Severe turbulence/mountain wave 10th March 2007

[Fast Erect]

Thanks to the TCX chappie today who advised us of what was about to break loose, none of our pax were hurt..


Much appreciated.


:ok:

[BOAC]

A good call by the sound of it. Probably the worst turbulence I have experience in airline flying has been there.

[Easy Ryder]

Just got back from my 2 sectors, rough as hell south of the pyrenees. Worst i've experienced to date! Speed control... whats that?

[propaganda]

Similiar experience a few years ago. unfortunately, it was an inaugural flight and the plane was full of VIP's, press and the airlines MD....14 injured, not an experience you ever want to repeat..
Safe Flying.:ok:

[Farmer 1]

There were lenticular clouds over Norfolk yesterday.

Terribly hilly, Norfolk.

[Shoo shoo]

Anybody care to let me know what levels you experienced it at?

SS

[transilvana]

That wind over the Pirineos is called "Tramontana", it´s local wind in all the region, it get´s really bumpy.

You also can get this type of heavy turbulence in the Approach at Malaga airport on Rwy13, it´s called "terral" and mainly on the summer, that has been my worst experience on winds.

[BOAC]

Anybody care to let me know what levels you experienced it at? - re Post#2 it was FL360 - until we did an emergency descent due to pending loss of control.

[Caracas]

Also experienced this yesterday at FL360 crossing outbound from MAD.

Speed decayed very rapidly.

[The Real Slim Shady]

Last night it was at all levels from FL290; we had to squeal for an immediate descent from FL370 north of MLA. Speed all over the place and bouncing around like a kid on a trampoline. One easyJet crew asked for descent and were told to "Standby". Great reply from the crew "I don't want to standby I want to descend because of turbulence" Maybe the ATC guy in his warm stationary room won't ask a crew to "Standby" again!! North bound it wasnt too bad over Bilboa, got lumpier near Nantes. Have the joys of the same route tonite:eek:

[No longer ATC]

My other half flew LGW-PMI with Easyjet yesterday morning , and said turb was like nothing he's ever seen...and he flies 744 with BA so has seen a bit of it! NLA.

[aw8565]

So thats why all those aircraft were asking for extra cleaning yesterday... :yuk: :yuk: :yuk:

[garp]

One easyJet crew asked for descent and were told to "Standby". Great reply from the crew "I don't want to standby I want to descend because of turbulence" Maybe the ATC guy in his warm stationary room won't ask a crew to "Standby" again!!
Would you prefer ATC to descend you into another plane? I will tell pilots to standby when needed, different pilots have different degrees of turbulence tolerance and I will certainly not loose separation because of a pilot feeling a bit uncomfortable. Whenever possible he will get descend, if he has to wait and cannot he should declare that he's unable to maintain level and emergency separation can be applied. This happened once to me during the past 20 years in probably the busiest airspace over Europe. The idea that you even think ATC would not give descend because they don't feel like it is revolting and shows very little appreciation of our jobs. Have a great Sunday.

[kick the tires]

Agress with GARP. However, some Eurpoean ATC is most definatley not in the same class as the likes of UK and doesnt instill the confidence that we would prefer!

I have only ever ONCE experienced what I would class as severe turbulence - we couldn't read any instruments, took a few goes at getting hold of the ALT selector and cockpit was full of charts, meal packs, papers etc etc!

This was south of alps over Italy and ATC did same, responed to our request for descent with 'standby'. However our reply was 'Mayday, we are descending to FL200' and down we went. That cut through the red tape!

[Avman]

The Real Slim Shady, you show an incredible lack of knowledge and maturity. Wonder what you would have posted if the controller had given immediate descent slap bang into some other traffic. Rest assured my friend that no controller will deliberately make you ride heavy turbulence just for the fun of it. Try and understand that if an aircraft in the cruise unexpectantly requests descent the controller may well first have to initiate co-ordination with an adjacent sector or unit. Spend a day in an en-route ATC centre before you mouth off so stupidly.
Kick the tires, by all means call "Mayday - am descending to FL200". Then it's your responsibility. But if you "request" descent the controller will not move you until he/she is satisfied that it is safe to do so and all necessary co-ordination has been effected - because it's his/her responsibility.

[Wee Weasley Welshman]

All fair comment. I suspect that very very few cockpit crew are ever trained in emergency descent due to turbulence. Decompression - all the time.

The latter is black and white. The former grey and grey.

Its a topic that Air traffic control Officers and Pilots should perhaps discuss in more detail for mutual benefit.

Cheers

WWW

[IcePack]

Mmm!

Severe turbulance means the A/C is temporalily out of control.
Standby well yes, will be followed very shortly by a jet upset.
That means mayday if you can get the words out with a mouth full of cockpit clutter.
ATC if an a/c is screaming for descent due severe turbulance he/she means it, it is just a matter of timing before the mayday. Severe turbulance can be the most frightning thing a pilot experiences in his/her career, he/she is NOT a wimp. Those who think he/she is, have never been in severe turbulance.
Mother nature is bigger stronger than any human built machine or person, luckily it does not happen that often.:cool:

[JW411]

Wasn't any of this severe turbulence forecast?

[Wee Weasley Welshman]

No, not really. And it was bad.

WWW

[Shoo shoo]

WWW - re you comment on training. A very good point.

After some thousands of hours, quite a few global, I've never experienced it nor heard it mentioned by trainers apart from a video on Jet Upset on one type rating course.

Certainly never seen it in the sim.

Well worth inclusion.

SS

[BOAC]

It is PAN PAN PAN "xxx Emergency Descent". If, as we are led to believe, the Spanish and French do not understand this emergency prefix, then make it "Mayday". Turn off track (helps the descent) and down you go. ATC can sort it out. The odds are stacked in favour of not hitting anything against losing control.

Do not linger in SEVERE turbulence waiting for Pedro or Louis to respond, or you will find yourself descending anyway, but out of control.:)

[Final 3 Greens]

garp

I will tell pilots to standby when needed, different pilots have different degrees of turbulence tolerance and I will certainly not loose separation because of some whimp feeling a bit uncomfortable.

Your attitude is idiotic.

Aircraft have bee destroyed by severe turbulence.

[Caracas]

Well said.

Have been in severe turbulence in the Madrid area. Cabin was a mess speed all over the shop.

Not the place to linger for too long.

[Desk Bound]

An interesting debate. Severe turbulence is never pleasant. A few years ago I was flying south west from Dakar at night and entered severe turbulence that induced a 3000'/min ROD in a 4-engine heavy with max thrust applied. I would have dearly liked to have had an air traffic controller respond to my RT as they will in Europe - even if it is 'Standby'!

That said, I also had severe turbulence (mountain waves) east of the Rockies where the Mach went from 0.86 to 1.1 and down to 0.5 quicker than I can type it and all we could do was to hang on and attempt to fly attitude. Sadly, the US controller seemed less than interested - but fortunately we came out the other side fairly quickly.

In both cases, it is something I would prefer not to experience again - and night always makes it worse. However, whenever I find myself in an emergency or urgency situation I welcome the crisp and professional response of the UK controllers - in my experience they are generally superb.:ok:

[garp]

F3G, it seems you haven't read my complete post which continues as follows
"Whenever possible he will get descend, if he has to wait and cannot he should declare that he's unable to maintain level and emergency separation can be applied."
From your comment I understand that every a/c reporting turbulence has to be descended/climbed regardless of traffic or degree of turbulence. Good going. Again, just for the sake of clarity, when you declare that you are unable to maintain level you will be descended/climbed and emergency separation can be applied. Rest assured that any pilot asking for a level change due turbulence will get it but not at any price. As a final note you can also rest assured that we will try our very best to warn you about turbulence and try to plan you at different levels.

[woodpecker]

Garp...

Perhaps your "some whimp..." understandably upset a few.

Having used Pan Pan at 6000 in the LHR TMA in a 767 and ended up in Stansted with an AOG a/c (following the QAR "G" record) I would have objected to being called a whimp.

[Wannabe1974]

Would severe turbulence justify a mayday? Before anyone starts, I am not getting at the guy who posted that! Just wondering...
I would have thought a Pan would be more appropriate until actual bits of aeroplane start worrying the Pyrennean goats...
Am I talking rubbish?

[BOAC]

Am I talking rubbish - possibly. Please re-read post #22

[tbaylx]

I think it's the wimp comment that riled a few guys. ATC isn't going to clear you to a lower level without making sure you have seperation. We ask for lower or higher all the time due turbulence, most of the time we can wait for them to check with another sector for conflicting traffic. The guys on the ground don't know how bad it is, or that you need immediate descent. If its bad enough that you're about to run the airspeed indicator out the bottom and plummet from the sky declare the pan, or mayday..turn offtrack and down you go.

You can sort the rest out later and keep an eye on TCAS in the meantime. ATC won't give you a clearance, nor should they unless its safe and legal for them to do so. If you want down before that, do what we'd do in any other situation that warrants it, declare an emergency, take your own seperation into account and descend.

[Bandit650]

Just out of interest ... could someone outline what this severity of turbulence actually feels like? I'm imagining a scene where instruments can hardly be read, you'd immediately and violently depart your seat if not stapped in, wings flexing all over the place, or in other words like being violently shaken as if in a cocktail shaker...would appreciate an insight for future reference. Thanks.

[TotalBeginner]

Interesting thread!

Is the turbulence that you talk about in this region a seasonal thing?

[RV1]

Controllers will always try to give you descent due to turbulence if you request it but there are a number of reasons why you may be told to standby, such as...
1. You're still in another sectors airspace (especially if you've just been transferred) and we need to co-ordinate descent with the previous sector before we can descend you.
2. There's other conflicting traffic which we need to get out of the way first.
3. We're busy trying to give descents to the other a/c experiencing the same turbulence. Weather and turbulence can really increase our workload. We will try to give you what you want as soon as we can as we all know what it's like to be in the back of a plane in turbulence but bear with us!

[BOAC]

Bandit - not necessarily - it could be severe mountain wave where the speed goes from stall warning with full power to limit speed with throttles closed. Descent is the only option. Luckily only seen that once. Also came close in a twin piston over the Scottish Highlands.

Not always a 'shaking'. :)

[Bandit650]

Bandit - not necessarily - it could be severe mountain wave where the speed goes from stall warning with full power to limit speed with throttles closed. Descent is the only option. Luckily only seen that once. Also came close in a twin piston over the Scottish Highlands.

Not always a 'shaking'. :)

Thank-you. I didn't know that. Got me curious now..will have to go and read all about it!:ok:

[Shoo shoo]

On the last page WWW said it was not forecast. I understand that the Tramontana was forecast on local radio & TV for Catalunya, with windspeeds "Up to 140kph"

Maybe not joined up met reporting?

[Caracas]

There was nothing on the significant weather charts or any SIGMETS.

The only SIGMET was for the Barcelona FIR expiring around 1500Z.

[tired]

Many thanks to the southbound Speedbird who warned us about this whilst we were still in Algerian airspace (heading northbound). They went through the area at F310 and apparently had a very rough time. When we got there we were at F400 and it wasn't bad at all - a couple of minutes of "moderate", with speed excursions of +/- 10 knots - no sweat. Sometimes it pays to go high!! :)

[J430]

I know this might be a "how long is a piece of string" question, but i see most folk are wanting a decent. I only fly bugsmasher altitudes and getting away from mountain induced turbulence is usually by flying as high as you can. Obviously with very high terrain its different and maybe you are flying below the waves, is that what you are trying to achieve? how do you determine which is better climb or decend?

J:ok:

[Wee Weasley Welshman]

The lower you go the thicker the air the more scope your wing has to avoid a stall or overspeed. To put it in stupidly simple terms.

I don't know of many that would prefer to climb closer to coffin corner to avoid turbulence...

Cheers

WWW

[411A]

Severe turbulence is easily handled....let the co-pilot fly the aeroplane.
No one is the wiser...:}

[Ignition Override]

If it was severe in a 737 or A-320 etc, imagine what it was like in the back of a 757-200 or 300?

There is nothing wimpy about what happens to passengers or flight attendants who are thrown sideways on top of beverage drink carts or are thrown into the ceiling....feet first, one presumes? What we call light-moderate 'code 3' up front in the c0ckpit is worse in the back of many aircraft, near the aft galleys.

Read the article in (US) "Airways" magazine about two or three months ago about what a pilot learned regarding certain cavalier ATC attitudes (among some, but not all) towards many pilot requests which he was expected to learn and apply, when he then became a controller.
His article is titled "Circle of Jerks" : his words, not mine. Y'all remember who we carry around.

[garp]

Wimp comment: I agree, not being a native English speaker I thought the meaning of wimp is less inflamatory than it turned out to be. My post is edited for this. The rest of my post remains valid however.

[Avman]

Ignition Override: U.S. controllers and European controllers are two entirely different breeds, believe me.

[The Real Slim Shady]

Garp
I asked for, and got, my requested descent from FL370 to FL330: not that the turbulence particularly mitigated but it did give me a tad more space between the yellow bars on the PFD - 1.3 g buffet limit. When the speed is varying so fast that you are going from full thrust to idle to try to stop it hitting the red, and the you can't maintain altitude and the aircraft is rolling violently, you don't want to hang around in it.

That type of motion isn't a problem for the guys at the front, strapped in and with very few loose articles on the flightdeck, but for pax and cabin crew it can be terrifying and dangerous respectively.

The sig wx chart indicated nothing: Bordeaux were warning of "turbulence" over the Pyrennees at all levels but no indication of the severity. Last night with the same northerly wind, albeit a tad stronger at FL370 the ride was occasionally choppy, no more.

The easyJet wasn't a Wimp: he was simply trying to get his aircraft out of the turbulence for safety. If the ride he was suddenly subjected to at FL390 was anything like ours at FL370 he would have had even less of a margin than us.

Following requests from half a dozen aircraft for immediate descents from 370 and 390 other aircraft following were requesting early descents before the wave hit them: if the controllers already knew that 370 and 390 were bad why did they not warn the crews and offer descents?

[ZeeDoktor]

Turbulence conditions can change rapidly. Suddenly, the lower levels are affected and not the upper ones. Would you offer a different altitude if you were an ATC? I wouldn't - I would let them know that previous a/c were encountering these problems at said levels, but the decision is up to the PIC.

If you offer actively your name might show up in the accident report...

[ABO944]

Perhaps some of the ATC-ers dont quite understand the conditions that we can experience in severe turbulence.


Send them up for a fam flight in Scotland during a stormy night in a small turboprop, and they'll soon realise.

I have had the pleasure(:yuk: ) of experiencing some sporting weather conditions this winter, and it wasn't much fun. Add some icing to the equation just to make it a little more interesting.

All vomit bags full !

:\ :cool:

[Shoo shoo]

If ATC knew of the turbulence - esp the severity experienced by previous a/c - then I would expect at least they passed the info on & at which levels they had reports from.

[Wee Weasley Welshman]

ATC are our allies, not our foes. Keep that for management..

WWW

[tommoutrie]

slowing down helped us a lot - didnt hear anyone else calling to slow down though. Doesn't that help you chaps in the airliners?

[Shoo shoo]

Sorry, I wan't attacking ATC, merely wondering if they provided warning? Was that what the original poster meant? If not, why?

"Just out of curiosity,what was the wind doing around that region of the Pyronees on that day?" Dwaine Pipe

It was very strong gusting to 140Kph at the surface apparently.

[The Real Slim Shady]

At 370 it was around 040/41 just north of MLA

[Caracas]

South of the Pyrenees (north of Zaragoza) it was 000/65 at FL360

[tubby linton]

Were there any lenticular clouds around?

[Caracas]

There were not any lenticular clouds in the west Pyrenees at least.

[merlinxx]

This is a PIREP situ, were any passed to ATC? Were you ACRAS equiped so Ops/Dispatch could log?

[Capt H Peacock]

I wasn’t there and didn’t experience this event, but I have in the past.

I would suggest that this was a manifestation of rotors. The strength of the wind is not the issue here, but the presence of a deep, stable layer with little vertical shear throughout the troposphere.

In such circumstances, when the wind is incident on a barrier such as a mountain range, longitudinal harmonic vortices called rotors can form just like from the reed in an organ pipe. The question of lenticular cloud is germane because the presence of such clouds is a sign of the possibility of rotors.

Stacked lenticularis, particularly when in regularly spaced groups is a harbinger of the presence of rotors and the possibility of severe turbulence. Also the clouds produce severe icing as a result of forced uplifting of saturated air. They should be avoided if possible. The rotors will be between and below the lenticularis as they generally form in the 'troughs' of the lee wave. Conversely, the clouds mark the peaks of the wave.

Such phenomena may not be forecast on significant weather charts, since no winds below 80 kts are shown, and their incidence may be temporary and sporadic. The art of the professional airman is to recognise the warning signs, and be prepared:

- A deep stable layer with little shear up to the trop. Check the wind charts.
- An incidence over a lateral barrier of less than about 30˚
- A warm moist airmass

If you’re not fortunate enough to avoid it, keep the attitude as constant as you can, ditch the autothrust and make smooth adjustments with power, remember you may be close to the surge boundary, tolerate the variations in speed and altitude within reason.

Make a ‘securité’ broadcast on the frequency in use and 121.5 giving your position, level and heading.

You won’t be able to maintain RVSM, and the call to ATC is MAYDAY if you can’t achieve a sympathetic reclearance.

[garp]

@ Real slim Shady, your milder tone makes much more sense to me now.
"When the speed is varying so fast that you are going from full thrust to idle to try to stop it hitting the red, and the you can't maintain altitude and the aircraft is rolling violently, you don't want to hang around in it."
I guess my reply makes as much sense to you
"Whenever possible he will get descend, if he has to wait and cannot he should declare that he's unable to maintain level and emergency separation can be applied."
Your quote: "The easyJet wasn't a Wimp"
I went over that already, took that word back.
Your quot: "Following requests from half a dozen aircraft for immediate descents from 370 and 390 other aircraft following were requesting early descents before the wave hit them: if the controllers already knew that 370 and 390 were bad why did they not warn the crews and offer descents?"
My quote: "Rest assured that any pilot asking for a level change due turbulence will get it but not at any price. As a final note you can also rest assured that we will try our very best to warn you about turbulence and try to plan you at different levels."
There's a big difference between your initial post and this subsequent post, I'll buy the second real slim shady a beer :-)

@ WWW "ATC are our allies, not our foes. Keep that for management..

WWW"
I'll buy you a beer anytime.

[India Four Two]

I have been following this thread with interest. I have had a fair amount of experience with wave and rotor, both as a passenger flying up and down the Rocky Mountains and as a tow pilot up to 10,000' and in gliders up to FL240.

I have always found (and read) that the worst turbulence is associated with the rotors which usually occur at or below the tops of the mountains and that above the mountain tops, the flow is laminar and often uncannily smooth.

Was the high altitude turbulence encountered over the Pyrenees due to wind shear or high speed penetration of short period waves? I imagine waves that appear smooth to me at 50 kts, might seem quite different at 500 kts.

Classic "rotor" seems unlikely at the altitudes reported. Are there any meteorologists who can comment?

[Jagohu]

The question popped up, why ATC doesn't inform pilots in time offering other levels... Well, I'd say that as it was written before our workload can get really high even with a few aircraft in turbulence, but if there's medium or heavy traffic and/or military traffic then especially.

For example... The top of the lower sector is FL345. You're flying at FL370, wanting to know about the turbulence. If you wanna go down below we need to coordinate with the lower sector if they can take you.

If the sectors are collapsed into one, one problem less, but still if everyone wants to fly on the same levels it's not that easy to manage sometimes for 15-20 planes in the sector, especially that you can't base your separation even on the 'more or less same speed for same type a/c'...

Other thing is that we might be busy with arranging something for someone else and/or trying to figure out how's it going to work with all of you going up/down... It takes time as well.

If there's MIL traffic in the area talking to MIL controllers only, they might also wanna change level. The we only got a phone call saying he's going to that level due turbulence and the rest is up to us. :ugh:

We're trying to help as much as we can, but sometimes we simply don't have the time to tell you about the turbulence 10 minutes ahead just when you're 2-3-4 minutes ahead. Sorry, but I think you might be able to pick up some clues if you're listening carefully to the frequency which is not always the case for certain (not all) people. It's really annoying in a busy enviroment if you need to give the instruction 3-4 times because someone's just not listening. And the others are waiting in the meanwhile, because we're taught to follow the routine 'first things first'. You might be shaking up there for a minute more but first of all two others shouldn't hit...

It also takes a time from our thinking time (you might notice, this is the thing what we lack of at most) if someone's talking about his turbulence for a minute on the frequency - "eeer, radar we're picking up some turbulence here at FL390 overhead xxx, do you have any reports on eeeer lower levels because we're not able for higher today since we're too heavy or do you know if it'll smooth out in a few minutes or for how long will it last?"
Avoid it as much as you can pls. We can see where you are, what is your level - just give us the info and what you want so we can think of something. Thanks :)

We do our best guys to help you out, but with your help in small issues we can help you maybe even better.


Make a ‘securité’ broadcast on the frequency in use and 121.5 giving your position, level and heading.
I'm not quite sure it's a good idea, since 121.5 should be used only for emergency purposes... I'd rather prefer you to inform others on the 'chat' frq or to tell the ATC - as briefly as you can pls.

[stator vane]

i love it when in french and often spanish airspace, you can hear the controller and other aircraft speaking quite energetically in french/spanish and having a recognizable term "turbulence."!!!! etc

not much help for non english speakers, and we have to tie up the frequency even more with questions in english about the same information!!

and like it or not the native language aircraft get priority for sure. only human nature i suppose, especially when the controller is under a load. the native language must be a lot easier!!

cheers;

[B757-200]

Worst turbulence i experienced was approaching London-Luton on a 757-200, it was quite heavy, quite bad. I wished i looked out the window then because at cruising altitude we experienced a few, tiny bumps for about 10 seconds, i'm a nervous flyer and it was scary seeing the wings flex whilst it was going on. I realised that this was not my calmest of flights!

[FullWings]

Was the high altitude turbulence encountered over the Pyrenees due to wind shear or high speed penetration of short period waves? I imagine waves that appear smooth to me at 50 kts, might seem quite different at 500 kts.
Classic "rotor" seems unlikely at the altitudes reported. Are there any meteorologists who can comment?
IANAM(eteorologist) but from the wind reports given earlier, it sounds like the strongest winds were in a lower layer near the mountain tops. When this happens and the temperature profile is suitable for wave, the waves get steeper with increasing height and may actually "break". This can generate some pretty nasty turbulence, especially if you're travelling fast.

I remember wave soaring behind the Brecon Beacons in a southerly wind. At ground level it was 180/25 but became virtually calm at 6-7,000', then about 350/5 above that. This produced a wall of cloud that became steeper and steeper until it actually started to overhang; you could see amazing ripples and vortices forming and decaying on the cloud edge, some with real violence. There was narrow lift up to 1,500 fpm which stopped abruptly at the shear level. I wouldn't have liked to fly an aircraft through there at that height...

[Rod Eddington]

Jagohu,

That all sounds good in theory, however we were offered no warning whatsoever by Bordeaux (who's frequency was pretty quiet). On handover to Barcelona we were warned but by that stage we had sudden moderate turbulence and were idling the thrust to avoid an overspeed. Perhaps more communication between Bordeaux and Barcelona - because either Bordeaux didn't know about it, or they did know about it and didn't warn anyone. I'm hoping it waws the former.

[Jools66]

Oh My God, I´m another wannabee and you´ve all just frightened the life out of me! I´m still going for it though. See you all in the clear blue skies (and hopefully no turbulence) soon!!:eek:

[Parapunter]

FWIW, I climbed in a straight line last year on a paraglider just north of Brighton for about 1.5 miles at a climb rate of about 500 fpm in the 'nice' part of some wave set up off the north downs. I gues we are still talking the nasty stuff as below?

http://i17.tinypic.com/2moxxk0.jpg

[will fly for food 06]

Pretty bumpy coming back from canada monday night. About 3 hours west of Ireland. The A330 had to descend (engines idle nose down) out of auto pilot to get out of it. It was disconcerting because i was in the back and not up the front where i prefer to be. On the turbulence thread, low level in a Tucano through the lakes can get very bumpy indeed.

[axv]

"........... before aircraft start diving for safer conditions!"
Or climb to FL410/430: I love the Falcon! :)

[Nightrider]

Coming from Lyon (LYS) the Bordeaux controller advised about "light to moderate" reported turbulence south of the Pyrenees. Maintaining FL310 as higher levels were occupied, just north of ZAZ we had 355/95 kts winds.
Within about 3-5 seconds the wind dropped to absolute 0 and the IAS dropped by about 40 kts with the autothrottle figthing at max thrust settings. The OAT increased by about 7 degrees.
Recovering the aeroplane from about 12 degrees nose up pitch we were hit by a sudden 50 -65 kts headwind, bringing the IAS very close to VMO. At the same time we experienced gusting effects which forced up to 25 degrees bank in both directions......
We got an immediate descent to FL 270 and all was fine there.... beside the cabin, my dinner all over the cockpit, my coffee dripping from the roof.
Beside a thorough cleaning of the aeroplane from inside, the engineers were just excited to go through a complete "severe turbulence check"....
No, there was no warning, no, there were absolutely no clouds around....
And no, never experienced anything like this before

[India Four Two]

I see in the wave illustration you posted, that the Aussie sense of humour is alive and well at Flight Safety Australia:

http://i30.photobucket.com/albums/c309/india42/rotor.jpg

[ruddman]

During severe turbulence, what's the rule regarding a/p usage? Does it remain on? Or better to hand fly it?