AA Crash Jamaica

[PJ2]

misd-agin;

And stating that idle is acceptable for stabliized approach criteria???

Essentially, yes, I think so. That statement is not likely just in one airline ops-manual either. An ops manual requirement for a stabilized approach* by 1000' IMC/500ft VMC remains a mandatory requirement and a go-around if unstable, but nowhere does it state that the engines must be spooled up; the statement just requires that the thrust is "utilized to maintain target speed". The decelerated approach technique is the result - reduced flap, lower power settings, idle reverse after t/d.

My post is intended to highlight an ongoing, serious operational procedure which reinforces a mentality that "normalizes the deviance" (idle thrust/late gear/reduced flap), and which thereby desensitizes a crew to the risk of overrun when, on occasion, a full effort stopping action may be required.

I hope this clarifies the post.


*which includes all the criteria with which we're both familiar

[411A]

The decelerated approach technique is the result - reduced flap, lower power settings, idle reverse after t/d.

This has somehow become the norm at some airlines.
It didn't work so well for QANTAS at BKK some years ago.
Dumb and dumber if the conditions aren't just right, or the runway is contaminated.
AA found out the hard way.

[PJ2]

The decelerated approach has it's place so long as everything is still on the numbers. The flight data backs this up - it works. The problem is habit; - it's done so often that there is a heightened propensity to do it the same way all the time; most of the time it works well and we save a bit of gas, wear and tear on the equipment and keep neighbours who built near the airport happy. Once in a while it needs all the flap the airplane has, all the brakes and a mitt-full of reverse and to hell with the noise, the fuel flow and the maintenance costs on the reversers.

[Sciolistes]

The following is part of the industry standard definition of a stable approach fromthe Flight Safety Foundation.

Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as defined by the aircraft operating manual;

The appropriate power setting for flap 30 is not idle, it is somewhere above 50% for a 737.

[IGh]

USA- TURBOJET pilots: FAA "engines spooled-up"

PJ2 -- just to clarify one ongoing DIFFERENCE for TURBOJET pilots employed by any FAA Part 121 operator: You pointed out the lack of any "energy management" ELEMENT in the Stabilized Approach criteria for many Euro'-pilots --

"... nowhere does it state that the engines must be spooled up ...".

However, for Part 121- pilots, the FAA retained (though FAA's Southwest Region's TX-based company's RESISTED) the "energy management" ELEMENT "engines spooled-up". The citation (source) is the legal requirement imposed on the FAA's CMO & POI to ensure that each operator includes SPECIFIC wording:

FAA Order 8900.1 CHG 0; 9/13/2007;
VOLUME 4 AIRCRAFT EQUIPMENT AND OPERATIONAL AUTHORIZATION
CHAPTER 2, ALL-WEATHER TERMINAL AREA OPERATIONS
Section 3 Factors Affecting All-Weather Terminal Area (AWTA) Operations

4-221 STABILIZED APPROACH CONCEPT … Significant speed and configuration changes during an approach can seriously complicate tasks associated with aircraft control, increase the difficulty of properly evaluating an approach as it progresses, and complicate the decision of the proper action to take at the decision point. The handling and engine response characteristics of most turbojet aircraft further complicate pilot tasks during approach and landing… A stabilized approach for turbojet aircraft means that the aircraft must be in an approved landing configuration … must maintain the proper approach speed with the engines spooled up, and must be established on the proper flightpath before descending below the minimum “stabilized approach height” specified ...

"NOTE: Principal inspectors shall not approve an operator’s procedure unless the stabilized approach concept is used for all turbojet aircraft operations…."

Previously (before 2007) the "engines spooled-up" requirement & wording was in FAA's Order 8400.10. During the 1990's and 2000 there were repeat efforts to get FAA's SW Region to comply -- but the Texas companies controlled the local regulator. Some TX-company pilots did not know about the FAA's "engine spooled-up" requirement (their company didn't want their pilots to know about the more co$tly requirement).

For pilots employed under other reg's, the ALAR standards avoided FAA's wording "engines spooled-up", instead the ALAR "energy management" element is:

"Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as defined by the aircraft operating manual...."

Basically, FSF's ALAR "energy management" element is NONE AT ALL, but the FSF's ALAR Briefing Note 4.2 does offer some background (the engine accel' curves). The weasel-wording relieves the manufacturer and the airline of any responsibility (pilots get full blame for results of un-spooled ARC-mishaps).

[411A]

...(pilots get full blame for results of un-spooled ARC-mishaps).

As they should, in my opinion.
Older pilots long remember the old turbojet engines (versus turbofan more modern varients) and the slow acceleration times experienced with these older engines.
New(er) engines are better, however...unspool 'em on approach for long periods can lead to severe problems.

[paparomeodelta]

Just came to think about this one

ASN Aircraft accident McDonnell Douglas DC-10-30 LN-RKB New York-John F. Kennedy International Airport, NY (JFK)

[WhatsaLizad?]

If Flaps 30 is used on a 737-800, that setting is more likely used because the aircraft flies like a drunken pig on ice skates at Flaps 40 with any cross/tailwind.

Maybe it's just me, but I've found I've had more control hitting a landing spot with Flaps 30 in wind than suddenly wallowing at less than 300' with Flaps 40. Cue in the tailstrike risk in that situation also.

That being said, I try to maintain currency with Flaps 40 and the crappy handling characteristics of the B737-8.

The recent discussion of idle power approach and landings as it pertains to AA is ridiculous. Same for the use of reverse thrust.

[Green Guard]

If Flaps 30 is used on a 737-800, that setting is more likely used because the aircraft flies like a drunken pig on ice skates at Flaps 40 with any cross/tailwind

Most probably if you use the same speed (even bit higher due to wind),
for both flap settings...
and it is common for speed to rise just before or during flare with any tailwind..

nowhere does it state that the engines must be spooled up

You are most probably right. But why should have it been stated at all ? How can you be stabilized at 500' or 1000' with IDLE power ? Unles you are in a glider..

[misd-agin]

The entire discussion about idle thrust being acceptable is a red herring, or a 'wind up' as the Imperialists like to say.

[ManaAdaSystem]

For the 737-800 this is taken care of with the approach idle. Happens automatically when you select landing flap or eng a-ice ON.

The -800 is not a prehistoric aircraft where a minimum thrust setting is needed in order to be stabilized.

[captjns]

Personally, I don't like setting land speed records with flaps 30 at 66,360 tons with flaps 30. Hense flaps 40 is my preferred flap setting. I've never experienced the so-called drunken pig sensation, even with strong cross winds.

Easier on the brakes and better for the quick turns. 8 knots difference in Vref puts about 800 feet of runway in the bank.

[411A]

66,360 tons

Hmmm, that's really some heavy airplane you have there, captjns....

[BOAC]

Indeed - in fact .011T over my max landing weight for the8/900

[ManaAdaSystem]

66,360 tons is the max landing weight for our -800's as well. While it's not a "heavy" aircraft, it's heavy for a 737. Why? Because the brakes are designed for 737 weights, not for a 747. Grandpa should know this, if he is not demented.

By the book, the -800 does not use much more runway that a -700, but in real life? It's a totally different beast to stop, and it pays to stay on the conservative side.
If you fly -800's and you have never experienced the extreme roll sensitivity when you land with FL 40? Luck? Ace pilot? Never done it in windy conditions?
I don't know, but it handles so bad I'm a bit surprised it got certified for FL 40 landings in windy conditions in the first place.
It also has a very small gap in the speed window (ref to overspeed) at max weight and FL 40. Not ideal for gusty conditions.

[IGh]

"Appch IDLE" no solution

Comment above:

"For the 737-800 this is taken care of with the approach idle..."

Check the engine's acceleration curves: Does Approach Idle avoid the flat portion on the left-side?? Does Approach Idle get the engine "spooled-up" -- over into the pilots' desired steeper right-side linear-slope??

Manufacturer contributions are not real good (not so explicit), but the curves shown with industry's ALAR Briefing Note 4.2 suggest that their "Approach Idle" is NOT into the linear, STEEPER right-side slope: Approach Idle (even according to the manufacturers) is still two seconds behind their estimate for power needed on approach G/S.

[galaxy flyer]

Unless you are flying the Electro-Motive version of the 737, it's maximum LGW must be 66 DECIMAL 36 tons.

GF

[misd-agin]

Flaps 30 vs. Flaps 40 shows a difference of 370' at max landing weight.

Less likely to float with Flaps 40 but if you touchdown at the same spot, and use max performance stopping, it's 370'.

[captjns]

411 adds

Hmmm, that's really some heavy airplane you have there, captjns....

Well 411, perhaps the -800's not as heavy as the 1011 you flew but still it's ligher than the 747-400s I used to fly during one of my many former lives.

At 79 tons takeoff weight the -800 tends to be a land yacht. And we're not talking very hight temperatures either,

[MilktrayUK]

Unless you are flying the Electro-Motive version of the 737, it's maximum LGW must be 66 DECIMAL 36 tons.

GF

Correct, this is how it appears to be written. 66,360 is quite correct for 66 DECIMAL 36 tons in a good many countries. Check the language settings in Windows, you will find that it even changes the decimal key on the numeric keypad. It is sad that cross cultural acceptance is so low, that even where the meaning is quite clear, posters are so quick to jump on such insignificant details.