prevented the generator start function from coming on line since that was powered by the UPS.

 

At Swampy the problem is going to be different. The sensors didn't go off line but the displays and processing systems did. They couldn't switch to the DMG radar because those sensors are off line an the local DMG controllers do not have feed from Swampy. What the feck went wrong at Tung Mahamek I don't know, they said it was unmanned. More likely the feed from Swampy to TMK is from modems fed from the same ups. Radar data is not overly intensive, usually only updates running over a simple leased line modem at 9600 baud is enough and they probably either lost the link or had no feed to send anyway.

 

Kong, you mentioned integrating safety alarms when the UPS is in Bypass and conditioning stepped shutdown systems but I can tell you outside of the UK, Canada and US, the only places I have seen the aviation business take safety case studies anything like serious, the rest of the worlds air traffic business operates largely on a wing(sic) and a prayer. Operation of each nation states ATC is guided only by standards and recommended practices laid out in Annex 10 to the convention on International Civil Aviation. Many of which are whilst not ignored not exactly adhered to either in many cases. Here's what Annex 10 says about backup power supplies:

 

2.9 Secondary power supply for radio navigation aids and communication systems

2.9.1 Radio navigation aids and ground elements of communication systems of the types specified in Annex 10 shall be provided with suitable power supplies and means to ensure continuity of service appropriate to the needs of the service provided.

 

Translate that to Thai and they have some latitude on the design front!

 

I could go on for hours too, indeed I've been going on this very topic for the last 33 years.

[Mekong]

RM,

 

Thanks for the post mate very informative, whilst we probably have the same background and similar degrees it it is obvious we work in different industries.

 

I never realized the rules in the Aviation Industry were so lax, damn scary if you ask me. In my industry we first carry out a HAZOP (Hazard and Operability Study) and then SIL assessment to determine the level of safeguarding required. We use a formula to calculate it such as frequency, and consequences, Loss of Life >1 means we have to be SIL3 (Most Strict for Onshore) regardless of other factors yet aviation industry risks 250+ Lives every 90 seconds un(fucking)believable

 

Off to read Annex 10 to the convention on International Civil Aviation before the football starts

[Gadfly]

When in Bypass on the system I referred to the batteries were not being charged. After about 5 months they were sufficiently depleted that when called upon there was insufficient for them to operate. It also prevented the generator start function from coming on line since that was powered by the UPS.

 

At Swampy the problem is going to be different. The sensors didn't go off line but the displays and processing systems did. They couldn't switch to the DMG radar because those sensors are off line an the local DMG controllers do not have feed from Swampy. What the feck went wrong at Tung Mahamek I don't know, they said it was unmanned. More likely the feed from Swampy to TMK is from modems fed from the same ups. Radar data is not overly intensive, usually only updates running over a simple leased line modem at 9600 baud is enough and they probably either lost the link or had no feed to send anyway.

 

Kong, you mentioned integrating safety alarms when the UPS is in Bypass and conditioning stepped shutdown systems but I can tell you outside of the UK, Canada and US, the only places I have seen the aviation business take safety case studies anything like serious, the rest of the worlds air traffic business operates largely on a wing(sic) and a prayer. Operation of each nation states ATC is guided only by standards and recommended practices laid out in Annex 10 to the convention on International Civil Aviation. Many of which are whilst not ignored not exactly adhered to either in many cases. Here's what Annex 10 says about backup power supplies:

 

2.9 Secondary power supply for radio navigation aids and communication systems

2.9.1 Radio navigation aids and ground elements of communication systems of the types specified in Annex 10 shall be provided with suitable power supplies and means to ensure continuity of service appropriate to the needs of the service provided.

 

Translate that to Thai and they have some latitude on the design front!

 

I could go on for hours too, indeed I've been going on this very topic for the last 33 years.

[Gadfly]

This was very interesting. The part about, "Operation of each nation states ATC is guided only by standards and recommended practices laid out in Annex 10..." is frightneing when you think about how Thailand fails to even comply with straightforward regulations and treaty obligations and throws a temper tantrum, screaming interference with national sovereignty, if anyone even mentions the subject.

[gobbledonk]

Spend enough time over-thinking life and you will never get on a plane or eat at a restaurant. A millionaire called Dick Smith has been making noises about Australian Aviation for many years - if we cant get it right with only 3 or 4 'large' airports governed by a single authority, what hope Asia ? We all knew Swampy was a little too good to be true, given the backstory - it may be that the chickens are coming home to roost.

[radioman]

Most places do tend to be reasonable and to be fair the reliability of most systems today is pretty good, both prime contractors and their subs are mostly reputable companies. Problems crop up when demands for (or a belief in) localization go beyond what can be achieved, then it can get scary. Again most civil organizations are pretty good but there are exceptions. The following concerns the FAA downgrading Philippine airspace from Cat 1 to Cat 2:

 

Bad Press for CAAP

Posted on March 20, 2012 by waebi

 

In a press conference held at the CAAP headquarters in Pasay City yesterday morning, the Civil Aviation Authority of the Philippines (CAAP) informed that the US Federal Aviation Administration (FAA) has found 23 “critical elements†which the Civil Aviation Authority of the Philippines needs to address before the country can regain its “Category 1†safety status.

 

In 2007, the FAA downgraded the Philippines to Category 2 status after finding 88 critical elements. The CAAP has since addressed 65 issues.. The ICAO later conducted its own audit in October 2009 that resulted in findings of a Significant Safety Concern, thereby reinforcing the FAA findings. It cited “open items†or unmet issues on the implementation of air safety oversight, and inadequate security systems.

In 2010, the European Union, following the FAA’s lead, also blacklisted the Philippines and banned Philippine carriers from flying to Europe.

 

The CAAP technical team will fly to the FAA headquarters in Washington next month to present the agency’s action plan on how to address the 23 critical elements.

 

 

My link

 

and here

 

My link

 

 

 

Another element is to remember that ATC is fairly well fragmented and uses a very reliable means of maintaining communication, AM voice communication on VHF primarily. Breaks in the system, can usually be quickly filled by other centre. Much more emphasis on safety is placed on the aircraft and it's operation then on simple stuff like communication and navigation aids though like with the PI it's not always perfect. A friend had a daughter who was an FA for Gulf Air, she quit after she learned about gaps in maintenance, said it was just taking too much of a risk to do it day in day out.