flying through cb(s)
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flying through cb(s)
I am reading up on CB and how it affects flights. But I can't seem to find what kind of equipment or aids we have to navigate safely in those conditions.
I assume that it would be best to steer around them, but when there is no choice, what do you guys do?
Aside from radar and several pairs of eyes in the cockpit, what other equipment are available on the plane to fly through CBs?
thanks
e.
I assume that it would be best to steer around them, but when there is no choice, what do you guys do?
Aside from radar and several pairs of eyes in the cockpit, what other equipment are available on the plane to fly through CBs?
thanks
e.
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Flying through CB's is obviously never a good situation.
The best thing to do (certainly from what I have been told on the 737) is to increase the WX radar range and navigate round them, of course advising ATC at the time. You have to increase the range on the radar, there is nothing like dodging one small one, but not seeing a massive one just off screen straight in your path. This of course applies to enroute CB's, now CB's on final approach.........
The 737NG has something called PWS (predictive windshear), it notifys the pilots (below 2,300ft I believe) of any windshear ahead of the aircraft. I have not seen this in operation, apart from a demonstration during my type rating.
The best thing to do (certainly from what I have been told on the 737) is to increase the WX radar range and navigate round them, of course advising ATC at the time. You have to increase the range on the radar, there is nothing like dodging one small one, but not seeing a massive one just off screen straight in your path. This of course applies to enroute CB's, now CB's on final approach.........
The 737NG has something called PWS (predictive windshear), it notifys the pilots (below 2,300ft I believe) of any windshear ahead of the aircraft. I have not seen this in operation, apart from a demonstration during my type rating.
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Eyes won't help you a lot when flying through a CB--you won't be able to see anything clear in the cockpit due to turbulance 
You should never fly through a cb with an airliner...at cruise it's maybe easier to avoid them as you can plan well ahead. During take-off or landing it may be harder to avoid,but at least you can try to avoid the center of the TS,delay your take-off or hold untill the CB pass the field.
Most of the CB's are moving fast..remember once getting the ATIS with CAVOK (perfect) ,and next one,in about 20 min was +TS (heavy thunderstorm) , so we just reduced speed at min ,and in about 15 min the weather was ok again.
About Cb encouter ,well, i've had once a faulty radar,I think ,cause it didn't show a thing ,while we were experiencing severe turbulance ,with vertical speeds ranging from -2000 feet/min to +1500 feet/min (we were descending in clouds ).A lot of lightning around the plane ,also static on the windshields...I've had bruises from the seatbelts that time.
Ans one friend of mine lost in a blink 7000 feet while trying to pass bellow a high base CB in Africa ,at around FL100.
So,they are not something to mess around with,no matter what gizmos you have on board.
You should never fly through a cb with an airliner...at cruise it's maybe easier to avoid them as you can plan well ahead. During take-off or landing it may be harder to avoid,but at least you can try to avoid the center of the TS,delay your take-off or hold untill the CB pass the field.
Most of the CB's are moving fast..remember once getting the ATIS with CAVOK (perfect) ,and next one,in about 20 min was +TS (heavy thunderstorm) , so we just reduced speed at min ,and in about 15 min the weather was ok again.
About Cb encouter ,well, i've had once a faulty radar,I think ,cause it didn't show a thing ,while we were experiencing severe turbulance ,with vertical speeds ranging from -2000 feet/min to +1500 feet/min (we were descending in clouds ).A lot of lightning around the plane ,also static on the windshields...I've had bruises from the seatbelts that time.
Ans one friend of mine lost in a blink 7000 feet while trying to pass bellow a high base CB in Africa ,at around FL100.
So,they are not something to mess around with,no matter what gizmos you have on board.
DON'T FLY THROUGH CBs!
Although aircraft are designed and built to withstand an inadvertent entry to cbs, such situations should be avoided. Personal experience during planned testing involved a minor (20 sec) flight in the edge of a cb. In this period, flying at turbulence speed, the limits of certified normal-acceleration (+ & -) were experienced, including stick shake. The flight brief was to maintain constant attitude, however with the level of buffet, and rapid reversals in pitch, roll and yaw, all that could be accomplished was to hold everything in the centre.
During other tests adjacent to cbs, the cloud build-up was at least 3000 ft/min and possible as high as 6000 ft/min; so don’t think that you can out-climb the cloud formation. Also, beware of flying through or just under the anvil. Although the turbulence levels are low, often severe-icing conditions exist, including super cooled ‘liquid’ water. Generally the advice is to avoid cbs by a minimum of 5nm; however, to provide a margin for errors in detection (different radar systems and their responses in these conditions), rapid cloud formation and movement, anvil conditions, and misjudgment, then my experience suggests that aiming for a 15nm miss distance is safer.
Although aircraft are designed and built to withstand an inadvertent entry to cbs, such situations should be avoided. Personal experience during planned testing involved a minor (20 sec) flight in the edge of a cb. In this period, flying at turbulence speed, the limits of certified normal-acceleration (+ & -) were experienced, including stick shake. The flight brief was to maintain constant attitude, however with the level of buffet, and rapid reversals in pitch, roll and yaw, all that could be accomplished was to hold everything in the centre.
During other tests adjacent to cbs, the cloud build-up was at least 3000 ft/min and possible as high as 6000 ft/min; so don’t think that you can out-climb the cloud formation. Also, beware of flying through or just under the anvil. Although the turbulence levels are low, often severe-icing conditions exist, including super cooled ‘liquid’ water. Generally the advice is to avoid cbs by a minimum of 5nm; however, to provide a margin for errors in detection (different radar systems and their responses in these conditions), rapid cloud formation and movement, anvil conditions, and misjudgment, then my experience suggests that aiming for a 15nm miss distance is safer.
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Although aircraft are designed and built to withstand an inadvertent entry to cbs,...
Right now my sole function is flying turbojet airplanes into storms for weather research. I generally fly a Lear 35A into convective weather to study it, sample it, and in some cases, experiment with modifying it.
DO NOT FLY INTO THE STORM!!!
Think of the thunderstorm as the Finger of God. You're a gnat. There are forces inside more powerful than what you think they will be. Scott Crossfield, a well known name in flight test and aviation history, was killed not long ago when he flew through a thunderstorm; his aircraft broke up and he lost his life. The storm is not a respecter of persons; you may fly through one a dozen times or a hundred times and one the next one, it will take you. Don't put yourself, your aircraft, or your passengers or company in that position.
Weather radar is only partially able to see what's out there. Frozen precipitation doesn't paint well at all; dry hail, dry snow, ice, all can be invisible to radar. We hail, slush, graupel, and other features containing at least some liquid water are visible, but can be very misleading. What you think is a level 1 return or even a blank spot on the radar, can hide some very nasty surprises. Hail may not show up at all, and it can be very large, very fast, and do an increadible amount of damage, even far from a cell. Miles away.
Up and downdrafts have been recorded in excess of 12,000 fpm in the cells. Going into a sheer zone between such changes means a 24,000 fpm vertical shear, and your aircraft was most definitely not designed for that.
Ice buildup can be very rapid, and not at all where you expect it. Supercooled water between -10 and plus several degrees can form extremely rapidly; I've picked up three inches of ice in very short periods when penetrating cells, and others I fly with have experienced severe engine damage as a result of rapid ice buildup and shedding into intakes, etc. Even with everything working. Even when the last few penetrations through the same cell were uneventful. Even when it doesn't look so bad on radar. Even when a team of scientists are guiding the flight by radio, watching you on some very sophisticated radar...even with a team of scientists on board and a full suite of electronic sensors giving you detailed analysis of the storm and atmospherics as you go through.
When YOU penetrate a Cb, you don't have any of that going for you. What you have going for you is guesswork and luck, and that's no way to live.
Autopilot function may become impossible in convective weather. You're back to handflying it. If you're getting slammed, you may not be able to clearly see your instruments. You may be subject to injury. Your headset quite possibly won't even stay on your head. If you're below maneuvering speed, as you should be, you may find yourself stalling repeatedly. We often get the stick shaker and even the pusher when it gets rough, and we stay out of most of the serious weather.
As SP noted, weather can come from below with rapidity. When I start working a cell, I often make a pass through the upper parts of it first, and start making passes through the rising turrets alongside the main tower. Fresh starts are of the greatest interest, but these are often rising at thousands of feet per minute. Even if the convective activity at the surface isn't that great, the vertical velocity of rising air is cumulative. If a parcel of air rising at 300 fpm bumps into another parcel of air moving at 200 fpm, it now rises at 500 fpm, and soon bumps into more air rising at 400 fpm...now it's 900 fpm and rising. You get the idea. As this happens relative humidity in the parcel of air climbs, temperatures drop, and the parcel can remain liquid for a considerable time and well above normal freezing altitudes. On the same storm that 12,000 fpm vertical was located, the temp with liquid water was found at -38 C. High, wet, rough.
On another flight, what appeared to be a normal entry into a rapidly rising white puffy cumulus cloud turned out to be hail and weather that engulfed the ariplane, causing over three hundred fifty thousand dollars in damage to engine inlets, nacelles, damaged or destroyed fan blades, destroyed leading edges, radome, etc. In seconds. That with the penetration initiated with radar tilted down considerably to view the cell; it rose and enveloped the airplane quickly and with a vengence. You don't want to be there at a time like that.
When passing from one level of convective activity to another, inside the weather, the changes may appear subtle, but the results encountered (and the aircraft reactions) may be markedly diverse. A level 1 green return with speckles of yellow, suggesting level 2, appears benign sometimes. Almost calm. Elements of graupel and rapid ice buildup give way to dryness, and nothing, and then suddenly heavy rain. Doesn't appear like much on radar, but it's there, and on the second pass after a quick turn to re-enter the cell from the opposite direction, the character has grown ugly. Ice builds so rapidly it can't be shed. Noise, lightening, thunder we can hear, and then lightening strikes. Is this the time you want to lose your radar because of an electrical discharge or lightening strike? How about your isntruments, radios, or instrument displays?
We get frequent precipitation static such that one we're in the weather, we're not talking to anyone; we can't. The radios just hiss and growl, and at night we can see it corresponding to sporadic buildups of corona and St. Elmo's fire. Occasionally a discharge occurs; completely blinding if you happen to be looking out at a tip tank for ice or to see the St. Elmo's at the time. A few weeks ago it burned holes through our elevator, and melted pits down one tip tank, blew out static wicks, and put burns on the radome. In times past I've seen it burn holes through elevators, flaps, propellers, and melt pitot tubes, ice detectors, and AoA vanes in varying degrees. You don't want that.
Take great pains to avoid weather. What is inside, you shoudn't experience. There are things inside which can hurt you, disorient you, sap your performance, break your airplane, tumble your gyros, leave you covered in ice, and pull you to pieces. Not every storm is like that, but do you really want to pick and choose?
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Thanks for sharing your experience SNS3Guppy 
Sounds like you do some interesting flying, gotta save you some bucks going to Space Mountains and the like
My little experience dates a few years ago in the MD80, flying thru a smallish undetected CB, leading to some frightening turbulence and hail, and then the replacement of our radome as well as the engine inlets... no desire for a repeat, thanks!
Sounds like you do some interesting flying, gotta save you some bucks going to Space Mountains and the like
My little experience dates a few years ago in the MD80, flying thru a smallish undetected CB, leading to some frightening turbulence and hail, and then the replacement of our radome as well as the engine inlets... no desire for a repeat, thanks!
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I think SNS3Guppy's post should be made a sticky. Well said by someone with more experience than I personally would like to achieve! I'm more than happy to take his word for it.
Psychophysiological entity
There is ALWAYS a choice!
Viscount. No radar fitted. LHR to Spain
Night after night being flashed and banged at. No communication due to static. No chance of conversation due hail noise on screens.
One particulary bad night we took 45 mins on one 20 min leg. Total flight nearly an hour longer than planned.
Thrown below Min Safety over the Pyrenees. Repeated full range application of controls. Horizon bar off the scene...top and bottom, time and time again. Passengers unstrapping to kneel and prey. Sick and blood dripping from the ceiling.
When we got there the captain told me to hurry to do the turnround cos we were late! I finally persuaded him to let me re-plan over Marseilles. As mentioned above, these things move quickly, and in no time we were in it again.
After another thrashing we popped out of cloud into post frontal clear air. We could see the lights of Paris from 200 miles away. Skipper told me to fly cos he was knakkerd. He pushed a cigarette into his mouth and struck his Zippo. At that precise second, we were struck by a single bolt which blew a 4" hole in the starboard wing. I had seen it coming. It popped out of the higher region of a vast Chinese lantern that was way behind us. Zig Zagged up for what must have been a mile...then came streight for our wing...yep, like a finger of God. The burn went round the fuel bags and came out in line with the top hole.
To this day I have the clearest memory of the skipper's face, his eyes bulging in his ashen face which was illuminated by the little flame from the Zippo. "Did I do that?" type of expression.
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Some amazing experiences potrayed here.I have the greatest respect for CB's, when I'm flying I like to see them, but as far away from us as possible.
Micro Bursts, Ice , hail, uncontrolled vertical speed deviations, tornadoes....... enough reasons to stay clear?
I have so much respect for the regional pilots in the US who dodge super cells during Mar-Jun over tornado alley, I would not have the stomach for it.
Micro Bursts, Ice , hail, uncontrolled vertical speed deviations, tornadoes....... enough reasons to stay clear?
I have so much respect for the regional pilots in the US who dodge super cells during Mar-Jun over tornado alley, I would not have the stomach for it.
SNS3Guppy re your statement – “Aircraft most certainly are not designed to withstand entry into cumulonimbus storms”.
I suggest that a more circumspect approach is required.
We may have differences in our opinions or in the use of the wording between ‘entry into’ and ‘withstanding inadvertent entry’.
There could also be differences in the design and certification levels of the aircraft being considered. A light aircraft or bisjet might not meet the structural requirements of FAR/JAR 25 - Large Commercial Aircraft; the aircraft which I flew did (but it was still damaged).
In my experience I have yet to see a commercial aircraft flight manual which prohibits fight into cbs i.e. a restriction requiring avoidance ‘at all cost or else’. This suggests that those aircraft have at least some protection against inadvertent cb entry, but there again not all cbs are equal! Similarly this does not imply that flight into cbs should be done.
A major point of my response is to avoid leaving some pilots with the belief that an inadvertent entry into a cb will be fatal. It certainly will be hazardous and the situation should be avoided, but provided the manufacturer’s advice is followed the aircraft should remain structurally sound albeit slightly dented.
Aircraft that do not survive cbs might have been handled incorrectly, thus placing them beyond design limits, or in some circumstance the aircraft could already be structurally weak. Examples of the latter can be found in reports of turboprop accidents in S America; structural inspections were not completed – post accident inspection identified pre existing wing cracks.
This topic is a good example of Threat and Error Management. The threats from a cb should be identified and avoided, but if through error – failure to identify, equipment failure, or human involvement, then the resultant (inadvertent cb entry) must be managed. This can be done by following AFM advice which is designed to mitigate (not eliminate) the risk of the threat and/or error.
I suggest that a more circumspect approach is required.
We may have differences in our opinions or in the use of the wording between ‘entry into’ and ‘withstanding inadvertent entry’.
There could also be differences in the design and certification levels of the aircraft being considered. A light aircraft or bisjet might not meet the structural requirements of FAR/JAR 25 - Large Commercial Aircraft; the aircraft which I flew did (but it was still damaged).
In my experience I have yet to see a commercial aircraft flight manual which prohibits fight into cbs i.e. a restriction requiring avoidance ‘at all cost or else’. This suggests that those aircraft have at least some protection against inadvertent cb entry, but there again not all cbs are equal! Similarly this does not imply that flight into cbs should be done.
A major point of my response is to avoid leaving some pilots with the belief that an inadvertent entry into a cb will be fatal. It certainly will be hazardous and the situation should be avoided, but provided the manufacturer’s advice is followed the aircraft should remain structurally sound albeit slightly dented.
Aircraft that do not survive cbs might have been handled incorrectly, thus placing them beyond design limits, or in some circumstance the aircraft could already be structurally weak. Examples of the latter can be found in reports of turboprop accidents in S America; structural inspections were not completed – post accident inspection identified pre existing wing cracks.
This topic is a good example of Threat and Error Management. The threats from a cb should be identified and avoided, but if through error – failure to identify, equipment failure, or human involvement, then the resultant (inadvertent cb entry) must be managed. This can be done by following AFM advice which is designed to mitigate (not eliminate) the risk of the threat and/or error.
As a reminder, this is what might happen:
http://flightlevel.20megsfree.com/
Oh and safetypee; it should be drilled to avoid Cbs. Remember the F28 losing a wing while circumnavigating?
http://aviation-safety.net/database/record.php?id=19811006-0〈=en
I still have to find the guy that can teach me which Cb will be fatal and which one not.
http://flightlevel.20megsfree.com/
Oh and safetypee; it should be drilled to avoid Cbs. Remember the F28 losing a wing while circumnavigating?
http://aviation-safety.net/database/record.php?id=19811006-0〈=en
I still have to find the guy that can teach me which Cb will be fatal and which one not.
Psychophysiological entity
In my experience, the sheer belt-slapping, spar-snapping peaks of turbulence have come in clear air. The flight system a vertical blur and hands flailing about trying to grab at the power and the brakes have happened with not a cloud in sight.
When this hits wing resonance, they really do start to twang.
One time we put ten miles between us and the core of the CB which was way below us. We could see it on radar and flashing in stratus below. Suddenly we descended in violent lumps just like crashing down concrete stairs 1,000 feet a step. My jacket swung on its hook and almost hit the roof. No record of negative g on our old BAC1-11, but it was more than a little.
I fear that often the damage done to aircraft is caused by attempts to correct unusual attitudes. I'll risk stating the obvious, but it's vital not to be blinded by the flashes, and also vital not to try to correct a severe upset too quickly.
I'll stop now before I'm tempted to say what I think about the removal of good old tied-gyro turn indicators.
When this hits wing resonance, they really do start to twang.
One time we put ten miles between us and the core of the CB which was way below us. We could see it on radar and flashing in stratus below. Suddenly we descended in violent lumps just like crashing down concrete stairs 1,000 feet a step. My jacket swung on its hook and almost hit the roof. No record of negative g on our old BAC1-11, but it was more than a little.
I fear that often the damage done to aircraft is caused by attempts to correct unusual attitudes. I'll risk stating the obvious, but it's vital not to be blinded by the flashes, and also vital not to try to correct a severe upset too quickly.
I'll stop now before I'm tempted to say what I think about the removal of good old tied-gyro turn indicators.
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I have yet to see a commercial aircraft flight manual which prohibits fight into cbs i.e. a restriction requiring avoidance ‘at all cost or else’.
Neither is the aircraft designed for that event, neither is it designed, nor intended, to be flown into a cumulonimbus cloud.
Part 25 makes you no gaurantees.
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safetypee, If you would like some sobering reading re jet transports and CB's google up
Northwest Airlines Boeing 720 N724US 12th Feb 1963
Braniff BAC-111 N1553 6th Aug 1966
Southern Airways DC-9 N1335U 4th April 1977
Interesting that WWII US Army Air Corps met books had reference that a crews inability to fly successfully through CB's was down to lack of skill. Gann in his "Fate Is The Hunter" makes reference to how airline crews of his day (30's and 40's) dealt with CB's. Makes for harrowing reading and explains perhaps both the coast to coast litter of bent airline aluminium in the US during those years and the page upon page of names to whom memory his book is dedicated.
Northwest Airlines Boeing 720 N724US 12th Feb 1963
Braniff BAC-111 N1553 6th Aug 1966
Southern Airways DC-9 N1335U 4th April 1977
Interesting that WWII US Army Air Corps met books had reference that a crews inability to fly successfully through CB's was down to lack of skill. Gann in his "Fate Is The Hunter" makes reference to how airline crews of his day (30's and 40's) dealt with CB's. Makes for harrowing reading and explains perhaps both the coast to coast litter of bent airline aluminium in the US during those years and the page upon page of names to whom memory his book is dedicated.
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All my respects to you SNS3Guppy ,you are doing an incredible job. I don't know if I'll have the gut to do it.I did all kind of flights ,but I have a deep respect for weather and I don't know if i'll enter it voluntarily.Unless flying a military high performance jet,maybe..
Energie ,SNS3 is one 'device' i'd like having on my plane when flying around Cb's
Energie ,SNS3 is one 'device' i'd like having on my plane when flying around Cb's
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In the 'ole piston airliners of yesteryear, it was more or less common practise to fly thru CB's, if they couldn't be avoided.
Slow to maneuvering speed, and press on.
Then came the early jets.
Up high, they went...and then, just like in the old days, slowed way down, and pressed on...straight into the weather.
Enter the classic jet upset.
On the way down, engines chucked right off the pylon...try explaining this to the fleet manager.
Then folks got wise.
They went around the nasty weather.
Gee, what a surprise....
Slow to maneuvering speed, and press on.
Then came the early jets.
Up high, they went...and then, just like in the old days, slowed way down, and pressed on...straight into the weather.
Enter the classic jet upset.
On the way down, engines chucked right off the pylon...try explaining this to the fleet manager.
Then folks got wise.
They went around the nasty weather.
Gee, what a surprise....
Quite. Doubtless you've also not seen a commercial aircraft flight manual which specifically prohibits flight directly in to the face of a granite wall...yet somehow we all know it's a stupid thing to do.
I'm truly amazed by the responses here -- I can only imagine that you all stay on the ground in spring and summer if you religiously avoid CBs. The key to safe flight is in avoiding the flight conditions associated with convective weather that are going to kill you. That means working out which CBs you can fly in and which you can't.