Tinfoil hat backup airspeed sensor proposal
 

The many suggestions of using GPS and/or INS for backup airspeed come up short when it comes to correcting for wind, especially in turbulent conditions with the up and down drafts throwing off vortices.

I modestly propose force transducers on the radome mounts. The forces from the transducers could be algebraically summed to produce a net force which could then be processed against radome drag coefficient to produce airspeed.

Differentials between opposite sensors could even be used to derive AOA and yaw.

I hope those suffering boredom from trawling through the hamster wheel may have found some amusement ;)

And I notice that many of these so called experts aren't airline pilots themselves. I don't believe any current airline pilots would dare damage their own credibility and say anything to the media at this early stage because the fact of the matter is, we won't know what happened until the FDR and CVR has been recovered and analysed.

The media, especially in Indonesia, will continue to milk the story for a few weeks; the same as what happened previously with the Sukoi SJ 100 CFIT.

I don't know what to make of subjective words like "high rate of descent" etc. without verified data.

But if you want to restart engines you should be thinking of controlling your speed within restart limits, while at the same time extending your glide to give yourself enough time to benefit from a restart attempt. If they really are screwed up, they will be very sluggish in spooling back up at altitude and easily fool you into thinking they have flamed out (ala the China Air dive bomber on the way to SFO)

Then again the structure of the aircraft doesn't like vertical overspeeds as well. Make of it what you will but I doubt the pilots would command something of great extent

@HarryMann -- Do the math. Downdraft of 250+ mph?? I mean I'm the one speculating about unprecedented tropical weather phenomena, but that is beyond even my ability to conjecture.

Several days ago, SIN announced in was sending Sonar Locators. Nothing heard since.

Leaving a managerial position at Total to join P2F for Air Asia with that education..with all respect for the poor guy seems odd. I happen to have friends in Air Asia recruited as direct upgrade FO .... they actually paid for their upgrade as well. Time to say enough with P2F.

That apparently doesn't apply to many posting here. Perhaps anonymity allows them to ignore your very sensible point, particularly when it comes to sticking the boot in to Airbus or its engineers, for some reason.

That's not an altogether stupid idea. The only problem is changes in apparent drag due to accumulated ice or water striking the surface in rain.

Back in my micrometeorolgy days I'd considered and discarded this approach when looking at low cost wind speed and direction sensors.

But 10/10 in the lateral thinking stakes!

Jesus wept!:rolleyes:

I see your photo Mach2point7, wooden airframe parts in an A320....seriously??

This is the topic that mass media will not discuss...not even the affable Richard Quest...

It is off limits! :=

I think you are right, there needs to be a discussion about this business practice. When lives are at stake, you need 2 equals up in the cockpit who can figure things out together. The FO needs to step in if need be.
Does P2F compromise this? That is the question...

For all against P2F.
Even if this was P2F, l would have thought that after over 2000 hrs he would have leaned a lot more than just asking if the Captain wanted sugar in his tea.

First funeral held for passenger on AirAsia flight QZ8501

Hope that they did not miss to examanine "cause of death"

The news report only says that victims are being identified.

Mach2point7 : if this photo is a debris from the aircraft we are talking about here, then this kills the "nice smooth " water ditching theory of some journos.

Yes I would agree too, but not sure to what extent...

I think the real issue is the dynamics in the cockpit. Is there true respect and and positive working environment? or is it dysfunctional with the with the old air force pro wary of jumping off to the toilet for a few minutes?

Is there really that much fact in any so called news
 

For those of us who actually do this for a living, for those who have done so previously or even are just really interested, not to say incredibly knowledgeable, in aviation as a whole this is a Rumour Network so people can and do say, declare and claim their bit of rumour, theory or supposition.

That said of course when we who know something look at the sensationalism and wild ass claims of the media with their so called experts in, well to be frank, any thing really, are we really suprised that it is so wrong. Not only that, if you take aviation as a single subject and look wider across All news from finance to auto motive or conflict to the culinary arts say. Journos are the self licking lolly pop that sensationalises everything to grab the interest of the lowest common denominator and give them "Facts" of News that they can talk about. When we see from our part of ship the tripe they and their experts come up with is it not somewhat indicative of the made up and hyped nature of pretty much everything else within the media circle we read about, listen to and watch. Simply declaring their facts not surrounded by subterfuge, gossip, rumour and sensationalism wouldn't be half as interesting to the general public.....
This, our Rumour Network, also has Wild Ass guesses of reason and cause but we can sift it and discredit it amongst ourselves....relying on the commercial media to give us our facts, well quite frankly, maybe worth an over view but then leave it in the back ground. Eventually more real facts wil come out and we can look back, say " ah so that's why it climbed, descended, pitched, rolled and our companies will like as not throw in some delayed but enhanced training package as mitigation of what we have found out was sadly lacking before.
So rumour on and let everyone have their say............:)

Families evicted from hotel
 

AirAsia flight QZ8501: Families of victims 'evicted from their hotel on New Year's Eve' - Asia - World - The Independent

Search Navy Admiral’s statement posted on AirAsia Ceo’s pg
 

Area covering 1,575 square nautical miles will be scoured by three vessels equipped with underwater detection equipment, said Admiral Abdul Aziz Jaafar.

KUALA LUMPUR: In Day 6 of the search for the missing AirAsia flight QZ8501, the search zone has moved 30 nautical miles east from the previous day, while an area covering 1,575 square nautical miles has been established as the “Most Probable Area” where the wreckage will be found, according to the Malaysian Chief of Navy.

“This is the most likely area of the missing plane,” said Admiral Abdul Aziz Jaafar on Twitter on Friday morning (Jan 2).

Three ships – KN Baruna Jaya 1, KN Hidayat and MV Geo Survey - have been tasked to The Most Probable Area, which spans 45 by 35 nautical miles, he said. All three vessels are equipped with underwater marine detection systems, including side-scan sonar and pinger-locators, to help search for the missing plane.

Also on Friday morning, France's air accident authority, BEA, announced that it will send a specialist black box search team to assist in the search. The team is expected to arrive at the search zone on Friday.

The crash investigation agency will bring detection equipment including hydrophones to the search zone, in the hope of detecting signals from the flight recorder - commonly known as the black box - from the missing AirAsia plane, said the BEA.

"Jientho"=Look...it isn't 'Math' it's primary school arithmetic !

Terminal velocity concepts apply only within the air mass you exist in...

if your T.V. is say 120 kts down and you're in a downdraught of the same it would seem to radar that you are descending faster than terminal velocity, by a factor of two (and you would be)

So quite possible to descend much faster than T.V. and climb much faster than the aircraft max. climb... and there is also no presumption the aircraft would be stalled either.. ask any glider pilot.

...and more wreckage

https://www.facebook.com/ngenghen.de...e=1&permPage=1

...picked up by Singapore Navy...

cwatters

"it is our priority to look after the relatives and love ones of the passengers".

The big thing affecting recovery from a stall at high altitude is that there is very high drag at such low speed, and little thrust available from the engines due to the low air density. You need to descend to allow the speed to increase. In the high altitude flight testing I've done on transport category aircraft (various business and regional jets), it usually takes a descent of 2000 ft or so to build enough airspeed so the drag is low enough to allow the available thrust to be sufficient for a reasonable acceleration.

At 20,000 ft, the engines have much more thrust available, so it should be possible to recover from the stall with less than 1000 ft altitude loss, assuming a sharp pilot (but a sharp pilot should never have stalled in the first place, so we can't assume he suddenly becomes razor sharp during the stall recovery).

All the stalls I've done on large airliner types (various Airbus products, in direct law, to confirm Airbus's claimed CL Max value) have been at lower altitudes, but the same should apply to them at high altitude. The interesting thing about aerodynamic stalls in the Airbus is that from the perspective of the pilot's seat it is very difficult to identify the moment when the aircraft stalls. Light buffet starts prior to the stall, but there is no aircraft wing drop or nose down pitch to identify the moment of the stall. We relied on the flight test engineer in the back, who was monitoring the output of the flight test instrumentation, to call out "CL Max", as the point to initiate the recovery.

Note: all the above comments are with respect to an aerodynamic stall - i.e. the angle of attack has exceeded the value for maximum lift. If the pilot recovers at stall warning the drag is somewhat lower, and thus less altitude loss is required for the recovery.

khorton

Thanks for your insight... I think many on this thread are missing the difference between a "Stall Warning" (which AF447 got prior any stall), and a "Stall" which you cover. Your post indicates the difficulty in recovering from a genuine stall, albeit seemingly (in AoA terms) approximately at the stall?

AF447 got way beyond this, 40 AoA, long period >35AoA, so the recovery would have been far more difficult one assumes?

Finally, your post refers to the thrust required to recover from the stall. Clearly our "QRH Drills" will differ from your Test procedures, but our drills require us to recover from the stall without the use of power (certainly none added, and reduce in case of pitch authority issues). We only add power once the Stall Indications are removed. This can only add to the difficulty / height loss / nose down attitude required to recover?

Any insight / estimate you could give as to the height / pitch / technique required to recover a modern Airbus from a 40AoA stall would be much appreciated :ok:

24,000 fpm = approx 250 knots. How could that be anywhere near terminal velocity?

A plea to potential journalists who seek yummy stories out there.

ELT's do not always work. That's a fact. They are NOT 100% reliable, not even on land. Many fatal accidents have happened without ELT even whispering about it. On land.

In water and especially in the ocean they do not work at all (ELT is radiowaves = EMwaves) unless someone survived a ditching and managed to activate an ELT in a life raft.

Absence of ELT activity means diddly squat. You can draw zero conclusions on this. So PLEASE stop reporting about magical scenarios. Do some research. And please for once, ask some insightful follow up questions next time.

And for all of you prunes who want real time streaming of FDR data, please look up what "data congestion" means in networking terms before even attempt to bore me again, please.

(Yes, I come across as somewhat annoyed in this post. That's because I am. I like to think that I know enough to know I know nothing, but I do know when I see someone who thinks he knows everything but really hasn't got a clue.)

...and more wreckage

https://www.facebook.com/ngenghen.de...e=1&permPage=1

...picked up by Singapore Navy...



Thanks for the link.
Pretty suggestive of forceful breakup when composite panels are sheared this way.

The most wise statement of have heard yet on this thread...

chefrp

Agreed. His post was excellent.

Would an ex military pilot be more comfortable to fly through storms and carry less fuel than pilots from other back grounds ?

Suggestive yes. This is the interior wall of the cabin. If you look closely you can see the snap-ons on the lower parts of the wall. These are for easy removal during various in-depth checks of the aircraft.

The lower part of the interior wall seems pretty intact, a little crushed from the above maybe. What this tells us is not much though, unless seen in context with other parts of the adjacent structures.

Presumably it's possible for the Indonesian authorities to make a good guess as to who was flying the plane at the time, as I imagine whoever asked for FL380 wasn't the PF, and the accent should be fairly easy to identify (Indonesian vs French)?

Also - and echoing an earlier post - no information has come out about the cause of death identified in the bodies brought back to shore. Distressing as it is to the families, the condition of the bodies may be an important clue as to what happened to the plane.

Yes, khorton's post was excellent.

However, recovery from a stall requires:

1. reduce AoA, and
2. regain airspeed

Training emphasis has recently shifted towards the first, and I miss that in his post.

Navy vessel detects an object suspected to be tail
 

Strait Times reports:PANGKALAN BUN/JAKARTA - An Indonesian Navy vessel detected an object suspected to be the tail of AirAsia flight QZ8501 on Friday, Metro TV reported.

"At 7.34am, we detected a piece of wreckage suspected to be a plane's tail," said KRI Bung Tomo commander, Colonel Yayan, in a phone interview with Metro TV on Friday.

The ship's sonar detected the object located 29 metres deep in the Karimata Strait.

According to the report, visual checks are needed to confirm if the object is indeed a plane's tail.

As I've been trying to make clear... terminal velocity has little meaning when there are massive vertical up or downraughts about...

jientho -- Up/downdrafts of similar speeds would be extreme but not beyond the realms of possibility. We've measured updrafts of around 195kts and were only prevented from measuring higher values by equipment limitations. Those were over the Atlantic but I suspect the region where this aircraft went down would see similar.

Just watching BBC. Now 30 bodies recovered. Mainly being recovered by the USNAVY ship that's in attendance for this search. Pinger searching by the Singaporean and Indonesians for the wreckage/FDR CVR, ineffective due weather.

@Nemrytter -- Thanks! It seems that even my imagination regarding tropical extremes, which was so far "out there" that a comment got mod-deleted (in fairness maybe because I referenced global warming :)), nonetheless was apparently "on the bubble". What would be the limit of conceivability given current knowledge, up/downdraft of 300kts? 400?

Journos
 

"Some of the conjecture by so-called media "experts" is just stunning in its nonsense. It is hard to believe that these statements are being printed and given credence"


Journos don't make stuff up. You are quoting a Walkley award winning Australian journalist of high standing. They look for people of credibility and standing and report what they say. Its been mentioned elsewhere that Professional Pilots hold back their views until the evidence is in - so who is going to be quoted in the early days of a tragedy when the public is interested to know a reason presented at a level they can understand?


Newspapers in Australia target a mass audience not an audience of professional pilots with ultimate and superior expertise and experience - although I have seen a few wacky ideas on this forum too.

Cause of Death
 

"Hope that they did not miss to examanine "cause of death"

The news report only says that victims are being identified"


In this country a cause of death will not be stated on a death certificate unless an autopsy is done. Muslims prefer their departed to be buried quickly. Hint for foreigners who don't understand: They died from a plane crash.

Circulating on Twitter that AirAsia have had their route permit for Surubaya to Singapore revoked.

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