SFO- Asiana 777 crash

[sascha 314]

 

 

So why not remove one more element of risk by having controllers vectors plane with safety in mind instead of airport arrival rate?

 

That would be sensible, so it's not going to happen ...

[Spam3d 54]

I'm beginning to think that the FADEC stuff doesn't increase engine responsiveness in the approach phase, but dampens thrust variations at higher altitudes (mainly in cruise). Damping then is removed for approaches.

 

Is that about what it's like?

 

Yes it does a lot for the engine, the fadec system uses sensors such as temp, pressure sensors through out the engine to correctly set VSV actuator positions, bleed valves etc, and feed data to the HMU servos to correctly set fuel flows for combustion, it calculates the best and fastest way to deliver fuel and set compressor configurations, without surging the engine. Thats a very basic description but it is an integral part of the engine operation.

[3-2-1-Now 126]

I really can't be bothered to explain things to you guy's anymore... The diagram posted clearly shows that you have to descend in V/S with the MCP window above present altitude.

 

No it doesn't. It says exactly as I quoted. Boeing *suggest* that you set the go-around altitude around 300 ft before MDA(H) - NOT before. The Asiana crew did it a long time before then, which is extermely bad practise.

 

The PPruNe link that you provided says exactly what I did - namely that you must actively and consciously fly the aircraft away from the selected altitude. Several posts clearly state the obvious danger of descending at already low altitude with the altitude set above the aircraft.

 

This guy says it best:

 

 

 

of course if you do nothing the autopilot will happily descent you into the ground

 

As always, "just because you can, doesn't mean you should".

 

If you really, seriously think that flying away from the selected altitude in vertical speed mode is a safe thing to do, then I await to read the findings of your future crash. Not everything on PPruNe is accurate, safe, or "the only way to fly".

 

Best regards,

Robin.

[FLEX1978 373]

No it doesn't. It says exactly as I quoted. Boeing *suggest* that you set the go-around altitude around 300 ft before MDA(H) - NOT before. The Asiana crew did it a long time before then, which is extermely bad practise.

 

The PPruNe link that you provided says exactly what I did - namely that you must actively and consciously fly the aircraft away from the selected altitude.

 

As always, "just because you can, doesn't mean you should".

 

If you really, seriously think that flying away from the selected altitude in vertical speed mode is a safe thing to do, then I await to read the findings of your future crash. Not everything on PPruNe is accurate, safe, or the only thing to do.. 

 

Best regards,

Robin.

 

Jeez,  we are talking about a SOP for every single company I know off (SOP combined with common sense) . Many single actions on the flight deck can be considered unsafe if other safety nets are not put in place. It is not considered dangerous because the flight crew are trained to monitor the situation. 

 

What part of approved procedure do you not understand? And what makes you think that because you are flight simmer you know best?.... In fact don't even bother answering :)   If you still don't get it refer to FTCM 6.4.1

 

For obvious reasons I cannot post the FTCM here - This is a cut & paste from an ILS approach after being held high by ATC above the G/S

 

The following procedure should only be applied when established on the localizer.

 

There are a number of factors which might lead to a glide slope interception from above.

 

In such a case, the crew must react without delay to ensure the aircraft is configured for landing and stabilised before 1000 ft AAL.

 

In order to get the best rate of descent when cleared by ATC

and below the limiting speeds, the crew should lower the landing gear and select Conf 2.

Speedbrakes may also be used.

 

The recommended target speed for this procedure is VFE Conf 2 minus 5 kts. When cleared to intercept the glide slope, the crew should:

 

· Press the APPR PB on FCU and confirm G/S is armed (G/S Blue).

· Select the FCU altitude above aircraft altitude to avoid unwanted ALT*.

· Select V/S 1500 FPM initially, then adjust the V/S as required keeping in mind that a V/S

in excess of 2000 FPM will result in the speed increasing towards VFE

 

 Your post's are ridiculous Robin, I am not even going to humor you by replying to rest of your posts.  I have nothing else to say on the matter.

[3-2-1-Now 126]

And what makes you think that because you are flight simmer you know best....Your post's are ridiculous Robin

 

Uhh... who said I only did flight simming? I don't just write software... that is only my day job. :lol:

 

Besides, I think ad hominem attacks are the very reason this thread is being monitored. :mellow2:

 

Regarding the stuff you posted about an intercept of a GLIDE SLOPE from above just demonstrates your lack of understanding of the problem. In the case of glide slope intercept from above, the system will (correction: should) capture the GLIDE SLOPE. It is not being left to run itself into the ground at 1500+ ft/min 3 miles from the airport boundary.

 

I can quote procedure manuals all day (any preference?) but it has little bearing to the discussion.

 

Golden rule: Never let the AP fly the aircraft in VS mode with the altitude selector set in the opposite direction.

 

Thus endeth the lesson.

 

Still has no relevence as to why the Asiana flight crew used FL CH (with the altitude set above the aircraft no less) to try and descend faster to intercept the desired approach path on a visual approach. I think we will never know the answer to that.

 

Best regards,

Robin.

[FLEX1978 373]

I'm done here Robin, and I apologize if I caused any offence.

 

Regards 

[3-2-1-Now 126]

This is similar to the Asiana crash: http://lessonslearned.faa.gov/ll_main.cfm?TabID=1&LLID=71&LLTypeID=2

 

* OP DES (FL CH in Boeing terms)

* Altitude selector set such that it would never capture (in this case, below the altitude of the terrain).

 

I can find many more examples of why you should NEVER do this...

 

Best regards,

Robin.

[FLEX1978 373]

Yes very familiar with this accident.  Just like Asiana the issue here is the monitoring,CRM, and incorrect use of modes OP DES (FLCH)

 

If they flew the approach according to Airbus SOP we wouldn't be discussing this accident.  The use of open descent in that situation is completely inappropriate.  I haven't looked at that airline SOP but would be willing to bet my house that they where not taught to fly like that. 

 

The issue is not about dangerous SOP, the issue is not following SOP. 

[Don t moderate me this way 882]

This is similar to the Asiana crash: http://lessonslearned.faa.gov/ll_main.cfm?TabID=1&LLID=71&LLTypeID=2

 

(...)

 

 

Good find, Robin. Almost like Asiana 214 with an Airbus.