Airblue down near Islamabad
Here i would like to put some thing very straight for the record that pervaiz iqbal the captain had been in islamabad since we all started flying .
the way things work is usually hush hush.
I had asked this question on one of the forum that ,would the EGPWS work in case of radar jamming
or
since the bus is fly by wire all the systems work computer in case of a total jamming would the control function.
Secondly we all know as professional pilots that he should nor be there where he was so what made him go there was it am armed intrusion or it a sabotage or simply the radar guidance
those of u who have flown in Pakistan would bare with me it is always a very difficult approach in isb reason the area is so restricted because of prohibited areas
very little one can do
i do agree at the same time the procedure or the airman ship is in doubt
get out from there as for his training for mr mekel he was trained by the pia flying academy
no offence for any, the circling man . is easy to execute in the bus then any ac i have flown
by the way mr mekel i have also flown for the last 43 years BY THE GRACE OF GOD an all the airplane pia as well
the bus most modern
the point to emphasis is not the ac but the simplicity of the procedures and the evolution of the aviation toward the user friendly concept
the way things work is usually hush hush.
I had asked this question on one of the forum that ,would the EGPWS work in case of radar jamming
or
since the bus is fly by wire all the systems work computer in case of a total jamming would the control function.
Secondly we all know as professional pilots that he should nor be there where he was so what made him go there was it am armed intrusion or it a sabotage or simply the radar guidance
those of u who have flown in Pakistan would bare with me it is always a very difficult approach in isb reason the area is so restricted because of prohibited areas
very little one can do
i do agree at the same time the procedure or the airman ship is in doubt
get out from there as for his training for mr mekel he was trained by the pia flying academy
no offence for any, the circling man . is easy to execute in the bus then any ac i have flown
by the way mr mekel i have also flown for the last 43 years BY THE GRACE OF GOD an all the airplane pia as well
the bus most modern
the point to emphasis is not the ac but the simplicity of the procedures and the evolution of the aviation toward the user friendly concept
As to radar jamming having an effect on fly by wire suites in modern aircraft, consider this: fly by wire capability is organic to most modern fighters, fighters that are expected to operate in a jamming environment. Do you have any reason to believe that fly by wire in the Airbus is susceptible to jamming? (Do any of the Airbus pilots on this board know of cautions in that area??) Airbus A400M has fly by wire in its design, for military environment. I think you are making some unfounded guesses ... unless you have evidence of jamming or EMI signal source ... is that what you mean by hush hush?
EMP is another matter, but why would it be related to this case? What about the crash would lead one to consider that?
EMI is another matter (did a bunch of passengers all turn on their remote electronic devices?) and I'll let that guess sit for a moment. What evidence is there to support that causal factor?
If EGPWS was to be jammed (what, jam the radar altimeter?
) how would one know? How would one do it, given how radar altimeters work? I think you are fishing, and I think this idea is a red herring. Sabotage or armed intrusion ... the CVR data might help analyze that odds of that. Guessing again?
Lastly, on radar jamming, if one is executing a circle to land, a visual procedure, how would radar jamming influence you since you are not using radar cues to fly?
How thoroughly have you thought through this?
Last edited by Lonewolf_50; 3rd Aug 2010 at 15:27.
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It is inevitable that national issues and sensitivities among friends and colleagues will surface here, but we must re-focus on the basic question. Why did this crew fly straight towards the hills for what must have been nearly 3 minutes through what must have been pretty 'difficult' visual weather - scud and showers, and remain at the same height at which they probably broke off their initial approach, when they should have stepped out about 2 miles, flown downwind and landed - or gone around.
We really should leave all more complicated questions aside. We need the CVR.
We really should leave all more complicated questions aside. We need the CVR.
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Lonewolf 50
Very well said.
BOAC yes, I think we are allowing personal issues to intrude into the discussion. As his friend I too would be aggrieved at fingers pointing at the flight crew -- and specifically the aircraft commander and would come up with anything to try an exonerate him -- jamming, sabotage and so on.
I was wondering, if the ATC tapes that were published are to be believed, was the captain on the radio AND flying the plane as well? Obviously it could not be the co-pilot sitting to his right telling ATC he had the runway in sight as well as the Margalla hills?
Very well said.
BOAC yes, I think we are allowing personal issues to intrude into the discussion. As his friend I too would be aggrieved at fingers pointing at the flight crew -- and specifically the aircraft commander and would come up with anything to try an exonerate him -- jamming, sabotage and so on.
I was wondering, if the ATC tapes that were published are to be believed, was the captain on the radio AND flying the plane as well? Obviously it could not be the co-pilot sitting to his right telling ATC he had the runway in sight as well as the Margalla hills?
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Too right BOAC. I wondered the same myself, almost three minutes at their likely groundspeed, one can only imagine that there was some huge distraction in that cockpit. The hackles on my neck would have been raised long before one minute, let alone more.
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Neptunus Rex:
They would have been in compliance with the procedure flying at an IAS of as high as 205 knots. Do you have any idea what Airbus would recommend as an IAS for downwind on a circle-to-land?
Too right BOAC. I wondered the same myself, almost three minutes at their likely groundspeed, one can only imagine that there was some huge distraction in that cockpit. The hackles on my neck would have been raised long before one minute, let alone more.
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I just received this week's Aviation Week. They have a short article on the accident. They state there was heavy rain at the time, TRW, surface wind 050-16 knots, visibility 2,000 meters.
That visibility is well below the 3,600 meter minimum.
That visibility is well below the 3,600 meter minimum.
Nothing.
FYI though the GPWS manoeuvre is:
1. AP off.
2. Pitch: full up. Full backstick and keep it there.
3. Thrust levers: TOGA.
4. Speed brakes: check retracted.
5. Bank angle: Level (or adjust).
In reality just pulling back the side stick will do the trick. This will disconnect the AP and rapidly raise the AOA, which will give you TOGA thrust, which will automatically stow the speed brakes. Slamming the levers forwards though will give you the thrust marginally sooner and is part of the general Airbus escape manoeuvre of stick slammed back and levers slammed forward. The array of computers and sensors will give you every last ounce of performance available.
FYI though the GPWS manoeuvre is:
1. AP off.
2. Pitch: full up. Full backstick and keep it there.
3. Thrust levers: TOGA.
4. Speed brakes: check retracted.
5. Bank angle: Level (or adjust).
In reality just pulling back the side stick will do the trick. This will disconnect the AP and rapidly raise the AOA, which will give you TOGA thrust, which will automatically stow the speed brakes. Slamming the levers forwards though will give you the thrust marginally sooner and is part of the general Airbus escape manoeuvre of stick slammed back and levers slammed forward. The array of computers and sensors will give you every last ounce of performance available.
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HundredPercentPlease:
That is great technology. What about when the speed is at minimum for a given flap configuration, say whatever is required to fly the CTL downwind at 150 KIAS. Presumably, the aircraft was at 2510, msl, and had to clear terrain that topped out at 4,000-4,300, msl, or thereabouts. The terrain would have been unknown to the crew until the EGPWS/TAWS started its first stage of alert.
In reality just pulling back the side stick will do the trick. This will disconnect the AP and rapidly raise the AOA, which will give you TOGA thrust, which will automatically stow the speed brakes. Slamming the levers forwards though will give you the thrust marginally sooner and is part of the general Airbus escape manoeuvre of stick slammed back and levers slammed forward. The array of computers and sensors will give you every last ounce of performance available.
aterpster;
(I don't think the terrain in that area was much above 3000', but that is immaterial.) HundredPercentPlease's statement provides an important key to your question: "The array of computers and sensors will give you every last ounce of performance available." This applies regardless of aircraft configuration. The available performance energy at slow speed, Config 3 may or may not be sufficient as an escape maneuver. A TAWS Caution of Terrain is approximately one minute's distance and a TAWS Warning is approximately 30 second's distance. Sixty seconds distance is plenty of time to climb 2000' in a GPWS escape maneuver; even 30" distance would be sufficient if the maneuver were done briskly. This is assuming no map-shift of course. I have read the arguments for GPS-linked EGPWS systems and have made the argument myself at my own airline to no avail...the SOP in the FCOM is to switch off the TAWS if NAV ACCURACY is LOW.
I think the aircraft was travelling faster than near the min-speeds for Config 3 as has been posited. I think the aircraft was at Config 2. Regardless however, we know that the TAS would have been slightly higher than the CAS, and, taking the wind information (albeit on the ground) from your post just above, there may have been a tailwind component, strong if they went straight ahead over the airport, stronger if they turned left, (NW), more of a crosswind than a tailwind if they turned right. I think the speed was closer to 180kts.
My reasoning is, by the FCOM, Config 3 is the normal Landing flap, although Config FULL is always available. Both Config 3 and 2 are Takeoff and Approach (maneuvering) flap settings, and Config 3 is also a Landing flap setting. Config FULL is only a Landing Flap. Although maneuvering at Config 3 is a normal procedure and is a plausible scenario here, "Landing flap", whatever the setting is, (3 or FULL), is not normally selected until established on final.
I'm thinking here of the distance travelled past the airport in poor vis; - In short, a possible loss of SA. Whether any of this is the case here or not, cannot be said until the recorders are read.
PJ2
What about when the speed is at minimum for a given flap configuration, say whatever is required to fly the CTL downwind at 150 KIAS. Presumably, the aircraft was at 2510, msl, and had to clear terrain that topped out at 4,000-4,300, msl, or thereabouts.
I think the aircraft was travelling faster than near the min-speeds for Config 3 as has been posited. I think the aircraft was at Config 2. Regardless however, we know that the TAS would have been slightly higher than the CAS, and, taking the wind information (albeit on the ground) from your post just above, there may have been a tailwind component, strong if they went straight ahead over the airport, stronger if they turned left, (NW), more of a crosswind than a tailwind if they turned right. I think the speed was closer to 180kts.
My reasoning is, by the FCOM, Config 3 is the normal Landing flap, although Config FULL is always available. Both Config 3 and 2 are Takeoff and Approach (maneuvering) flap settings, and Config 3 is also a Landing flap setting. Config FULL is only a Landing Flap. Although maneuvering at Config 3 is a normal procedure and is a plausible scenario here, "Landing flap", whatever the setting is, (3 or FULL), is not normally selected until established on final.
I'm thinking here of the distance travelled past the airport in poor vis; - In short, a possible loss of SA. Whether any of this is the case here or not, cannot be said until the recorders are read.
PJ2
Last edited by PJ2; 4th Aug 2010 at 16:06.
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A321 full loaded has a VApp higher than 145Kts...
Isn't A321 a class D aircraft?
I would imagine a speed of around 170Kts during go-around.
Loss of SA, definitely a factor. But what caused it?
I would imagine a speed of around 170Kts during go-around.
Loss of SA, definitely a factor. But what caused it?
Hello aquadalte;
Yes, likely that speed, but only after the Thrust Reduction/Acceleration Altitude which is usually 1500' AGL.
On the go-around, the flaps are raised one step - From FULL to Config 3, for from Config 3 to Config 2. The FMGEC SRS (Speed Reference System) maintains the go-around speed for the configuration until the Thrust Reduction/Acceleration Altitudes, usually 1500' AGL although there is provision for 3000' AGL for Acceleration. The initial SRS go-around speed is maintained until that point - that speed would be around Vapp to Vapp +10kts, (that is not a computed speed - I'm just estimating here to illustrate that flaps are not retracted, climb thrust is not set and the airplane does not accelerate until after the Thrust Reduction/Acceleration Altitude of 1500' AGL).
Aircraft behaviour at the Thrust Reduction/Acceleration Altitude is, - the thrust is manually set to CLB, and, if on autopilot, the nose lowers slightly, the aircraft continues to accelerate and the flaps are raised to the next step, usually Config 1 and then when the speed is above the minimum for Config 1, flaps are set to the Clean configuration. The aircraft then continues to accelerate to 'Green dot', (Max L/D speed - that would be around 205 kts or so but it varies with weight, etc) or 250kts depending upon what is set in the FMC.
I would imagine a speed of around 170Kts during go-around.
On the go-around, the flaps are raised one step - From FULL to Config 3, for from Config 3 to Config 2. The FMGEC SRS (Speed Reference System) maintains the go-around speed for the configuration until the Thrust Reduction/Acceleration Altitudes, usually 1500' AGL although there is provision for 3000' AGL for Acceleration. The initial SRS go-around speed is maintained until that point - that speed would be around Vapp to Vapp +10kts, (that is not a computed speed - I'm just estimating here to illustrate that flaps are not retracted, climb thrust is not set and the airplane does not accelerate until after the Thrust Reduction/Acceleration Altitude of 1500' AGL).
Aircraft behaviour at the Thrust Reduction/Acceleration Altitude is, - the thrust is manually set to CLB, and, if on autopilot, the nose lowers slightly, the aircraft continues to accelerate and the flaps are raised to the next step, usually Config 1 and then when the speed is above the minimum for Config 1, flaps are set to the Clean configuration. The aircraft then continues to accelerate to 'Green dot', (Max L/D speed - that would be around 205 kts or so but it varies with weight, etc) or 250kts depending upon what is set in the FMC.
PJ2/Hundred Percent Please:
I put your two posts together. It made me think. So, of course, my brain hurts.
Is the escape maneuver based on best angle of climb or best rate of climb? Which "best" is "every ounce of performance" trying to achieve for you?
Also, Hundred Percent points out that the pitch change will disable auto pilot ... by that do you mean that you go into Alternate Law? If so will Alternate Law provide AoA protection (in terms of control of pitch rate) to avoid stall from too abrupt an AoA change in this transition to an emergency climb configuration?
I hope this question isn't too elementary ...
The idea that this crew had a TAWS originated thirty seconds of warning for terrain does not seem to fit the flow of events, as we try to decipher them in the absence of FDR/CVR information.
I put your two posts together. It made me think. So, of course, my brain hurts.
A TAWS Caution of Terrain is approximately one minute's distance and a TAWS Warning is approximately 30 second's distance. Sixty seconds distance is plenty of time to climb 2000' in a GPWS escape maneuver; even 30" {thirty seconds} distance would be sufficient if the maneuver were done briskly.
Also, Hundred Percent points out that the pitch change will disable auto pilot ... by that do you mean that you go into Alternate Law? If so will Alternate Law provide AoA protection (in terms of control of pitch rate) to avoid stall from too abrupt an AoA change in this transition to an emergency climb configuration?
I hope this question isn't too elementary ...
The idea that this crew had a TAWS originated thirty seconds of warning for terrain does not seem to fit the flow of events, as we try to decipher them in the absence of FDR/CVR information.