Caribbean B738 at Georgetown on Jul 30, 2011, overran runway

[nitpicker330]

Wrong, if you're on a stabilized approach with Flap 40 at about 130 kts and you run the Flaps up by mistake then you most certainly will need TOGA thrust to accelerate the Aircraft ASAP above the clean stall speed of around 180 kts, Even then it maybe be too late.

Boy there is some absolute rubbish being written in this thread.

[F14]

As speculation, how about balked landing, followed by flaps selected up rather than F15. (is this a PtF recruiter?) Then a stop which sadly led to an over run?

I guess we have to wait for the preliminarily report. Nevertheless no fire and a good evacuation. Another good test of the B737-800 durability & survivability.

[focault]

They could have achieved taxi speed well before the runway end, stowed reversers. F/O starts his after landing flow, selecting flaps up, then arriving at the turn-off point at runway end, find nil braking on a flooded, ungrooved runway... nose wheels just slide when turned. Capt reselects reverse, but too late to prevent over run. I've seen it happen...but on a -200 where much more effective reverse saved the day.

I think BobM2 got the point. If the runway is flooded and you misjudge your speed (at night could happen) you may not stop it even with 15 kts and once out of the concrete there is no more friction.

[Magplug]

Rushed Checks & Speed Misjudgement ?

Landing on a 2200m runway even in pouring rain should not normally present a problem. This runway looks in good condition with no evidence of heavy rubber deposits that would degrade braking when wet.

If this upwind excursion was as the result of an unstable approach or a deep landing I would expect to see the aircraft come to rest in the landing configuration.... which it is not.

The flap/slat config seems to suggest that the after landing checks were initiated by the NHP abnormally early. I say 'abnormally' because normally there is no need to commence lights/flaps/apu etc. until the aircraft has vacated the runway. Here the checks have been started so early that by the time the excursion takes place the flaps & slats are stowed. The reversers deployed may simply be evidence of very late recognition of excess speed by the PF.

It seems highly likely given the LDA and the wet conditions that the crew would be planning to vacate 06 by turning left onto the parallel taxiway at the runway end.

It is quite possible that this was a normal approach and touchdown albeit in heavy rain.

With the crew already in the mindset of rolling to the end it is possible that the after landing checks were initiated prematurely, maybe even selecting both engines to Fwd Idle. As the runway end approached the speed was misjudged by the PF (PNF maybe still heads-down in checklist) and max manual braking and the reapplication of reverse were insufficient to prevent the excursion.

[Henri737]

Or the aircraft broke, severing the flap controls, commanding flaps-up on electric hydraulics with the flaplever in 40 : lets wait for the investigation results.

[nitpicker330]

Mate, Alternate Elec Flaps will only retract the trailing edge and not the leading edge. Have another look at the pictures.

The leading edges are retracted, it would have to have been via System B 3000 psi Hydraulic pressure and selection by the crew pre impact. That wouldn't have happened post impact when both Engines failed.

Some serious crap in here.

[16024]

Electric flaps wouldn't go with generators lost, and wouldn't retract L/E devices anyway.

(And just realised Nitpicker beat me to it...)

However, as somebody suggested, with flap lever signal dirupted due to fuselage damage and engines spooling down, but still providing some hydraulic pressure...

[J.O.]

What is being missed by some here is that any attempt to approach the ground with no (or minimal) flaps / slats would have resulted in a GPWS warning that is impossible to miss. All this talk of an inadvertant "miss" of the flaps is way off base, IMHO.

There will be lessons to learn from this accident. But is it really that hard to wait for some official information, rather than engaging in ridiculous speculation?

[TacomaSailor]

No tracks down the embankment?

I measure approximately 45 feet from the lip at the top of the embankment down to where the ground levels off under the tail. I see no tracks down that embankment in the photos in message 75.

How fast would the aircraft have to have been moving (at the top of the embankment) to have enough inertia to continue off the top of the embankment so that both the nose gear and MLG remain off the ground, leaving no tracks, until the aircraft settled into it's final resting location?

How slow would the aircraft have been going when it hit the dirt at it's final resting location so that it left no tracks other that the holes the gear made when they came to rest?

[Azumi]

passenger or witness reports?

While we're waiting on the actual report, this passenger reports Trinidad and Tobago's Newsday : newsday.co.tt :

"Elias recalled two flight attendants being on their feet at the time the aircraft hit the runway. ... When the aircraft hit the ground, he said, the flight attendant who was in the aisle in front of him fell to the floor and the impact sent her sliding along the aisle. He does not know what happened to the other attendant."

At what point in a landing are attendants asked to take their seats? How soon after landing do they get back up?

Thanks for the perspective on the landing gear tracks.

[Limer12345]

HOGWASH Speculation....

All this hogwash speculation about flaps/slats/approach speeds/touchdown point etc......



All until the flight recorder shows that the aircraft was being operated by the 23 year old "ACE" in the RHS !!


And then we bitch and moan about the "paid RHS" seat jobs in Europe....and the infamous Indian fake CPLs etc....

[Curry Goat]

Two things of importance that a little birdie at the scene has told me.

1. Flap handle in the cockpit is selected to something other than up.

2. Aircraft left the paved surface doing at least 40 kts. This would rule out a previous theory of taxiing gone bad.

[seckin]

also look at the rudder position in the pictures before.. somebody was trying to make a desperate left turn..
also I believe the first pic in the following link was never posted. gives little more clue..
Accident: Caribbean B738 at Georgetown on Jul 30th 2011, overran runway

[Shorrick Mk2]

I measure approximately 45 feet from the lip at the top of the embankment down to where the ground levels off under the tail. I see no tracks down that embankment in the photos in message 75.

How fast would the aircraft have to have been moving (at the top of the embankment) to have enough inertia to continue off the top of the embankment so that both the nose gear and MLG remain off the ground, leaving no tracks, until the aircraft settled into it's final resting location?

The slope is to steep and the distance between the nosewheel and the MLG too long to expect nosewheel tracks down the embankment. The moment the nosewheel goes past the lip, the plane will drop onto the engine nacelles, like with a nosewheel collapse. If you look at the 3rd photo here you can see what looks like the track of the left nacelle dragging along the embankment (right behind the left stab - there's one guy clad in black walking down it). Once the nose will have impacted the ground below, it's quite likely that the MLG will not necessarily roll down the embankment, its task being taken over by the aft fuselage.

[dhardesthard]

Rudder position.

The rudder position or the position of any other flight control surface with zero hydraulic pressure to the systems means nothing for obvious reasons. The DFDR will be the ONLY reliable source of information.

[WHBM]

Setting aside the aircraft handling aspects for a moment, the runway design looks notably poor, immediately at the end of the paved surface is an earth lip and a small drop (which has nevertheless broken the fuselage), and a vehicle track unnecessarily close to the runway end, followed by a flat grassed area out to the aerial array well beyond the aircraft, all withn the airfield fence. One day's work regrading with a bulldozer at the time of the runway construction, and some appropriate drainage, would have made a very adequate and level grassed overrun area. Quite what that earth lip achieves in civil engineering terms I cannot imagine.

Did anyone ever say "risk assessment" to the runway designers ?

[lomapaseo]

Risk Assessment?

Setting aside the aircraft handling aspects for a moment, the runway design looks notably poor, immediately at the end of the paved surface is an earth lip and a small drop (which has nevertheless broken the fuselage), and a vehicle track unnecessarily close to the runway end, followed by a flat grassed area out to the aerial array well beyond the aircraft, all withn the airfield fence. One day's work regrading with a bulldozer at the time of the runway construction, and some appropriate drainage, would have made a very adequate and level grassed overrun area. Quite what that earth lip achieves in civil engineering terms I cannot imagine.

Did anyone ever say "risk assessment" to the runway designers ?

Poor designed runway

I tend to look at anoother way. The airport designer initially looked at a much shorter runway with a nice flat overrun area as far as they could fill. Then along comes some big iron operators and says we will fly into your airport if you lengthen your runway as far as it can go.

So whose decision is it?

Is it poor design or poor decision making about the plane chosen to use the runway?

I've yet to see anything that regulates these kind of decisions in the mind of the pilots.

[safetypee]

Did anyone ever say "risk assessment" to the runway designers ?

Does anyone say “risk assessment” to the operating crews?

If a runway does not have a reasonable overrun safety area (length or condition), then perhaps the runway length available should be reduced in the pre landing (pre-operation) risk assessment.

[simtronix]

Updated info on Avherald

Accident: Caribbean B738 at Georgetown on Jul 30th 2011, overran runway

according to the latest update on the incident entry on Avherald:

Georgetown Airport's fire commander told the investigators that firefighters observed the aircraft as it approached but touched down only about half way down the runway abeam the terminal building with about 3000 feet of runway remaining. They needed to douse engine #2 (right hand engine) which was emitting smoke after the aircraft came to a stop.

Aviation sources said, the aircraft touched down with flaps fully extended (40 degrees).

[hetfield]

Aviation sources...

Who ist that?

Cleaners, Loaders, Security-Sheriffs...?