AirAsia Flight QZ8501 Missing

[fly_tornado]

ice theory

 

http://www.smh.com.au/world/ice-may-have-caused-airasia-engine-damage-says-indonesias-weather-agency-20150104-12hry9.html

 

 

[facthunter]

That's not a bad article. GG. The title is not completely indicative of the content which was really about appropriate training and situation appreciation and management.

 

Unless you are trained to respond to what probably happened you are unlikely to survive.

 

Even if you are trained, the situation is so dire there is no guarantee you will survive, but at least you have a fighting chance. My view is since the weather is so dangerous AVOID IT. Inflight weather radar is capable of showing what is ahead . Better results if used properly. A good operator will derive more information than others.

 

There is little margin of performance at normal cruise levels . If you lose an engine or perhaps even turn on the anti ice systems you would need to descend to maintain your stall margin which may only be 10 knots. In turbulence that is not enough anyhow.

 

Regardless of the automation, the human must MANAGE the flight. Things like selecting flight level and storm avoidance are basic to the safety of the aircraft.

 

ATC are there to essentially provide separation. If you are falling out of the sky you don't rely on a clearance. You tell them when you have time. Aviate first. Nev

 

 

[planedriver]

The fact that someone goes by the title of a scientist, don't read too much into that and fool yourself.

 

About 4 decades ago I did some work with a scientist? who wrote a paper on the flammability of materials for use in amongst other things, aircraft.

 

He was well paid for his? so called research, and I have never read a bigger load of guestimate drivel in my life, so don't get too impressed by a title alone.

 

If some pilots were to read about the demise of the early DH Comets, they might learn that Cb conditions are not to be taken lightly.

 

As the saying goes, there's no substitute for real experience

 

 

[fly_tornado]

american scientists from mid western christian universities are the best

 

 

[Downunder]

A christian scientist?.........an oxymoron if ever I saw one........

 

 

[AVOCET]

A christian scientist?.........an oxymoron if ever I saw one........

Ignorant twallop

 

 

[kgwilson]

Just to change the subject back, Have they located the CVR & FDR yet?

 

 

[bexrbetter]

Just to change the subject back, Have they located the CVR & FDR yet?

No, bad weather, rough seas.

 

Sonar has identified five large objects that are believed to be chunks of the fuselage on the ocean floor, but strong currents, silt and mud have kept divers from seeing or reaching the objects. No signals have been heard from the cockpit voice and flight data recorders, or black boxes.

 

 

[Yenn]

Are modern jets too automated to fly?

 

I don't think they are, but what worries me is that Asian pilots seem to have a reputation of doing every thing by the book and never challenging authority. Those pilots requested higher altitude due to weather and were denied. If they really needed higher they should have declared an emergency. Obviously they were going along with what the ATC told them to do. Maybe they were blindly putting themselves into danger rather than rock the boat.

 

Hopefully we will find the flight recorders and learn what happened.

 

 

[facthunter]

I think they requested a diversion first and were denied it. Climbing the aircraft will not top the type of cloud /weather at the time and may place the plane at a level where it will easily lose control. Nev

 

 

[Old Koreelah]

Which service do you use for the breadcrumbs?

Sorry about the delay, Rank. I currently use Glympse.

 

 

[rankamateur]

Sorry about the delay, Rank. I currently use Glympse.

Thanks I will have a look at it.

 

 

[Rotorwork]

Update from ABC

 

http://www.abc.net.au/news/2015-01-09/airasia-crash-qz8501-pings-detected-investigator-says/6008994

 

AirAsia QZ8501: Pings detected in search for crashed plane's black box, investigator says

 

Updated 12 minutes agoFri 9 Jan 2015, 2:36pm

 

Search and rescue teams hunting for the wreck of an AirAsia passenger jet have detected pings in their efforts to find the black box recorders, Santoso Sayogo, an investigator at the National Transportation Safety Committee has told Reuters news agency.

 

Indonesia AirAsia flight QZ8501 vanished from radar screens on December 28, less than half way into a two-hour flight from Indonesia's second-biggest city of Surabaya to Singapore.

 

There were no survivors among the 162 people on board.

 

Indonesian search teams loaded lifting balloons on to helicopters on Friday ahead of an operation to raise the tail section of the jet, although Sayogo said it appeared that the black box was no longer in the tail and divers were confirming its position.

 

 

[jeffd]

As i dont much about the aircraft involved or actually to much about flying as i am just a student could 1 of the more experienced people here give me an idea how high the aircraft can fly and how high was the storm ceiling etc.i would imagine if you cant go over you go around and i think it was nev who said that atc is there to provide separation. I certainly would think though that the pic of the aircraft is supposed to be the pic of the aircraft and not atc,although as i said i am just a newby and will never have to make that decision ,although i suppose deciding for the safety of 1 or the safety of hundreds is the same principle

 

 

[Old Koreelah]

You are right, Jeff. The PIC is the bloke in charge. Others on this forum are far better qualified to answer you questions about ATC.

 

Metal tubes full of people can approach 40,000 feet, but these equatorial storm clouds can rise thousands of feet higher. That part of the world has large areas of warm ocean which absorbs so much solar radiation that evaporation has been measured to lower the sea surface. That water vapour carries an incredible amount of latent energy up to condensation level, where it gets released again, fuelling the violent up drafts which sensible aviators stay clear of.

 

 

[facthunter]

How high the jet aircraft cruises at it dependent on weight and engine power. Ie IF you lose an engine you have to immediately descend (usually about 8,000 feet minimum) Normal cruise levels would be from FL32o to 370. When there is rough weather you would allow a bigger safety margin Storm cells around the thermal equator which corresponds to the Inter Tropic Convergence Zone terminology often go to to FL 600 and have strong vertical currents turbulence and often HAIL Since Icing was mentioned the aircraft has deicing systems but they get their heat at the expense of engine power and loss of range. If you have full anti ice on your Rate of Climb and cruise level are less. Nev

 

 

[jeffd]

You are right, Jeff. The PIC is the bloke in charge. Others on this forum are far better qualified to answer you questions about ATC.Metal tubes full of people can approach 40,000 feet, but these equatorial storm clouds can rise thousands of feet higher. That part of the world has large areas of warm ocean which absorbs so much solar radiation that evaporation has been measured to lower the sea surface. That water vapour carries an incredible amount of latent energy up to condensation level, where it gets released again, fuelling the violent up drafts which sensible aviators stay clear of.

thanks for that old koreelah ,this best asked in the other a/c forum.but what do u think of the jodel a/c as u have 1 on your avatar or once did

 

 

[Old Koreelah]

thanks for that old koreelah ,this best asked in the other a/c forum.but what do u think of the jodel a/c as u have 1 on your avatar or once did

You noticed? A big mistake to ask about my Jodel. It's a long story...

I love my little Jodel. It was designed around a little French bloke in the 1940s and is built from plans almost entirely of wood. Despite it's age and tiny size, few aircraft can match it's performance.

 

 

[Stoney]

You noticed? A big mistake to ask about my Jodel. It's a long story...I love my little Jodel. It was designed around a little French bloke in the 1940s and is built from plans almost entirely of wood. Despite it's age and tiny size, few aircraft can match it's performance.

Old Koreelah, please start another thread and tell us about your plane, the person who designed it, and the building and flying of it.

 

It was in the back of my mind to ask one day, and I thank jeffd for bringing it up.

 

It may be a long story, but we have the time to listen to one from a passionate aviator.

 

After seeing the job you did on the trailer, I now want to know about the plane and the person behind it.

 

 

[kgwilson]

This article is an interesting read on what possibly happened. http://quadrant.org.au/opinion/travel-qed/2015/01/clouded-judgment-consequences/

 

 

[Old Koreelah]

Old Koreelah, please start another thread and tell us about your plane, the person who designed it, and the building and flying of it.It was in the back of my mind to ask one day, and I thank jeffd for bringing it up.

It may be a long story, but we have the time to listen to one from a passionate aviator.

 

After seeing the job you did on the trailer, I now want to know about the plane and the person behind it.

All right you blokes; thanks for the interest. I'll put together a short piece, sanitising my contribution...

 

 

[dutchroll]

The thrust-pitch coupling of underslung (i.e. wing pod mounted) engines on commercial jets has been known about for a long, long, long time.

 

On the B767 the standard nose high + low airspeed jet upset recovery was to reduce thrust (which seems counter-intuitive at first) for that very reason. Piling on the thrust could, and generally does, prevent timely reduction of the high nose attitude at low airspeed where elevator and stabiliser effectiveness is reduced. Interestingly Airbus doesn't publish an upset recovery procedure in their FCOM, presumably due to the fact that the aircraft has attitude and speed protections built into the fly-by-wire system. However these protections (well most of them) only function in Normal Law, not the backup flight control laws which you can find yourself operating in with certain other malfunctions. One of these situations is invalid air data due to icing, whereupon the aircraft can revert to Alternate Law in the flight control system and lose the attitude and speed protections.

 

But this is, or should be, common knowledge across any Airbus fleet. Not only that, there are a number of aural and particularly visual cues on the EFIS which make it obvious that this has happened. And the stall warning system still functions normally no matter what control law you're in (assuming AoA data is valid of course).

 

We fly the A330 on routes through that airspace all the time. ITCZ weather is very fickle although that storm system at the time was particularly large. Several factors lead to decisions 99% of the time to go around, not over it:

 

1) The air routes there are pretty busy. Altitude blockages are quite common across Indonesia.

 

2) Big CBs can often have tops at or above typical cruise altitudes for commercial jets (typically FL350-FL410).

 

3) Although you can get a rough idea where the tops might be on radar by manually using the radar tilt, it's not precise. The more modern radars are supposed to vary the tilt automatically and only display threatening weather while not displaying stuff you'll comfortably pass over the top off. That's the theory. They don't always do this perfectly though.

 

If ATC is busy or comms are bad and there's an excessive delay in getting the clearance, we start deviating anyway while we're waiting for the clearance. The risk of going into or very close to a CB cell exceeds the risk of deviating without a clearance, bearing in mind that you're cruising already separated from other traffic at semi-circular altitudes, and you have TCAS. To try to avoid this happening we ask ATC for weather deviations quite early, usually 80nm or more (about 10 minutes or more) before the weather. However if you're in the dark of night and it pops up on the radar at the last minute, well you just do what you can, even if that means turning and deviating while you're trying to get onto ATC.

 

Airbus Cruise altitudes:

 

The Airbus FMGEC (it's abbreviation for the flight management system) computes two altitudes and displays them on a particular page. The "optimum" altitude is best fuel economy taking into account aircraft performance and the loaded high altitude winds. This is where the aircraft will normally be planned to cruise, all other things being equal. Next to it the "recommended max" altitude is displayed, and is purely aircraft performance based. It gives the highest altitude you can climb to and still have a 0.3G buffet margin while maintaining level flight at max cruise thrust (which is less than max climb or max continuous thrust). We don't go there unless it's really smooth, and only then if we really feel we have to. When you're deviating around weather and associated turbulence you absolutely don't want to climb an Airbus to "recommended max". It's really not a nice (or safe) place to be, sandwiched between the high speed (mach) and low speed (stall) buffet margins on your airspeed display! You may have heard this referred to as "coffin corner".

 

This is not to say that we would't climb if we could. Climbing before you get to the weather is often desirable to make it easier to go around, or increase the chance you'll get over the top, but only if you can get a clearance to do so, and only if you have a good enough margin to your "recommended max" altitude.

 

I'm a little bit reluctant to trust the Indonesian radar data and I think it's unwise to be already forming conclusions from it. Having said that, and as much as I dislike Quadrant, I tend to agree with the author's conclusion of the likely outcome of the investigation linked above. Airbus + bad weather + bad crew training and response = disaster.

 

 

[jeffd]

You noticed? A big mistake to ask about my Jodel. It's a long story...I love my little Jodel. It was designed around a little French bloke in the 1940s and is built from plans almost entirely of wood. Despite it's age and tiny size, few aircraft can match it's performance.

yes i hav actually looked up a bit about it and its history the trend is obviously for people to buy better and better if they can afford to or wish to however some of the older aircraft if maintained and serviced properly should still hav years of fun in them, what is the idea of the wings bent upwards does it improve lift during a bank or ?

 

 

[jeffd]

The thrust-pitch coupling of underslung (i.e. wing pod mounted) engines on commercial jets has been known about for a long, long, long time.On the B767 the standard nose high + low airspeed jet upset recovery was to reduce thrust (which seems counter-intuitive at first) for that very reason. Piling on the thrust could, and generally does, prevent timely reduction of the high nose attitude at low airspeed where elevator and stabiliser effectiveness is reduced. Interestingly Airbus doesn't publish an upset recovery procedure in their FCOM, presumably due to the fact that the aircraft has attitude and speed protections built into the fly-by-wire system. However these protections (well most of them) only function in Normal Law, not the backup flight control laws which you can find yourself operating in with certain other malfunctions. One of these situations is invalid air data due to icing, whereupon the aircraft can revert to Alternate Law in the flight control system and lose the attitude and speed protections.

 

But this is, or should be, common knowledge across any Airbus fleet. Not only that, there are a number of aural and particularly visual cues on the EFIS which make it obvious that this has happened. And the stall warning system still functions normally no matter what control law you're in (assuming AoA data is valid of course).

 

We fly the A330 on routes through that airspace all the time. ITCZ weather is very fickle although that storm system at the time was particularly large. Several factors lead to decisions 99% of the time to go around, not over it:

 

1) The air routes there are pretty busy. Altitude blockages are quite common across Indonesia.

 

2) Big CBs can often have tops at or above typical cruise altitudes for commercial jets (typically FL350-FL410).

 

3) Although you can get a rough idea where the tops might be on radar by manually using the radar tilt, it's not precise. The more modern radars are supposed to vary the tilt automatically and only display threatening weather while not displaying stuff you'll comfortably pass over the top off. That's the theory. They don't always do this perfectly though.

 

If ATC is busy or comms are bad and there's an excessive delay in getting the clearance, we start deviating anyway while we're waiting for the clearance. The risk of going into or very close to a CB cell exceeds the risk of deviating without a clearance, bearing in mind that you're cruising already separated from other traffic at semi-circular altitudes, and you have TCAS. To try to avoid this happening we ask ATC for weather deviations quite early, usually 80nm or more (about 10 minutes or more) before the weather. However if you're in the dark of night and it pops up on the radar at the last minute, well you just do what you can, even if that means turning and deviating while you're trying to get onto ATC.

 

Airbus Cruise altitudes:

 

The Airbus FMGEC (it's abbreviation for the flight management system) computes two altitudes and displays them on a particular page. The "optimum" altitude is best fuel economy taking into account aircraft performance and the loaded high altitude winds. This is where the aircraft will normally be planned to cruise, all other things being equal. Next to it the "recommended max" altitude is displayed, and is purely aircraft performance based. It gives the highest altitude you can climb to and still have a 0.3G buffet margin while maintaining level flight at max cruise thrust (which is less than max climb or max continuous thrust). We don't go there unless it's really smooth, and only then if we really feel we have to. When you're deviating around weather and associated turbulence you absolutely don't want to climb an Airbus to "recommended max". It's really not a nice (or safe) place to be, sandwiched between the high speed (mach) and low speed (stall) buffet margins on your airspeed display! You may have heard this referred to as "coffin corner".

 

This is not to say that we would't climb if we could. Climbing before you get to the weather is often desirable to make it easier to go around, or increase the chance you'll get over the top, but only if you can get a clearance to do so, and only if you have a good enough margin to your "recommended max" altitude.

 

I'm a little bit reluctant to trust the Indonesian radar data and I think it's unwise to be already forming conclusions from it. Having said that, and as much as I dislike Quadrant, I tend to agree with the author's conclusion of the likely outcome of the investigation linked above. Airbus + bad weather + bad crew training and response = disaster.

thanks dutchroll that was a very interesting read am glad that you took the time to type it in for those that are interested .I know i certainly am.jeffd

 

 

[Old Koreelah]

...what is the idea of the wings bent upwards does it improve lift during a bank or ?

I'll start a new thread when I get home this week.