US Air in the Hudson

[Bruce Fenstermacher]

Thanks Voorheesh I had wondered about the electrical and hydraulic power.

I was also wondering if they where able to actually stall the aircraft into the water. Or would the on board computers of the fly by wire system not allow the pilot to do that and they where forced to enter the water at a higher speed.

[johneeb]

I am wondering, don't the engines have to be operating to apply reverse thrusters for landing on short runways? My thoughts are this was his only option.

John

Thrust reversers are not considered in calculating landing or stopping distances. (That way their failure to perform doesn't penalize the anticipated operation.)

They do or did at Southwest until they went of the end of 31 at Midway. A policy that I hope Southwest has now dropped.

http://www.ntsb.gov/pressrel/2006/060127.htm


FOR IMMEDIATE RELEASE: January 27, 2006 SB-06-06

NTSB URGES FAA TO PROHIBIT AIRLINES FROM USING THRUST REVERSER CREDIT IN DETERMINING RUNWAY STOPPING DISTANCES (Safety Recommendation A-06-16)


--------------------------------------------------------------------------------


WASHINGTON, D.C. - The National Transportation Safety Board today urged the Federal Aviation Administration to prohibit airlines from using credit for the use of thrust reversers when calculating stopping distances on contaminated runways.
The urgent safety recommendation is the result of information learned by the NTSB during its investigation into a fatal runway overrun in Chicago last month.

"We believe this recommendation needs the immediate attention of the FAA since we will be experiencing winter weather conditions in many areas of our nation for several more months to come," NTSB Acting Chairman Mark V. Rosenker said.

On December 8, 2005, Southwest Airlines flight 1248, a Boeing 737-7H4, landed on runway 31C at Chicago Midway Airport during a snow storm. The aircraft failed to stop on the runway, rolling through a blast fence and perimeter fence and coming to rest on a roadway after striking two vehicles. A 6-year-old boy in one of the automobiles was killed.

While approaching Chicago on a flight from Baltimore, the pilots used an on-board laptop performance computer (OPC) to calculate expected landing performance. Information entered into the computer included expected landing runway, wind speed and direction, airplane gross weight at touchdown, and reported runway braking action. The OPC then calculated the stopping margin. Depending on whether WET-FAIR or WET-POOR conditions were input, the computer calculated remaining runway after stopping at either 560 feet or 30 feet.

Both calculations were based on taking a stopping credit assuming engine thrust reverser deployment at touchdown. Flight data recorder information revealed that the thrust reversers were not deployed until 18 seconds after touchdown, at which point there was only about 1,000 feet of usable runway remaining.

The FAA does not allow the use of the reverse thrust credit when determining dispatch landing distances; in fact, historically decreases in stopping distances due to thrust reverser deployment were used to offset other variables that could significantly degrade stopping performance. However, the FAA does permit thrust reverser credit for calculating en-route operational landing distances for some transport category aircraft, like the 737-700 series, but not for others, like the 737-300.

If the thrust reverser credit had not been allowed in calculating the stopping distance for flight 1248, the OPC would have indicated that a safe landing on runway 31C was not possible. "As a result," the Board said in its recommendation letter, "a single event, the delayed deployment of the thrust reversers, can lead to an unsafe condition, as it did in this accident."

Although the recommendation would prohibit the thrust reverser credit on all runways, its practical effect would be felt on planned landings only on contaminated runways, which is when the credit is included in stopping distance calculations.

Therefore, the Board is recommending that the FAA:


Immediately prohibit all 14 Code of Federal Regulations Part 121 operators from using the reverse thrust credit in landing performance calculations. (A-06-16) (Urgent)

A copy of the recommendation letter may be found at the following link on the Board's website: http://www.ntsb.gov/recs/letters/2006/a06_16.pdf



NTSB Media Contact: Keith Holloway, (202) 314-6100
hollowk@ntsb.gov

[voorheesh]

I stand corrected on the SW accident. It appears they did have permission to use reverse in their performance calculations. I flew different airplanes and Part 121 required us (our dispatchers) to calculate our planned landing weight at destination and alternates so that we met the runway length rule. Our Part 25 performance data from the AFM did not take credit for lack of reverse thrust. I remember our ground instructors made a big point of that in training. Once released, we had a performance manual in the airplane that had max landing weights for each runway we used and it was the pilot's job to check on actual temp, wind, and runway contamination when we got our numbers for the actual landing. I do not remember if reverse was considered in our performance manual. I flew one airplane, the BAE 146 that did not have reverse but relied on lift spoilers and killer brakes. If we had an emergency like US Air, we could deviate from regulatory requirements and use any runway that would work. Regarding whether the flight computer of an airbus will allow it to stall, I do not know the answer to that. From looking at pictures on the internet, it appears he flew it on at a pretty good speed and let the tail contact first. Then it appears to slow down because of drag from the water and settle in for a smooth landing. I don't know any more about ditching then anyone else in this forum but from pictures I have seen, if you were to catch a wing tip, it would cartwheel and if the nose were to impact H2O, the fuselage would likely fail/break up. It will be interesting to learn about the birds. How many, what kind, etc. Engines are supposed to be able to withstand bird strikes up to a certain point. I wonder if there will be fall out or changes in procedures after this accident.

[johneeb]

Source of the below information is unknown.

There's been much discussion about US Airways Flight 1549 and the extraordinary circumstances that befell the Airbus A320-200 (N106US) and her compliment of 150 passengers and 5 crew. At least preliminarily, it appears a double bird strike disabled each of theCFM56-5B4/P engine forcingCaptain C.B. Sullenberger IIIand his First Officerto ditch the jetliner in the Hudson River.

As the aircraft was making its 'final approach' to the Hudson, the crew was preparing the aircraft and its passengers for the water landing, including, some speculate, by activating the ditching system on the A320. The button, cleverly labeled 'ditching', is located on the 'Cabin Press' section of the overhead panel shown above.

So what does that infrequently used button actually do?

When pressed, it commands the aircraft operating system to close the outflow valve, emergency ram air inlet, avionics inlet, extract valve and flow control valve. In addition, it will immediately shutdown the cabin fans. The button itself has a guard over it to prevent accidental activation. The system is available on all A320 family, A340/A330 and A380 aircraft.

According to the A320 quick reference guide, the ditching procedure calls for Flaps 3 and a minimum approach speed of 150 kts. The system should be activated at 2000 feet AGL and Airbus recommends 11 degrees of pitch at the time of touchdown.

The ultimate purpose of the system is to seal the aircraft to prevent water from undermining the buoyancy of the aircraft to keep it afloat in the event that the airframe remains intact after impacting the water. Federal Aviation RegulationPart 25, Section 801describes the safety requirements in the event of a ditching:

(d) It must be shown that, under reasonably probable water conditions, the flotation time and trim of the airplane will allow the occupants to leave the airplane and enter the liferafts required by25.1415. If compliance with this provision is shown by buoyancy and trim computations, appropriate allowances must be made for probable structural damage and leakage. If the airplane has fuel tanks (with fuel jettisoning provisions) that can reasonably be expected to withstand a ditching without leakage, the jettisonable volume of fuel may be considered as buoyancy volume.

It's not hard to imagine that this live test of the 'Ditching' system was a resounding success.

[4-Shipp]

According to several professional pilot forums, the button was not pushed. It was on page three of the appropriate checklist and they simply did not get that far before they landed. Very busy they were. However, there are accounts of the flight attendant in the aft galley actively intervening in a passenger's attempts to open the aft cabin exits. If this turns out to be factual, she may be the true hero of the day, preventing the cabin from filling quickly filling with water. More to follow, I'm sure.

Bruce

[russfarris]

From the damage I've seen to the aft fuselage - skin ripped off and mangled over quite a large area - I don't think the "ditching" button would have made a bit of difference.

I wasn't suprised to see this. On two previous "water landings" (not intentional ditchings, they landed short) a Japan Airlines DC-8
and a National Airlines 727, the fuselage skins were similarly shredded on the lower rear fuselage. The DC-8 was even repaired and flew another 30 plus years. This Airbus was in a textbook ditching, and damage was still substantial.

I've seen pictures of tests done in the 1960s, of a dynamic-scaled model of a 707 ditching in a test tank. The damage to the fuselage skins were remarkably accurate.

At 130 knots, that water's hard! Russ Farris

[4-Shipp]

More interesting reading...

From USAPA...

A second issue Communications would like to address is the way the press has emphasized the Captain of the flight, seemingly ignoring the crew. This has not gone un-noticed by any of us. It is apparent the press wanted a “hero” and Captain Sullenberger was selected. It is ironic that Captain Sullenberger’s prime concern throughout the entire event was the welfare of his crew as demonstrated by his remarks to President Bush and the entire crew’s inclusion of and visit to Doreen Welsh, the hospitalized B Flight Attendant.

On speaking to the subject, Media Sub-Committee Chairman, Captain James Ray, stated that we all share the frustration about the press omitting, to a large degree, the efforts of First Officer Jeff Skiles and the three Flight Attendants. In talking to countless reporters over the last several days Captain Ray attempted to stress the point and educate them on the matter of crew concept. For whatever reason, they generally chose not to mention this in many of their reports. Unlike previous media events and due to the sensitivity of NTSB communications, up to this point Captain Ray has generally stayed off-camera and the press has run off with the “hero” concept, rather than the “crew” concept. Captain Ray believes we will have opportunities to educate the public on this issue in the near future. All of that said, we want to re-emphasize the phenomenal experience of the remainder of this crew which, without a doubt, contributed to the successful outcome of this event:

* First Officer Jeffrey B. Skiles, joined US Airways (USAir) in 1986. He has a total of 15,643 flight hours and previously flew as Captain with US Airways.
* Flight Attendant Sheila Dail joined US Airways (Piedmont Airlines) in 1980 and has more than 28 years experience with the airline.
* Flight Attendant Doreen Welsh joined US Airways (Allegheny Airlines) in 1970 and has more than 38 years experience with the airline.
* Flight Attendant Donna Dent joined US Airways (Piedmont Airlines) in 1982 and has more than 26 years experience with the airline.

NTSB press conference:

* NYPD has good radar “hit” on the lost engine. NOAA boat is en-route
* 3rd F/A has been released from hospital. Her account - "loud thunk, smelled electrical smell". Harder landing description than other F/A’s described (AFT B flight attendant position). No broken leg, deep lacerations.
* This was the last leg of a 4-day trip. They had flown PIT-CLT-LGA & were on their way to CLT
* Captain, 3800 hrs in A-320
* First Officer, 35 hours in an A-320
* First Officer was initial PF
* First Officer stated he saw birds 3-5000’ off to his right
* Captain looked up & said the windscreen was filled w/big dark brown birds. Said his reaction was to duck
* Captain smelled burning birds
* Loss of thrust, Captain, “my aircraft”. First Officer, “your aircraft”. Captain lowered nose because speed had decreased
* Captain said power loss was symmetrical
* Captain took over as PF & called for the Dual Engine failure check list
* Captain said initial plan was to return to LGA. He said he was too slow & too low, it was too populated. Teterboro was too far, populated and would be catastrophic if he didn’t make it. As stated in earlier brief, he stated, "going to be in the Hudson".
* Captain focused on flying
* First Officer focused on checklist & starting engines
* This checklist is meant to run at FL350
* Captain called for flaps 2
* Captain made the “brace” call over the P/A
* Captain said he had been trained to ditch near a vessel if able, so he tried to land close to a boat
* The aircraft lost electrical once in the water
* Captain called for Evacuation, F/A’s had already initiated it
* Captain stated that, "he could not be more happy that he got everyone off”.


Question session:

* First Officer saw the birds, noted to himself that they were in a nice line
* Ditching P/B was not pushed. It is on page 3 of the checklist; they didn’t get to it
* First Officer, while low time in AB, but typed in other aircraft, glass cockpit, has been a Captain before, IOE was completed.
* Captain estimated the aircraft hit the birds between 220 & 250kts
* How did F/A get lacerations? Don’t know. Water was cold; she didn’t know she was hurt initially. After she sent passengers up the isle, she realized she was bleeding & got herself out and into the raft
* Is CVR powered after crash? Powered until power goes out.

[sloPoke]

Anybody on in the 170 group fly A320s? I found this on an internet search about EEC's for CFM56 engines on an A340:

Fire and Overheat Protection: Automatic engine shutdown, initiated by the EC when detection of fire or overheat, the philosophy being to avoid failure of EEC
components which could lead to hazardous effect to the A/C.

That is from an A340 airbus manual. Sounds like if you get an detection of fire or overheat they shut themselves down to
"prevent hazardous effect to the A/C" from failure of EEC components. Hopefully this is not the case. I'd rather have out of limits EGT or even fire warnings but still keep the engines running to get to an airport, then buy new engines.

[170C]

Article in the Fort Worth Star Telegram stated the ditching button wasn't activated as mentioned above. I had wondered if it would have made a difference and as was pointed out the rear skin was compromised so that would explain why the rear of the fuselage began sinking so quickly. One passenger in row 20 or 22 was on Fox & Friends (I think it was that network) and stated he and others attempted to go to the rear of the plane to exit, but that the doors weren't open. Probably because the flight attendants knew not to do so. Passenger stated that as the group of rear cabin passengers headed forward that water had risen to the top of the seat backs and there was difficulty getting passengers to move forward quickly. A job well done by all involved to say the least. I, too, had misgivings about the hero accolades. The captain, no doubt is a hero as is the remainder of the crew and atc probably played a role too. Unfortunately the media chose to focus only on the captain. The problem is the news media knows little about aviation and focus only what they deem to be sensational things that sell papers, news broadcasts, etc. No doubt some networks have aviation experts employed, but the editors still go for being first with the worst. (IMHO)

[sweet p]

Another theory as to the cause of the ditching.

[GAHorn]

Another theory as to the cause of the ditching.

Canadians!

[c170b53]

Those are not cheese balls George

[johneeb]

Those are not cheese balls George

c170b53, George said Canadians not Wisconsiens

[cholzer]

russfarris: The JAL plane was a DC-8-62. It was bought by Airborne Express in 1986 and converted to a freighter. It was registered N808AX, and is in my log book several hundred times during my years with Airborne. 808 was actually a very good flying, and dependable aircraft. Sold, and scrapped in 2001. Watched it shredded, and every time I have a drink from a can, I wonder if I used to fly that can.

BTW, the JAL captain lost some serious 'face' over that incident, and on returning to Japan, fell on his sword, literally.

[johneeb]

This is a bit like Gallows Humor, it was just a matter of time before someone came up with this. It is a good thing it was not me flying that Airbus as I did not get it right the first time.
http://www.addictinggames.com/heroonthehudson.html