Tag Archives: KSFO

[Animation] The most detailed and realistic look at the Asiana Air 214 crash landing at San Francisco

A new “forensic animation”, made by Eyewithness Animationas and published by several media outlets, provides the most detailed and realistic look (in terms of airspeeds, altitudes, etc. ATC audio recordings are not synchronized), of the crash landing of Asiana Air 214 at San Francisco.

The animation is particularly interesting as it also shows the path the plane should have taken and the path it did take as it crash landed on runway 28L at KSFO on Jul. 6, 2013.

The animation shows the plane getting below the glide path and the pilot pulling up when it’s already too late to recover: the main landing gear hits the sea wall and the tail detaches from the plane.

Then, the left engine breaks away from the wing and the plane becomes airborne once again as it yaws and slides on the grass.

Even if all new aircraft seats are designed to withstand 16g forward, 16 forward at 10 degrees and 14g down, many passengers flying in economy class suffered spinal injuries: unlike business class section passengers, who had harness seat belts that prevented such injuries, passengers in the back had only lap belts, hence they slammed their heads into the seat in front of them.

Still, the aircraft did not capsize, otherwise very few passengers would have survived.

The scene of the aircraft about to hit the sea wall with the gear reminds the following famous U.S. Navy photo, showing Lieutenant Tom Reilly, a Landing Signal Officer (LSO), racing across the deck to avoid an approaching F7U-3 Cutlass about to crash on the Hancock aircraft carrier on Jul. 14, 1955.

Cutlass

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[Updated] Asiana Air 214 crash landing analysis: the B777 flew a high, fast and steep approach and almost stalled on final

On Jul. 6, 2013, at around 11.28 LT, Asiana Air 214 Heavy (OZ214), a Boeing 777-200 (HL7742) operated by Asiana Airlines from Seoul to San Francisco International with 291 people on board, crash landed on runway 28L at KSFO.

As a consequence of the impact with the ground the tail separated along with several parts of the fuselage, undercarriage and engine before the main part of the airframe came to a rest next to the runway.

Two passengers died and 49 were seriously wounded.

AAR214

Based on the reports and analysis of the images of the wreckage, it seems that the 777 touched the ground short of runway threshold. Asiana representatives said the aircraft did not suffer any technical failure. However, the NTSB investigation will say what went wrong.

In the meanwhile, we can try to analyse the details already availabel.

The aircraft flew the approach as expected: under VMC (Visual Meteorological Conditions) with visual final (since the ILS was under maintenance according to NOTAM for KSFO).

The playback feature of Flightradar24.com for AAR214 shows the standard route for 28L. Still, by comparing the type of approach flown on the day of the incident and the one flown for instance on Jul. 4 (again with FR24 playback), you’ll notice that on Jul. 6, the final approach started a bit higher. This is not a big deal, unless the crew set a steep approach that, for one reason or another one, did not properly correct until the aircraft was a few feet above the water.

Indeed, the Vertical Speed (at least the one broadcast using ADS-B by the airplane and recorded by FR24) is higher than one would expect (-1,536 fpm at 1,000 ft). Few seconds later, as the aircraft is at 75 feet of altitude, the airspeed falls to 85 kts with a vertical speed of -768 fpm, meaning that the plane is almost falling from the sky.

Provided the data collected by FR24 is correct, it seems to prove that for whatever reason, the incident unfolded as follows:

1) the aircraft under almost perfect weather was radar vectored for the final approach

2) the flying pilot flew the final approach higher and faster than expected: you can compare the approach of the AAR214 with the one of the All Nippon B777 that preceeded it. Abeam Coyote point, the ANA8 (NH7) is at 1,500 ft, -896fpm of vertical speed and 167 kts of horizontal speed whereas the doomed AAR214 is at 2,175 ft, -1,152 fpm and 186 kts. In other words, the Asiana was higher, faster and descending steeper (spoilers, full flaps etc) to intercept the proper glide path.

3) Most probably for a human error (whose root cause may be attention focused elsewhere, another type of cabin problem, distraction, not enough experience in flying visual approaches with the type, etc.) the aircraft approached the runway with a steep angle, the pilots tried to correct it with a bit of nose up to make it to the runway and avoid the plane from touching down before the threshold (if not in the sea) and this caused the aircraft to strike its tail first and then fall on the runway.

4) All the incident unfolded in front of UAL 885. Investigator will probably get some interesting details not only from the crew and CVR (Cockpit Voice Recorder) but also from the pilots of the United 885, a B747 holding short for departure to Osaka.

The above development is coherent with the video just released by the CNN.

You can see the final seconds of the flight: the B777 looks slow on final with a significant nose up attitude. It is struggling to remain in the air enough to get into the runway.
Beware: the video shows the very last part of the flight, when the pilot flying the plane has already applied the correction (advancing throttles to gain speed).

Noteworthy is also how the aircraft pivoted after impacting the ground: it’s a miracle almost everyone survived the incident.

Update: it looks like the pilot flying was actually in training, had just 43 hours of experience with the B777 and had never landed at San Francisco before. These could be contributing factors to the incident.

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Qantas uncontained engine failure

The recent Qantas B747-400 engine failure that compelled the QF74 on Aug. 31, 2010, to land only 41 minutes after departure from San Francisco (with destination Sydney), has already made the news. Unlike other minor failures occuring almost daily everywhere, an uncontained failure (that is quite different from an engine explosion….), is somehow rare, but not a big deal (if there’s no damage to the wing or fuselage caused by a separated engine part), especially if happening in the vicinity of the departure airport. Now have a look at the route followed by the aircraft from departure to landing taken from FlightAware.com:

The route clearly shows that upon experiencing the n.4 engine failure, flying at FL300, some 270NM to the West of San Francisco, the QF74 headed back to SFO and, instead of proceeding directly to landing, it performed a couple of 360s to dump fuel. Someone asked why the pilot did not proceed straight towards the airport after loosing one engine (out of 4…) but I think that there’s nothing weird on such a behaviour: as the aircraft can fly safely also with a single engine (in particular circumstances…), it is safer to land the heavy plane (with 212 passengers) after loosing some thousands lbs of fuel. Indeed, much interestingly, the pilot did not (at least until the very last part of the flight) declare emergency (even if most news reports didn’t mention this detail or mistakenly stated that the flight had declared emergency) as the aircraft could be safely flown back on the remaining engines.

The analysis of the ATC recording is quite interesting: QF74 first call to the radar is to request descent to FL200. When requested if a vector back to San Francisco was needed, the pilot replies with a “stand by”, followed, minutes later by a request for radar vectors back to KSFO. Fuel dumping was performed from FL200, eastbound, then the aircraft was cleared to descend to 10.000 at pilot’s discrection (even if the aircraft maintaned FL200 and later “moved” on RAINS waypoint to continue its holding/fuel dumping).

Interestingly, a replacement engine was carried (as 5th engine) by QF73, Qantas B747-400 “VH-OJQ”, on Sept. 1.

Some videos taken with mobile phones from the passenger cabin of the aircraft can be found on the Internet.

The following article, published by the Sydney Morning Herald, on Sept. 2, 2010, provides some details dealing with airworthiness directives issued for the RR RB211 engines fitted to the QF B744 aircraft focusing on possible uncontained engine failures.

Qantas engine explosion followed safety warning
Andrew Heasley and Matt O’Sullivan
September 2, 2010

THE Qantas jet engine that exploded on Tuesday after take-off from San Francisco had not been inspected after safety warnings issued two weeks ago.

The safety bulletins in Australia, Europe and the US had warned of ”uncontained” engine failure – the technical term for when components are sprayed out of the engine enclosure during a malfunction.

The airworthiness directives were issued for Rolls-Royce RB211 engines, the model fitted to the Qantas 747-400 that was forced to make an emergency landing at San Francisco.
A Qantsa jet was forced to turn back to San Francisco after a hole was blown in the shell of the engine.

Qantas confirmed the jumbo’s engines had not been inspected because it was not due for its regular maintenance checks. The engine that failed was last inspected on July 8. Some of the 212 passengers on QF74 reported seeing flames and sparks fly out of the plane’s fourth engine about 20 minutes after take-off.

The explosion ripped a hole through the engine’s cowling, causing the aircraft to shudder and requiring the pilots to dump fuel before making the emergency landing.

One passenger recalled seeing flames ”like a giant Roman candle stick” shooting towards the back of the aircraft from the failed fourth engine.

Another passenger panicked and yelled, ”We’re going to go down, we’re going to go down’,” but most handled the emergency calmly. Those who were not able to cope were ushered to the front of the aircraft.

Kirk Willcox, from Randwick, was seated in a row near the wing when he ”suddenly heard a loud pop and a swish” as the fourth engine caught fire.

”We knew we had not hit turbulence,” he said.

”We made a bit of a skid to the left, got the wobbles and then dropped in altitude.

”The girl I was sitting next to said, ‘the engine is on fire’, and I looked out and saw what looked like a giant Roman candlestick.

”It varied in intensity and was quite extraordinary.”

The airworthiness directive warned that ”several low pressure turbine shafts had been found with cracks originating from the rear cooling air holes”.

Qantas said that it was ”fully compliant” with the airworthiness directive, which required that the engine be inspected the next time it was due for maintenance.

A replacement engine has been flown to San Francisco.