Paphitis wrote:Kikapu wrote:Paphitis wrote:Kikapu wrote:In the AF447 case, once the pilots no longer knew which way was up or down and had no clue what they were doing, had they just switched the Auto Pilot back on again, would the computers on board could have solved the problem in seconds and set the plane back on on it’s normal attitude again with the information that was already pre programmed into the system?
Also, does the cockpit not have a GPS, telling pilots how fast they are moving separate from the information they get to the air speed from the pitot tubes? The passengers get to see how fast they are moving on the Flight maps back of the seat screens. Are the passenger’s map screen information coming from the plane’s cockpit instruments or are they independent with GPS system?
There are three options in flying complex planes in seems.
1. Pilots monitoring automation
2. Automation monitoring Pilots
3. Automation monitoring Automation
In the long run, I believe option 3 will become the norm for safely flying in future planes, which are likely to be more complex than the planes we have today.
I'm not very up to date with this crash right now Kikakpu. I read the report a long time ago, and vaguely remember that there was a Pitot Static Failure which results in erroneous Indicated Airspeed readings. The Flight Management Computer might not have been much help at all.
Yes aircraft have GPS and this gives them Ground Speed (speed over the ground). Indicated Airspeed and Ground Speed are 2 separate things. When we fly an Aircraft we fly an Indicated Airspeed or speed through the air. All our approaches are flown on IAS. True Airspeed (TAS) is another thing again.
TAS - no pressure correction
IAS - applies a pressure correction
GS - speed over the ground (takes into consideration winds)
As to your options, there have been numerous studies into this conducted by the military, NASA, and manufacturers like Boeing, and they are finding that the 2 pilot crew is critical to safety and only a 2 pilot crew is able to deliver the nuances of aviation safety because automation is not able to assess risk or have the AI to comprehend and decipher all the variables and assess all the risks and take the most appropriate action. A Flight Managment Computer isn't going to make those critical decisions on whether it should conduct a Missed Approach or Go Around, or not depart at all due weather. We already have the automation and the FMC can indeed fly an entire flight from 200FT to virtually on the ground with a CAT 111 Instrument Landing System but those 2 pilots are very much in charge and absolutely critical.
So it is a incorrect to suggest that the AF447 pilots crashed this aircraft. It is also incorrect to suggest that the FMC would have saved the flight. The Autopilot would have blown a gasket if it was getting erroneous IAS readings and would have either failed or the auto throttle would have reduced power further thus deepening the stall.
Basically, the swizz cheese holes lined up, and AF447's number was up. It was a doomed flight.
For as long as people cross the road, people will get run over. For as long as cars travel the roads, their will be fatal crashes and for as long as aircraft take to the air, there will be a small number of flights that will meet their end. It will never change. the only thing that changes is that we get better and better and safer and safer but I don't think we can ever be infallible.
Paphitis, I was referring to the guardian article you had posted earlier mainly on the AF447. I thought you had read it.
In the article, the forward motion of the aircraft at one point was just over 70 knots as it was falling to the sea with a very nose up attitude, as the aircraft had stalled. As confused as the pilots were in the beginning because of the frozen pitot tubes giving erroneous instrument readings which caused the Auto Pilot to kick out, at this point, all the pilots had to do was to keep the plane level at the present power setting, just as it was just before the AP kicking out. Once the de-icing was activated and the pitot tubes were free from icing, it started giving the correct information to the instruments, even though the pilots did not trust these readings and continued to pull back on the stick making matters worse. Once the instrument were getting the correct information, couldn't the AP correct everything if it was switched back on again to resume flying on previous computer settings?
As a sailor, I understand the differences between True Wind (Speed + Direction) and Apparent Wind (Speed+ Direction), and even if the GPS was reading Apparent Speed (speed over the ground) at 70 knots forward motion, that is about 20% of normal speed surely at 35,000ft for the Airbus 330. That would require almost a 400 knots headwinds, which is unheard of to get such a low GPS speed for the pilots to not to realize they were in a stall and falling out of the sky, since the GPS speed was totally separate from instrument speed fed by the pitot tubes.
The FMC will not take into consideration the Ground Speed.
The only time we even look at it is when we are given speed restrictions or told to cross a particular way point at a certain time for Flow management into busy ports to achieve our slot time.
Other than that, it's all IAS and the Autopiliot will only fly an IAS. If the IAS is showing 250 knots, then that is what the autopilot and pilots will interrogate.
And because we are children of the magenta line, we will just input the time and the FMC takes care of the rest and adjusts airspeed as necessary.
I don't take media articles that seriously. I just posted it because it was a lazy source and someone asked for a source. I would much rather read the reports but I literally don't have the time right now and would rather not read it because my brain is going to explode. Need some time out of aviation dude. I got all these online re-currency exams to do and am in the sim on the 7th and 8th at like 3 am ...
Totally understand you needing time for your profession, Paphitis.
Come back soon refreshed and ready to go.
