Diamond down Dubai

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Re: Diamond down Dubai

Unread post by southside » Fri May 17, 2019 5:52 pm

Dougie maybe I misunderstood you but I have never considered wake turbulence to be affected by density altitude. Can you elaborate? Thanks
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Re: Diamond down Dubai

Unread post by Dougie » Fri May 17, 2019 6:20 pm

southside wrote:
Fri May 17, 2019 5:52 pm
Dougie maybe I misunderstood you but I have never considered wake turbulence to be affected by density altitude. Can you elaborate? Thanks
I'm saying Dubai gives a false impression that you are pretty close to sea level, but the heat and Humidity makes the DA higher. If they encounter wake, their escape manoeuvre can easily be affected by the DA and they may not be able to escape the Wake due to the lack of performance the higher DA may leave. Usually when these guys do calibration they fly circuits at about 1500 to 3000ft AGL.

Add the fact that the wind was light and variable and hot muggy summer evening in Dubai, the wakes tend to sit around longer than dissipating like they would elsewhere. If you encounter wake you would normally want to apply power and fly out of the wake, the DA may have affected this (this is a may and an opinion only) plus the mugginess makes the wakes stay round longer.

Pitch and bank changes can result in quicker deceleration when at a higher DA and a wake encounter would easily cause a pitch or bank change. Although the Diamond should be able to perform well in the DA of 3000ft, its possible an unexpected upset from something like wake caught them off guard and the lag in performance could have been enough to negatively disadvantage the flight to this outcome.
ok now what do we do


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Re: Diamond down Dubai

Unread post by ACE MAN » Fri May 17, 2019 8:07 pm

2700’ vs SL in a DA62/42 would have very little DA issues.

Wake turbulence at any alt with the previous heavy in a high lift configuration of course would. But I am sure seasoned calibration pilots will be well familiar at high traffic density airports with heavies while doing calibration.
Last edited by ACE MAN on Sat May 18, 2019 12:06 pm, edited 1 time in total.
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Re: Diamond down Dubai

Unread post by Fransw » Fri May 17, 2019 8:43 pm

Isn't that a DA42?
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Re: Diamond down Dubai

Unread post by CWS » Fri May 17, 2019 8:50 pm

Fransw wrote:
Fri May 17, 2019 8:43 pm
Isn't that a DA42?
Nope it’s the DA42’s big brother
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Re: Diamond down Dubai

Unread post by MemyselfandI » Fri May 17, 2019 9:04 pm

Guys at DXB say they positioned too tight behind a Thai A350 and may have hit severe Turbulence!
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Re: Diamond down Dubai

Unread post by jimdavis » Fri May 17, 2019 10:52 pm

MemyselfandI wrote:
Fri May 17, 2019 9:04 pm
Guys at DXB say they positioned too tight behind a Thai A350 and may have hit severe Turbulence!
Geeeee! Poor muggers, but that makes perfect sense.

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Re: Diamond down Dubai

Unread post by Tallies » Sat May 18, 2019 12:16 pm

Yip. Happened to me once on the extended centre line of 30. Cruising down the coast to Abu Dhabi. Cleared to expedite crossing the extended centre line behind a departing A320. Next thing that 182 bliksemmed me so hard on the head that I nearly passed out. From then on Cannot Comply became a regular part of my conversation with ATC.
Last edited by Tallies on Sun May 19, 2019 2:57 pm, edited 1 time in total.
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Re: Diamond down Dubai

Unread post by MemyselfandI » Sat May 18, 2019 12:49 pm

Still no names yet?
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Re: Diamond down Dubai

Unread post by ACE MAN » Sat May 18, 2019 2:48 pm

Tallies wrote:
Sat May 18, 2019 12:16 pm
Yip. Happened to me once on the extended centre line of 03. Cruising down the coast to Abu Dhabi. Cleared to expedite crossing the extended centre line behind a departing A320. Next thing that 182 bliksemmed me so hard on the head that I nearly passed out. From then on Cannot Comply became a regular part of my conversation with ATC.
03? Times have changed , between 98 and 2001 I used to do circuits in Dubai In Cherokees amongst the heavies, mostly in A6-DXB and A6-DUB.
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Re: Diamond down Dubai

Unread post by Tallies » Sat May 18, 2019 6:17 pm

03? Times have changed , between 98 and 2001 I used to do circuits in Dubai In Cherokees amongst the heavies, mostly in A6-DXB and A6-DUB.
[/quote]

Remember DXB and DUB well. Times did indeed change. Those days you could go and shoot night touch and goes all night long.
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Re: Diamond down Dubai

Unread post by MemyselfandI » Sat May 18, 2019 7:49 pm

I'm sure he means 30.
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Re: Diamond down Dubai

Unread post by tansg » Sun May 19, 2019 6:15 am

GL wrote:
Fri May 17, 2019 8:23 am
Iceberg wrote:
Fri May 17, 2019 8:01 am
Very bad news. Very capable aircraft.
What could have gone wrong?
Speculation mode ON: Calibrating an ILS requires quite heavy maneuvering to box the glideslope. Not impossible to have power surge and then stall spin. It would be interesting to see a pic of the wreck as regards forward speed.
Speculation is a bit off. Was not an ILS calibration. It was an Aerodrome Ground Lighting (AGL i.e. Papis) calibration on 30L which is the runway under rehabilitation so no other traffic on that runway so Wake Turbulence unlikely.
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Re: Diamond down Dubai

Unread post by jimdavis » Sun May 19, 2019 8:17 am

tansg wrote:
Sun May 19, 2019 6:15 am
It was an Aerodrome Ground Lighting (AGL i.e. Papis) calibration on 30L which is the runway under rehabilitation so no other traffic on that runway so Wake Turbulence unlikely.
How far is it from 30R? Wake turbulence spreads out, and it can drift in a light wind.

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Re: Diamond down Dubai

Unread post by ACE MAN » Sun May 19, 2019 9:11 am

jimdavis wrote:
Sun May 19, 2019 8:17 am
tansg wrote:
Sun May 19, 2019 6:15 am
It was an Aerodrome Ground Lighting (AGL i.e. Papis) calibration on 30L which is the runway under rehabilitation so no other traffic on that runway so Wake Turbulence unlikely.
How far is it from 30R? Wake turbulence spreads out, and it can drift in a light wind.

jim
Correct Jim , light winds and 30R is close but staggered but 1500m further in - perfect conditions IMO for wake if these aircraft were too closely spaced
Last edited by ACE MAN on Sun May 19, 2019 10:51 am, edited 1 time in total.
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