Cathay Pacific Emergency

[thehawk]

Surprised no-one has mentioned this : (I couldn't find any mention of it on here)

http://www.reuters.com/article/idUSTRE63D0DI201004...

[Blue Meanie]

I hope Deepak Chopra hasn't been meditating too much, and caused a near aircraft disaster, after all, he is clearly responsible for a quake.

http://www.aolnews.com/nation/article/chopra-blame...

Edited by Blue Meanie on Thursday 15th April 13:37

[Ledaig]

£50 says it comes out as ice in the fuel

Blue Meanie said:

I hope Deepak Chopra hasn't been mediating too much, and caused a near aircraft disaster

Arbitration through transcendental meditation?

[Blue Meanie]

Ledaig said:

£

Blue Meanie said:

I hope Deepak Chopra hasn't been mediating too much, and caused a near aircraft disaster

Arbitration through transcendental meditation?

fksocks!

[scarebus]

Not quite as dramatic as it sounds.... both engines went into a fail safe mode which gives you a high power setting, therefore plane does not come down. Turn off one engine, plane comes down slowly. Land, turnoff other engine and stop...simples!


http://avherald.com/h?article=42a1000b&opt=0

[maser_spyder]

OK, this is all great news.

I was supposed to be flying to HK tomorrow afternoon with CP.

No there's no way they could fly through the ash, and if they did, the fuel would go 'bad' and we would have an emergency landing.

Managed to change my flight to (provisionally) Saturday night, but it's not looking good.

Bugger.

[scarebus]

Ash has no effect on the fuel, it ends up becoming molten as it heats up, slowly choking the engine by blocking the gasflow through the compressor/turbine blades.

[Simpo Two]

scarebus said:

Ash has no effect on the fuel, it ends up becoming molten as it heats up, slowly choking the engine by blocking the gasflow through the compressor/turbine blades.

I thought it was rather excessive to ban helicopter Air Ambulances - they fly low thereby avoiding the ash, no?

Plus, does ash affect propeller-driven planes?

Edited by Simpo Two on Friday 16th April 09:47

[Merritt]

The multiple flame out on the 747 in the 80's was traced back to volcanic ash & tiny rock particles that had been turned molten by the extremely high combustion temperatures. In the combustion area that proceeds the HP turbines, the molten rock apparently blocked the fuel nozzles (which are in a hot area of the engine) which caused the flame out. (in addition to basically sand blasting the entire air frame). Ironically, as the engines cooled in the glide descent, the now hardened rock cooled, cracked and broke off enough areas of the fuel supply nozzles to allow a restart.

In a piston engine prop, as im sure you're aware the principle of operation is different and may be considered by some as less likely to cause problems. The carb on most piston props sits in reduced pressure and colder than ambient temperatures so fuel is unlikely to be a problem. The possibility is however that it could be harmful in the cylinder could cause detonation / preignition / failure of bearings etc.

The authorities have allowed piston flights to continue but no instrument flights in IFR are being granted.

Edit to say that the NOTAMS (warnings to pilots) start at ground level and go up for the Ash clouds. At some point, some of the ash is likely to descend through the atmosphere to low levels

Edited by Merritt on Friday 16th April 13:50

[Engineer1]

Simpo Two said:

scarebus said:

Ash has no effect on the fuel, it ends up becoming molten as it heats up, slowly choking the engine by blocking the gasflow through the compressor/turbine blades.

I thought it was rather excessive to ban helicopter Air Ambulances - they fly low thereby avoiding the ash, no?

Plus, does ash affect propeller-driven planes?

Edited by Simpo Two on Friday 16th April 09:47

At an uninformed guess yes ash would affect a piston engine as it could clog air filters or radiators meaning either no air or overheating engines.

[Beyond Rational]

scarebus said:

Ash has no effect on the fuel, it ends up becoming molten as it heats up, slowly choking the engine by blocking the gasflow through the compressor/turbine blades.

BA flight 009 - 1982

"Engines one, two and three were replaced at Jakarta, as well as the windscreen, and the fuel tanks were cleared of the ash that had entered them through the pressurisation ducts, contaminating the fuel and requiring that it be disposed of."

[scarebus]

Beyond Rational said:

scarebus said:

Ash has no effect on the fuel, it ends up becoming molten as it heats up, slowly choking the engine by blocking the gasflow through the compressor/turbine blades.

BA flight 009 - 1982

"Engines one, two and three were replaced at Jakarta, as well as the windscreen, and the fuel tanks were cleared of the ash that had entered them through the pressurisation ducts, contaminating the fuel and requiring that it be disposed of."

But the fuel contamination did not cause the engines to flame out! I agree ash in the fuel is not good for the pumps, fuel nozzles etc, but I hardly think a short encounter in an ash cloud will render the fuel useless.

[foilist]

Simpo Two said:

scarebus said:

Ash has no effect on the fuel, it ends up becoming molten as it heats up, slowly choking the engine by blocking the gasflow through the compressor/turbine blades.

I thought it was rather excessive to ban helicopter Air Ambulances - they fly low thereby avoiding the ash, no?

Plus, does ash affect propeller-driven planes?

Edited by Simpo Two on Friday 16th April 09:47

Almost all helicopters have jet engines though- gas turbines that turn the roter via a gearbox

[Geneve]

foilist said:

Almost all helicopters have jet engines though- gas turbines that turn the roter via a gearbox

They do have particulate filters and air scavenge systems and fly vfr at low level. Risks are minimal but most operators are being cautious because of the potential costs of any long-term internal damage.

I flew a piston helicopter today with no issues. Did check the leading edges of the rotor blades carefully (they turn at nearly 500mph).

[S3_Graham]

Geneve said:

foilist said:

Almost all helicopters have jet engines though- gas turbines that turn the roter via a gearbox

They do have particulate filters and air scavenge systems and fly vfr at low level. Risks are minimal but most operators are being cautious because of the potential costs of any long-term internal damage.

I flew a piston helicopter today with no issues. Did check the leading edges of the rotor blades carefully (they turn at nearly 500mph).

We deal with the company that runs the air ambulance heli's in scotland. They continued running until a filter was pulled and found to be full of ash. Unsuprisingly the fleet was grounded upon this find!

[Simpo Two]

S3_Graham said:

We deal with the company that runs the air ambulance heli's in scotland. They continued running until a filter was pulled and found to be full of ash. Unsuprisingly the fleet was grounded upon this find!

Perversely, that means the filter was doing its job. But let's leave everybody to die in the fields and on the mountains while we have a cup of tea. I hope the 13A plug has been tested.

[cs02rm0]

Surely the air flow through the filter is compromised though if it fills with ash?

[Simpo Two]

cs02rm0 said:

Surely the air flow through the filter is compromised though if it fills with ash?

Yes but what are filters for if they don't filter out stuff? The trick is to change them as required.

[cs02rm0]

Which is fine, so long as they don't clog up during a single flight?

[S3_Graham]

Simpo Two said:

S3_Graham said:

We deal with the company that runs the air ambulance heli's in scotland. They continued running until a filter was pulled and found to be full of ash. Unsuprisingly the fleet was grounded upon this find!

Perversely, that means the filter was doing its job. But let's leave everybody to die in the fields and on the mountains while we have a cup of tea. I hope the 13A plug has been tested.

If you knew the situation... then you'd know that they are still flying HEMS flights....