Northwest Jet Suffers Similar Malfunctions to Air France Flight

Wall Street Journal ^ | 26 June 2009 | ANDY PASZTOR and DANIEL MICHAELS

[Erik Latranyi]

He [Sullenberger] sure did get the landing angle perfect though, and that certainly didn’t happen by itself.

No it didn't. Another pilot may have tried to make it to Teterboro (which they had a visual on). Sullenberger knew from his gliding experience that his Airbus would not make it, leaving the tricky water-landing as the only option.

Yes, it was only a few seconds, but the skills Sully had as a glider pilot paid off.....huge.

[gusopol3]

Oh I don’t know, one time I was changing a tire and the voice said, “you’re jacked, man.”

[cynwoody]

GPS on Tomtom etc tells you how fast you’re going. 3d vs. 2d makes this impossible in the air?

Wind makes that impossible in air. The GPS calculates your speed through space just fine, but the air is moving, too, and you must take that into account to get airspeed. On airplanes, they measure the airspeed directly, using pitot tubes. Malfunctioning pitot tubes and/or the computer systems they feed are probably at the root of these incidents.

[GovernmentShrinker]

But Sully did first say he was going to turn around and go back to LaGuardia (clearly impossible) and then subsequently inquired about the Teterboro option (also clearly impossible). With a couple of minutes to think through the available data, and given his gliding knowledge, he certainly could have figured out that both these options were absolute physical impossibilities. But he just didn’t have time to apply the knowledge. I think when he finally realized that the “where” decision was being made for him — probably when he saw the surface of the Hudson right in front of him, right where the runway should be on a normal landing — he instantly concentrated on the landing angle, and that made all the difference between 100% survivors and 100% fatalities. Honestly, before that, I think he was having some of the same trouble the TRACON controller was having, accepting the reality that the only place this plane was going to go down was in the Hudson. If you’d showed him a video of an identical flight, before this incident ever happened, along with all the data that was available to him in the cockpit, I’m sure he could have said within 15-20 seconds of the bird strike that, absent a miraculous engine restart, the only option was the Hudson, and that no time should be wasted thinking about any other option.

[cynwoody]

From an interesting thread on rec.aviation.piloting, dated 25 June:

Well, I'm sure you have all heard of the Air France accident. I fly the
same plane, the A330.

      Yesterday while coming up from Hong Kong to Tokyo, a 1700nm 4hr.
flight, we experienced the same problems Air France had while flying
thru bad weather.
I have a link to the failures that occurred on AF 447. My list is almost
the same.
http://www.eurocockpit.com/images/acars447.php
            
      The problem I suspect is the pitot tubes ice over and you loose
your airspeed indication along with the auto pilot, auto throttles and
rudder limit protection. The rudder limit protection keeps you from over
stressing the rudder at high speed. 
      
      Synopsis;
Tuesday 23, 2009 10am enroute HKG to NRT. Entering Nara Japan airspace.

      FL390 mostly clear with occasional isolated areas of rain, clouds
tops about FL410.
Outside air temperature was -50C TAT -21C (your not supposed to get
liquid water at these temps). We did.

      As we were following other aircraft along our route. We approached
a large area of rain below us. Tilting the weather radar down we could
see the heavy rain below, displayed in red. At our altitude the radar
indicated green or light precipitation, most likely ice crystals we
thought.

      Entering the cloud tops we experienced just light to moderate
turbulence. (The winds were around 30kts at altitude.) After about 15
sec. we encountered moderate rain. We thought it odd to have rain
streaming up the windshield at this altitude and the sound of the plane
getting pelted like an aluminum garage door. It got very warm and humid
in the cockpit all of a sudden.
Five seconds later the Captains, First Officers, and standby airspeed
indicators rolled back to 60kts. The auto pilot and auto throttles
disengaged. The Master Warning and Master Caution flashed, and the
sounds of chirps and clicks letting us know these things were happening.
      Jerry Staab, the Capt. hand flew the plane on the shortest vector
out of the rain. The airspeed indicators briefly came back but failed
again. The failure lasted for THREE minutes. We flew the recommended
83%N1 power setting. When the airspeed indicators came back. we were
within 5 knots of our desired speed. Everything returned to normal
except for the computer logic controlling the plane. (We were in
alternate law for the rest of the flight.)  

      We had good conditions for the failure; daylight, we were rested,
relatively small area, and light turbulence. I think it could have been
much worse. Jerry did a great job fly and staying cool. We did our
procedures called dispatch and maintenance on the SAT COM and landed in
Narita. That's it. 

[patton]

“accepting the reality”

That is always the hard pard - we ALL tend to hang on to what we believe we know, when reality has changed.

[Liberty Valance]

*

[sionnsar]

GPS on Tomtom etc tells you how fast you’re going. 3d vs. 2d makes this impossible in the air?

Airspeed and groundspeed are two different things. GPS won't tell you the former.

[libh8er]

GPS on Tomtom etc tells you how fast you’re going

Ground speed (as measured by GPS) has little relevance in the air. What matters is how fast air is flowing relative to the airplane body -- also called airspeed. The two could be quite different, especially in stormy/turbulent weather.

[libh8er]

Ground speed (as measured by GPS) has little relevance in the air

Let me take that back. Ground speed will tell you when you will reach your destination. Airspeed is required for flight control.

[safisoft]

Heat kills electrical circuits FAIL ever notice the cases of smoke in the cockpit of late the curve in hydraulics has less effect with heat.As far as designers how about a/c units mounted near fuel cells?was it flifgt 300 that went down near New york?

You are confusing two different accidents. TWA was a Boeing 747 which blew up because of a center fuel tank. American 587 was a A300 which crashed because the first officer over-reacted to wake turbulence and over-controlled the rudder.

[safisoft]

Do any heavy metal drivers out there know if the aircraft had mechanical backup insturmentation for an artificial horizon? Or is the whole damn thing computer generated?

There is ALWAYS a mechanical backup, even in instrumentation. Ever Airbus even has a "whiskey compass" - what is at issue is reliance on flight computers. If the flight crew does not respond correctly to a failure of autoflight systems, then the redundancy of mechanical backups is lost. The A330, has a standby instrument gauge which displays horizon (roll and pitch), altitude, vertical speed, and airspeed. It is independent - but most importantly, the autoflight computers do NOT use it, so the crew must take over manually and transition to the standby instrument for some failures... there is the rub - knowing what to do, and doing it.

[UCANSEE2]

How do you measure air speed, as distinct from ground speed, with GPS?

You throw the GPS out the window, and see how fast it disappears.

[safisoft]

Airbus unaccountably insists on making large composite panels without incorporating metallic spars to distribute shear forces.

You are confusing modern aircraft manufacturing processes with aircraft manufacturers. Every aircraft designed post 1990s does similar manufacturing with regard to composites. All those "Boeing" apologists never mention that the B787 is not only not majority "American made" - it is also largely made of composites... and yes, with similar processes used by the military and Airbus. Compare 1970 era Boeings to 2000 era Airbus, and you see different uses of composites etc. Compare 2000 era Boeings to Airbus, and you do not see those differences.

Ironically, the cancellation of the original design of the A350 was on account that the (yet to fly) Boeing 787 was more composite than the A350. Airbus went back to the drawing board and designed the A350XWB to be even more efficient.

Bottom line: if a 12-g fighter can be manufactured this way, what makes an airliner different? This whole nonsense is nothing more than a "buy American" strawman. But like I said, the A350XWB will be more American-made than the Boeing 787.

These Boeing vs Airbus comments are as silly as Apple vs PC. An airplane is an airplane. Some good, some not so good. My airline's fleet is evenly divided between Boeings and Airbus. I have 10,000 hours in Boeings, and 6,000 hours in Airbus. I know them BOTH intimately.

[safisoft]

Yes, it was only a few seconds, but the skills Sully had as a glider pilot paid off.....huge.

All experience is valuable, but glider experience vs no glider experience is irrelevent. It was not glider experience that worked for him that day, it was simply HIS experience. Glider experience counts ZERO in an Airbus. IT DOES NOT EQUATE.

For the record, numerous simulations have been done and making it back to La Guardia could be done as well as Teterboro... but at less than even odds. The fact that he made the right decision is born out by the results, and that is all. That is why pilots are who we are: we aren't good for skill reasons alone... it is about judgment.

[safisoft]

The pilot said the airspeed indicators returned to normal, but the flight-control computers never did

SOME of the flight control computers did not return (called FAC, or Flight Augmentation Computers), but those are not needed to fly normally, and not returning to normal law is by design. It is designed so that if the aircraft achieves alternate flight control law, it remains that way until landing. It is a NON-EVENT to be in alternate law. Every airline that flies Airbus has a significant amount of their training done in alternate law. Pilots are trained to deal with it, and its effects are minimal (specifically, the aircraft lands slightly different, but that is the most of it).

[UCANSEE2]

Glider experience counts ZERO in an Airbus.

Unless you are landing the Airbus with 'wheels-up'.

There is much more forgiveness in landing an aircraft that has a nosewheel and mid-fuselage (or wing) wheels.

Most gliders have only one, or even no wheels, so the landing is very similar to landing on water.

[slowhandluke]

I’ve driven a car with a broken speedometer but a functioning tachometer.

For a stick shift, there is a fixed relation ship between RPM and road speed, as determined by the gear you are in, caused by fixed mechanical linkage from the engine to the transmission to the wheels to the road. There is no such fixed relationship for an aircraft and airspeed.

How does using a tach work as a speedometer when the car is hydroplaning? That's closer to what happens in the air.

[em2vn]

I wasn’t trying to indicate a relationship between road speed and airspeed.
I was commenting on the pilot’s reliance on the known speed of the engines and the conditions in which he was flying appeared to make the difference between a value rich event and a crash into the ocean.
There was no comparison made other than the relationship of experience to one’s reactions to an event.

[El Gato]

Pilots are trained to deal with anomolies, and we deal with them REGULARLY.

Which is why cutting back on simulator time is Not a Good Thing. Most, but not all, of that training for "anomalies", occurs in a simulator, not a full sized aircraft out over the ocean or desert.