PDA

View Full Version : 15 injured in ‘serious’ stall alert incident on Qantas flight


Cralis
12th Apr 2017, 12:38
Sounds quite sensationalised, but... a close call?

Qantas incident, Melbourne to Hong Kong, serious stall alert (http://www.news.com.au/travel/travel-updates/incidents/15-injured-in-serious-stall-alert-incident-on-qantas-flight-from-melbourne-to-hong-kong/news-story/395bccd81f1e3729ee176cbe8fea2a78)

"FIFTEEN passengers were injured on a Qantas flight from Melbourne to Hong Kong after a serious stall alert last Friday, it has just emerged.

Authorities will now begin a serious incident investigation after a ‘stick shaker’ warning activated on the QF29 service on April 7.

Stick shaker is an industry phrase used to describe a stall warning, where the controls shake to warn the flight deck of an imminent stall.

Details of the in-flight incident, which took place at the end of the Boeing 747’s 9.5 hour flight, some 110 kilometres south of Hong Kong, have only just emerged."

gerry111
12th Apr 2017, 13:17
"Geoffrey Thomas, an aviation expert, told The Australian that such an incident was.."

Horatio Leafblower
12th Apr 2017, 14:19
With or without Geoffery Thomas's "expert" testimony, Stick Shaker + 15 injured = smoke + fire

JohnMcGhie
12th Apr 2017, 17:20
According to the report in the Sydney Morning Herald (from newswire AAP...) which got it from the ATSB https://www.atsb.gov.au/publications/investigation_reports/2017/aair/ao-2017-044/ the aircraft was in the Hold at 22,000 feet and on autopilot at the time.

My question is "How is it that the autopilot could get the aircraft into this condition?" Does this suggest it may have been in the wrong mode?

Obba
12th Apr 2017, 17:58
15 Injured after a Melbourne to Hong Kong Flight.

Reportedly on Apr 7th.

QF29 - Boeing 747, 110kms south of HK.


"The flight crew disconnected the autopilot and maneuvered the aircraft in response,” the Australian Transportation Safety Bureau (ATSB)..."

“Fifteen passengers received minor injuries. As part of the investigation, the ATSB will interview the flight crew and gather additional information.”

Girlfromoz
12th Apr 2017, 18:10
I was on this flight, severe vibration and a loud vibrating whooshing sound and then plummeting turbulence came out of no where, many passengers and crew hit their heads on the roof, overhead compartments opened and our bags from under the seat in front of us ended up behind us. There were also smoke alarms going off at the rear of the plane.Crew were initially running down the isles to see if there was any fire but said it was a false alarm due to turbulence, it would turn off and then start again the whole way into landing. It was very scary to say the least. Crew said we hit the wake of another plane, I don't know but I'm thankful we landed safely.

1a sound asleep
12th Apr 2017, 19:30
Oh bugger. Qantas was going to keep this one hush hush

Cralis
12th Apr 2017, 20:42
How does 15 people get injured from a stall alert? Or did the plane actually stall and I'd guess there might be a period of 0g? And the recovery might be a bit strange?

Angle of Attack
12th Apr 2017, 21:36
Aviation Herald is saying the aircraft was just entering a hold at FL220 when stick shaker activated. Autopilot was disconnected and the altitude fluctuated almost 2000ft in the recovery.

Accident: Qantas B744 near Hong Kong on Apr 7th 2017, stick shaker activation in holding pattern injures 15 passengers (http://avherald.com/h?article=4a787699&opt=0)

CurtainTwitcher
12th Apr 2017, 21:39
My question is "How is it that the autopilot could get the aircraft into this condition?" Does this suggest it may have been in the wrong mode?
We will know when the report(s) are released. Until then there could be 1000 different reasons conjectured.

How does 15 people get injured from a stall alert?
It probably wasn't the alert, but subsequent recovery actions that would likely cause injury, but that is pure speculation on my behalf :) . I will be waiting for the report.

airtags
12th Apr 2017, 22:01
Still a lot of questions which is probably why Fairfax was given a soft drop almost a week later in an effort to flatten the story - the 'say nothing' lessons learned ex QF32 clearly have been forgotten

Crew operated back although at least one CC suffered injuries. Understand that crew de-brief didn't happen and CC & pax were told it was turbulence.

If Avionics and FMS was the cause of a/c condition then I would want more than an LAME ramp check in HKG

Report v data will be very interesting

AT

Keg
12th Apr 2017, 22:52
I don't know the details but I can see a scenario where min speed entering a hold and wake turbulence could cause a combination of jet upset, 'turbulence', pax injuries, etc. I got caught in some wake behind another Dugong into DXB. We ended up at 25 degrees AoB very quickly before the A/P let go. There was little time to react as it occurred.

601
12th Apr 2017, 23:33
A report will be released within several months.

I was under the impression that the ATSB had to have a preliminary report released within 30 days of the incident.

Metro man
12th Apr 2017, 23:34
How does 15 people get injured from a stall alert?

Because they were not using their seat belts. QF announce on the PA that it is a requirement to have your seat belt fastened when seated even if the sign is switched off. Obviously some people would be moving around, especially cabin crew, but the injury toll would almost certainly have been lower if everyone in their seat was properly restrained.

Ida down
13th Apr 2017, 01:10
How does 15 people get injured from a stall alert? Or did the plane actually stall and I'd guess there might be a period of 0g? And the recovery might be a bit strange?
Would have been clackers going off everywhere, mate.

The Green Goblin
13th Apr 2017, 02:06
A 747 getting into trouble from wake turbulence?

Okay.....

Bit low for a jet stream, but if they are at min speed to avoid flying a heap of circles I'm assuming a sudden wind change can cause some issues.

Will be an interesting read.

Icarus2001
13th Apr 2017, 02:17
I'm assuming a sudden wind change can cause some issues.

The old "turned downwind from a headwind at low speed" chestnut. Yawn.

gordonfvckingramsay
13th Apr 2017, 02:44
A 747 getting into trouble from wake turbulence?

Okay.....

Bit low for a jet stream, but if they are at min speed to avoid flying a heap of circles I'm assuming a sudden wind change can cause some issues.

Will be an interesting read.

Whaaaaaa? Do you even fly bro?

Wake turbulence is not a jet stream issue, it's caused by another aircraft, presumably 1000' above burning circles with you. And yes a 747 is very susceptible to it. :ok:

mrdeux
13th Apr 2017, 02:52
I know that FR24 doesn't have a great deal of data resolution, but the minimum IAS as they enter the hold seems to be around 226 KIAS. I haven't flown the 747 for a long time, but I'd have thought that was nowhere near the stick shaker activation.

Keg
13th Apr 2017, 03:11
Given the weird winds with wake turbulence (if thats what it was) i would guess its pretty easy to get to an AoA limit in a short period of time.

keepitrealok
13th Apr 2017, 03:25
A 747 getting into trouble from wake turbulence?

Okay.....



Goblin,

Yes - the 747 very much get's affected from wake turbulence. Especially from a 380, and also from a 777. A 777 can get badly upset by wake turbulence from other 777s and 380s.

Certain very busy airports are applying minimum separation standards behind 380s, and have them stacked very high in holding patterns. Anybody who has flown into these places knows exactly how badly, and very, very quickly that wake turbulence can affect a Heavy.

I am tipping something greater than an 'Incident' will occur at one of these places due to wake turbulence, and then the regulators will make the changes that should be in place now.

The Green Goblin
13th Apr 2017, 04:11
Well I've never flown a jumbo, so it's interesting to find out a different perspective. I would have thought when you're one of the bigger birds in the sky, you're reasonably safe.

I wasn't suggesting it was a jet stream, I was discounting it as it was at F220. I was suggesting it could perhaps have been stronger upper winds and a change in the turn. However from some experience in Asia you don't usually see more than 30 kts of wind below about F250 unless there's something going in. Particular closer to the equator.

Yes I agree with the trippler, the worst encounter I had with wake was one.

The 380 has been an issue a few times crossing its path north south as it heads west.

Anyway as I said it'd be an interesting read.

AerialPerspective
13th Apr 2017, 04:33
Still a lot of questions which is probably why Fairfax was given a soft drop almost a week later in an effort to flatten the story - the 'say nothing' lessons learned ex QF32 clearly have been forgotten

Crew operated back although at least one CC suffered injuries. Understand that crew de-brief didn't happen and CC & pax were told it was turbulence.

If Avionics and FMS was the cause of a/c condition then I would want more than an LAME ramp check in HKG

Report v data will be very interesting

AT
"Say nothing lessons" What???
So, Alan Joyce fronting media and being broadcast all over the world within an hour of the QF32 incident (once the aircraft had landed safety) and grounding the entire A380 fleet was 'saying nothing'. Further, after the whole thing had been dealt with Qantas allowed crew to speak openly about the incident to Four Corners, as did Joyce and senior engineering people.
Again, how is that 'say nothing'.
I believe the Qantas reaction to QF32 was lauded as an excellent example of how a company should respond and the Rolls-Royce reaction was used as an example of the complete opposite.
On top of that, the media glossed over the fact that another prominent and supposedly 'untouchable' carrier based in Asia had their A380s back in the air within days in circumstances that couldn't possibly have provided enough time for the proper inspections to be done but as they are a media darling and don't have a kangaroo on the tail, this was completely ignored by the media at the time.

dragon man
13th Apr 2017, 06:46
Data off the ADS-B capable transponder of the aircraft suggest the aircraft was descending to enter the hold at about 340 knots over ground on a track of 315 degrees, when descending through FL229 at 17:47L (09:47Z) the speed decayed to 290 knots over ground still on a track of 315 degrees before increasing to above 400 knots over ground in altitude fluctuations between FL214 and FL230 before levelling off at FL220 at 390 knots over ground subsequently reducing to 340 knots over ground.

unobtanium
13th Apr 2017, 06:53
On top of that, the media glossed over the fact that another prominent and supposedly 'untouchable' carrier based in Asia had their A380s back in the air within days in circumstances that couldn't possibly have provided enough time for the proper inspections to be done but as they are a media darling and don't have a kangaroo on the tail, this was completely ignored by the media at the time.

A country of zero tolerance to defamation and nil free speech, journalists have been hauled up for inaccurate articles, JT would be in jail for daring to tarnish the image of the national carrier.

framer
13th Apr 2017, 06:55
So has anyone got any temperature and wind information ( presumably from online) so the above post can be used meaningfully?

esreverlluf
13th Apr 2017, 08:29
Had to laugh when Ch 9 annouced that "the stick shaker alerts the cabin crew to an impending stall". I hope the cabin crew remember to tell the pilots. . . .:ugh::ugh::ugh:

LHLisa
13th Apr 2017, 09:33
Yeah, maybe... at the 20 min check in

V-Jet
13th Apr 2017, 09:33
Well said keg..

Nemrytter
13th Apr 2017, 09:42
So has anyone got any temperature and wind information ( presumably from online) so the above post can be used meaningfully?Both winds and temperature were pretty standard, nothing special. See this graph:
http://i.imgur.com/lB0nFtRl.png

Blue line is wind speed and red line is direction. X-axis is atmospheric pressure and this incident happened somewhere around 430hPa (a little to the left of centre). Of course, this data is slightly uncertain (it's from a forecast model, not an actual observation) but I don't see anything to suggest there'd be a much windshear at their altitude.

Airmann
13th Apr 2017, 12:11
The A380 is a menace to anyone flying behind it or through its wake. Was recently shaken up pretty badly while flying through the wake of a 380 10NM in front of us (and we were in a heavy).

Unfortunately, instead of increasing separation margins ATC is pushing to reduce them and in Europe have done that with the recent RECAT minimums.

Was reading a recent article in the Airbus safety magazine that more or less defended the reduced minimum by saying that they had never seen any major incident on approach as a result of wake turbulence and hence no one had anything to worry about. As for enroute, no one should be worried as the turbulence is sudden and only lasts 10 seconds or less.

lurker999
13th Apr 2017, 14:29
Because they were not using their seat belts. QF announce on the PA that it is a requirement to have your seat belt fastened when seated even if the sign is switched off. Obviously some people would be moving around, especially cabin crew, but the injury toll would almost certainly have been lower if everyone in their seat was properly restrained.

OJU has 10 dunnies. If you pop down the back, you'll find people using them or waiting to use them. Hard to do either of those things strapped into a seat.

Others might be avoiding DVT. Then CC.

On an aircraft with 364 pax and up to 16 CC. The fact only 15 were injured is some sort of miracle.

OldLurker
13th Apr 2017, 14:37
As for enroute, no one should be worried as the turbulence is sudden and only lasts 10 seconds or less.I guess these guys weren't worried then:
Accident: Emirates A388 over Arabian Sea on Jan 7th 2017, wake turbulence sends business jet in uncontrolled descent (http://avherald.com/h?article=4a5e80f3)
Nor these:
Jumpseat: Assaulted by an A380 (http://www.flyingmag.com/pilots-places/pilots-adventures-more/jumpseat-assaulted-a380)

PJ2
13th Apr 2017, 14:50
China Airlines 006 (https://en.wikipedia.org/wiki/China_Airlines_Flight_006)
NTSB Report (https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR8603.pdf)

AerialPerspective
13th Apr 2017, 14:55
A country of zero tolerance to defamation and nil free speech, journalists have been hauled up for inaccurate articles, JT would be in jail for daring to tarnish the image of the national carrier.
I don't know who JT is supposed to be but I wasn't talking about media on the island, but media here... they just love this offshore carrier and they wouldn't dare mention anything derogatory about it even when it does something dodgy.

Eyes only
13th Apr 2017, 15:34
The only A380 operator that flies into Hong Kong from the south is Qantas.

There is an appearance that Qantas has covered up the evidence here, the CVR and FDR should have been quarantined in the Hong Kong to the investigators, not waiting for it to be overwritten by flying it back to Australia.

Stall warning events are required reporting events in Hong Kong, just like in Australia. Qantas failed to follow its mandatory reporting requirements to the Hong Kong authorities.

What are they hiding ?????

Dale Hardale
13th Apr 2017, 21:28
From memory, buffet speed at MLW clean is about 200 KIAS (straight flight path). This will increase significantly if the aircraft is turning.


TAS around FL 220 ISA+10 with that indicated airspeed is about 290 KT


Looking at the FR ground speeds and even allowing for some error, these speeds tend to support the stall event scenario - what the events leading up to it were will be very interesting.:confused:


Be surprised if wake turbulence had much to do with it.

Keg
13th Apr 2017, 23:19
The only A380 operator that flies into Hong Kong from the south is Qantas.

I've no idea of the relevance of this. Are you suggesting that because QF is the only operators of A380s from the south, and given there were no QF A380s in the vicinity, that a 744 couldn't have been affected by wake turbulence?

As at this stage we don't even know if wake was to blame but writing it off as a possibility due to the lack of QF A380s in the area at the time seems particularly daft unless you have an agenda to push.

But wait....


There is an appearance that Qantas has covered up the evidence here, the CVR and FDR should have been quarantined in the Hong Kong to the investigators, not waiting for it to be overwritten by flying it back to Australia.

Really? You know the specifics of what happened so well as to make such a determination? Multiple people across multiple departments have covered up evidence? Nice slandering of the crew, engineering in HKG (still HAECO?), QF safety personnel, etc.



Stall warning events are required reporting events in Hong Kong, just like in Australia. Qantas failed to follow its mandatory reporting requirements to the Hong Kong authorities.

You know this event wasn't reported? You base this assessment on what? Given the event appears on the ATSB website it appears it was reported IAW current procedures.

By George
13th Apr 2017, 23:20
Dale your figures are close to the mark but I would have thought a more typical weight arriving on that run would be much lower, say around 240 ton. With a Vref around 140 adding 80 kts up to FL250 would give a rough holding speed of 220 something. Don't have any charts in front of me but I would have thought buffet would pop up around 185kt.
Descending in V/S, turning and with a subtle A/T failure you could get into the brown stuff very quickly. The main thing is, they caught it. As for the injuries, the poor old F/A's are always at risk. The idiot passengers without seat-belts never cease to amaze me. I don't know how you fix that, apart from chaining them to the floor.
As for wake turbulence, I got rocked about quite badly after take-off in LHR by a 757. That aeroplane punches above its weight for some reason and I am still very wary of them.
I feel sorry for the tech Crew, can happen to anybody.

caneworm
14th Apr 2017, 00:16
Heard the crew operated back the next day. Is this normal following a serious incident?

maggot
14th Apr 2017, 01:01
There was an ek 380 in the betty hold the other day

But as others have alluded to it doesn't need to be a super, sometimes you just get nailed. If that's even what happened

ruprecht
14th Apr 2017, 02:08
From QF Pravda:

The passengers on board experienced what felt like severe turbulence

Interesting choice of words.

airtags
14th Apr 2017, 02:37
"Say nothing lessons" What???
So, Alan Joyce fronting media and being broadcast all over the world within an hour of the QF32 incident (once the aircraft had landed safety) and grounding the entire A380 fleet was 'saying nothing'. Further, after the whole thing had been dealt with Qantas allowed crew to speak openly about the incident to Four Corners, as did Joyce and senior engineering people.
Again, how is that 'say nothing'.
I believe the Qantas reaction to QF32 was lauded as an excellent example of how a company should respond and the Rolls-Royce reaction was used as an example of the complete opposite.
On top of that, the media glossed over the fact that another prominent and supposedly 'untouchable' carrier based in Asia had their A380s back in the air within days in circumstances that couldn't possibly have provided enough time for the proper inspections to be done but as they are a media darling and don't have a kangaroo on the tail, this was completely ignored by the media at the time.

Just to clarify QF32 was far an ideal example of proactive crisis communications - it is used by several comms professionals to demonstrate what not to do. As a reminder: QF initially denied the event - in fact there's a grab from Sky where Olivia is denying outright saying words similar to: "there is no evidence whatsoever to suggest the aircraft is a Qantas plane" vision cuts to twitter pic of villager holding up panel with logo - then to grab of ATC comms recorded by planespotter and posted to soc media.

Joyce was MIA for a considerable period (it was more than hour BTW) with the exec focus being one eye on the IOC the other on the ASX - I can tell you authoritatively that the initial media requests were met with an absolute fob off. (that's one of the reasons why so many journos write crap because airlines don't get proactive)

As for your reference to the open access given to 4 corners etc... two well connected experienced journos had the RR link and evidence absolutely nailed on the day as they were already working on the RR story with a lot of evidence from local and OS insiders. Prior to Joyce appearing they were asked (begged) to 'hold it' on the promise of an absolute exclusive and that no one else would get given this 'access' - they honoured the request in good faith and didn't slam Joyce with it at the presser; but they were later ripped off when they objected to the Q requested, highly massaged production approach that 4 corners and 9 eventually agreed to. (In fact one of them was lied to about crew not being avail for a pre-arranged interview....said journo then saw a camo from another network at Syd Dom on his way to shoot them beside the 380 parked in the hanger)

Regarding last Friday's incident - it was denied with the standard "we are not aware of any incident" last weekend. The CC debrief and follow up in HKG was (I'm told) far from best practice - the CC were not even told the truth and I hear that their union was kept in the dark and had to extract info.

The current anecdotal reporting, pax quotes coupled with the brush off 'it was just unexpected severe turbulence line' only has escalated the scare factor in this story eroding public faith.

Baseline: in a crisis an organisation has 3 minutes at best to set the agenda present the facts or if the facts are unknown, take control. Like with 32, it didn't happen.

Had QF acted last Friday with a proactive factual statement immediately after receiving the info in the IOC, they could have opened up the issue and closed it back down - the net outcome would have been appropriate recognition of the operating crew rather than the mish mash of out of context tech facts.

Such prompt action also eliminates the speculation and (less than responsible often uninformed) 'suspicions' that are now being circulated in some areas.

I do however agree with you 100% that RR in the 32 incident acted arrogantly and was wilfully misleading and deceptive.

I'll will wait for the investigation report - as we all should!

AT
:E

AerialPerspective
14th Apr 2017, 07:36
Just to clarify QF32 was far an ideal example of proactive crisis communications - it is used by several comms professionals to demonstrate what not to do. As a reminder: QF initially denied the event - in fact there's a grab from Sky where Olivia is denying outright saying words similar to: "there is no evidence whatsoever to suggest the aircraft is a Qantas plane" vision cuts to twitter pic of villager holding up panel with logo - then to grab of ATC comms recorded by planespotter and posted to soc media.

Joyce was MIA for a considerable period (it was more than hour BTW) with the exec focus being one eye on the IOC the other on the ASX - I can tell you authoritatively that the initial media requests were met with an absolute fob off. (that's one of the reasons why so many journos write crap because airlines don't get proactive)

As for your reference to the open access given to 4 corners etc... two well connected experienced journos had the RR link and evidence absolutely nailed on the day as they were already working on the RR story with a lot of evidence from local and OS insiders. Prior to Joyce appearing they were asked (begged) to 'hold it' on the promise of an absolute exclusive and that no one else would get given this 'access' - they honoured the request in good faith and didn't slam Joyce with it at the presser; but they were later ripped off when they objected to the Q requested, highly massaged production approach that 4 corners and 9 eventually agreed to. (In fact one of them was lied to about crew not being avail for a pre-arranged interview....said journo then saw a camo from another network at Syd Dom on his way to shoot them beside the 380 parked in the hanger)

Regarding last Friday's incident - it was denied with the standard "we are not aware of any incident" last weekend. The CC debrief and follow up in HKG was (I'm told) far from best practice - the CC were not even told the truth and I hear that their union was kept in the dark and had to extract info.

The current anecdotal reporting, pax quotes coupled with the brush off 'it was just unexpected severe turbulence line' only has escalated the scare factor in this story eroding public faith.

Baseline: in a crisis an organisation has 3 minutes at best to set the agenda present the facts or if the facts are unknown, take control. Like with 32, it didn't happen.

Had QF acted last Friday with a proactive factual statement immediately after receiving the info in the IOC, they could have opened up the issue and closed it back down - the net outcome would have been appropriate recognition of the operating crew rather than the mish mash of out of context tech facts.

Such prompt action also eliminates the speculation and (less than responsible often uninformed) 'suspicions' that are now being circulated in some areas.

I do however agree with you 100% that RR in the 32 incident acted arrogantly and was wilfully misleading and deceptive.

I'll will wait for the investigation report - as we all should!

AT
:E
Personally I think that's a little harsh. As anyone in the industry knows, rumors can be rife and uninformed comment can come from anywhere. I can well imagine there was confusion initially while facts were ascertained. I seem to remember MW were monitoring the the aircraft data and were trying to establish in the absence of comms with the aircraft what was going on. I think any reasonable organisation would hold off until it had verified facts. I do remember reading there was initial confusion but that is surely more to the do with the nature of modern communications and not some oblique attempt to cover something up. When Qantas denied the incident, they could not possibly have known someone on Bantam Is was about to post a tweet of an engine cowling or part thereof. I think FAR too much emphasis and credence is put on individuals posting on social media who are largely uninformed and I blame the media for that because they promote it the interests of sensationalism rather than good journalism - and I can imagine the confusion, does Qantas confirm it on the basis of a tweet or do they say 'no comment' and appear to be hiding something or do they just remain silent for a short period of time and then come out with correct information that they have been able to verify. I think this is now days like peeling away the layers of an onion and all companies need to adapt to how to manage this, as does the media need to do somewhat better than run front page headlines based on the figurative 'epic fail' tweet.
I can't comment on the 4 corners info you've provided because I am not privy to that information. I have heard numerous corporate image consultants however, report that in their view the final analysis was that Qantas came out of this looking fairly professional whereas RR had a lot of work to do to restore their credibility. All companies will attempt at times to ensure a message is crafted in a way that is perceived in the right light and is not misconstrued and this can sometimes appear as evasive. I don't see here the type of action carried out by other operators in the past such as raiding a Pilot's house (allegedly) and seizing documents material to an investigation or practically perverting the course of justice to protect an image ("an orchestrated litany of lies...").

Finally, absolutely... we should always wait for the final report and last word would be there were probably several ways it could have been handled better but certainly the actions of the crew played very positively for Qantas.

andyprune
15th Apr 2017, 00:10
To get back to QF 29 for a minute...Holding at FL220 seems a bit high only 60 miles out, unless there is a circuit somewhere over Macau?!

donpizmeov
15th Apr 2017, 08:17
Not uncommon during busy times.

AerialPerspective
15th Apr 2017, 09:15
To get back to QF 29 for a minute...Holding at FL220 seems a bit high only 60 miles out, unless there is a circuit somewhere over Macau?!
Not sure if relevant but a friend was on the flight (in J Class) and they told me they were on their way back from the loo and the aircraft seemed to pitch nose up but not so that they lost their footing and flew off the floor but when it came down it was quite severe and this person said their legs felt like they were crumpling under them - also said it was not like described by other pax and the other thing was it was very, very smoggy outside similar to when there are lots of bushfires in Sydney or Melbourne and the friend was not sure if that was a factor in what might seem like severe turbulence. Alarm went off yes but was not fire related, no emergency of any kind in terms of landing and the aircraft did hold disembarkation at the gate for a while until one pax was taken in ambulance and others were attended to and released.

josephfeatherweight
15th Apr 2017, 10:10
they told me they were on their way back from the loo and the aircraft seemed to pitch nose up but not so that they lost their footing and flew off the floor but when it came down it was quite severe and this person said their legs felt like they were crumpling under them

That's completely the wrong way around.
If you pitch up, you crumple to the floor as a walking pax.
When you pitch down, you float off the floor.
Has your friend got it right - did you read your own post?

maggot
15th Apr 2017, 11:45
To get back to QF 29 for a minute...Holding at FL220 seems a bit high only 60 miles out, unless there is a circuit somewhere over Macau?!

60 track miles to go or 60dme? Gotta go around lan tau...

AerialPerspective
15th Apr 2017, 12:23
That's completely the wrong way around.
If you pitch up, you crumple to the floor as a walking pax.
When you pitch down, you float off the floor.
Has your friend got it right - did you read your own post?
Fair comment, I just checked their message and you're right, my bad. Of course I know that is the wrong way around, just in a hurry and was heading out the door so I didn't re-read before I posted.

Derfred
15th Apr 2017, 17:16
This seems to be what we know:

1. The aircraft encountered severe turbulence approaching the hold at a low speed, and a low speed is normal approaching a hold.

2. A stick shaker activated.

3. Autoflight was disconnected.

4. Some passengers were injured.

What we don't know is what caused the severe turbulence - was it wake turbulence or was it pilot induced due to the stick shaker, in which case what caused the stick shaker?

Now, all professional jet pilots will know:

1. Intermittent stick shaker is not unusual when encountering severe turbulence (particularly when back at holding speed), whether it be caused by wake or other. As has been mentioned above, stick shaker is largely controlled by AoA vanes, which could easily be disrupted in a wake turbulence encounter. It doesn't mean the aircraft is about to stall out of the sky. On the other hand, a stick shaker caused by high level windshear which could also be accompanied by turbulence, may mean the aircraft is about to stall out of the sky.

2. The normal response to severe turbulence in a Boeing is to disconnect autoflight and maintain appropriate attitude and thrust (which would include increasing to turbulence penetration speed).

3. The normal response to a stick shaker in a Boeing is to disconnect autoflight and apply forward elevator.

Of course, 2 and 3 are mutually exclusive, so a pilot chooses to either employ 2 or 3. Or, in the event of both, they would employ 3 and then 2, once 3 is complete.

My money is on severe turbulence caused by wake, which also gave them a stick shaker, and they applied 3 then 2. Which would be completely approriate. Passengers may have been injured prior to, or during that process. Either is possible. I've encountered high level wake turbulence before, it's not fun and it's hard to predict (short of grossly increasing separation minimums).

RubberDogPoop
16th Apr 2017, 00:00
Derfred, can you confirm the Boeing procedure for encountering "severe turbulence" is to disconnect?????

crosscutter
16th Apr 2017, 02:31
Derfred, can you confirm the Boeing procedure for encountering "severe turbulence" is to disconnect?????

Lol..

In reality, a severe turbulence encounter may result in an inappropriate attitude which would validate disengaging the autopilot. You then set an attitude as per Derfred's explanation. (Which is also what the book says... right?... or is it just the first sentence in the manuals which is important?)

Enuff Said
16th Apr 2017, 02:49
Maybe a very simple"Cancel hold continue right turn heading 240".....grabbed the speed knob instead of heading..Wouldn't be the first airline that had done that.
We will just have to wait and see.

Lookleft
16th Apr 2017, 03:39
This is what was actually stated:

While holding at flight level 220, the flight crew received a stick shaker activation and detected airframe buffeting.

When did it turn into an encounter with severe turbulence? Lets rewrite Derfred's statement of fact with the real facts and take a different point of view.

1. The stick shaker activated and theaircraft encountered airframe buffeting while in the hold at FL220.

2. A .

3. Autoflight was disconnected.

4. Some passengers were injured.

Lookleft
16th Apr 2017, 03:50
This is what was actually stated:

While holding at flight level 220, the flight crew received a stick shaker activation and detected airframe buffeting.

When did it turn into an encounter with severe turbulence? Lets rewrite Derfred's statement of fact with the real facts and take a different point of view.

1. The stick shaker activated and the aircraft encountered airframe buffeting while in the hold at FL220.

2. The autopilott was disconnected and the flight crew maneuvered the aircraft in response.

3. Passengers were injured.

Now for the conjecture. The hold speed for a 747 is approx. 230-240kts at a rough guess. That's not slow! If you were coming into land at that speed it would be frighteningly fast. The stick shaker activates approx.10kts before the stall which would be possibly around the 120-130kt range. What was the A/T doing during this time? I would hazard a guess that it was not armed but the crew thought it was, not unusual in a Boeing if recent history is anything to go by. It would not take long for a 747 in level flight to have its speed decrease to the point of stick shaker activation. Something was distracting the crew so the speed was not being monitored. Why the speed wasn't being monitored and why the A/T didn't maintain the holding speed will come out in due course.

ACMS
16th Apr 2017, 08:45
120 to 130 kt range?
It's been a while since I flew the Queen but I can easily tell you that clean at FL220 at their weight the Vs would have been a lot higher than that, up around 180 to 190 KIAS. And that's wings level......in a 25 deg AOB a fair bit higher.

RubberDogPoop
16th Apr 2017, 09:21
I don't know Crosscutter, what does the book say?
Is hand flying in "severe" turbulence a recommended practice? Would V/S mode 0fpm work?

PW1830
16th Apr 2017, 09:46
Look left, you may be surprised to hear that holding at fl220 is not in the approach config.
It is close to min drag speed clean( holding at min fuel flow is prudent)
At this speed a/c is vulnerable to stickshaker through turb from whatever source. Crew response will be dictated by their perception of the reason for this. For that information ask the crew.

crosscutter
16th Apr 2017, 10:14
I don't know Crosscutter, what does the book say?
Is hand flying in "severe" turbulence a recommended practice? Would V/S mode 0fpm work?

Book says to leave autopilot in...unless speed, altitude or attitude deviations dictate otherwise.

VS mode would make no difference. In level flight thrust controls speed in both VS and other level flight autopilot modes.

Lookleft
16th Apr 2017, 10:45
So if Vs at FL220 is around is 180-190 what would the holding speed be, 240? In this incident turbulence has nothing to do with it. The stick shaker and the airframe buffeting seemed to occur at the same time. Possibly the A/T has not maintained the hold speed and the crew had taken their eyes off the ball.

PW1830
16th Apr 2017, 10:54
For the Vref, ask the crew, for the MCP selected holding speed, ask the crew, for A/T engagement/serviceability, ask the crew,for weather, other aircraft in the hold, ask the crew.
An enquiry perhaps and wait for the results.

Bug Smasher Smasher
16th Apr 2017, 15:15
Most of you are as bad as Today Tonight / A Current Affair / Geoffrey Thomas.

Show a little professionalism and STFU until the final report is released. Until then, all this conjecture makes you sound like a pack of idiots.

Autobrakes4
16th Apr 2017, 20:43
Agree totally BSS. You have got to love these Monday morning quarterbacks who come out with some outrageous suggestions. I'd suggest the closest most have come to the flight deck of a Boeing (anything) is an after landing visit. Google is their friend, they hide behind a Pprune handle and pretend to be airline pilots.

RubberDogPoop
16th Apr 2017, 23:07
Book says to leave autopilot in...unless speed, altitude or attitude deviations dictate otherwise.

VS mode would make no difference. In level flight thrust controls speed in both VS and other level flight autopilot modes.

Interesting.
Isn't that what I want? THR commanding 280kts or M.82 (SPD INT, of course), or whatever that second line says (I never read it anyway), and the auto flight system commanding a pitch, rather than an altitude.

Lookleft
16th Apr 2017, 23:25
Are you boys new to pprune then? If you want to wait for the final report then see you in 2020 when it is released. Even then a lot of people won't agree with its findings. Until then a discussion about the facts that have been released is what this particular bulletin board is for. Do you have any ideas about how to avoid airframe buffeting and a stick shaker activating when in a holding pattern? What do you think the A/T was doing and why did it not prevent the speed decaying to the stall speed? Or do you just occupy a control seat with your mind in neutral?

Avinthenews
17th Apr 2017, 00:56
You can bet they were descending at near minimum clean speed the significance being they were above FL200 where minimum clean speed is not displayed on the PFD.
Entered the hold, thrust at idle (speed on elevator) autopilot possibly reduced the bank angle to protect itself from the slow speed thus didn't follow hold, crew disconnected rolled pulled G and bingo stick shaker. Thrust takes time to advance from idle to something decent at high altitude. Crew does stall recovery maneuver.

RubberDogPoop
17th Apr 2017, 01:03
Lookleft, imagine what PPNe would look like....

RubberDogPoop
17th Apr 2017, 01:11
...autopilot possibly reduced the bank angle to protect itself from the slow speed thus didn't follow hold, crew disconnected rolled pulled G and bingo stick shaker.

Assuming that happened, an UNABLE HOLD AIRSPACE, or the like (don't have a 747 rating), at FL240 with nothing to hit terrain-wise, should this be an overpower or otherwise disconnect AP situation anyway? Practically, what is the implication of straying outside the confines of a hold (but unlikely outside the protected airspace of the hold) in a radar environment?

PW1830
17th Apr 2017, 07:11
Look Left - there are many here who have been around longer than you, actually fly the aircraft in the scenario involved - don't think any of them have been rushing to conclusions.
After 50 years, 20 years Cat B on 767/747, I'm not.
Pprune is a rumour network - however it is not an alternative truth network. The danger is that rubbish written here may be taken as fact by some of the armchair aviators -( nothing wrong with armchair aviating -interesting subject to take an interest in) but "facts" peddled often enough are mistaken for the truth.

Lookleft
17th Apr 2017, 11:31
The scenario involved is that the aircraft experienced buffeting and a stick shaker activation whilst in the hold at FL220. They are the facts as stated by the ATSB. The alternative truth as peddled by QF media and others here is that the aircraft encountered severe turbulence which the caused the stick shaker to activate Feel free to correct me where I am wrong in the statement of the facts. So how often have you found yourself in the scenario as described, regularly get the aircraft to the stick shaker do you?

I made it quite clear that my discussion about the autothrust was entirely my conjecture.Given all your experience maybe you could provide some insight as to what may have occurred whereby a 747 enters a holding pattern and then nearly stalls?

I have a feeling that had this occurred to an Asian carrier then the calls for "wait for the report" would not be so prevalent and that plenty of experienced pilots would be posting about where the crew went wrong.

bigal cessna
17th Apr 2017, 14:37
There is lots of talk about the stick shaker activation and the crew taking over------ but no mention of the -- last resort , [ bugger the crew ] the stick pusher activating to save the aircraft , that will stick heads in the ceiling panels-------did it activate --

Bleve
17th Apr 2017, 15:08
---- but no mention of the -- last resort , [ bugger the crew ] the stick pusher activating to save the aircraft , that will stick heads in the ceiling panels-------did it activate --

Haha, a B747 stick pusher, that gave me a good laugh. Reminds me of the old saying: 'Better to keep your mouth shut and let people think you are a fool than to open it and have it confirmed'.

Nuasea
17th Apr 2017, 19:17
Haven't the time to sift through the submissions but has anyone mentioned FLCH?

Derfred
17th Apr 2017, 19:31
Lookleft, relax.

I take your point about "facts", but I never said they were facts, I said: This seems to be what we know:

My comments about wake turbulence, and severe turbulence didn't come from the ATSB but I didn't make them up, they "apparently" came from the crew:

I was on this flight, severe vibration and a loud vibrating whooshing sound and then plummeting turbulence came out of no where, many passengers and crew hit their heads on the roof, overhead compartments opened and our bags from under the seat in front of us ended up behind us. There were also smoke alarms going off at the rear of the plane.Crew were initially running down the isles to see if there was any fire but said it was a false alarm due to turbulence, it would turn off and then start again the whole way into landing. It was very scary to say the least. Crew said we hit the wake of another plane, I don't know but I'm thankful we landed safely.

… CC & pax were told it was turbulence.

The passengers on board experienced what felt like severe turbulence. (from QF PR)

One source says the "crew" told them it was wake turbulence. Three sources use the word "turbulence", and one uses the word "severe".

So how often have you found yourself in the scenario as described, regularly get the aircraft to the stick shaker do you?

Never had a stick shaker in an aircraft, but I've had a few in the simulator when practicing turbulence, aircraft upsets and other non-normal manoeuvres.

I just find it hard to imagine that an approach to stall recovery manoeuvre would cause anything like the mayhem in the cabin as described. Would applying forward elevator really set off smoke alarms and open overhead compartments? Sounds more like turbulence to me. Hence my conjecture that it may have been turbulence which caused the stick shaker rather than the other way around.

As for the "conjecture police" - thinking about real aircraft incidents and discussing all the possible reasons it may have happened, and how it may be avoided in future makes us all better aviators. If you don't like it, don't read it.

Lookleft
17th Apr 2017, 21:18
Derfred point taken regarding the origin of the reported turbulence. Passenger reports of turbulence are not inconsistent with the ATSB statement of airframe buffeting but the two are very different in origin. I could imagine that a distracted crew would experience a fair bit of a WTF moment if their first indications of a problem was buffeting and the stick shaker. They would have realised that the aircraft was about to do something nasty and reacted accordingly.

A significant application of forward elevator would have resulted in the chaos down the back of the aircraft as reported. Not dissimilar to the A330 incident off WA where a sudden nose down pitching manoeuvre led to injuries in the rear of the cabin.

Completely agree with your last statement.

Ushuaia
18th Apr 2017, 01:57
Having heard the FACTS now, as related by the CAPTAIN of the aircraft, I can confirm that 95% of what gets written on PPrune is complete tripe! 5% excellent, but I'm sorry, the other 95% need a reality check.

Stick pusher on a B747..... for heaven's sake....

maggot
18th Apr 2017, 02:08
Having heard the FACTS now, as related by the CAPTAIN of the aircraft, I can confirm that 95% of what gets written on PPrune is complete tripe! 5% excellent, but I'm sorry, the other 95% need a reality check.

Stick pusher on a B747..... for heaven's sake....

Well then... cough it up!
Rumours and BS only really develop well in lieu of facts. So out with it

Please

Ida down
18th Apr 2017, 02:30
So if Vs at FL220 is around is 180-190 what would the holding speed be, 240? In this incident turbulence has nothing to do with it. The stick shaker and the airframe buffeting seemed to occur at the same time. Possibly the A/T has not maintained the hold speed and the crew had taken their eyes off the ball.

Why don't you just sell it, to Sixty Minutes? To make a ststement like that, in public, when you are assuming, is not cricket. Perhaps next time you will give it some thought, first.

Lookleft
18th Apr 2017, 03:35
To make a ststement like that, in public, when you are assuming, is not cricket.

"Not cricket", really? What does that even mean:ugh: Once again had this happened to anyone else then I don't think the indignation would be so righteous.

In case anyone is in any doubt this aircraft was about to stall. The crew responded in an appropriate way but how did it get to that point in the first place? In TEM terms, this aircraft was in an UAS after an undetected threat and/or error occurred. I have now idea of the sequence of events that allowed it to get to an UAS but I do know that if the attitude was appropriate then the only thing not providing the required performance was the thrust. it applies to any aircraft.

If you actually know something about the incident then more than happy to be set straight.

Ushuaia
18th Apr 2017, 03:44
Well then... cough it up!
Rumours and BS only really develop well in lieu of facts. So out with it

Please

And break the confidence of the Captain? Of Qantas? Of the ATSB investigators? Not going to happen.

I do agree with you though re rumours and BS. This is the trouble with social media/internet stuff these days - the facts, crew sensitivity, privacy, etc, simply don't have a chance anymore. The media, the GT's, etc, don't care about that stuff, just as long as something, anything, is said to fill copy. And frankly PPrune is just as bad. Some people just have to say anything to appear relevant, even if it's total tripe.

Not just PPrune, not just aviation; it is a sad indictment of life in the 21st century.

Glorified Dus Briver
18th Apr 2017, 04:12
Most of you are as bad as Today Tonight / A Current Affair / Geoffrey Thomas.

Show a little professionalism and STFU until the final report is released. Until then, all this conjecture makes you sound like a pack of idiots.

Are you serious? I've got nearly 9000hrs of flying time on the PMDG 737 on flight simulator 2004, so I can vouch for myself when I say there is 100% credibility on whatever I say :E:}

CurtainTwitcher
18th Apr 2017, 04:26
Once again had this happened to anyone else then I don't think the indignation would be so righteous
Really? You are making a wild assumption there. I've made the same comments on other threads about incidents and accidents that happened to "other peoples" (if I am getting your "you are all racist" drift there, you've twice mentioned it). In fact here is a link to a google search (https://www.google.com.au/search?q="wait+for+the+report"+curtaintwitcher+site%3Apprune.org&oq="wait+for+the+report"+curtaintwitcher+site%3Apprune.org&) for my posts on pprune with "lets wait for the report".

I wait to read the reports, then comment on what is written in the report. Then I start my learning. I may go back and read previous posts in conjunction with the report to provide any extra knowledge that I'm deficient in.

Recently there was a long and extensive thread on the B747 - Turkish Airlines cargo 747 crashes in Kyrgyzstan (http://www.pprune.org/rumours-news/589633-turkish-airlines-cargo-747-crashes-kyrgyzstan.html). After 17 pages the preliminary report was finally released in post #326 (http://www.pprune.org/rumours-news/589633-turkish-airlines-cargo-747-crashes-kyrgyzstan-17.html#post9717959). You know what? Not a single post prior to that close to the ultimate cause of the accident - the fact the B747-4 will capture a 3° path using inertial guidance with a false glideslope.

17 pages of speculation & drivel, about the only piece of additional information that came out of it prior to the report was the Dutch Safety Board Report on Pitch-up Upsets due to ILS False Glide Slope (https://www.onderzoeksraad.nl/en/onderzoek/2047/pitch-up-upsets-due-to-ils-false-glide-slope). I literally learnt nothing else, and posters just went round and round in circles on progressively hair-brained speculation because they had no new information other than the initial report that there had been an accident.

Same with the DXB B777 (http://www.pprune.org/rumours-news/582445-emirates-b777-gear-collapse-dxb.html) accident, plenty of speculation, but not a single poster got the fact the G/A was initiated after the RAAS callout and the fact that one wheel had touched down and the autothrottle G/A was disabled catching both pilots by surprise.

If you really want to understand why you shouldn't speculate with almost no information, take an hour to sit through John Boyd's "Conceptual Spiral" playlist

playlist?list=PL10569CDF59FE54A3 following along with his slide pack (http://pogoarchives.org/m/dni/john_boyd_compendium/conceptual-spiral-20111100.pdf) for the presentation. Then finish off with his paper Destruction and Creation (http://pogoarchives.org/m/dni/john_boyd_compendium/destruction_and_creation.pdf). Once you have done all that, you will realise how in the absence of updated information that you will end up totally and utterly confused and so far away from the truth that it will leave you embarrased when the report is actually released. There is very little in the way of learning that can be done without direct knowledge of the facts.

This isn't about racism, its about avoiding confusion and being clear about what actually occurred & what lessons we can learn. That starts after the facts are known.

Conceptual Spiral playlist link for browsers that don't embed properly https://www.youtube.com/playlist?list=PL10569CDF59FE54A3

maggot
18th Apr 2017, 05:37
And break the confidence of the Captain? Of Qantas? Of the ATSB investigators? Not going to happen.


Cmon at least throw us a bone man! :D
I dont wanna have to actually talk to any jumbo crew for this

Lookleft
18th Apr 2017, 05:48
After 17 pages the preliminary report was finally released in post #326 . You know what? Not a single post prior to that close to the ultimate cause of the accident - the fact the B747-4 will capture a 3° path using inertial guidance with a false glideslope.

And what was the first safety recommendation of that report CT?

Most of the posts directed at me are not about any flaws in my hypothesis but all about the fact that I have dared to offer a hypothesis at all. That hasn't been my experience when I have commented on other incidents and accidents so my conclusion has been that it must be about the operator of the aircraft. BTW I did have a look at your links and there is a reason I have never studied philosophy, the links provide a good example.

If you want to wait until the report then like I said see you in 3 years time when the final might be released. Until then, if you don't want to provide comment on what you think might have happened then exercise your absolute right not to do so.

This had me laughing though:

Having heard the FACTS now, as related by the CAPTAIN of the aircraft, I can confirm that 95% of what gets written on PPrune is complete tripe! 5% excellent, but I'm sorry, the other 95% need a reality check.

is followed up by this:

And frankly PPrune is just as bad. Some people just have to say anything to appear relevant, even if it's total tripe.

It is your absolute right to post, but sometimes it might be better not to.

CurtainTwitcher
18th Apr 2017, 08:28
BTW I did have a look at your links and there is a reason I have never studied philosophy, the links provide a good example.
That's interesting, because he was a fighter pilot who literally wrote the dogfighting manual Aerial Attack Study (http://code7700.com/pdfs/aerial-attack-study-1964_john_boyd.pdf)in 1958 (I'm reliably told that a copy is still in every fighter squadron around the world, and not a single manoeuvre has been added) and eventually declassified in 1964, who then studied engineering and thermodynamics.

He also single handily came up with the of Energy-Manoeuvrability theory (https://www.archives.gov/files/declassification/iscap/pdf/2011-052-doc1.pdf) that fundamentally changed the design of all modern fighters in 1966.

Then he went on to provide the conceptual design & ideas for the F-15, F-16, YF17 (FA18) and the A10, showed up the flaws prior to flight of the F111 to its designer. He Helped Plan Desert Storm, Saved the F-15, a Famous Fighter Pilot…But You’ve Never Heard of Him (http://duotechservices.com/10-things-you-didnt-know-about-col-john-boyd). He was an incredibly practical individual, and his theories were focused on just one thing, killing the other guy before he killed you. He based his theories on engineering, physics, thermodynamics and quantum mechanics. Some philosopher! But yeh, whatever. You might actually learn something by studying him & his work.

No, the thing that really gets me is the slur of "racist", once explicitly and then implicitly a second time.
I have a feeling that had this occurred to an Asian carrier then the calls for "wait for the report" would not be so prevalent and that plenty of experienced pilots would be posting about where the crew went wrong.
post #71 (http://www.pprune.org/australia-new-zealand-pacific/593411-15-injured-serious-stall-alert-incident-qantas-flight-4.html#post9743185)

Once again had this happened to anyone else then I don't think the indignation would be so righteous.
post #80 (http://www.pprune.org/australia-new-zealand-pacific/593411-15-injured-serious-stall-alert-incident-qantas-flight-4.html#post9743912)

I provided a link to a google search of MY posts (https://www.google.com.au/search?q=%22wait+for+the+report%22+curtaintwitcher+site%3App rune.org&oq=%22wait+for+the+report%22+curtaintwitcher+site%3Apprune.o rg&) with calls for "wait for the report" - Guess what? One of the those calls were for an Asian operator. I don't see people the calling "wait for the report" to protect, shieldor cover up for any particular race or pilot group, I see it because sensibly, most recognise there are so few facts on the table.

Lookleft
18th Apr 2017, 08:35
Yep, and if I was a fighter pilot then I would pay much more attention to him. The stuff you posted links for had very little to do with ACM from what I could tell.

most recognise there are so few facts on the table.

The fact is a 747 was close to stalling, worth a bit of discussion beyond "you are obviously not a pilot" I would have thought.

Capt Fathom
18th Apr 2017, 11:05
The fact is a 747 was close to stalling
Do we know that, as a fact?

Square Bear
18th Apr 2017, 12:00
[QUOTE]Do we know that, as a fact?/QUOTE]

No, but we know the following.........

The ATSB is investigating a stick shaker activation involving a Qantas Boeing 747, VH-OJU, 110 km SE of Hong Kong (BETTY IFR), on 7 April 2017.

While holding at flight level 220, the flight crew received a stick shaker activation and detected airframe buffeting. The flight crew disconnected the autopilot and manoeuvred the aircraft in response. Fifteen passengers received minor injuries.

People can stick their head in the sand as much as they like, but where there is smoke there is probably a little bit of fire...Lookleft makes more sense than those that state "NOTHING TO SEE HERE FOLKS, MOVE ON NOW..."

wiggy
18th Apr 2017, 12:46
Haven't the time to sift through the submissions but has anyone mentioned FLCH?

Funnily enough, not that I have seen,.....but FLCH nearly caught a couple of our guys out in a hold not long after we got the 744.

bigal cessna
18th Apr 2017, 13:22
Ok --stick pushers or stick nudgers were fitted to british b747 --applied a force at the same time as the stick shaker activation-- maybe qantas did not fit them to their aircraft----they were lucky it happened at altitude and not 200 feet ---------- still lots of questions

KABOY
19th Apr 2017, 02:19
they were lucky it happened at altitude and not 200 feet ---------- still lots of questions

Altitude deviations in holding pattern also raise the issue of a breakdown in separation. Holding at that altitude would certainly have seen aircraft below them in the hold.

Stick shakers and TCAS TA/RA would have been quite an event....

underfire
20th Apr 2017, 00:35
I was on this flight, severe vibration and a loud vibrating whooshing sound and then plummeting turbulence came out of no where,

KH wave?

Whaaaaaa? Do you even fly bro?

Wake turbulence is not a jet stream issue, it's caused by another aircraft, presumably 1000' above burning circles with you.
Sorry, he is not saying that WT is a jetstream issue...he is stating 2 different scenarios...

Dale Hardale
20th Apr 2017, 03:16
severe vibration and a loud vibrating whooshing sound and then plummeting turbulence


Translation:

Severe vibration - pre stall buffet
loud vibrating whooshing sound - more severe buffet
plummeting turbulence - Stick pusher operating or aircraft stalling:{

Bullethead
20th Apr 2017, 04:20
A lot of rubbish in this thread.

Stick shaker activation is a PRE-stall warning for such aircraft which have indistinct naturally occurring pre-stall buffet and stick shakers are installed on such aircraft to alert the pilots that a stall is imminent and not to indicate that a stall has already happened.

So at stick shaker activation the aircraft is fully controllable and not stalled.

In my previous pre-airline life I flew for two transport squadrons, one flying Hercs and the other the B707.

Stalling and the recovery was part of the training on both types and on the B707 stalling the aircraft, both clean and fully configured was part of the post heavy maintenance flight check schedule.

The fully developed clean stall and recovery maneuver in the B707 was a relatively mild experience and certainly nowhere near violent enough to cause injuries as suffered on the QANTAS aircraft.

Now before anyone leaps down my neck, I am fully aware that a B707 is not a B747 but I have flown many thousands of hours on both aircraft types and although I haven't had the pleasure of stalling a B747 aircraft I have done the stall and recovery exercise in the B747 flight simulator and it is most definitely not a boneshaker. The simulator remained firmly attached to it's mounting bolts! I have no reason to suspect that the stall characteristics of the B747 would be any different to that of the B707.

My opinion is that the QANTAS B747 had a wake turbulence encounter with a higher heavier aircraft in the same holding pattern.

There was a recent A380 wake turbulence incident where a Challenger aircraft was affected and lost control and and after recovery was eventually written off so wake turbulence encounters can be violent and should be avoided at all costs.

Cheers,
BH.

itsnotthatbloodyhard
20th Apr 2017, 04:50
BH
Please stop trying to inject knowledge and experience into this discussion. Try instead to use terms like 'plummeting turbulence', if you don't mind.

Thank you.

Derfred
20th Apr 2017, 20:32
Yeah, "plummeting turbulence" is my trademark excuse for my landings... let us not mis-use the phrase lest I be all out of excuses.. :)

Dora-9
21st Apr 2017, 02:48
stall and recovery exercise in the B747 flight simulator and it is most definitely not a boneshaker.

It is in the aeroplane though!

LeadSled
21st Apr 2017, 02:53
Folks,
I have stalled a "Classic" (-200) in training, clean at high levels and approach/landing config. at mid-levels ------ the degree of buffeting and vibration is quite startling.
If you understand the different certification of the -400, close to a stall I guess it would be even more startling, because the horizontal stab is going to be even deeper in the turbulent wake from wing root.
The Classic simulator stall is nothing like the "real thing", the -400 sim. has the same shortcoming, based on my having done countless low speed sim.exercises.
The B707-320B/C stalls in the air are tame by comparison, the B707-300 even more tame, as long as you do not get into a dutch roll, again I am speaking from experience.
Final comment, we have a lot to learn about downwash from an aircraft above, I have had some mild encounters holding in the vicinity of EGLL and EGCC, and consider the recent written off Challenger near Dubai.
Tootle pip!!

Lookleft
21st Apr 2017, 03:58
The speculation about wake turbulence contributing to the stick shaker is interesting but I would have to ask whether an A380 could do this to a 747? An A380 throwing around a Challenger is understandable given the relative sizes, but if it is possible for an A380 to get a 747 close to the stall then there has to be a serious rethink of wake turbulence separation in a holding pattern! LS states that he experienced mild encounters which I assume was from other 747s. If it was an initial encounter with wake turbulence I would also expect that mention would be made of that in the ATSB summary.

zzuf
21st Apr 2017, 05:09
My recollection from many years ago was that the B744 clean stall was defined by deterrent buffet.
Boeing certainly did not stall this aircraft unless the tailplane was strain gauged. There was no correlation between the buffet levels experienced by the test crew and that experienced by the tailplane - structural damage could result.
I recall hanging around Boeing Field awaiting completion of strain gauge installation on a B744 up at Everett.

maggot
21st Apr 2017, 05:09
The speculation about wake turbulence contributing to the stick shaker is interesting but I would have to ask whether an A380 could do this to a 747? An A380 throwing around a Challenger is understandable given the relative sizes, but if it is possible for an A380 to get a 747 close to the stall then there has to be a serious rethink of wake turbulence separation in a holding pattern! LS states that he experienced mild encounters which I assume was from other 747s. If it was an initial encounter with wake turbulence I would also expect that mention would be made of that in the ATSB summary.
Yes can, will and does. Covered already.

donpizmeov
21st Apr 2017, 09:21
Had the [email protected] kicked out of us flying into AMS recently following one of those little 737 aeroplanes. We were in a 380. Have also been rolled left and right following 777, 747, 757, 380 while also in a 380.

The challenger being discussed, may have been bent from a less than graceful recovery.

Keg
21st Apr 2017, 10:48
Had injuries on a 767 years ago when at FL370 about 10-15 miles behind a 744. Had the A380 thrown sideways and A/P disengage behind another A380 into DXB. I can absolutely see the right kind of wake getting a 744 at min speed into an UAS.

Girlfromoz
21st Apr 2017, 12:12
BH
Please stop trying to inject knowledge and experience into this discussion. Try instead to use terms like 'plummeting turbulence', if you don't mind.

Thank you.

I am not a pilot, I'm not in the airline business either just a passenger onboard, I might not have the correct phrases you require. I'm just telling you how it felt on board that plane. Trying to shed a light on what might have happened that's all.