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-   -   AA Crash Jamaica (https://www.pprune.org/north-america/399798-aa-crash-jamaica.html)

Shore Guy 5th Jan 2010 00:48

According to an Australian report on Runway excursions, it lists the 737-800 having a tailwind limit of 10k. However, "A tailwind of 15 kts is sometimes certified for some specific types (B-737-8 being one of them)
following customer requests through a major change to the type certificate."

Does anyone know the tailwind limit for AA's -800? Does anyone know which operators have the 15K limitation?

Spooky 2 5th Jan 2010 13:09

I do not know what AA has on their 737-800s but the way this works is the operators gets 10kts as standard on a new Boeing. They can opt for 15kts with additional charges. You see this option on operators that utilize the aircraft at airports with winds that do not always favor the ILS runways. The Carribbean and northern Latin American airports are subject to this condition more than just about anywhere else in the world.

BTW, this 15kt option is available on most if not all current Boeing aircraft

Pugilistic Animus 5th Jan 2010 16:52

Finally got through the thread and I'm surprised that no one brought up th 'OPC' it was partially responsible for the SWA overrun perhaps they got 'good figures' but some assumptions were not shown??? you know GIGO?


PA

Spooky 2 5th Jan 2010 17:12

What makes you think AA s using a onboard performance computer...which they aren't.

IGh 5th Jan 2010 17:26

Low Energy Balked Ldg
 
Back in slot #250, dated 3rd, FS posed a sticky question:
"... when tight landing and stopping conditions are encountered in the civilian world ... both fixation to land and the need to go-around can co-exist in the same mind? Naval aviators do it all the time...."
Ya, but -- several civil mishaps point-out some weaknesses in civil TURBOJET design. Perhaps TC's Advisory Circular #0141 (13May98) said it best:
Advisory Circulars - Commercial & Business Aviation Advisory Circulars - Commercial and Business Aviation - Airlines & Aviation Operations - Air Transportation - Transport Canada
"... It is a common belief among pilots ... that aircraft are certified to successfully complete a balked landing or go-around from any point during the approach or landing phase. This is not the case. [see AC for Low Energy definition] ... The decision to place an aircraft into the low-energy landing regime is a decision to land. If there is any doubt regarding the probability of a safe landing, a go-around or balked landing must be initiated prior to entry into this regime.


"An attempt to commence a go-around or balked landing while in the low-energy landing regime is a high-risk, undemonstrated maneuver.

"In the extreme case where such action is required, pilots should be aware that ground contact is likely and any attempt to commence a climb before the engines have achieved go-around thrust may result in a stall. Turbo-fan engines may require as long as eight seconds to accelerate from idle to go-around thrust. Air operators should immediately ensure that their pilots are aware ..."
The NTSB has been incomplete in their analysis of this "energy management" aspect during prior ALA- investigations (see Board's botched investigation of DEN/21Mar06 ARC DEN06IA051 ). Tailwind approaches force the pilot back against the "energy management" element of the FAA's Stabilized Approach Concept: FAA's "spooled-up" requirement may not be attained with the tailwind. Board did little better during investigation of AA699/ 6Feb97
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001208X07395&key=1
which Board cited in their letter of Recommendations after the Rwy Excursion of AA1420/ 1Jun99.

Pugilistic Animus 5th Jan 2010 17:44


What makes you think AA s using a onboard performance computer...which they aren't.
I'm surprised,...new plane new gadgets,...I thought :confused:

well back to my cave:}

Doors to Automatic 5th Jan 2010 18:18

A flap 30 landing on a 737-800 at a high landing weight would result in a VREF of 148 kts as I understand it.

Would this mean that an aircraft landing with a 15kt tailwind would be approaching at 163kts?

Thats a hell of a speed if so.

Shore Guy 5th Jan 2010 20:27

I did find out from another source that the AA B737-8 series have a tailwind limit of 15 Kts.

IGh 5th Jan 2010 21:05

15kts Tailwind --- not available at most airports
 
Statement just above: "AA B737-8 series have a tailwind limit of 15 Kts"

At all airports?? Or, maybe authorized at only a few airports?

Suspect 10kt tailwind exemption (allowing up to 15Kt) was NOT authorized (for that operator) on the mishap RUNWAY (uncertain).

Just adding some early B737 Rwy Excursion mystery - Harold Marthinsen and Keith Hagy made a presentation at ISASI 1992 (reprinted later in _Air Line Pilot_, Oct/Nov93 & Dec93), "Boeing 737 Overruns: A Case History".

The mystery then (Rwy Excursion mishaps of 1980's) was how any single failure could disable both ThRvrs & Autospoilers. Harold and Keith explained the single failure, and the shortcomings of the initial Flight Test Certification in the late 1960's.

Flight Safety 5th Jan 2010 23:38

IGH, very interesting post.

This is also from the same TC advisory circular:


In brief, an aircraft is not certified to successfully complete a go-around without ground contact once it has entered the low-energy landing regime. For the purposes of this CBAAC, the low-energy landing regime is defined as:
  • aircraft flaps and landing gear are in the landing configuration;
  • aircraft is in descent;
  • thrust has stabilized in the idle range;
  • airspeed is decreasing; and
  • aircraft height is 50 feet* or less above the runway elevation.
* Note: 50 feet is a representative value. A given aircraft may enter the low-energy landing regime above or below 50 feet in accordance with approved landing procedures for that type.
I may be wrong, but this appears to refer to that portion of the landing (while in the flare) just prior to runway touchdown. I believe the advisory is communicating to pilots that runway contact is probably unavoidable at this point in the landing.

This is a different thing from intiating a go-around once on the runway. However the delay in engine spool up is certainly a factor once on the runway, thus the decision to go around has to be made pretty quickly. In the landing scenarios we've been discussing (no spoilers or brakes prior to thrust reverser deployment), that should be possible in most cases. I stand to be corrected however.

However the subject of this advisory circular makes for interesting reading in light of a long float over a short contaminated runway.

Spooky 2 6th Jan 2010 03:15

IGH, the 15kt tail wind "limitation" is not airport specific. It is a aircraft "limitation". For all we know there was no tailwinds allowed at this airport for any AA operations. That not withstanding, the airplane was certified for a 15 kt tailwind as it is a part of the AFM. Do you get it now? :}

rottenray 6th Jan 2010 04:29


Glueball writes:

"If I HAD to place a blame somewhere, I'd lay it right on the airport itself."
Captain rottenray . . . Please tell us how much longer than 8900 feet of non grooved, slick-when-wet pavement would be necessary for a B737-800 to land safely? http://images.ibsrv.net/ibsrv/res/sr...s/confused.gif
Thanks for the promotion, but I'm still merely self loading freight as some like to call us...

To speak to your remark -

In this case, looking at the pix, I'd guess the accident 737 could have flown out again the next day if the runway had been 9,200 feet.

What do you think?

Also, what do you think would have happened had the runway been 8,800 feet?

Could AA331 have shredded itself running through the concrete light pillars?

Also, as a side note, when I said "blame the airport itself," I did not mean the folks working there.

I meant the physical runway and its climate.

This is an 8,900 foot long runway in a rainy climate, without macrotexture grooving to shed water, rumored to have a lot of deposited rubber, which ends in a stone speed-bump and a road in a trench, followed by a shredder formed by end of runway lights, with a nice dump into the surf if one makes it that far.


But, finally, Glue, I really don't understand your reply. It's kind of contradictory in and of itself.

And, why do you attack when someone shows some understanding for the deck crew of a heavy flight landing on a lousy weather night on a somewhat less than best runway?


??

rottenray 6th Jan 2010 04:36


411 writes:

If I HAD to place a blame somewhere, I'd lay it right on the airport itself. 'Atta boy, spoken like a true APA guy...it was the 'airports fault'.:rolleyes:
Naw...nothing to do with the pilots inability to actually land the airplane within the confines of the requested runway.
We can now see the true arrogance of AA guys...blame everyone/else...but them.
Dude, you seem to have a permanent hardon for American Airlines, as far as I can tell, based on your posts here, on a.net, and elsewhere.

Not that AA is my favorite operation, either.

But it is a lousy runway, and it was a lousy night, and I'd rather wait for conclusive findings before I go blaming the crew in this one.

[imagine a scene from Silence of the Lambs]
So, 411, tell me... What did AA do to you?


LOL!

Doors to Automatic 6th Jan 2010 09:21


I'd guess the accident 737 could have flown out again the next day if the runway had been 9,200 feet
I don't think you have factored in the retardation effect of going straight through the fence, across a road and up a flood-break. Having your engines and undercarriage ripped off would help in getting a few knots off as well.

Shore Guy 6th Jan 2010 09:26

I will add a caveat to my previous post on tailwind limitations for an AA B737-8. There is reference to "may be limited by performance requirements". I am assuming that refers to AAL Airport Analysis charts, of which I am not privy to.

As posted many times in this thread, we should all wait for "official" data/reports before condemnation of the crew, airport, etc.

As (unfortunately) most threads these days on PPRUNE, this one has turned into a finger pointing rant.

Oh, how I miss the PPRUNE of five or so years ago (and previous). Much less whining, fewer tire kickers, PC pilots, etc., etc., etc.

Sigh......:bored::bored::bored:

waves-dubai 6th Jan 2010 11:15

IMO..I can't see why people love to circumnavigate certain issues...Why blame the physical conditions of the airport when a pilot decided to continue an approach and " touchdown" halfway down a 8,900 feet wet runway???..

vapilot2004 6th Jan 2010 11:34

I am agreed with you on the airport.
 

IMO..I can't see why people love to circumnavigate certain issues...Why blame the physical conditions of the airport when a pilot decided to continue an approach and " touchdown" halfway down a 8,900 feet wet runway???..
And after this late touchdown, what do you imagine then happened?

GlueBall 6th Jan 2010 12:04

rottenray

"...why do you attack when someone shows some understanding for the deck crew of a heavy flight landing on a lousy weather night on a somewhat less than best runway?"
Not an attack, sir, just a statement of fact. Unless there was a brake failure, it is self evident that the PF [pilot flying] had landed his "heavy flight" way too far down the pavement to get stopped before the end. And the PM (Pilot Monitoring) was not assertive enough to take corrective action and take over the controls and initiate a go around. At best, it can also be called crew incompetence if not wreckless operation of an airplane...

All this Mickey Mouse debate about: Non grooved runway; wet runway; tailwind; delayed reverser actuation; rain; max landing weight; . . . is neither cause nor reason for a B737 to have to run off the end of a 8900 feet pavement. For many moons much larger, heavier wide bodies have landed in the rain on this non grooved, slick-when-wet pavement. Get real. :ooh:

PantLoad 6th Jan 2010 12:43

Well, that settles it......
 
Investigation complete.....


Fly safe,

PantLoad

lomapaseo 6th Jan 2010 13:05

Most of what I read on these everyday incident/accident threads are really investigation issues to be considered and discussed as necessary in final reports.

However most posters tend to argue their points for consideration as if they are already obvious conclusions, hence the counter arguments in the repeated thread posts ad infinitum.

Speed reading threads helps :)


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