US Air 1549 update January 22, 2009

During the last days many new details surfaced about the 6 minutes (more or less) of the US Air 1549 that ended with a successful textbook ditching of an Airbus 320 in the cold water of the Hudson river, New York City. First of all, many videos have been released, some of which clearly show the aircraft touching softly the surface of water and stopping a few meters later. I would have expected it to “sail” a few more, but it seems that it came immediately to a stop. The following Youtube video provides views of the touch down from different angles:

For sure, it seems like the A320 has some unexpected amphibious capabilities, especially if you think the pilots had not pushed the Ditching button that closes all the “holes” of the airframe to enhance floating  ability of the aircraft at sea (because it was later on the ckecklist they were following and had not time to read it). This is one of the most interesting things that was explained in the last NTSB press conferences on the mishap. The other details deals with the following points:

• The aircraft touched down in the Hudson, where the water depth is around 50 feet. The weight of the plane, filled with water after sinking was about 1 million pounds and for this reason the aircraft had to be lifted by a crane very slowly in order to let the water drain.
• While the right engine is still in its original place, the left one was found some 50 feet below the surface.
• The crew members were the last to evacuate the aircraft and as it was recalled by the survivors, Capt. Sullenberger twice checked the cabin for missing passengers before escaping from the front door that was around 2 or 3 feet above the water level. Among the passengers there was also one lap child and a small one. The crew members were flying the forth leg of a 4 day shift (KPIT-KCLT-KLGA-KCLT).
• Capt. has 3.800 hours on the A320 while the First Officer, that was the initial Pilot Flying just 35. According to what they have recalled, the FO saw birds and shortly later the windscreen was filled by big dark (brown) birds. After experiencing the loss of thrust, the Capt. took the command saying “My aircraft!” then he lowered the nose in order to gain speed (that had reduced for the loss of both engines) while the FO began the Dual Engine flame out check list (and attempting to relight the engines). Turning back to La Guardia was discarded since the Airbus was too low and too slow; Teterboro was too far so the pilot called for Flap 2 and headed for the river trying to land as near to a boat as possible.

Noteworthy, Teterboro was considered too far. I initially thought that the Capt. had not opted for that airport because the runway was too short: actually, the airport has a runway (01/19) that is 2.134 mt long, equipped with ILS and PAPI that could be used by an Airbus 320. But, the runway orientation would have required the US1549 to perform at least a couple of turns to aligh, meaning that the distance for Teterboro could not be covered by the N106US flying without both engines. An Airbus 320 should have a gliding ratio of 17:1. This means that, with no thrust but in the correct configuration, starting from an altitude of 1.000 meters, it could fly for 17 chilometers before reaching the ground. Let’s say that that value is just theoretical and that, in that conditions, the N106US had a gliding ratio of 13:1. Since it was around 1.000 meters it should have been able to cover a distance of 13 chilometers (in straight line, without considering buildings in the overflown area). Using Google Earth I calculated that the distance from the birdstrike position to the airport (without considering any turn) exceeds 15 chilometers. So, Teterboro was indeed too far.

Furthermore, some journalists discovered that the same aircraft, whose registration is N106US, flew the same route as flight US1549 (AWE1549) on Jan 12 and that on Jan 13 it suffered a compressor stall. As it was reported by the CNN, about 20 minutes after departure from La Guardia, the plane “had a series of compressor stalls on the right engine. There were several very loud bangs and fire coming out of the engine. The pilot at first told us that we were going to make an emergency landing, but after about five minutes, continued the flight to Charlotte.” Since I have already reported the highlights of the press conference, the fact that the aircraft had a compressor stall on the same route 2 days prior to the dual engine failure is just pure coincidence (even if it is better to wait for the NTSB final report…).
Roland Posnett sent me the link to the full article about US1549 flight of Jan 13, 2009:

Passengers report scare on earlier US Airways Flight 1549

* Story Highlights
* Three say US Airways Flight 1549 nearly made emergency landing earlier last week
* Two days before last week’s crash-landing, passengers report loud bang on flight
* One passenger says he sent a text message to his wife: “I love you”

By Abbie Boudreau and Scott Zamost
CNN Special Investigations Unit

(CNN) — Two days before US Airways Flight 1549 crashed into the Hudson River, passengers on the same route and same aircraft say they heard a series of loud bangs and the flight crew told them they could have to make an emergency landing, CNN has learned.

Steve Jeffrey of Charlotte, North Carolina, told CNN he was flying in first class Tuesday when, about 20 minutes into the flight, “it sounded like the wing was just snapping off.”

“The red lights started going on. A little pandemonium was going on,” Jeffrey recalled.

He said the incident occurred over Newark, New Jersey, soon after the plane — also flying as Flight 1549 — had taken off from LaGuardia Airport in New York.

“It seemed so loud, like luggage was hitting the side but times a thousand. It startled everyone on the plane,” Jeffrey said. “We started looking at each other. The stewardesses started running around. They made an announcement that ‘everyone heard the noise, we’re going to turn around and head back to LaGuardia and check out what happened.’

“I fly about 50 to 60 times per year, and I’ve never heard a noise so loud,” he said. “It wasn’t turbulence, it wasn’t luggage bouncing around. It was just completely like the engine was thrown against the side of the plane. It just — it didn’t shake the plane but it shook you out of the seat when you’re drifting off, it really woke you up. And when it happened again, everyone just started looking at each other and there was a quiet murmuring around the plane, and you could feel the tension rising just in looking.

“I remember turning to my [business] partner and saying, ‘I hope you got everything in order back home, life insurance and everything, because that didn’t sound good.’ “

Jeffrey said he sent a text message to his wife about a “scary, scary noise on the plane. Doesn’t sound right. They’re flying back to LaGuardia to check it out. I’ll call you when we land. I love you.”

He added, “About 10 minutes later when we never made the turn, we kept going, that’s when the pilot came on and explained — I wish I could remember the words — I remember him using air, compression and lock — I’m not sure the right order, but he made it sound like the air didn’t get to the engine and it stalled the engine out, which he said doesn’t happen all the time but it’s not abnormal.”

Expert Aviation Consulting, an Indianapolis, Indiana, private consulting firm that includes commercial airline pilots on its staff, said the plane that landed in the Hudson was the same one as Flight 1549 from LaGuardia two days earlier. PhotoSee images from the rescue in last week’s crash »

“EAC confirms that US Airways ship number N106US flew on January 13, 2009, and January 15, 2009, with the same flight number of AWE 1549 from New York’s LaGuardia Airport to Charlotte Douglas [International] Airport in North Carolina,” Expert Aviation said in a statement to CNN.

The company said it checked with contacts in the aviation industry to confirm that it was the same plane.

The National Transportation Safety Board released the tail number of the downed Airbus A-320, which is N106US.

NTSB spokesman Peter Knudsen said as part of its investigation into the Hudson River crash, it will be looking at all maintenance activities, but has no indications of any anomalies or any malfunctions in the aircraft, so far in the investigation.

The Federal Aviation Administration referred CNN to US Airways.

US Airways would not confirm that the Flight 1549 that took off January 13 was the same plane that splashed into the Hudson two days later.

Valerie Wunder, a US Airways spokeswoman, said: “US Air is working with the National Transportation Safety Board in this investigation.” She would not comment on any other details, including Tuesday’s flight, though she did confirm US Airways is looking into it.

Jeffrey told CNN that US Airways earlier Monday confirmed to him that the Tuesday incident occurred aboard the plane that crashed.

John Hodock, another passenger on the Tuesday flight, said in an e-mail to CNN: “About 20 minutes after take-off, the plane had a series of compressor stalls on the right engine. There were several very loud bangs and fire coming out of the engine. The pilot at first told us that we were going to make an emergency landing, but after about five minutes, continued the flight to Charlotte.”

In an interview, Hodock said the pilot “got on the intercom and said they were going to have to make an emergency landing at the nearest airport. But then, only five to 10 minutes later, the pilot came back on and said it was a stalled compressor and they were going to continue to Charlotte.”

A third passenger, who did not want her named used, also said she heard a “loud banging sound” on the right side of the plane. She said she heard the pilot say the “compressor for the engine was stalled” and they needed “to turn around and go back.” However, she said, the problem was fixed and the flight continued without incident.

Pilots and aviation officials said that a compressor stall results from insufficient air getting into the engine and that multiple stalls could result in engine damage. However, the officials said, a momentary compressor stall may be less serious and could be corrected in flight by simply restarting the engine.

A bird strike could lead to a compressor stall, the officials said.

All AboutUS Airways Group Inc. • Air Travel

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