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Strategy for Thunderstorms on Approach

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Strategy for Thunderstorms on Approach

Old 17th Jul 2019, 06:54
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Strategy for Thunderstorms on Approach

Hi guys, I would like to get your take on the topic of thunderstorms around the final approach.

I have found that a number of pilots like to get below the cloud base as early as possible it the cloud base vs MSA allows that. Even so would you ever fly under the red of a CB? Is this even a good strategy anyway?

Do you have any limit on how close a CB could be to the airport for you to decide to shoot the approach (Assuming the final approach is clear)?

Thanks
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Old 17th Jul 2019, 07:45
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Hi,

have a look at Airbus_Safety_first_magazine_22, from page 24 there is a lot of valuable information covering your questions and not necessarily Airbus related.
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Old 17th Jul 2019, 10:03
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Angle the radar up 10 degrees and I do t fly under red/magenta.
Wind direction and storm movement?
Published missed approach clear or not?
Alternate escape route that allows to stay in VMC conditions?
Iíve done visual approaches with an alternate missed approach coordinated with ATC prior to commencement.
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Old 17th Jul 2019, 13:24
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Fly under the base of a red cell????

NO.
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Old 17th Jul 2019, 13:28
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If you have doubts about an approach don’t do it; wait hold.
You cannot guarantee that the radar or even visual will detect a down-draft or outflow windshear.
If a Cb has been over the runway, allow 15 min for the runway to drain, otherwise use flooded runway landing performance.
https://www.faa.gov/other_visit/avia.../SAFO19003.pdf

Heed the advice of those who survived.
https://www.dropbox.com/s/12k90qtpqf...shear.pdf?dl=0

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Old 17th Jul 2019, 13:43
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Originally Posted by ACMS View Post
Fly under the base of a red cell????

NO.
Isn't the argument that, once below cloud base, it is easier to see and avoid? Not that it is somehow safer to fly under rather than through.
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Old 17th Jul 2019, 13:46
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Originally Posted by B2N2 View Post
Angle the radar up 10 degrees and I do t fly under red/magenta.
Wind direction and storm movement?
Published missed approach clear or not?
Alternate escape route that allows to stay in VMC conditions?
Iíve done visual approaches with an alternate missed approach coordinated with ATC prior to commencement.
"Iíve done visual approaches with an alternate missed approach coordinated with ATC prior to commencement.".

Yep. I have done this many times at busy airports. 99% success while others diverted. Just coordinate with ATC. If you say "due to weather" local noise abatement procedures are voided.
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Old 17th Jul 2019, 14:41
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B2N2, gearlever,
Because you have done something before without event, does not change the inherent risk in the operation, thus never assuring success in the future.
The pre approach assessment is that of the risk in the plan depending on what is seen (or not seen) and judged as a justifiable course of action - what if this doesnít work out.
Itís a judgement - yours and should not assume too much about anyone elseís involvement including the operational pressures such as a busy airport.
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Old 17th Jul 2019, 16:55
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There is no flat yes or no. D191 L1011 at DFW on approach when passing through a single CB encountered a severe microburst and fatally crashed. That accident led to development of predictive winds sheer.​​​​​ All CBs are not same. If the CB is well developed with top closer to 30000 then it's dangerous and best avoided.
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Old 18th Jul 2019, 05:15
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In Florida, we get thunderstorms all summer long. The ATC here are top notch, and can seemingly thread a needle through the storm cells, and find a generally smooth ride.

My airline has provided us pretty good guidance on operating when there are storms by the field. One thing we like to do is carry a comfortable amount of fuel for the inevitable hold. (8-11,000lb of planned arrival fuel is not uncommon for an afternoon arrival in an A319/320/321). That being said, if there's a large cell on final, we'd rather land with a tailwind, with alternate missed approach instructions, than fly under the red.
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Old 18th Jul 2019, 05:33
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Do not take-off or land when thunderstorm is above the airport. Basic rule.
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Old 18th Jul 2019, 05:55
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I think there are many categories of storm, each with their own characteristics and risks. What level of maturity the cell(s) have, the environmental lapse rate, humidity, depth, etc. The effects range from benign to lethal.

If you can actually see whatís going on and combine that with the radar picture, it is possible to manage the risk but it takes a lot of experience, knowledge and readiness to throw it away if you donít like it. As per the previous poster, a storm over/proximate to the airfield is generally worth holding off for. On my type a lightning strike needs ~6 engineer hours of checking before it returns to service, so waiting 20mins for the storm to dissipate is cheap insurance...
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Old 18th Jul 2019, 08:45
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During the approach the crew lost situational awareness, with their attention channelised, and the aircraft entered the storm cell with heavy rain after passing the MAP. The PIC did not arrest the excessive rate of descent, and flew the aircraft increasingly below the Glideslope.”
From http://www.aic.gov.pg/pdf/FinRpts/20...l%20Report.pdf
Air Niugini Aircraft crash, Truk Lagoon
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Old 18th Jul 2019, 12:01
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Originally Posted by safetypee View Post
B2N2, gearlever,
Because you have done something before without event, does not change the inherent risk in the operation, thus never assuring success in the future.
The pre approach assessment is that of the risk in the plan depending on what is seen (or not seen) and judged as a justifiable course of action - what if this doesnít work out.
Itís a judgement - yours and should not assume too much about anyone elseís involvement including the operational pressures such as a busy airport.
Iím not sure what youíre trying to say here.
If you approach it as something ďyouíve done it many times beforeĒ then that attitude is wrong.
If you approach it as a challenge unique to that set of circumstances then youíre simply being a professional.
By doing this you develop a skill set.

Last edited by B2N2; 19th Jul 2019 at 09:00.
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Old 19th Jul 2019, 08:06
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B2N2,
Your appropriate professional view is only one of a range of outcomes dependent on how experiences in challenging situations are used. Risks assessed and adequately mitigated, the exposure reviewed and memorised, can contribute to professional expertise - professionalism.

Alternatives include inadequate risk assessment and mitigation, but with an acceptable outcome the exposure could be stored as a valuable lesson learnt (donít do that again), or as an overconfident self-assessment of future ability. The latter is a powerful human bias - egocentric bias, also confirmation bias, choice supportive bias.

In an anonymous forum we cannot determine which of the outcomes is being related without further explanation, thus the reader could be adversely influenced if less adequate posts are taken at face value.
Question #1 represents an alternative approach, requesting information and explanation.
Statements of ĎI have done that beforeí do not relate the actual situation to the experience gained, or the personal attitude of the poster - training capt or troll.
Biased memories can be hazardous because an unwary newbie could be adversely influenced.

Many posts in forums are opinion - Ďopinion is the lowest form of human knowledgeí Bill Bullard
In addition ďIím entitled to my opinionĒ is used to shelter beliefs that should have been abandoned. It becomes shorthand for ďI can say or think whatever I likeĒ. ďYou are not entitled to your opinion. You are only entitled to what you can argue for.Ē https://theconversation.com/no-youre...r-opinion-9978

My humble, argued, opinion.
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Old 19th Jul 2019, 09:04
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So whatís your point?
Question was posted and I gave an answer and without any knowledge of my background and experience youíre calling that unsafe.

Last edited by B2N2; 25th Jul 2019 at 00:32.
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Old 21st Jul 2019, 13:48
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Our lot stipulate not to continue an approach if visibility reduces to 2000M or less in rain,when associated with presence of CB.
Slightly off the original post subject,but idea is to avoid likelihood of flooded runway associated with tropical downpour,and therefore,possibility of aquaplaning..
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Old 21st Jul 2019, 14:41
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Originally Posted by Yaw String View Post
Our lot stipulate not to continue an approach if visibility reduces to 2000M or less in rain,when associated with presence of CB.
Slightly off the original post subject,but idea is to avoid likelihood of flooded runway associated with tropical downpour,and therefore,possibility of aquaplaning..
Must be an operator with an amazing safety record
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Old 21st Jul 2019, 20:58
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In Florida, we get thunderstorms all summer long. The ATC here are top notch, and can seemingly thread a needle through the storm cells, and find a generally smooth ride.
Concur...I was driving with the Panasonic/Avtech system onboard as well, which provides FMS winds thorough the IFE system ...

sharing winds through the network....golden.
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