Messin' with 'em at Edmunds

That was evil!! You know that some of the idiots wil believe that and quote it to all their friends.

 

Anyone who was rethinking a whole purchase on this one concern obviously wasn't the brightest fish in the barrel (especially when he starts equating this to the side drift from crosswinds).

I just hope he gets set straight and doesn't spread false info, I wouldn't be surprised if someone believes him.

 

But Edmunds is one of the definitive sources of any car info. False info like that might be fun, but it's going to be there a LONG time.

 

A guy could have a lot of fun there.

"I heard someone say that in the event of an emergency (such as the electric steering failure), there is an emergency "panic button" on the dashboard that jettisons the battery from the car. With the cables still attached, the battery will act as an anchor and bring the car safely to a stop."

And you could go on...

"I also read that this WILL destroy the battery pack and it will cost $8,000 to replace."

"PLEASE FORWARD THIS EMAIL TO EVERYONE IN YOUR ADDRESS BOOK!!! YOU MIGHT JUST SAVE A LIFE!!! Don't let a hybrid car give you a battery jump! The evening news reported that a guy tried to jump start a friend's dead battery with a Prius. The Prius has a 500 volt battery, so when they connected the cables, they blew up his friend's car!!!"

It must be true. I read it on the Internet!

 

I hate Edmunds hybrid boards. There are so many idiots posting there! The biggest loser is someone named gagrice. What a phucking moron!!!!!!

 

I just met a guy who said he had heard that the battery needed to be replaced every 30,000 miles.

 

Would it help the people at Edmunds if we mentioned that fly-by-wire steering technology has been available in the finest aircraft for years?

Of course, when the battery runs out, the plane can't land. :mrgreen:

 

Was it the Edmunds car review guy who remarked, assessing the handling of the Gen 1, that it was like "driving an appliance"? If not, it was the MSN guy.

He was basically saying that there's no road feel, everything's insulated courtesy of drive-by-wire. I don't think he was far off the mark. At least it gave me a mental image I carry around that makes me chuckle.

(Trying to resuscitate old threads following 10/05 crash.)

 

It's not a major problem to me. I do prefer more road feel---but not to the level of steering-wheel-shaking. Just a sports-car personal preference. My Honda Odyssey had good road feel.

 

That is the bad thing about The Internet in general, and forums/blogs in particular: everybody, and I mean EVERYBODY, is suddenly a genius.

Anybody with half a brain would have confirmed that the Prius steering is electric ASSIST. If worse comes to worse and the electric assist quits on you, there is still a DIRECT MECHANICAL LINKAGE between the steering wheel and the steering rack.

Just like conventional hydraulic assist power steering, if it quits you can still safely steer, though with much increased effort.

True military aircraft have had fly-by-wire since the early 70's, and civillian airliners since the mid 80's with the Airbus A319-321. There is no direct connection between the little video arcade style "sidestick" and the flight control surfaces.

AFAIK there have been no total failures, but the degree of CMM and FMECA/DMECA required to achieve that level of reliability is $$$$.

The comments about getting a boost from a hybrid car and causing the dead car to explode doesn't even deserve a response.

 

There were a least three incidents where an Airbus A320 flew into terrain and crashed when the computers overrode the pilots' manual controls.

FYI, those are the first three on this list.

 

Hey, that would explain all those airplanes circling around airports!
And they don't have much road feel, either. It must be true!

 

Actually that isn't true.

I hate to break this to you, but Boeings and MD aircraft crash too. In some cases there are mechanical problems (The servo valve in the rudder of older Boeing 737’s, the elevator jackscrew assembly on DC-9/MD-80 aircraft) but the vast majority of cases are pilot error or maintenance error.

In the case of that Alaska Air MD-80 that went down off San Diego, Alaska thought they could save a wad of money by not properly lubricating the threads on the jackscrew that moves the elevator. The elevator controls pitch in an aircraft.

The threads ran dry and galled/stripped. Finally, the aerodynamic forces in flight forced the entire jackscrew assembly out the top of the tail fairing, the aircraft entered a steep nose-down pitch, and was unrecoverable. The decent was witnessed by other commercial aviation pilots and they noted the wild corkscrew decent, pieces of aileron and other flight control surfaces departing the aircraft until it violently impacted the water.

The incidents you cited are more properly categorized as CFIT or “Controlled Flight Into Terrain.†CFIT has been a problem for a long long time now, not just with Airbus. How about that American Airlines Boeing 757 that crashed into the mountains near Cali, Columbia, in 1995? The pilot lost spatial awareness and allowed the aircraft to fly into the side of a mountain.

The big issue raised with the Cali crash was how inadequate conventional terrain warning systems were. Most are based on radar altimeters, which work fine if the terrain doesn’t dramatically change too much. In the case of the Cali crash the pilot had less than 20 seconds to recover, which was impossible.

According to the accident investigation once the pilot received the “Too Low Terrain†and “PULL UP! PULL UP!†aural warnings, he hit TOGA and pulled to the shaker. Unfortunately, it was simply impossible to recover and the aircraft crashed.

CFIT is so subtle and so deadly because, in essence, the flight crew will lose spatial/terrain awareness and allow an otherwise perfectly functioning aircraft to fly into the ground. Thus, “controlled†flight into terrain.

The Air France Airbus that crashed into the trees past the airshow runway was crashed on purpose. The pilot wanted to do a very low and slow flyby the crowd for dramatic effect, but the logic in the Airbus refused that maneuver. The Airbus flight control logic depends on – among other things – input from the radar altimeter, and is allowed to take action to protect the aircraft.

For example, if the pilot enters into too steep a climb for the configuration, Alpha Floor will inhibit the AOA (Angle Of Attack) and prevent a stall. In the case of the airshow crash, the flight control logic will use aural warnings (Too Low Terrain, pull up pull up, etc) and advance power to prevent a stall.

The Airbus fly-by-wire series does have means of disabling the flight protection envelope. This is required by LAW as there is always a very slight probability (Nothing can be zero probability) the flight protection envelope will malfunction. The pilot can “dump†the protection system by reaching overhead and disabling the automated flight control computers.

An example of “dumping†a system is a malfunction in the Stick Shaker that is supposed to alert a pilot to impending stall on a conventional aircraft. There is a Dump lever on the center console near the power levers to disable the stick shaker in the event of a false stall warning. By “dumping†the automated systems, the pilot forces the aircraft into Direct Law.

That is exactly what the Air France pilot did, then he could throttle to Flight Idle and stall the aircraft. Once the stall starts – especially at very low altitude - it’s a bit too late to hit the TOGA button (Take Off and Go Around: maximum engine thrust that is allowed by the engine maker) and recover. A classic “deep†stall is when the tail goes down and the flight deck points skyward.

The Air Inter Airbus that crashed was caused by the flight crew using the improper mode selection for the autoflight system. Instead of selecting FPA (Flight Path Angle), on the same knob they inadvertently selected F/S (Feet per Second). There is only a very dim LED to indicate which mode that button is in.

The correct FPA would have been around -3.4 degrees FPA. But the knob was in the wrong mode, so the display indicated “34.†Note it didn’t indicate “3.4†but again the LCD and LED displays in most flight decks are somewhat dim and hard to read, especially if you’re in a rush.

Instead of the mode putting the autoflight system into the proper -3.4 angle FPA for decent to the airport, it instead put the aircraft into a 3,400 feet per second decent. Flying in clouds, you would quickly experience spatial disorientation and probably not even be aware of how quickly the aircraft was descending. A good article on stall protection and terrain avoidance was prepared by the Airline Pilots Association:

http://www.bluecoat.org/reports/Rogers_99_CFIT_FBW.pdf

A lot of these CFIT incidents and crashes, and in general the altitude “busts†that appear to be occurring more frequently, can more properly be blamed on poor understanding of Human Factors Engineering. In other words why did the pilot not understand what was going on? What barriers in the information display or arrangement of controls turned a minor event into a deadly event?

I do HFE for industrial control systems and also for aviation (The company I contract for is a global engineering firm with a lot of involvement in those areas), and the biggest problem I have found is that the overall system design is haphazard and not very intuitive. For example, instead of using “soft key†buttons around the edge of the screen like on the new Boeing 777 fly-by-wire or the newest Airbus, a lot of the older designs still assign 2-4 modes per switch/knob.

A huge problem with assigning multiple modes to a single knob is the poor feedback and confirmation of mode change. I mentioned the slight but deadly difference in a display that indicates “34†and “3.4†but look how easy it is to overlook that decimal marker. A “soft key†should provide relevant selection based on current mode, and should be easy to understand. Though in cases of something designed “by software engineers FOR software engineers†that isn’t always the case.

I would prefer more tightly integrated avionics and better adoption of EGPWS (Enhanced Ground Proximity Warning System), so the autoflight can avoid known terrain issues, or at least have aural warnings of a terrain issue while there is still time to recover.

As a final thought, what do you do if a pilot REFUSES to heed warnings or information? An example is the Canadian charter airline Air Transat Airbus A330 in 2001 that ran out of fuel over the Atlantic and glided to the Azores to make a safe landing.

Improper maintenance started the chain of events: a new engine was installed but an accessory bracket was the wrong type. This allowed the fuel line to chafe against the bracket. More information:

http://www.iasa.com.au/folders/images/airt...evelations.html

About 200 km from the Azores, odd things started to happen onboard. The engine temperature went very low and the oil pressure went very high. Once the fuel line chafed through, cold jet fuel sprayed all over the engine, cooling it so much the oil pressure went up. It’s a wonder the aircraft didn’t burst into flames right then and there.

The flight crew became so preoccupied with the odd temperature and pressure readings they didn’t even notice the fuel onboard level. When they received the low fuel warning the pilot refused to believe it. He thought it was a computer “bug.†Even when the first engine flamed out they refused to believe the situation.

When the second engine flamed out, everything became VERY quiet. Fortunately the RAT (Ram Air Turbine) deployed, so basic hydraulics and electrical still worked. They glided around 20 mins and luckily nobody was killed.