Massive hailstorm in Istanbul 27.07.2017

[neila83]

Originally Posted by PENKO

I have seen many crews willingly fly into an obvious massive thunderstorm on approach, relying on previous pilot/ATC reports of 'it's just rain', or 'three aircraft in front of you landed successfully'. I am not talking monsoon conditions but obvious cells above the runway. Why risk it?

It might be 'just rain'. Then again, it might not. Or you might be the unlucky one to catch the first line of hail and lightning. Why risk it? The storm will move away in minutes.. And remember, the first one in the hold is the first one out. It takes just one 'negative request to hold at the IAF for the rest to follow'.

I have no idea what was painting on the wx radar in front of these Turkish crews, this is just my 2p worth.

Indeed, I do appreciate that weather avoidance is harder in the climb and approach phases due to the regular and often large heading changes, along with altitude, and needing to see a much closer picture of what is ahead that at cruise. Where ground radar is available I would hope ATC are proactive and assertive in steering pilots away form the bad stuff. Are they though, or do they assume pilots are responsible for avoidance? I wouldn't blame ATC if they shied away, given some of the aggressive responses seen here in other discussions to any suggestion ATC should tell a pilot what to do...

It is hard to believe that there was a storm of this size near the airport and no-one knew about it. I would imagine the old Mark I eyeball would have been enough. And as others have said, it would most certainly have painted on radar. I’ve been on flights when we’ve entered something on approach that I’m quite sure ‘by the books’ we shouldn’t have done. I remember taking off in a storm from Kigali once when as we were boarding lightning struck just off the runway. And this continued until we departed. What we were doing boarding using external stairs in those conditions god only knows, let alone taking off. I was pretty nervous till we cleared the cloud that day.

What it seems to reflect is the common observed behaviour of pilots to very regularly penetrate radar returns at low altitude that they would never go near at high altitude. There is a study on this that I read, I don’t have time to try and find it now, but it matched ground radar with flight paths at a US airport over a period of time, and showed while pilots nearly always avoided storms at altitude, they rather regularly penetrated at low altitude. The normalisation of deviancy I believe is the apt phrase. And rather dangerous if pilots begin to believe it’ll always be OK. Until it isn’t of course.

The industry really needs to get to grips with this, is enough emphasis being placed on how dangerous this can be in training? Is it a few days of meteorology theory and then it’s never discussed again? Is it drilled into pilots that they must never knowingly enter a thunderstorm whatever the circumstances? Or it is left ambiguous because actually airlines quite like pilots taking shortcuts every now and again? I really don’t appreciate pilots taking us on a test flight. Would you expect a train driver to see a tree on the line ahead and just plough on, because he doesn’t want to be late? It seems like the ‘don’t enter thunderstorms’ rule is often treated more as guidance than a strict rule.

I’d also add my observations having lived in Bogotá and now Mexico City, two cities regularly affected by very large thunderstorms, and I’m quite astonished sometimes to note the weather I am experiencing, and seeing on the departure route, and then to look at FR24 and see flights taking the SID straight into it. Of course, as someone notes above, as soon as one goes around and holds, everyone else behind them holds. What kind of nonsense is that?

[FlightDetent]

IST is a major aviation hub with quite busy SAW in close proximity. If the cell was fierce enough to create hail capable of damaging the aircraft as seen (on ground videos too!), it raises a question:

Why were only 3 (4-10) aircraft damaged, and not all of the 30-80 that were around?

neila83: Thunderstorms are not like monasteries that you either enter or not, with walls around.

[neila83]

Ok, perhaps you could enlighten us? Because that's contrary to everything I've ever read or heard said on the matter of entering CBs.

What's the old saying I remember someone quoting once, something like 'there's no peacetime reason to enter a thunderstorm'.

[Herod]

This one?

There is no reason to fly through a thunderstorm in peacetime.
(Sign over squadron ops desk at Davis-Monthan AFB, AZ, 1970) (allegedly)

[RAT 5]

The industry really needs to get to grips with this, is enough emphasis being placed on how dangerous this can be in training?

During initial line training on various types there was very little 'use of Wx radar' instruction. I didn't get too many answers to my questions. There was naff all in FCOM. Manipulation of tilt is an easy one, but the use of gain + tilt & at what heights was missing. It was from various old farts that I learnt most.
Regarding ATC <5000' and on vectors. I was into a major UK airfield coming downwind, IMC. Lots of Wx had been visible higher up. I asked ATC about CB's in the vicinity and they said they has suppression on so couldn't see. They then gave me wide base leg vectors straight at a tomato. I refused. They switched their primary back on and said they could see nothing. I accepted the vector and they were correct. All those damned little villages around airports do cause havoc at low level. You tilt up, into the weather and are confused: you reduce the gain until the tomato disappears and have false sense of security, perhaps. It does seem, at times, a low tech and unreliable process for such a dangerous critical phase of flight.

[neila83]

Originally Posted by Herod

This one?

There is no reason to fly through a thunderstorm in peacetime.
(Sign over squadron ops desk at Davis-Monthan AFB, AZ, 1970) (allegedly)

Thank you!

[FlightDetent]

There's a difference between CB and a TS, to begin with. No worries though, I do share most of your sentiment displayed in the post above, and especially this:
"Is it drilled into pilots that they must never knowingly enter a thunderstorm whatever the circumstances?" gets an enthusiastic YES from me.

There needs to be a judgement about what constitutes a hazardeous CB or not, the danger becomes unacceptable of course much sooner before a TS develops from one. Your post evolves around a clear cut distinction which airmass is TS and which not, and it is never as perfectly discrete as that. Question remains why the few aircraft were not able to steer far enough in IST.

[Murexway]

Originally Posted by lomapaseo

OK, sounds about right

now for anybody, how often is that done for weather you have been vectored into?

Obviously we know where it wasn't done.

I'm not trying to find fault but just to get a feel for what actually is being done both on the ground and in the air.

This is supposed to be a forum for professional pilots.... not an question and answer forum for the education of the general public. If you'll simply read the posts of the pilots here you'll learn a lot.

[Avenger]

FWIW we were making an approach to IST at the very time the activity occurred. Aircraft were initially asked to hold at various points on the star, in our case they asked Corlu and then advised holding would be 10/15 minutes and expect ILS for 35R. We could not hold in exactly the right location but did our best at FL180. There were maybe 5 aircraft below us. The activity quickly moved towards us and we took a non-standard hold at BA690 for another 10 minutes before being advised the runway was changing to 05 ILS. The problem with this hold was that approach could not see us on their system as a "waypoint" as it was off the STAR. It was impossible to make the approach to 05 from our position without going directly through the cells. Although we were holding in " clear air" we got a good old bashing from smaller hail, but the game changed after Atlas declared an emergency and several others declared "minimum fuel". Quite frankly ATC did a good job considering there was a great deal of blocking of transmissions and Sabiha was closed at the time. Eventually we did a drive and dive to the fix and landed on 35R , but others were still expecting 05 or even 23. On the fleet we are equipped with both Collins and Honeywell with threat detectors ( stripes and symbols) the area of "hail" was showing as projected turbulence in clear air, the edges of the clouds could be clearly seen. Aircraft on departure may have seen the " clear spots" on the WX radar and without threat detection been unaware of the extreme hail which we observed from FL170 downwards. The general thoughts seemed to be that IST has no doppler radar and thus it is left up to pilots to arrange their avoiding. The phrase "all deviations approved" which we have heard several times in Istanbul FIR was not apparent and it was obvious ATC had their hands full. Listing to the 17 traffic that were advising " minimum fuel" it was also obvious that little "inflight planning" on where to go next was going on. SAW was not an option, Corlu was definitely out and Ankara was stretched, we heard several divert to Izmir. This was a "freak" storm and vertical lighting could be seen at times travelling 25 miles or more, I doubt Atlas jet even saw the threat.

[Lat3ralus]

Atlas pilot awarded for bravery

?Blind? hero pilot lands plane with 127 passengers on board

[Alber Ratman]

Yes, the VOR/LOC antenna were likely to be toast, so any CAT3 , perhaps any ILS approach on the AP would likely have been rejected by the AP system due to the conflicts arising. They did a fine job of getting her on the ground.

[Trim Stab]

Originally Posted by neila83

Ok, perhaps you could enlighten us? Because that's contrary to everything I've ever read or heard said on the matter of entering CBs.

I once got hammered by hail in a Citation flying in bright sunshine in VMC. I thought we were well clear of the obvious CuNim. The hail presumably got sucked out of the top of the CuNim and then got dumped onto us. Both leading edges of the wings had to be replaced. So yes, Cunims can still be dangerous even if you are not flying in them.

[PENKO]

Originally Posted by Avenger

FWIW we were making an approach to IST at the very time the activity occurred. Aircraft were initially asked to hold at various points on the star, in our case they asked Corlu and then advised holding would be 10/15 minutes and expect ILS for 35R. We could not hold in exactly the right location but did our best at FL180. There were maybe 5 aircraft below us. The activity quickly moved towards us and we took a non-standard hold at BA690 for another 10 minutes before being advised the runway was changing to 05 ILS. The problem with this hold was that approach could not see us on their system as a "waypoint" as it was off the STAR. It was impossible to make the approach to 05 from our position without going directly through the cells. Although we were holding in " clear air" we got a good old bashing from smaller hail, but the game changed after Atlas declared an emergency and several others declared "minimum fuel". Quite frankly ATC did a good job considering there was a great deal of blocking of transmissions and Sabiha was closed at the time. Eventually we did a drive and dive to the fix and landed on 35R , but others were still expecting 05 or even 23. On the fleet we are equipped with both Collins and Honeywell with threat detectors ( stripes and symbols) the area of "hail" was showing as projected turbulence in clear air, the edges of the clouds could be clearly seen. Aircraft on departure may have seen the " clear spots" on the WX radar and without threat detection been unaware of the extreme hail which we observed from FL170 downwards. The general thoughts seemed to be that IST has no doppler radar and thus it is left up to pilots to arrange their avoiding. The phrase "all deviations approved" which we have heard several times in Istanbul FIR was not apparent and it was obvious ATC had their hands full. Listing to the 17 traffic that were advising " minimum fuel" it was also obvious that little "inflight planning" on where to go next was going on. SAW was not an option, Corlu was definitely out and Ankara was stretched, we heard several divert to Izmir. This was a "freak" storm and vertical lighting could be seen at times travelling 25 miles or more, I doubt Atlas jet even saw the threat.

Just to be clear for my understanding, did you experience/observe hail in the clear (i.e. out of cloud) or do you mean clear as in nothing being painted by standard radar?

I still have a hard time believing that at lower levels noting was painting on the radar. At FL180 yes, but in summer on the ground? If true that's a very scary thought.

Anyway, if ATC tells all aircraft to avoid at own convenience then it is way past time to go elsewhere

[Fursty Ferret]

Was the radar turned on?

Doubt it. Half the pilots at my company (not Turkish...) turn the weather radar off at every opportunity based on some urban legend that they're continually irradiating themselves. One despairs.

[BluSdUp]

ATC primary radar capability?

Can any of You ATC fellas enlighten us on what ATC has for primary radar and WX detection?
It seems non for most places I go , as some are miffed as we ask for left or right to avoid. Some times big cells sitting on waypionts and getting clearances direct to. I am talking Europe, US and Canada is different I think. Not my current playground.

In the early 1990s I was FO on Beech 200 in Norway and we had no AP or radar.
ATC gave us vector around the big stuff, the small stuff, well: Rock and Roll.

Now I bring plenty of fuel and chicken out as per SOP.
Getting older and less bold.

Hail is indeed predictable in a CB, but as pointed out it is when it starts spitting it outside the cell its time to pay attention.

Had some light hail a few times and always wondered how bad it was going to get.

And the lightning strike that eventually follow is at least 2 hrs plus delay .
Done a few of those, so with plenty of fuel I tend to let someone low on fuel do the first few.
Both for arrival AND departure.
I think my record is 55 minutes idle on ground at LondonCity, due to a cell that covered Greater London area.

Anyway, all well that ends well. I think this one , if well documented is a nice case study. After all at least 3 aircraft got grounded for no good reason whatsoever.

[rak64]

Many sources available for present weather and for local forecasts. See following links.

https://mgm.gov.tr/sondurum/radar.as...=00&rU=ppi#sfB

https://mgm.gov.tr/sondurum/radar.as...34X&rU=max#sfB

Lightning & Thunderstorms - Greece, Turkey

HNMS

Regional Forecast Animation

Interestingly mgm.gov.tr showed clearly 2 massive thundrstorm systems aproaching from south-west but TAF forcast was only RESHA. In addition the forecast was addapted for the actual weather.

[Avenger]

PENKO, our Honeywell 3D radar shows areas of predictive turbulence and signal attenuation. At the time our system was showing the cells as normally displayed and the areas of overflight turbulence in the " unpainted "areas between the cells , approx 30/50 miles apart. When we entered was was apparently "safe" areas, i.e no painting other than the odd magenta stripes, we still experienced hail falling from the clouds although we were actually clear of cloud, maybe 20 miles away at times. If we had manually selected a down tilt probably the cells below the flight path would have been painted. From the ground they may well have chosen a path between cells not realising that the apparently best option route was hailing from above. IST departures are stepped climb and thus the level flight segments would again only show the threats in the flight path.

[underfire]

Video showing the quite a bit of the ac. Does not look like any damage to leading edge or cowl.

https://www.youtube.com/watch?v=wCqYBOgfFSE

[FlightDetent]

Avenger: that is excellent insight, much appreciated!

[lomapaseo]

Video showing the quite a bit of the ac. Does not look like any damage to leading edge or cowl.

Damage goes with hail size, aircraft speed and structure impacted.

Radoms show it first, followed by wind screens, then LE devices, then inlet cowls and lastly engine fan blades.

Damage to engine fan blades is extremely rare in a hail encounter compared to all other surfaces.

The hail concern with the engines is internal cycle effects of processing ice instead of air.