SATA brand new A320 ; hard landing in Lisbon
 

rumors about a real hard landing (4.6G) on a brand new SATA A320 in Lisbon (Portugal)

quote AVHerald : SATA A320 at Lisbon on Aug 5th 2009, 4.6G landing By Simon Hradecky, AVHerald

A SATA Internacional Airbus A320-200, registration CS-TKO performing flight S4-124 from Ponta Delgada to Lisbon or flight S4-466 from Funchal to Lisbon (Portugal), experienced a very hard landing on Lisbon's runway 03 causing substantial damage to the airplane. No injuries occured.

The airline reported in a press release, that the newest airplane of their fleet, which entered service only in May 2009, will be out of service until September to repair the damage following the heavy landing on Lisbon's runway 03. The accident occured at the end of a flight originating in Ponta Delgada on Aug 6th...

source : http://www.avherald.com/h?article=41e7623d&opt=0

I think the key understanding to clarify here is whether the aircraft flew two more sectors after the hard landing:

Just out of interest:

1) What's the max "g" loading that an A320 (or indeed any commercial acft) can have on landing without structural damage? What kind of "g" loading would effectively result in the aircraft being declared a write off (for example, the FR aircraft at CIA, last Nov)?

2) Is it possible to translate this into a descent rate - e.g. 12-15'/sec?


Photos: Airbus A320-214 Aircraft Pictures | Airliners.net

Airliners are certificated to a rate of descent and weight combination. Sadly it is not easy to turn this into a simple g reading as the value that would be shown on any particular g meter would depend in where it was mounted and indeed the nature of its mounting.

Clearly people experienced on a particular aircraft type may well be able to correlate damage (or not) to a particular g meter reading but that is not the same thing as coming up with a simple number to cover a range of types.

Airliner airframes structural mininums are:

Up 3G
Fwd. 9G
Down 6G
Laterally 1.5G

Question about the fwd load rating
 

Okay, this makes me curious. What is the reason for a 9G fwd requirement? Seems to me longitudinal accelerations would be pretty small normally (less than 1 G). Is it something to do with withstanding minor taxi collisions?

Or is it just a typo - should have been .9G perhaps?

The 9G could be taking into account a sudden deceleration such as running off the runway end and ending with the nosewheel in soft ground which would stop the aircraft quite rapidly?

In practical terms how is it possible to land a plane at 4.6g? Even if you don't flare and ram it straignt in it would surely be less than that?

IIRC the A320 family a/c have a mandatory hard landing check after a touchdown of 2.6G or more, regardless of a/c weight.

The G is as measured by the IRS's. An auto print out of the landing stats +- 5 secs from first main gear touchdown comes out on the acars printer so there's no way the flight crew could miss it.

4.6 G is achieveable, my company had a 3.5G touchdown during windshear. They touched down with a lot of backstick and TOGA power applied and flew it off the bounce. Less or no corrective action would have resulted in a much harder landing. The a/c was found to be undamaged after the check, airbus build 'em strong!

even when its calm, lisbon can be sporty....when its windy, one has to be at the top of their game....period.

Hello,

The hard landing was not in Lisbon, but in Ponta Delgada in Azores on the 4th of August .

It flew at least 1 more time in the 5th of August.

How could the crew possibly think it was ok to fly the aircraft after a 4.6G landing? Or, how could a first engineering inspection not spot obvious damage such as popped rivets?! :confused:

If it is subsequently found that the crew have been "economical with the truth" w.r.t tech log entries/tried to cover it up, I would imagine no biscuits - possibly no tea.

Reminds me of the Scandi (Finnair?) botched B757 go around (which when you read the report will give you goosebumps). That wasn't entered in the log and the aircraft flew for several days before being inspected. It was found to have been majorly overstressed. Don't know what happened to the crew.....

Think about your fellow aviators who are about to take the aircraft from you. Would you want something kept from you?

A4

A4,

I do believe that you mean the Islandicair botched approach and go-around to ENGM where all thinks went out of control for a period of time :=.

Mj

A4,

do you hvae a link to this report? Finnair guys look mysteriously at me when asked...do you mean as the other poster said the ENGM incident?

fc101

You can calculate the minimium g if you know the vertical velocity and the "stopping distance". The stopping is roughly the vertical undercarriage travel.

From the equations of motion..

V^2 = U^2 + 2aS

V = final vertical velocity (hopefully zero)
U = Initial velocity (rate of descent at contact)
a = acceleration (will be negative in this case)
S = displacement (undercarriage travel)

This makes a lot of assumptions but it gives the minimium g that will be experienced. In practise the shock absorber won't be linear and I guess it may "bottom out" under high load. That would increase the g considerably.

"a" will be in meters per second. Needs to be divided by 9.8 to get a "g" ratio.

Edit: Report shows this to be irrelevant though. The peak g occured in the air.

fc101
 

Here you are:

ASN Aircraft accident Boeing 757-208 TF-FIO Oslo-Gardermoen Airport (GEN)

DB

wow that was some ride.

Altflaps,

Ask your companies engineers about the build quality difference between A & B. The reason the a320 hard landing limit is so high is that they're solid bits of kit. If it had been a 737 or 757 that touched down at 3.5G we'd have been picking bits up off the runway.

Don't let your (unjustified) prejudices about flying airbusses lead on to the structure too.

LD

ps. That Icelandair incident (so nearly a hull loss) couldn't have happened on an airbus (time to feed the trolls.....)

Printout or not depends on the programing

So, do we know for sure yet, whether the aircraft flew again after the "4.6g" touchdown? Is there some kind of incident report out yet?

IGh - the go-around upsets you're referring to were on an Airbus A300. The A320 types wouldn't have behaved the same way, although mode-confusion/vestibular disorientation is a factor in at least three 320 go-around accidents - two in the Ukraine, (Black Sea was one?) and Gulfair at Bahrain if I recall.