A320 tailstrike after radalt failures
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i think the aircraft was designed with the pitch and roll stability of a fighter jet, and thats why its so sensitive to control manually in direct law, remembering that roll will still be on roll rate demand in direct law until sometime after touch down.
i think, therefore..
i think, therefore..
Ut Sementem Feeceris
swh,
The reference you make to FLARE MODE at gear extention is when transitioning from ALTN LAW. In a double RA Failure you are going from NORMAL straight to DIRECT ("Flare mode without the nose down bias" = PITCH DIRECT with no Autotrim = DIRECT LAW?)
I think we're splitting hairs here between Laws and Modes.
On a normal approach we go from:
NORMAL Law Flight Mode to NORMAL Law Flare Mode (at 50'RA) to NORMAL Law Ground Mode after landing. Autotrim available throughout.
For a typical Degraded Abnormal Approach (ALTN Law) the sequence is:
ALTN Law Flight Mode (Usually Pitch ALT, Roll DIRECT, Yaw ALTN) - At Gear Down ALTN Law FLARE Mode (Pitch+Roll DIRECT, Yaw ALTN, No autotrim). After landing ALTN GND Mode.
For Double RA
Normal Law Flight Mode -at Gear Down DIRECT Law (Pitch + Roll DIRECT, Yaw ALTN with No Autotrim = Same as FLARE Mode from ALTN Law). After Landing ALTN Law GND Mode.
Or are you saying that TRUE DIRECT LAW is only if you have PITCH & ROLL in DIRECT and YAW MECHANICAL?
Your quote also states that no approach modes are available. FCOM states LOC can be engaged but APPR cannot be armed -true.
You are evidentally well informed and experienced but do you not think that comes across as a bit arrogant?
Good discussion.
A4
The reference you make to FLARE MODE at gear extention is when transitioning from ALTN LAW. In a double RA Failure you are going from NORMAL straight to DIRECT ("Flare mode without the nose down bias" = PITCH DIRECT with no Autotrim = DIRECT LAW?)
I think we're splitting hairs here between Laws and Modes.
On a normal approach we go from:
NORMAL Law Flight Mode to NORMAL Law Flare Mode (at 50'RA) to NORMAL Law Ground Mode after landing. Autotrim available throughout.
For a typical Degraded Abnormal Approach (ALTN Law) the sequence is:
ALTN Law Flight Mode (Usually Pitch ALT, Roll DIRECT, Yaw ALTN) - At Gear Down ALTN Law FLARE Mode (Pitch+Roll DIRECT, Yaw ALTN, No autotrim). After landing ALTN GND Mode.
For Double RA
Normal Law Flight Mode -at Gear Down DIRECT Law (Pitch + Roll DIRECT, Yaw ALTN with No Autotrim = Same as FLARE Mode from ALTN Law). After Landing ALTN Law GND Mode.
Or are you saying that TRUE DIRECT LAW is only if you have PITCH & ROLL in DIRECT and YAW MECHANICAL?
Your quote also states that no approach modes are available. FCOM states LOC can be engaged but APPR cannot be armed -true.
You are mixing up pitch attitude with angle of attack, a common mistake made by amatures.
Good discussion.
A4
FatFlyer,
See A4s explanation of the flare mode when gear goes down in altn law. There is a diagram explaining this in FCOM 1.27.30 (A320) To all intents & purposes Flare mode is direct law.(Pitch & Roll direct)
Having had a quick look at the A330 FCOM on smartcockpit (never had the chance to fly one.....yet!) there seems to be a slight downgraded version of the normal flare mode when putting gear down in alternate mode.
As far as I can see there is a difference between the A320 & A330 series.
SWH if you look further at your instructors manual it says for Normal Law:
However it then says for Alternate Law:
See A4s explanation of the flare mode when gear goes down in altn law. There is a diagram explaining this in FCOM 1.27.30 (A320) To all intents & purposes Flare mode is direct law.(Pitch & Roll direct)
Having had a quick look at the A330 FCOM on smartcockpit (never had the chance to fly one.....yet!) there seems to be a slight downgraded version of the normal flare mode when putting gear down in alternate mode.
As far as I can see there is a difference between the A320 & A330 series.
SWH if you look further at your instructors manual it says for Normal Law:
Hence the computers adapt AUTOMATICALLY the control laws to the flight phases, transparently to the pilot:
GROUND LAW ➔ the control law is DIRECT law and
FLARE LAW, ➔ the control law is PITCH law.
GROUND LAW ➔ the control law is DIRECT law and
FLARE LAW, ➔ the control law is PITCH law.
The ALTERNATE LAW characteristics (triggered usually in case of 2 failures) are:
- Pitch Law = same as normal law with FLARE in DIRECT
- Pitch Law = same as normal law with FLARE in DIRECT
Last edited by Right Way Up; 12th Oct 2010 at 13:05.
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I guess the last few posts explain why I like Boeing so much. You pull back it goes up, you push forward it goes down, you want to go faster you push those levers on the center up. It is unbelievably simple. I don't have to know any laws. If you get a tail strike you are incredibly stupid.
Of course a Boeing could not have a controllability problem 
........
http://www.ntsb.gov/Recs/letters/1994/A94_64_66.pdf
All aircraft have their issues. Not a perfect aircraft built yet.
........http://www.ntsb.gov/Recs/letters/1994/A94_64_66.pdf
All aircraft have their issues. Not a perfect aircraft built yet.
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Originally Posted by P51guy
I guess the last few posts explain why I like Boeing so much.
...
I don't have to know any laws.
...
I don't have to know any laws.
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Probably the reason I didn't fly the 777 my last seven years doing all nighters on reserve. Enjoyed the 757,767 and loved every minute of my daylight flying flying to my favorite airport, TGU, the second most dangerous airport in the world according to a 2 hr. report on TV. It is wonderful to have choices. I think I made the right one.
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The problem is that when the artificial feels are removed on an Airbus, the instinctual responses to flight control must be discarded and the aircraft flown in accordance with how it responds in its current condition. In this it is not unlike engine out control, cargo door open, and other adjusted flight abnormalities in traditional airplanes.
If you're quick enough, you can fly by observing responses to your control inputs to place the aircraft over the runway in a position to land. Or you may wish to go around to gain a better feel for the abnormal flight control regime into which you've been placed.
The case of the United DC-10 that lost all hydraulics over mid-America is instructive. Those pilots had to learn in short order how to fly in a situation that had never been trained or even anticipated. Their short course involved assessing what worked and what didn't. It was a great lesson for all of us in how to not ever give up.
If you're quick enough, you can fly by observing responses to your control inputs to place the aircraft over the runway in a position to land. Or you may wish to go around to gain a better feel for the abnormal flight control regime into which you've been placed.
The case of the United DC-10 that lost all hydraulics over mid-America is instructive. Those pilots had to learn in short order how to fly in a situation that had never been trained or even anticipated. Their short course involved assessing what worked and what didn't. It was a great lesson for all of us in how to not ever give up.
Ut Sementem Feeceris
....daylight flying flying to my favorite airport, TGU, the second most dangerous airport in the world according to a 2 hr. report on TV.
May even be the same programme.
A4
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"You pull back it goes up, you push forward it goes down, you want to go faster you push those levers on the center up."
Gee, I was always taught that if you want to go slower, you pull back. Faster, you push forward. Up and down, use the throttle...
Gee, I was always taught that if you want to go slower, you pull back. Faster, you push forward. Up and down, use the throttle...
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Amazing that there are pilots (presumably) who still don't get it, but then there certainly has been plenty of discussion on this forum about the decline in basic airmanship.
http://williams.best.vwh.net/smxgigpdf/smxall.pdf
Pitch controls speed, throttle controls altitude. Suggest you also go back and re-read "Stick and Rudder." Or maybe read it for the first time.
http://williams.best.vwh.net/smxgigpdf/smxall.pdf
Pitch controls speed, throttle controls altitude. Suggest you also go back and re-read "Stick and Rudder." Or maybe read it for the first time.
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Originally Posted by swh
You are mixing up pitch attitude with angle of attack, a common mistake made by amatures.
You assertions that a higher attitude or AoA would have resulted in a better outcome are not based upon any fact. Vertical speed is the killer, and I have yet to see a single aerodynamics text that states that minimum vertical speed is only achieved at maximum AoA or maximum pitch angle.
Even on the 777/787 (QRH Ditching checklist) they say to maintain VREF+30 until touchdown and flare to achieve the minimum rate of descent. Even Boeing does not advocate maximum AoA or pitch attitudes, they advocate minimum ROD.
You assertions that a higher attitude or AoA would have resulted in a better outcome are not based upon any fact. Vertical speed is the killer, and I have yet to see a single aerodynamics text that states that minimum vertical speed is only achieved at maximum AoA or maximum pitch angle.
Even on the 777/787 (QRH Ditching checklist) they say to maintain VREF+30 until touchdown and flare to achieve the minimum rate of descent. Even Boeing does not advocate maximum AoA or pitch attitudes, they advocate minimum ROD.
Please quote !
Who is talking about minimum vertical speed is only achieved at maximum AoA or maximum pitch angle ?
Am I ?
Please quote !
Higher does not mean maximum, does it ?
Isn’t it what it’s all about the flare sequence : Raising the nose to decrease the rate of descent ?
Please explain if it’s not the case because it's what I'm doing for the last 20 years or so ...
One more question :
Why Sully was full aft stick for the last 2 seconds … ?
Is it by Amateurism too ?
Originally Posted by guiones
As you know AoA would vary to maintain V Alpha Max with engines at idle
Is it a new concept of your own ?
Please elaborate ...
Originally Posted by protectthehornet
more pilot training...more simple planes that don't have bad habits
It seems this is a trend in our society, or at least our industry : Justify you can lower the training and you have a 'good' reason to lower the wages …
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stepwilk, I have heard your theory of flying before but what do you do when you are a tad fast and half a dot below glideslope on an ILS? push the throttles up at 300 ft? I would prefer to bring up the nose a tad. Actually it is a combination of power and pitch that controls the flight path of an aircraft. We all do the same thing but saying pitch controls speed only works if you don't care about the flight path.
Per Ardua ad Astraeus
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Ah well, I guess Stepwilk has never tried flying a glider
Seriously, however, I don't think I have ever rigidly applied any particular technique since my very early basic PPL days (except when hovering in a Harrier when I agree about throttle for up and down
)
Every requirement for any change is always (with me) made by a combination of stick and throttle - you just cannot isolate conventional aircraft control into 2 separate channels like that. Change one channel and sure as eggs are eggs you will need to change the other, so why not just FLY the aeroplane and do both together?
Seriously, however, I don't think I have ever rigidly applied any particular technique since my very early basic PPL days (except when hovering in a Harrier when I agree about throttle for up and down
)Every requirement for any change is always (with me) made by a combination of stick and throttle - you just cannot isolate conventional aircraft control into 2 separate channels like that. Change one channel and sure as eggs are eggs you will need to change the other, so why not just FLY the aeroplane and do both together?
you just cannot isolate conventional aircraft control into 2 separate channels like that. Change one channel and sure as eggs are eggs you will need to change the other, so why not just FLY the aeroplane and do both together?
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Smudge:
Let's start with Habsheim.....
Let's start with Habsheim.....
Neither outcome is great, but which is survivable?
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"Ah well, I guess Stepwilk has never tried flying a glider..."
Got my glider rating in 1969. You?
Yes indeed it's a blending of flight controls and systems, and I really don't see what "swept wings and jet engines" have to do with an aeronautical concept that dates back to 1903. I could also assign you to reread Davies' "Handling the Big Jets" if you scorn Wolfgang.
If you're a bit above a glideslope and you need to recapture it while maintaining bug + 15, say, you leave the yoke alone and pull off a bit of power, whether that power comes from gasoline, diesel oil, kerosene or the sun.
If you're cruising and are assigned a higher altitude, you add power and retrim.
I'm simply saying that the original post that I was answering--"you push forward to go down and pull back to go up"--is a silly oversimplification and one that is immediately seen as nonsense by most--thank god--pilots.
Got my glider rating in 1969. You?
Yes indeed it's a blending of flight controls and systems, and I really don't see what "swept wings and jet engines" have to do with an aeronautical concept that dates back to 1903. I could also assign you to reread Davies' "Handling the Big Jets" if you scorn Wolfgang.
If you're a bit above a glideslope and you need to recapture it while maintaining bug + 15, say, you leave the yoke alone and pull off a bit of power, whether that power comes from gasoline, diesel oil, kerosene or the sun.
If you're cruising and are assigned a higher altitude, you add power and retrim.
I'm simply saying that the original post that I was answering--"you push forward to go down and pull back to go up"--is a silly oversimplification and one that is immediately seen as nonsense by most--thank god--pilots.
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CONF iture:
I should have used "reach" V Alfa Max instead of "maintain", my bad.
I think we agree that as speed decreases, angle of attack must increase to maintain the same lift; and in this case it went from 123 Kts to 112 Kts in 6 seconds.
If your question was the actual AoA at V Alfa Max, I did not find it in the report; but can probably calculate it close enough if you really want it.
And no, no theories of my own; just a simple Pilot here that loves his job.
G
I should have used "reach" V Alfa Max instead of "maintain", my bad.
I think we agree that as speed decreases, angle of attack must increase to maintain the same lift; and in this case it went from 123 Kts to 112 Kts in 6 seconds.
If your question was the actual AoA at V Alfa Max, I did not find it in the report; but can probably calculate it close enough if you really want it.
And no, no theories of my own; just a simple Pilot here that loves his job.
G