Practical IFR advice

[RobertE]

I've not yet encountered this situation but am sure that at some point I will.  I'd like the benefit of other's practical knowledge.

 

Imagine you are on an IFR flight plan at 15K flying above cumulous tops that vary from 10K - 13K and 40 miles ahead you see a buildup to what looks to be 18K.  If you request a diversion but are denied do you a) cancel IFR and go around VFR or fly through it?  Please assume you have no nexrad or spherics device.

 

Does your answer change if you do have a stormscope and it shows there is electrical activity in the area but not in the particular buildup ahead? 

 

 

[Nathan Peterson]

Use your emergency authority and turn to a heading that will keep your aircraft and crew from damage.  Tell ATC I need and will be turning to this heading to remain clear of the TS.

 

Nate

[Mooneymite]

In my experience, ATC does not deny a request to avoid weather. ATC may not be able to grant your specific request. You may want to go left, but have to go right, but you will be granted a deviation. Sometimes ATC will ask you to accomodate other deviating traffic by delaying a turn, but in all these years, I've never been forced to fly through hazardous weather, nor have I ever had to use my emergency authority to avoid it.

ATC is very accomodating, but you have to understand that hitting another aircraft is not a suitable alternative to cloud avoidance!

Clear, concise communications are essential.

[kmyfm20s]

If they dont grant you a heading change it would be because of traffic conflicts. Since you said you where above the layer you can request a "VFR on Top" clearance and then you would be responsible for your own traffic but with advisories. That way you can go the direction needed.

[Mooneymite]

In such a case, I would prefer staying on an IFR clearance. Dodging build-ups tends to funnel aircraft into the same avoidance paths. Wandering about VFR is not my idea of clean, safe, fun.

[Bartman]

I have never been unable to negotiate a new clearance that is acceptable to both me and ATC. It may not be my first choice, but I have never been forced into something I insisted was not a good option.

[N201MKTurbo]

I have to agree with everyone else. I've never been denied a deviation around weather.

I've been vectored into storms before. I just say resolutely "UNABLE".

At that point they usually ask? "Where would you like to go?"

[kmyfm20s]

In such a case, I would prefer staying on an IFR clearance. Dodging build-ups tends to funnel aircraft into the same avoidance paths. Wandering about VFR is not my idea of clean, safe, fun.

We differ, I would rather look for traffic and have advisories than go through a build up blind as the OP's original question was. IFR on Top is an IFR flight plan but with benefits of VFR which gives you more flexibility.

5-5-13. VFR‐on‐top

a. Pilot.

1. This clearance must be requested by the pilot on an IFR flight plan, and if approved, allows the pilot the choice (subject to any ATC restrictions) to select an altitude or flight level in lieu of an assigned altitude.

NOTE-

VFR-on-top is not permitted in certain airspace areas, such as Class A airspace, certain restricted areas, etc. Consequently, IFR flights operating VFR-on-top will avoid such airspace.

REFERENCE-

AIM, IFR Clearance VFR-on-top, Paragraph 4-4-8.

AIM, IFR Separation Standards, Paragraph 4-4-11.

AIM, Position Reporting, Paragraph 5-3-2.

AIM, Additional Reports, Paragraph 5-3-3.

2. By requesting a VFR‐on‐top clearance, the pilot assumes the sole responsibility to be vigilant so as to see and avoid other aircraft and to:

(a) Fly at the appropriate VFR altitude as prescribed in 14 CFR Section 91.159.

( Comply with the VFR visibility and distance from clouds criteria in 14 CFR Section 91.155, Basic VFR weather minimums.

© Comply with instrument flight rules that are applicable to this flight; i.e., minimum IFR altitudes, position reporting, radio communications, course to be flown, adherence to ATC clearance, etc.

3. Should advise ATC prior to any altitude change to ensure the exchange of accurate traffic information.

b. Controller.

1. May clear an aircraft to maintain VFR‐on‐top if the pilot of an aircraft on an IFR flight plan requests the clearance.

2. Informs the pilot of an aircraft cleared to climb to VFR‐on‐top the reported height of the tops or that no top report is available; issues an alternate clearance if necessary; and once the aircraft reports reaching VFR‐on‐top, reclears the aircraft to maintain VFR‐on‐top.

3. Before issuing clearance, ascertain that the aircraft is not in or will not enter Class A airspace.

[Mooneymite]

Yep. We differ.

:-)

[Marauder]

If I were in that situation, I would ask for a deviation. I doubt seriously they would not honor the request, especially if you tell them you are dealing wih weather.

VFR on top is an option but it doesn't alleviate you of the course requirements of the IFR flight plan. It might be a good choice if all of what you described was occurring a lot lower than Class A as you described.

Sent from my iPad using Tapatalk

[RobertE]

Thanks, gentlemen, but let me sharpen the question a bit. 

 

Do I sense from everyone that, absolutely, positively you're not flying into a cloud that has an 18K top?  After all, there are lots of cumulus clouds around that are benign.  The only difference is this one has an extra 5K or so of development.  And let's say my stormscope shows no activity.  Still a no go?  What I'm trying to get at isn't the likelihood of being granted a diversion or the alternatives if denied, but the danger that does or doesn't exist in a cumulus cloud with a little more vertical development than surrounding.  My training simply didn't address such subtles and, in California, you just don't get a lot of practice with such things.

[carusoam]

Canceling IFR above a cloud deck, with building storm intensity, would be challenging and add to your difficulty if the cloud coverage goes on for 100s of miles.

When this type of weather occurs (Spring near FL to TX) the ATC frequencies are lively place. You won't be the only one with requests.

That was the day I ordered my SkyRadar device. A week later, a tornado made a mess in SNF... The frontal activity was continuous, and 1000 miles long.

Below the deck is also something to consider. It is unlikely to be the answer though.

Knowledge of it being benign, and not that tall...slow to maneuvering speed for your gross weight?

It is probably smart to not cancel IFR until you are on the ground. Cell phones make it easy in most places.

Best regards,

-a-

Non professional advice, with low experience, and no currency....

[M016576]

In such a case, I would prefer staying on an IFR clearance. Dodging build-ups tends to funnel aircraft into the same avoidance paths. Wandering about VFR is not my idea of clean, safe, fun.

Being on an IFR flight plan in VMC does not relieve you of your visual lookout and collision avoidance responsibilities. I wouldn't consider VFR flight to be "wandering around" any more than I consider IFR flight to be "on rails." Each has their purpose and efficiency, and I use either/both when the situation dictates.

Personally, I find IFR flight in VMC the majority of the time tends to waste resources (both my $$$$ and the controllers time). Notable exceptions being class b/c airspace penetration where I'm unfamiliar and also training flights. Now if I need to shoot an approach or bust through some layers, get me a clearance and put me at the back of the conga line.....

That all said- I'd stay IFR in this scenario due to only being VMC on top and request "deviations right and left of course for weather."

JMHO

[Danb]

Robert, you question the buildup benign which is most likely not the case but assume it is, at 18000 ft. There is a Strong! Likely hood you will encounter ice most likely mean ice. The worse I iced over was at 18000 ft on a 95 degree day in N C, I ended up going to FL 240. Now I had a daunting task to get back down, the build ups went for about 200-250 miles. There is much more to be concerned about than turbulance, icing also has a habit to kill,you may have added thunderstorms along with ice quite a handful, also our Mooneys know how to do a 180 degree turn..stay smart and alive....

[Marauder]

Thanks, gentlemen, but let me sharpen the question a bit.

Do I sense from everyone that, absolutely, positively you're not flying into a cloud that has an 18K top? After all, there are lots of cumulus clouds around that are benign. The only difference is this one has an extra 5K or so of development. And let's say my stormscope shows no activity. Still a no go? What I'm trying to get at isn't the likelihood of being granted a diversion or the alternatives if denied, but the danger that does or doesn't exist in a cumulus cloud with a little more vertical development than surrounding. My training simply didn't address such subtles and, in California, you just don't get a lot of practice with such things.

The StormScope is only going to show convective activity. It won't necessarily show huge up and down drafts that accompany a quick developing unstable air mass. Best case situation, you get bumped around a little. Worse case, you run into supercooled droplets that turn you into a Popsicle or you encounter heavy turbulence.

In the summer time, I want to be above a layer to look for those developing clouds or well below so I can see what is coming out of the bottom.

Sent from my iPad using Tapatalk

[M016576]

The StormScope is only going to show convective activity. It won't necessarily show huge up and down drafts that accompany a quick developing unstable air mass. Best case situation, you get bumped around a little. Worse case, you run into supercooled droplets that turn you into a Popsicle or you encounter heavy turbulence.

In the summer time, I want to be above a layer to look for those developing clouds or well below so I can see what is coming out of the bottom.

Sent from my iPad using Tapatalk

Great points about the down / up drafts. Didn't legendary test pilot Scott Crossfield die when his Brand C aircraft broke up in flight as he flew into a virginia thunder bumper? As callous as this sounds- A lifetime of achievement and accolades flying all sorts of jet and prop aircraft past the edge of the envelope didn't save his life during a thunderstorm penetration... But turning around may have.

[Jeff_S]

Someone else already said the magic word: "unable."  The PIC has the last authority on the safety of the flight and the aircraft. Like everyone else, I have never NOT been granted leeway to avoid buildups, and you definitely want to avoid one that's towering to 18,000' because even with no electrical activity there will be strong convection (that is, after all, why it's building up).  So I can't imagine a scenario in which ATC will disallow your request, nor can I imagine a scenario where you would want to fly into that sucker.

[Marauder]

Great points about the down / up drafts. Didn't legendary test pilot Scott Crossfield die when his Brand C aircraft broke up in flight as he flew into a virginia thunder bumper? As callous as this sounds- A lifetime of achievement and accolades flying all sorts of jet and prop aircraft past the edge of the envelope didn't save his life during a thunderstorm penetration... But turning around may have.

Yep, exactly. When you read about these kinds of accidents and the pilots involved, it becomes clear that good judgement is an essential ingredient regardless of experience. And ironically the usage (or the lack therefore) of a StormScope was mentioned in the final report for this accident. http://www.ntsb.gov/aviationquery/GenPDF.aspx?id=CHI06MA115&rpt=fi Sent from my iPad using Tapatalk

[PMcClure]

+1 on UNABLE - one of the best words in aviation. 

Try to comply with ATC as they are usually trying to help but sometimes we just can't make the first turn off, fly through a build up or rush the decent, etc... 

[midlifeflyer]

Another one for ATC will not deny a request to deviate around weather in the absence of a safety-related reason like loss of separation with other aircraft. 

 

My personal example: Leaving KMYR for home as the build-ups were forming, I read back my clearance to CD and added, "we'd also like some initial vectors west of the buildups." "Readback correct. You can expect vectors on departure" was the reply.

 

Shortly before leaving the TRACON airspace, I got the call with a route change - a simple one to clear me to an NDB west of the buildups before proceeding to my next waypoint 

 

Upon checking in with Center, I was told I could proceed direct to my next waypoint "when able" and, on request was given the OK do deviate 10° left and right of course as needed.

 

It was an absolutely smooth flight all the way home.

[WardHolbrook]

One of the things a new instrument pilot needs to learn is that ATC clearances need to be treated as "suggestions" (albeit VERY strong suggestions)  and that occasionally, they will "suggest" you fly a route, heading or altitude that either isn't feasible or will put you at risk. That's when you have the obligation to say "unable". In the early 1980's I saw a Turbo Commander sitting in a hangar at a factory service center that had bent a wing spar during an inadvertent T-Storm penetration. (The airplane was totaled - the wings were bent upward and one of the engines was loose in the mounts! The pilot was able to keep the airplane in the air and make a safe emergency landing. Those things were built like bricks - GREAT airplanes!) It was a scenario where ATC wasn't willing to give the pilot a clearance to deviate the way the pilot wanted, it would have resulted in the airplane flying into Mexican airspace. The pilot's mistake was not insisting and simply telling ATC what he had to do to ensure the safety of his airplane and passengers. 

 

Guys, I've made this suggestion before and I'll make it again - go on Amazon and get two books, Weather Flying by Robert Buck and Instrument Flying by Richard Taylor. Read those books through cover-to-cover a few times. Take notes. Weather Flying will help you understand how to fly weather and Instrument Flying will help you to understand how to work "the system". You can learn this stuff the hard way, by getting a few hundred hours of actual under your belt, or you can learn it the easy way by doing some reading. Your choice.

[FlyDave]

One of the things a new instrument pilot needs to learn is that ATC clearances need to be treated as "suggestions" (albeit VERY strong suggestions)  and that occasionally, they will "suggest" you fly a route, heading or altitude that either isn't feasible or will put you at risk. That's when you have the obligation to say "unable". In the early 1980's I saw a Turbo Commander sitting in a hangar at a factory service center that had bent a wing spar during an inadvertent T-Storm penetration. (The airplane was totaled - the wings were bent upward and one of the engines was loose in the mounts! The pilot was able to keep the airplane in the air and make a safe emergency landing. Those things were built like bricks - GREAT airplanes!) It was a scenario where ATC wasn't willing to give the pilot a clearance to deviate the way the pilot wanted, it would have resulted in the airplane flying into Mexican airspace. The pilot's mistake was not insisting and simply telling ATC what he had to do to ensure the safety of his airplane and passengers. 

 

Guys, I've made this suggestion before and I'll make it again - go on Amazon and get two books, Weather Flying by Robert Buck and Instrument Flying by Richard Taylor. Read those books through cover-to-cover a few times. Take notes. Weather Flying will help you understand how to fly weather and Instrument Flying will help you to understand how to work "the system". You can learn this stuff the hard way, by getting a few hundred hours of actual under your belt, or you can learn it the easy way by doing some reading. Your choice.

 

I second Ward's recommendation on these books. I bought both of them on Ebay (less than $6 each) and just started Weather Flying.

Weather Flying was written in the 70's and revised in the 80's which makes it even more fun to read because Buck talks about how to get weather information LONG before the internet. Our ability to get a huge amount of info at any time, any where makes our flight planning sooooooo much easier than "back then".

I think it was one of Ward's posts that prompted me to get these books - Thanks Ward!

[Marauder]

I second Ward's recommendation on these books. I bought both of them on Ebay (less than $6 each) and just started Weather Flying.

Weather Flying was written in the 70's and revised in the 80's which makes it even more fun to read because Buck talks about how to get weather information LONG before the internet. Our ability to get a huge amount of info at any time, any where makes our flight planning sooooooo much easier than "back then".

I think it was one of Ward's posts that prompted me to get these books - Thanks Ward!

 

Same with me. I bought both books and learned (re-learned) a few things. Thanks Ward.

[WardHolbrook]

I second Ward's recommendation on these books. I bought both of them on Ebay (less than $6 each) and just started Weather Flying.

Weather Flying was written in the 70's and revised in the 80's which makes it even more fun to read because Buck talks about how to get weather information LONG before the internet. Our ability to get a huge amount of info at any time, any where makes our flight planning sooooooo much easier than "back then".

I think it was one of Ward's posts that prompted me to get these books - Thanks Ward!

FYI, Weather Flying is now up to the 5th edition. It's most recent edition was released last year. Caption Buck passed away a few years back, but his son, retired TWA Capt Robert O Buck, has included how to use the internet and other modern sources of weather info. The book remains one of the best sources of up-to-date weather training our there.   

[PTK]

Imagine you are on an IFR flight plan at 15K flying above cumulous tops that vary from 10K - 13K and 40 miles ahead you see a buildup to what looks to be 18K.  If you request a diversion but are denied do you a) cancel IFR and go around VFR or fly through it?  Please assume you have no nexrad or spherics device.

I cannot imagine ATC would deny a diversion for wx.

 

But... 

 

FAR 91.3, (a):

"The pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft."