Flying in a TCU
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Flying in a TCU
So let's say i fly my Cessna into a TCU, Can the Updrafts be so severe to cause the airplane to stall, even with the aircraft in a nose down type attitude?
Re: Flying in a TCU
If it is a well developed TCU - it's not stalling that you should be worried about. Your wings departing the fuselage is more likely.
Re: Flying in a TCU
SAR_YQQ wrote:If it is a well developed TCU - it's not stalling that you should be worried about. Your wings departing the fuselage is more likely.
Don't be silly, its his first time so he'll start with a small TCU and work his way up as he gets more experience
Let us know how it goes
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Re: Flying in a TCU
Upside down with no wings! You are an aviation master!
Re: Flying in a TCU
France in the summer... The moist air wafts over the coast forming little puffy cumulus clouds, great fun to bash if you are into that sort of thing...
By the time those clouds reach the eastern part of the country they are huge CB's and TCU's...
There I was in the little 150, a Jodel 150 Mascaret to be precise, same engine but 1,000 mile range at 105 Knots or more!
I was going northwest enroute Le Touquet from Basle and was confronted by a line of these massive monsters aligned NE - SW.
I flew besides them southwesterly and looking for a gap, the turbulence was strong but so is the Jodel.
Then smooth, really smooth, shocking! But a glance at the VSI was also shocking! Throttle closed, carb heat hot, nose down, 110 knots and she was climbing like a dingbat!
No NO No, you don't want to mess about with these monsters!
Ninety degree turn away from the line of CB's, through the turbulence, descend into Lons le Saunier, put all the aircraft into the hangar, nasty storm for 40 minutes, push the Jodel out again on to the glistening grass in the calm blue afternoon sunshine with the nasty CB's parading off south eastwards, and have a pleasant flight the rest of the way.
Yes a strong updraft could stall your Cessna and in the process remove the wings. You do not ever want to find out what's inside a TCU unless you have a parachute and have had your glass of sake and saluted the rising sun.
Glider pilots have a lot of info on this; those that didn't freeze to death on the way up.
By the time those clouds reach the eastern part of the country they are huge CB's and TCU's...
There I was in the little 150, a Jodel 150 Mascaret to be precise, same engine but 1,000 mile range at 105 Knots or more!
I was going northwest enroute Le Touquet from Basle and was confronted by a line of these massive monsters aligned NE - SW.
I flew besides them southwesterly and looking for a gap, the turbulence was strong but so is the Jodel.
Then smooth, really smooth, shocking! But a glance at the VSI was also shocking! Throttle closed, carb heat hot, nose down, 110 knots and she was climbing like a dingbat!
No NO No, you don't want to mess about with these monsters!
Ninety degree turn away from the line of CB's, through the turbulence, descend into Lons le Saunier, put all the aircraft into the hangar, nasty storm for 40 minutes, push the Jodel out again on to the glistening grass in the calm blue afternoon sunshine with the nasty CB's parading off south eastwards, and have a pleasant flight the rest of the way.
Yes a strong updraft could stall your Cessna and in the process remove the wings. You do not ever want to find out what's inside a TCU unless you have a parachute and have had your glass of sake and saluted the rising sun.
Glider pilots have a lot of info on this; those that didn't freeze to death on the way up.
Re: Flying in a TCU
Lifted from elsewhere...
Aircraft most certainly are NOT designed to withstand entry into cumulonimbus storms. I agree with the remainder of your statement.
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?
Aircraft most certainly are NOT designed to withstand entry into cumulonimbus storms. I agree with the remainder of your statement.
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?
You can interpret that however you would like.
Re: Flying in a TCU
Wow, every pilot should read that story. I met somebody who had the same job one summer and he had similar stories. Sounds like way too much adventure for me...
Re: Flying in a TCU
So here's a follow up question, should you fly close to a TCU ?
I've had mixed answers about this one. I've been told that NO you should stay away from TCU's by 20 nm, but isn't that the rule of thumb for CB's?
What's the actual break down in your opinion pika? 20nm from TCU's, or flying close to them is okay... ?
I've had mixed answers about this one. I've been told that NO you should stay away from TCU's by 20 nm, but isn't that the rule of thumb for CB's?
What's the actual break down in your opinion pika? 20nm from TCU's, or flying close to them is okay... ?
Re: Flying in a TCU
There are no hard and fast rules. Just avoid.
You can interpret that however you would like.
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floatplanepilot
- Rank 3
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Re: Flying in a TCU
TCU's are bumpy, and will have icing well above the FL. Avoid if you can for pax comport. They are not particularly dangerous. TCU's primarily are going up. When they are wispy at the top, and dont look like califlower, they are dissipating and usually wont be too bad for turbulence at the tops, but there will be downdrafts at under them. When they develop further and become CB's avoid completely.
If you need to fly close to a CB, or got yourself in a bad situation here are some tips:
Unless you seed clouds or do weather research there is no reason to be this close. WX RADAR is a must.
Stay away from the rain shaft at all costs. you'll find the shear and downdrafts when you get too close.
Avoid the SW corner of the cell, its wear the bad stuff is like tornado's and violent turbulence.
Tuck yourself just feet under the defined base, you'll find the smooth inflow, watch your airspeed and power. Could be strong enough to go idle power, and still be going up at high airspeed.
Darker area's mean more moisture, and heavier precip. This means more downdrafts. Stay away if you need to penetrate.
Use your WXRADAR, never go into the center! Stay away from fingers, hooks, and scalops. This means hail.
If you need to fly close to a CB, or got yourself in a bad situation here are some tips:
Unless you seed clouds or do weather research there is no reason to be this close. WX RADAR is a must.
Stay away from the rain shaft at all costs. you'll find the shear and downdrafts when you get too close.
Avoid the SW corner of the cell, its wear the bad stuff is like tornado's and violent turbulence.
Tuck yourself just feet under the defined base, you'll find the smooth inflow, watch your airspeed and power. Could be strong enough to go idle power, and still be going up at high airspeed.
Darker area's mean more moisture, and heavier precip. This means more downdrafts. Stay away if you need to penetrate.
Use your WXRADAR, never go into the center! Stay away from fingers, hooks, and scalops. This means hail.
Re: Flying in a TCU
There was a nasty CB east of Penticton when I arrived there in an Auster... The winds are modified by a local CB and you'd be advised to go elsewhere. I diverted to Oliver down the road.
Like Lons le Saulnier if there's a safer place nearby I'd go there.
CB's don't hang around too long so you are better off being on the ground until they abate.
A traumatic experience for me was riding in the back seat of a Cessna 172... The pilot had 400 hours but no sense at all.
There was a CB over Biggin and it was a nasty one.
We could have passed safely south of it and come in behind it as it cleared eastwards but this bright spark held to the east, and flew under the nasty thing when it was reported clear over the airfield.
By the time we got there a second CB was passing overhead the field!
In my French adventure above I was not that close to the CBs/TCUs when I was in the turbulence, and then the smooth lift!
CB's and TCU's are big and nasty but fortunately you can see them and stay well clear of them.
Like Lons le Saulnier if there's a safer place nearby I'd go there.
CB's don't hang around too long so you are better off being on the ground until they abate.
A traumatic experience for me was riding in the back seat of a Cessna 172... The pilot had 400 hours but no sense at all.
There was a CB over Biggin and it was a nasty one.
We could have passed safely south of it and come in behind it as it cleared eastwards but this bright spark held to the east, and flew under the nasty thing when it was reported clear over the airfield.
By the time we got there a second CB was passing overhead the field!
In my French adventure above I was not that close to the CBs/TCUs when I was in the turbulence, and then the smooth lift!
CB's and TCU's are big and nasty but fortunately you can see them and stay well clear of them.
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Slappy the Squirrel
- Rank 5
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Re: Flying in a TCU
Pika, I hope you get paid well to do your job! You'd have to pay me a lot of money to repeatedly fly through a cell just to see what happens!
Re: Flying in a TCU
Just to clarify... I lifted the post above from PPRUNE. I don't fly through CB's as that's for crazy people.
You can interpret that however you would like.
Re: Flying in a TCU
This is a Video that I had seen a number of years ago, seems to have been removed from most sites but here is a link to one site that still has it up. Darn hard to find again. But it's a slow site.
After watching this T-28 fly through a TCU you can, I'm sure, make your own informed decision on the outcome of flying anything less substantial than this specially prepared, armour plated aircraft through anything similar to that kind of weather.
Enjoy
http://video.timnhanh.com/trungphuong86 ... 57C1D.html
See the youtube link below, as long as it lasts...........
After watching this T-28 fly through a TCU you can, I'm sure, make your own informed decision on the outcome of flying anything less substantial than this specially prepared, armour plated aircraft through anything similar to that kind of weather.
Enjoy
http://video.timnhanh.com/trungphuong86 ... 57C1D.html
See the youtube link below, as long as it lasts...........
Last edited by Giveitago on Mon Jul 13, 2009 9:22 pm, edited 1 time in total.
Re: Flying in a TCU
OK, that site is BRUTALLY slow.
Uploaded to Youtube, don't know how long it will last.
Give
http://www.youtube.com/watch?v=taalRl0O9RE
Uploaded to Youtube, don't know how long it will last.
Give
http://www.youtube.com/watch?v=taalRl0O9RE
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wheeliedriver
- Rank 1
- Posts: 28
- Joined: Tue Sep 27, 2005 7:00 am
