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DILLIGAFF
21st May 2007, 03:14
Have heard that several A/C have been damaged after flying through a sandstorm over Turkey. Two BMI A320s and one each from Sabena and Martinair. BMI are sending some engineers out to look at their aircraft to see the extent of the damage, and they think they are going to have to change all the engines. I have already received a signal from Martinair to borrow two V2527s , but nothing heard from Sabena.
D

N1 Vibes
21st May 2007, 05:26
Could be that the turbine blade cooling holes have been blocked by glass, this is what happens when a lot of sand get's ingested into combustor/turbine area. Saw a lot on military heli's during the Gulf War. This may have been seen by an increase in EGT.

Or it could be something else....

Best Regards,

N1 Vibes

barit1
21st May 2007, 12:44
Glass formation is a typical hazard when ingesting sand or volcanic ash.

It not only blocks cooling passages, it tends to "plate" the HPT nozzle guide vanes and reduce the flow area, which drives up back pressure on the compressor. This may eat up available stall (surge) margin.

The other major problem is erosion of the compressor airfoils.

jedigtr
21st May 2007, 13:07
The 2 bmi a/c were caught up in the sandstorm on saturday and a couple of engineers were sent out there yesterday. I'll hopefully get the latest info on their condition when I get to work tonight.

411A
21st May 2007, 15:32
Ah well, I guess they don't make jet engines as robust as they used to.
Having flown TriStars in the mid-east for a long time, sand just didn't seem to bother the RR RB.211 engines.
OTOH, they were washed out with a fire hose a time ot two...especially when the fleet manager ran off the end of the runway in Taif, and used reverse to return to the pavement...:ugh::E

Flight Detent
22nd May 2007, 02:40
Taif, been there lots of times, with who else but AAI, many years ago.
I remember it as a fairly short strip up in the hills of Saudi, nothing there, but then again, that explains Saudi!
Cheers...FD...:\

jedigtr
22nd May 2007, 05:08
As of last night, 2 more bmi engineers have been sent out to Turkey with a boroscope kit. Definately looks like modern day a/c engines aren't as tough as they used to be!;)

CRS
22nd May 2007, 05:29
411a

Currently flying aircraft in the ME, with RR Trents & GE90's, we have no huge problems with sand ingestion. Which is an everyday occurence and sandstorms not uncommon. Even with MODERN engines

CRS

411A
22nd May 2007, 05:39
Glad to hear that, CRS...for a minute there I thought all the modern stuff was falling to bits...:}

no sig
22nd May 2007, 08:17
I am on the ground in Bodrum and the dumping of sandy rain we had certainly was out of the ordinary in my experience, the yellow clouds we had above us prior to the rain looked particularly ominous. Not too surprised that there were problems with airplanes that flew through that.

stator vane
22nd May 2007, 08:44
whilst here, could i ask you guys to tell me what you know about the life and death of sandstorms???

one night going from BRU to DJE and just coming overhead TUN, ATC called and told us that our destination and alternate were both below minimums. there had been nothing forecast and i was surprized. i asked him what the cause was and whilst waiting for his reply, i did look out my left window and saw TUN underneath as clear as a bell and looking very enticing at the moment. he then said it was due to sandstorms.

my first impluse: considering--1)-this was against the forecast wx that i had received, 2)-both dest and alt were afflicted by the same type wx, perhaps the mother of all sandstorms 3)-my ignorance about sandstorm life styles 4)-not having a whole lot of fuel to burn whilst flying in circles, 5)-concern that this unforecast sandstorm might last longer than my fuel and could grow to engulf the airport below me if i delayed, 6)-knowing that airports don't grow on trees in that area like they do in mainland europe--was to land just below me at tunis and then go from there. the FO thought that was a good idea as well, since he had no sand in his flight bag either.

we ended up waiting about an hour after landing before the wx had improved to above mins-which by the way, was non precision-due wind contrary to the ILS at dest, and went on.

to this day, i have not been able to find much information about the life style of the sandstorm. one person i flew with had extensive experience in the sandpit and he told me they could last from 30 minutes to 2 days.

any help would be appreciated.

no sig
22nd May 2007, 10:03
Stator
Having just completed almost 5 months in Riyadh over the winter, I too had an eyeopener with respect to the weather in the desert areas, not all sun and sand by any means. I experienced exactly as you did, completely unforecast, or at the very least grossly underestimated winds and vis. with PROB and TEMPo's way above the actual weather. In March we had three days of CB's, high winds and low vis due to blowing sand which typically lasted two hours staring around 1600L. There was a depression moving across Arabia from Africa which seemed to be cooler/moist air pushing up against the warmer drier air. The result was a dry gust front with winds and blowing dry sand which reduced vis to 200m or so, followed by rain and sustained winds of over 50 kts lasting an hour and one or two occasions. The single most important lesson I learned was a respect for desert weather and not to trust the TAF's I read. Alternate selection is one to consider carefully.
I just did a quick Wik search and came up with the following link which might be of interest. http://www.answers.com/topic/haboob#after_ad2.

411A
22nd May 2007, 15:04
In Libya you can see them coming, when on the ground.
They are called a ghibli, and the defined line of rising sand can cover the whole horizon, extend to 16,000 feet (or more) and reduce visibilities to less than 200 metres in five minutes, or less.
Not pleasant to be caught in, I can assure you.
Wind?
50 knots or more, and that nice sharp sand can indeed do damage, and sting the skin, big time.

What to do when airbourne?

Go somewhere else...anywhere else.

stator vane
22nd May 2007, 15:18
in the previously mentioned situation, would you too, drop down to TUN or would you consider that the life span of the sandstorm would be 30-45 minutes like a thunderstorm over an airfield?

we were still at cruise level, approx FL350--would that be safe to overfly a sandstorm? it was night so i couldn't see anything at all. and no radar returns of note.

still one of those events that i would like to learn from if possible.

any feedback will be appreciated.

no sig
22nd May 2007, 15:31
Stator,

After my experience, I'd say you did exactly the right thing to divert early. Also, well worthy of note, is that following the sand storm we had in RUH, the airport was closed for some hours while they cleaned up, swept sand and debris from the runway and movement areas, it took them a good few hours as I recall. So, unlike wind and rain which leaves the airport, usually, operational, after this sandstorm it wasn't.

Desert Diner
22nd May 2007, 15:48
The problem with a sandstorm is that the two ingredients, wind and sand, can be inexhaustable. The can last a few hours up to days. The only cretainty is the uncertainty of how long one is going to last.

I wonder what the extent of the damage is

max AB
22nd May 2007, 16:24
FO took this picture during a turn around at Khartoum recently, shows how quickly they move across an area, viz went so low we couldn't see the ground for 30 minutes. Didn't improve enough to take off for 3 hours! The ground crew scattered leaving the holds open...yes they filled up with sand.
http://www1.snapfish.co.uk/slideshow/AlbumID=160235203/PictureID=3256292461/a=95694427_95694427/t_=95694427

Nubboy
22nd May 2007, 20:28
During turnaround in AMS yesterday an engineer said they were doing a double engine change for Martinair. Said both engines were full of glass, sand that had melted and then vitrified(?).They had gone through the sand on arrival, and then brought the aircraft back from Izmir and had a second dose.

Glad everyone seems to be OK.

My only query is, having gone down through it and landed OK, why would you want to launch off and have another shot at it?:ugh:

Answers on a post card please.

jedigtr
23rd May 2007, 01:12
One of the bmi a/c has just got back to LHR without the need of any major engineering work, which seems quite fortunate considering the post above about the Martinair a/c.

lomapaseo
23rd May 2007, 02:08
During turnaround in AMS yesterday an engineer said they were doing a double engine change for Martinair. Said both engines were full of glass, sand that had melted and then vitrified(?).They had gone through the sand on arrival, and then brought the aircraft back from Izmir and had a second dose.
Glad everyone seems to be OK.
My only query is, having gone down through it and landed OK, why would you want to launch off and have another shot at it?

The problem with the report above is that it scares the crap out of me. Once you have factual eveidence (via borescope or teardown) that a single operation in an environemental encounter with sand or ash has produced glass deposits in the turbine inlet you must presume that similar encounters under similar turbine inlet temperatures (TIT) in other engines and aircraft flights has poisoned a much larger fleet (seen that before)
Glassification is permanent and only a teardown and overhaul will get rid of it. It also is deadly to the engine surge margin and safe operation and folks it's All engines on an aircraft so whether you're a 4 holer or a 2 holer somebody is going to end up as a glider.
The key to mitigation is avoidance and if that fails then reduce the turbine inlet temperature to something less than cruize temeperatures (you work out the math). Should you not be able to perform this mitigation do not ever fly these engines again until you have cleared it via borescope
No engine is immune from this if it is operating with a high enough turbine inlet temperature. So once one guy has it all engine manufacturers must be made aware of the findings and an all operator wire sent out immediately.
Right now I consider this still a rumor of the finding, but beware if it turns out to be true.

Gipsy Queen
23rd May 2007, 02:17
411A - you can see them coming from as far away as Malta!

I can't remember what the Maltese call these things - something hamra? - but they are a nightmare and the red sand (which has to be pretty fine to stay aloft over that distance) gets absolutely everywhere. Luqa should be avoided for several days after one of these has passed through.

llondel
23rd May 2007, 06:39
This sounds very much like the BA 747 and the volcanic dust cloud 25 years ago, I thought that proved how well fine dust could screw up engine performance.

Go Smoke
23rd May 2007, 14:48
Would it be the 'Harmattan' Gypsy Queen?

ChristiaanJ
24th May 2007, 10:28
...you can see them coming from as far away as Malta!
... the red sand has to be pretty fine to stay aloft over that distance...
Western Sahara sand regularly gets right across the Mediterranean to Southern France... we had a fine coating of the yellow stuff everywhere a few days ago. And yes, it's extremely fine, think talcum powder.
And about once a year it will get another 600km further North to Paris.... when I lived there I repeatedly have found the car coated with it.

But I assume that in the clouds carrying it that far, it's "diluted" enough not to be a hazard to aircraft engines.

cwatters
24th May 2007, 12:47
Can move as fast as a front passes...
http://en.wikipedia.org/wiki/Dust_storm