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Old 24th January 2015, 16:43   #376
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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I read in a few places about planes being grounded and subject to inspection after they had a hard landing. What's the reference in such cases to conclude it was a hard landing? Is it the number of g encountered on touchdown? Or is there any system to calculate and determine if it was a hard landing? Could anyone please throw some light on it?
On (most) large commercial aircraft the Gs and or Vertical Speed upon touchdown gets recorded. When over a certain value a hard landing inspection needs to done by the maintenance crew.

On smaller planes, such as I fly, it is really up to pilot to make that call. Its one of the reasons to always do a proper pre-flight and visual inspection and walk around of the plane. Especially on these little planes there is very likely to be visual evidence of a too hard landing. Eg. damage to the landing gear, buckled plates on the fuselage etc. On large planes, there might be visual clues, but it could be much more difficult and more components need to be inspected.

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Old 1st February 2015, 20:15   #377
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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Originally Posted by audioholic View Post
I read in a few places about planes being grounded and subject to inspection after they had a hard landing. What's the reference in such cases to conclude it was a hard landing? Is it the number of g encountered on touchdown? Or is there any system to calculate and determine if it was a hard landing? Could anyone please throw some light on it?
All modern airplanes have a certified limit of the G load they can achieve in flight and the maximum G load the landing gear can take before being inspected for damage. In the Airbus the aircraft doesn't allow the pilot from exceeding the positive or negative G load in flight, because each of his/her action is fed through different computers which have prescribed limits for each maneuver and filter out excessive inputs. During landing the computers measure the G loads 3 seconds before impact and analyze the G load experienced by the main landing gear (please note: The actual force experienced by the gear is not measured) and if the G load exceeds a pre set parameter (generally about 1.7/1.8 G) then the load report is automatically printed out, calling for a mandatory engineering inspection, to certify the aircraft before the next takeoff.
Our human bodies measure G loads more instantly and therefore a smooth landing detected by the computer may be experienced as a hard/firm landing by the passenger and vice versa. For example if the pilot is flying the airplane almost parallel to the runway (say 2-3 feet) with the power off, then the plane loses lift and touches firmly on the runway the passenger may call it a firm landing but the computer will show a low G load, vice versa if a pilot descends with a high rate of descent until about 20 feet and then firmly flares (rounds off the nose) to touch down smoothly, the passenger will praise the landing but the computer will show a relatively high G landing.
As a passenger we needn't worry, the airplanes are overbuilt to take care of all kind of landings and surfaces day in and day out. It is like taking a offroad vehicle over speed bumps at high speed and worrying about damage to the under body or components
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Old 17th February 2015, 09:52   #378
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Just came across this one: http://avherald.com/h?article=481de898&opt=0

You don't see Indian carriers very often on the avherald. Not because they have fewer incidents, but just fewer get reported in the public space such as this web blog. We will have to wait to see what happened based on the accident report. But these tail strikes are nearly always pilot error.

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Old 30th March 2015, 08:43   #379
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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Originally Posted by Jeroen View Post
Just came across this one: http://avherald.com/h?article=481de898&opt=0

You don't see Indian carriers very often on the avherald. Not because they have fewer incidents, but just fewer get reported in the public space such as this web blog. We will have to wait to see what happened based on the accident report. But these tail strikes are nearly always pilot error.

Jeroen
I would agree with you regarding this. In the airbus you can do either a full flaps landing or a configuration 3 landing with reduced flaps. In the reduced flap landing there is fuel saving and better go around performance, and is recommended by airbus during windshear etc. However the issue is pitch. In configuration full the pitch is about 5 degrees nose up and in flare about 7.5 nose up. In configuration 3 it is about 7.5 nose up and in flare it's required to be below 10 degree up to prevent tail strike.

If one flares too high then uses pitch to control sink rate the pitch can easily hit 11 to 12 degrees. 11.6 up with main wheel compressed is the limit for tail clearance

Last edited by apachelongbow : 30th March 2015 at 08:47.
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Old 31st March 2015, 19:55   #380
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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I would agree with you regarding this. In the airbus you can do either a full flaps landing or a configuration 3 landing with reduced flaps. In the reduced flap landing there is fuel saving and better go around performance, and is recommended by airbus during windshear etc. However the issue is pitch. In configuration full the pitch is about 5 degrees nose up and in flare about 7.5 nose up. In configuration 3 it is about 7.5 nose up and in flare it's required to be below 10 degree up to prevent tail strike.

If one flares too high then uses pitch to control sink rate the pitch can easily hit 11 to 12 degrees. 11.6 up with main wheel compressed is the limit for tail clearance

Thanks, scraping the tail happens quite a bit actually. You can search for it on AVHarald.

Try thrust instead of pitch.

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Old 1st April 2015, 09:52   #381
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

At long last some good news for the Indian aviation industry. Last year India lost its class I rating. Even since, India from an aviation safety point of view was in the what is known as SubSahara countries rating. Not a good place to be.

Looks like India will have its class I rating re-established soon:

http://timesofindia.indiatimes.com/i...w/46764356.cms

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Old 1st April 2015, 12:30   #382
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

Might be a another delay for the clas I rating?

http://www.pressdisplay.com/pressdisplay/viewer.aspx

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Old 2nd April 2015, 12:58   #383
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

Really remarkable to say the least, especially as it is not the first time.

http://www.firstpost.com/business/je...e-2183353.html

I simply fail to understand how a carrier and or a pilot willfully do not adhere to proficiency checks! Who will loose their job over this I wonder, probably nobody, which is probably a good indication on how serious this will be taken.

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Old 3rd April 2015, 12:15   #384
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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Thanks, scraping the tail happens quite a bit actually. You can search for it on AVHarald.
Jeroen
I have read in a lot of places that the Airbus A321 is prone to tail strikes due to its extended fuselage which allows for a very less margin of error.
Does anyone know how true this information is?
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Old 8th April 2015, 21:23   #385
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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Originally Posted by Jeroen View Post
Looks like India will have its class I rating re-established soon:
Finally FAA upgrades rating back to Class 1 from Class 2.

http://www.bloomberg.com/news/articl...on-improvement

http://www.wsj.com/articles/faa-rais...ing-1428479934
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Old 9th April 2015, 08:29   #386
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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I have read in a lot of places that the Airbus A321 is prone to tail strikes due to its extended fuselage which allows for a very less margin of error.
Does anyone know how true this information is?
Its true to an extent. The 321 is not prone to a tail strike in normal conditions, however one needs to be extra careful during reduced config landings (say with hydraulic or flight control degradations), because the aircraft is coming down with a nose high attitude, and during flare, there is very little pitch attitude (nose angle with respect to ground) available to play with. This is common to almost all jets which have an extended fuselage and under wing mounted engines.
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Old 9th April 2015, 10:29   #387
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

On the brighter side , the A321 has better stability due to the extended length. Also there is a dual flap setup on the leading edge. It is also much easier to land in heavy crosswind.
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Old 9th April 2015, 10:59   #388
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It is also much easier to land in heavy crosswind.

Why is that, could you elobroate please
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Old 15th April 2015, 12:33   #389
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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On the brighter side , the A321 has better stability due to the extended length. Also there is a dual flap setup on the leading edge. It is also much easier to land in heavy crosswind.

The leading edge has only slats not flaps. Slats are useful in high angle of attack and slow speed scenario. Infact the opposite is true, in mild to moderate turbulence where as the A320 or the 319 can stay comfortable, the 321 develops an exaggerated left right oscillatory movement, which even though is not unsafe, is highly uncomfortable for the passengers.
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Old 15th April 2015, 13:13   #390
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Default Re: Airbus A320 Long-Term, 3 Million KMs Review

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The leading edge has only slats not flaps. Slats are useful in high angle of attack and slow speed scenario. Infact the opposite is true, in mild to moderate turbulence where as the A320 or the 319 can stay comfortable, the 321 develops an exaggerated left right oscillatory movement, which even though is not unsafe, is highly uncomfortable for the passengers.

Thanks, but I'm not sure I follow. Are you saying the 321 has no flaps?
there are quite a few thread on PRuNe regarding flaps settings on the Airbus 319,320, 321. such as these:

http://www.pprune.org/tech-log/27216...ding-flap.html

I havent come across anything (yet?) that you suggest? The one thing I see is that most pilots/carriers will use flaps setting less then full when in a heavy crosswind. Which is more or less what you would expect for just about any type of aircraft.

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