weather avoidance

[Del Prado]

controlling aircraft into heathrow today we had at least 2 that were so insistent on avoiding weather that they elected to continue downwind and leave controlled airspace by a significant degree. The weather was satisfactorily negotiated by other aircraft.
Bearing in mind we're talking about UK weather, was it really the safest course of action to leave CAS, accepting a RIS or worse rather than bite the bullet and accept vectors as the other aircraft did?

[Bealzebub]

As a captain or as a pilot, if I believe that the weather ahead presents a risk to the safety or security of the flight then I am perfectly within my right to seek an alternative. Any deviation should be communicated in a timely manner (where possible) and an alternative course of action should normally be sought and co-ordinated with the air traffic controller. If the choice is the risk of injury or possible damage to the aircraft and its occupants or leaving the formal structure of "controlled airspace" then common sense ought to suggest that there is little choice ?

Obviously there are many more occaisions when the request to deviate will be made for factors that affect passenger comfort rather than the aforementioned risks, however such requests are not unreasonable. One pilots assesment may well differ from anothers and that might explain your observance.

Many aircraft will land and take off when thunderstorms are present in the vicinity, but that doesn't by any stretch of the imagination mean the one who might delay his landing or takeoff should be criticised for that decision simply because others elected not to.

I don't know many pilots that want to delay their arrival or otherwise cause significant disruption to ATC for no reason. Perhaps when you are on the ground it is an added workload and an inconvenience in a busy traffic environment. For the pilot it is a consideration for his responsibility which includes the aircraft, its crew and the few hundred passengers behind the door, some of whom would expect you to provide the least traumatic ride you can possibly give them.

[Dream Land]

People have the radar on, incorrectly adjusted or depicted along with being uniformed about local weather to begin with, for instance, being based at ATL, would be almost impossible to land there if I didn't fly through RED areas on a regular basis, really depends on shapes, many times RED is simply heavy drizzle from the associated stratus, nothing safety related.

[HEATHROW DIRECTOR]

<<As a captain or as a pilot, if I believe that the weather ahead presents a risk to the safety or security of the flight then I am perfectly within my right to seek an alternative.>>

I don't think any controller would question that, Captain. What controllers do find curious is the immense variance in the attitudes of crews to weather whilst flying through the same piece of sky. Given two aircraft of the same type, same airline, one will not even mention the weather whilst the one behind causes turmoil by requesting a significant re-routing. Only once can I ever remember refusing such a request, when the options were either to fly through the cloud or another aircraft! I've seen crews of heavy jets refuse to land for 45 minutes, and fly all round the outskirts of the London TMA because of bad weather on the approach, yet we landed 30+ other aircraft in that time.

ATC will always try to accommodate weather avoidance but such manouevres can be potentially dangerous in busy airspace. If all crews operated similarly in bad weather life would be much easier for ATC.

[ROSCO328]

Heard a few aircraft whilst flying into london yesterday telling Atc (around tea time) that they required weather avoidance for around 80 miles and if they where avoiding the cell we were looking at personally I thought they made the right call. I cant comment on the other guys who did accept to carry on but as you know the weather is constantly changing. I do disagree with other posts of people saying flying through wx returns which are painting RED is normal (if the wx radar is set correctly ofcourse). If the weather makes parts of me pucker up I stay away!! :}

[Doors to Automatic]

Speaking as a regular passenger I would much rather be behind the pilot who deviates miles around bad weather!

As a keen severe weather enthusiast I was also monitoring yesterday's storms. Whilst fairly isolated, yesterday's cells were unusually severe in nature. They also sprang up from literally nothing to fully grown storms within 30 minutes - not too dissimilar to the Dallas event in 1985 which brought down the Tristar.

[Del Prado]

Thanks for the responses.
I wholeheartedly agree with Bealzebub's comments however I was hoping to move onto a discussion beyond the 'book' answer.
For example how great is "the risk of injury or possible damage to the aircraft and its occupants" from red patches that have been reported as heavy rain?
I would judge the risk of flying a jet into unregulated airspace with primary contacts and 7000 squawks to be far higher. particularly 30miles from the radar head at 3000' when the radar performance is already poor due to terminal 5.
As a nervous passenger I don't like being caught in bad weather but the 'pucker factor' would go up ten fold if I knew we were flying around on a see and be seen basis in the vicinity of several busy local flying clubs.

Either the cells yesterday were the worst I have operated in in the last 12 years or some pilots are getting far too jumpy.


HD, bet you miss those bad weather days?

[HEATHROW DIRECTOR]

Del Prado... Yep, I guess so, but I used to enjoy it! I always told trainees that the worst situation they were ever likely to encounter would probably be down to bad weather and I don't think too many pilots appreciate what happens when half a dozen aircraft do the "can we turn 20 right to avoid a build-up" bit!

For Doors to Automatic's benefit.. The ATC system in a busy area such as London depends to a great extent on controllers anticipating what aircraft will do. For example, an aircraft climbing out of an airport, if left to follow the standard procedure, will fly a set track and climb to designated altitudes along that track without intervention. Controllers know this and if they are busy with other traffic they know that 999 times out of 1000 such an aircraft can be safely left to its own devices. Now if the pilot says he wants to turn left or right to avoid bad weather his aircraft suddenly requires 100% concentration from the controller because air routes are packed very close together. Such a deviation might result in conflict with other traffic, or the aircraft entering airspace controlled by another controller, not sitting alongside but maybe many miles away. This means one or more phone calls to effect liasion... which takes up valuable time. And the controller he is trying to contact might be tied up with weather problems and can't answer the phone... Then someone else says "can we turn right in 5 miles to avoid..." Another phone call... meanwhile other traffic doesn't stop; it just keeps coming. Think of the M25, 8 lanes wide, at rush hour. If someone in the inside lanes suddenly decided to turn right towards the inside lane on the other carriageway. Get the idea? Believe me, a perfectly manageable situation can go bananas in a very short time and toilets and laundries get very busy after such sessions!

Pheww, back to my rubber ring and slippers.

[LYKA]

To quote Archie Trammels guide

" Convective WX is a highly dynamic phenomen, often exploding from benign shower to severe thunderstorm in as litlle as three to four minutes. No presently available, or contmplated, airbourne radar can accurtely predict when such an explosion is immenent. Therefore, each pilot, in each situation, must make a judgement"

A little later on

" Is it a hazardous storm"

1. Is the local atmosphere significantly unstable?
2. Is the dewpoint greater than 10C?
3. Is the tempreture spread greater than 17C?
4. Is the speed of movement greater than 10 knots?
4. Is there a visible hazard?
6. Is the southernmost cell in a line?

How hazardous is it?

7. Is its height greater than 15,000 feet?
8. Is its gradient and shape asymetrical?
9. Is its reflectivity greater than 50 DBZ?
10. Is it casting a shadow?

This is mostly for N.USA ops, however it still works very well in Europe too. Hopefully this is (some of) what most pilots look at when making a WX deviation request.

[Wycombe]

I live about 30 miles West of EGLL and was under the storms yesterday afternoon. The TS and associated RA and GR yesterday afternoon was I would say severe by UK standards and did seem to come out of nowhere.

I saw hail at least 2cm across, an hour of constant lightning and intense rain. Difficult to tell from the ground, but I would say at least 4 or 5 cells passed over us, very close together and slow moving.

Definately not a UK "April shower".

[ROSCO328]

[QUOTE=Del Prado
Either the cells yesterday were the worst I have operated in in the last 12 years or some pilots are getting far too jumpy.
QUOTE]
Maybe you could call is that but i'd prefer to call it being cautious. Please don't get me wrong I'm not saying we should all avoid any build up that's seen because the hands start getting a little sweaty but as you are aware London Atc are so busy sometimes you can be hanging on 3-4 minutes just to get a call in at peak times and if we are covering 6-8 nm a minute heading toward a Ts then the option is gone to avoid. Each to their own though but don't think anyone can predict what mother nature is going to do????
P.s. That comment about waiting to get a call in was NOT a dig at Atc as you guys/gals do a fantastic job all day everyday!!

[180 Too Fower]

I was comming back into EGLF yesterday afternoon along Y8 and what an amazing sight it was to see visually and on radar. There were four cells painting Red, one with small area of Magenta (Tilt +8) and all quite close together.:}

If one had to you could navigate between them as aircraft were doing, but I would not go through them.:hmm:

CAA recommendation....15nm avoidance?...cannot be done on all occasions, however common sence must always prevail.

[Del Prado]

No one care to comment on the flight proceeding outside controlled airspace?

[Bealzebub]

Sure,

There are many times when we fly outside of the strictures of positive controlled airspace. Whenever practicable we don't but sometimes it is unavoidable. An alternative service would be sought such as radar advisory. There are aerodromes where this is often the only available service and sometimes not even that.

If weather avoidance results in the crossing of a controlled airspace boundary into a less controlled environment then that will have been judged to be the best alternative.

[Con-Trail]

Good post!

Could the variety in actions of pilots when facing weather be explained by the fact that every company has a different culture and therefore different attitudes to the penalties of circling a bit longer or using alternates?

C-T

[Brian Abraham]

"He must give at least some consideration to the fact that airline pilots are seperated into tribes in spite of their common occupation. Gossip has provided legend, which in turn leads to unavoidable generalisation. Thus United pilots are considered colorless and sticklers for regulations. American pilots are thought to be a mixed lot, prone to independant complaint and rebellion. TWA pilot, highly regarded individually, are pitied for the chameleon management of their company. Pan American pilots, admired and envied for their long range flying, are thought to be shy and backward in foul weather work. The tribes are each healthy and strong in their way, but their characteristics, conditioned by their aerial teritories, are as different as the Sioux, the Navahos, and the Cherokees. All this is recognised as debatable. Yet the legends had to start somehow.
Now it is important for Hughen to remember that Eastern Airlines pilots are singularly determined and clever. They are not given to timidity, and if the pilot now beneath us has refused to continue his approach, then the conditions must be very unpleasant indeed."

Forgive me, some how seemed appro. Quote from the Bible.

[Del Prado]

Thanks Bealzebub. On the occasions you describe the portion of flight outside controlled airspace is planned and briefed for and anticipated by the air traffic service unit.
On a sector that is arguably one of the most RT saturated in the world (so much so that more than your callsign on 1st contact can screw up the plan) I don't have time to offer a RAS/RIS and the majority of controllers on that sector have no experience of giving a RAS/RIS.
There are also issues with the performance of the heathrow radars due to Terminal 5 construction and coverage at 3000' 30 miles from the overhead is always going to be poor.
I think the next time I find myself in this situation a freecall to Brize or Farnborough may well be safest solution for all concerned.

[Cough]

Just a quick comment. If they are at 3000'/30nm from the radar head, would the safest option not be to climb the aircraft to regain CAS and increase radar performance?

I have been in the situation before when on a willo arrival to LGW from the North when we informed ATC about a single, but large cell on our track. (requiring a large/lengthy deviation but either to the east or west) I asked which direction was best for them and I was told to turn slightly west. Well 20nm later (just as we are starting to get to the side of the thing) I was instructed to turn back as I was to leave CAS. Simple answer, RAS please! Fine...

Thing was two frequencies later (just getting the other end of the cell) I was barked so seriously by the ATCO for being outside CAS and she screamed at me to turn back. It was not nice, but what I was doing was the safer thing... (She calmed down somewhat when I told her about the discussion 2 frequencies earlier, but she still managed to get my back up). Going outside CAS verses the damage that can be done by hail/lightning etc for me is a no brainer.

[Del Prado]

Pilot's request was to get lower and get under it.
You can request RAS all you want, we're not always in a position to offer it.

[Cough]

Del - Guess I was in a lucky position. I imagine that a RAS service is a lot easier to provide at FL150 vs 3000'. If the guys don't want to climb, then there isn't a lot you can do.

Sorry if my last post sounded a little narked...

[Del Prado]

Sorry if my last post sounded a little narked...

It didn't at all and I appreciate all the input.
I'm finding it really interesting to see the difference in attitudes to this between pilots and ATCOs. (that difference probably explains why Gatwick were screaming at you!)

[Cough]

Cool. The frequency in question was 133.175 (still London). It did help that apart from the 1 Thunderstorm, the rest of the sky was gin clear, so see/avoid could be undertaken. My decision in IMC...Dunno!

[matspart3]

A RIS outside CAS, presumably in good VMC, is hardly suicidal is it? Even around the LTMA...

[overstress]

in good VMC,

matspart, there is no such thing. You are either VMC or IMC. :)

[Dream Land]

Like to see some "real" Reds?Yes I'm sure you've flown in much worse conditions, much faster and higher than all of us, maybe next time you could read all of my post which indicates that it's not all about the color. Thanks for the education.:D

[Giles Wembley-Hogg]

Del surely "contact" Brize or LF rather than "freecall". Isn't that what GSs are for!

As for going outside controlled airspace. If it is the only sensible solution based on the information available to the flight crew, then there is not much else that they can do. Different crews may perceive the weather differently based upon whether they have been able to see the cells visually or if they are using radar alone. Different tilt settings on the radar can change the view considerably as well.

G W-H