Cargolux B748 substantial structural damage

[SMOC]

Accident: Cargolux B748 at Libreville on Nov 24th 2014, hard landing

Accident: Cargolux B748 at Libreville on Nov 24th 2014, hard landing

By Simon Hradecky, created Tuesday, Dec 16th 2014 20:14Z, last updated Tuesday, Dec 16th 2014 20:40Z
A Cargolux Boeing 747-800 freighter, registration LX-VCC performing freight flight CV-7101 from Luxembourg (Luxembourg) to Libreville (Gabon), landed in Libreville at about 19:30L (18:30Z) but touched down hard. The aircraft rolled out without further incident and taxied to the apron.

The aircraft continued its schedule returning from Africa to Luxembourg on Nov 26th, performed rotations from Luxembourgh to Shanghai (China) via Russia and back, flew from Luxembourg to Hong Kong (China) via the United States and back, and finally was removed from service in Luxembourg on Dec 2nd 2014 after substantial structural damage was detected as result of the hard landing in Libreville.

The damage is going to be assessed by a Boeing maintenance team to decide whether the aircraft can be repaired, preliminary estimation suggests the aircraft will be repaired.

Libreville features a runway 16/34 of 3000 meters/9850 feet length.

Any ideas on the location of the damage, would like to know if it could only be found by a detailed inspection such as removing panels, extending flaps etcetera, I gather it was not reported by the tech crew and was checked as a result of downloading the QAR.

[JammedStab]

I heard that it was a 4g landing. New FO.

[tdracer]

Reported as 3.14g, "initial inspection on-site was performed by local mechanic with nil findings"
Subsequent A check inspection found several deformed skin bays.

[kungfu panda]

3.14g is very very heavy, what does that equate to in terms of sink rate? I guess that depends on the weight.

[Flightmech]

As 30N30W says........
3.14g that's damn heavy, back breaking?

[Sop_Monkey]

Poetic if you ask me. F/O? Where was the Captain, asleep or is responsilitty delegated these days?

[silverknapper]

I guess I would have thought it would also tell the crew. Do no heavy boeings do this? Just curiosity.

[atlast]

3.14g? Sounds like a Pi ~ lot problem to me

[RedBullGaveMeWings]

How long on average does it take a pilot new to the 747 to get used to the eye height from a 737 or other aircraft with lower flight deck?

[Sop_Monkey]

Not long. Same Technic for any aircraft with audio/visual radio altimeter read out. 10 - 5 feet approximately, just close the throttles on a properly trimmed ILS and you should get a reasonable landing. Certainly not 3.14 G. Ground effect will arrest the R of D to an acceptable level, without a flare. IIRC.

[WhaleDriver]

It's safe to say that this was a dive into the runway. If stabilized and on glideslope at 800 FPM, you can not flare at all and not do damage. I had an FO drive into the ground at ANC one morning. I wrote it up but was told, if I did not get "Sink rate", I could not have had a hard landing.

[final06]

It is safe to say that most of the comments above demonstrate that the authors have no clue what they are talking about.

There is interesting reading in Boeings' AERO magazines.
(Try 'search' for overweight landing and also for conditional maintenance inspection procedures.)

It was a line training flight with a new F/O on his first flight on a 747.
The Cpt/Line trainer himself intervened during the landing, took control of the a/c and produced the 3.14g landing. A techlog entry was done. However maintenance could not find evidence of damage on their first inspection.

Btw
Retarding throttles on a 744/748 at 10-5" is too late.

Cheers

[Sop_Monkey]

Beg to differ.

I much preferred to touch down with the engines spooled as much as possible, to maximize the effect of reverse thrust after touch down. Engaging reverse when the nose wheel has touched is too late. I used to try and save my wheel brakes for the time I may really need them. The 744/748 is just another heavy Boeing aircraft, or am I on the wrong page?

I honed these skills when flying cargo before I became an SOP Monkey. You know, when pilots were able to think for themselves.

QF years ago have a fuel saving policy of engaging revers idle only and it cost them a hull.

[Intruder]

Wrong page.

On the 744, the N1 has to be at or near idle, as well as the main gear untilted, before the reverser locks unlock. Having the engines spooled up at touchdown actually delays reverser deployment.

On a nominal approach, the throttles can be brought to idle at 50', and the flare (minimal as it is) done at 30' to attain a smooth landing in the first 1000' of runway. The nose is brought down as the reversers deploy, and max reverse (if used) applied when available.

[Sop_Monkey]

Ok I stand corrected on that.

On first generation aircraft of the sought, we weren't hamstrung by the N1 restriction.

[Tank2Engine]

Beg to differ.

I much preferred to touch down with the engines spooled as much as possible, to maximize the effect of reverse thrust after touch down.

Which SOP is that? Turboprop/cowboy SOP? In most airlines, touchdown with thrust on is considered bad airmanship and a big no-no. Thrust on touchdowns can be smoother (good for some people's ego I guess) but you tend to float and as Intruder pointed out, it delays reverse thrust selection.

I used to try and save my wheel brakes for the time I may really need them.

"My" brakes?

For what it's worth, Libreville has quite a bump/upslope in the TDZ for runway 16 and at night it can be a bit of a black hole approach.

[tdracer]

On the 744, the N1 has to be at or near idle, as well as the main gear untilted, before the reverser locks unlock. Having the engines spooled up at touchdown actually delays reverser deployment.

Not quite - on the 747 the gear tilt has to set "Weight on Wheels" (WoW - which is based on gear tilt) true before the reversers can be deployed. But there is no N1 logic in the reverser controls on the -400. At some point the actuators may have difficulty in overcoming the aero loads, but you'd need to be well above idle before that came into play.
The 747-8 does have N1 logic that would prevent reverser deployment with N1 too high (structural reasons), but it's quite high (~75% N1 IIRC) and would only be expected to come into play during an RTO.

[Sop_Monkey]

Tank2engine.

What SOP is this? https://www.youtube.com/watch?v=bnBr3enzW1I SPS? (small p***s sydrome)

This clown not only risked the lives of all on board, but many on the ground by getting "his rocks off" by performing an AH stunt like this. If this is the behavior, not to mention the caliber at the "top" of the food chain at this outfit, there isn't a lot going for a lowly F/O on his first revenue landing is there?

[JammedStab]

Originally Posted by RedBullGaveMeWings

How long on average does it take a pilot new to the 747 to get used to the eye height from a 737 or other aircraft with lower flight deck?

The 747 has to be one of the easiest jets to land in normal conditions. I have been in the jumpseeat of a -400 with an ab initio guy doing his first two landings on the line after sim(and touch and goes). Total time...about 300 hours. First two landings...very, very nice. Last aircraft flown...a light piston twin probably more than half a year earlier.

On this thread we are talking about a 747-8 but a 747 test pilot told me that it was modified during the whole design process to fly as similar to the -400 as possible in terms of handling. Apparently took quite a bit of work to design these features into it.

And of course, there could be local conditions that had an effect on the Cargolux incident.

[main_dog]

Retarding throttles on a 744/748 at 10-5" is too late.

I'm not sure I agree, depends on many factors including engine type. I usually look at my speed one last time before commencing the flare and then reduce thrust accordingly, it might all come off by shortly after 30' (if, say, light weight, at or above Ref+5 and flying an engine with lots of residual thrust like the PW4062) or at the other extreme I may keep some of the thrust in until touchdown (heavy, gusty conditions and energy level low, especially on a Rolls Royce RB211 engine with its alarming lack of residual thrust).

Straight from our Boeing B744/748 Flight Crew Training Manual:

After the flare is initiated, smoothly retard the thrust levers to idle, and make small pitch attitude adjustments to maintain the desired descent rate to the runway. Ideally, main gear touchdown should occur simultaneously with thrust levers reaching idle.