Obstruction Clearance

[ToiletDuck]

ATC gives you this clearance: "Maintain your own terrain obstruction clearance through 3k."

The ceiling is at 2500ft msl. With this clearance can you enter the clouds at 2500ft?

ATC called the flight school and asked this... So we're guessing it's because their radar goes out 35nm and they can give you radar services but you need to be 3k for them to see you...

 

[avbug]

They may be able to see you, but for whatever reason, they are not accepting responsibility for your terrain separation and obstacle clearance until that altitude. It may be that the minimum vectoring altitude in that sector is at three thousand, you don't know.

If the ceiling is at 2,500, are you able to maintain your own separation from terrain? How about other traffic that might be descending down to your location? What are you going to do if you enter the cloud at 2,500 and experience a radio failure?

 

[aucfi]

probably because 3K is the MVA for that area. You have to maintain clearance from obstructions using your OROCA, MSA, or SID/DP

probably something else to be added but thats my thoughts on it...

 

[viper548]

yep. probably below the MVA

 

[ToiletDuck]

but the question is the ceiling is at 2500. ATC was debating on this, my guess is an aircraft had this happen earlier. So are you saying that unless the MSA is 2500 or the oroca is 2500 then no you can't? What solutions would you suggest for this?

 

[minitour]

I believe so. I was given this twice. Once when I was a student pilot (with a CFI) training and once while with a student doing some IMC time.

We were "cleared to ___ via ___ maintain ___ maintain own obstruction clearance through __ proceed direct ___ then on course.". So...it was an IFR clearance, but we had to not hit anything through ___ feet. Probably an MVA thing.

-mini

PS
The other question is...are you in controlled airspace. Yes, you're talking to someone but are you in class G? If so, then you can go through the clouds all you want
91.173
No person may operate an aircraft in controlled airspace under IFR unless that person has—
(a) Filed an IFR flight plan; and
(b) Received an appropriate ATC clearance.

 

[ToiletDuck]

Where is that located about class G. I read it in that everything explained book but I don't have it on me.

 

[avbug]

The statement "maintain your own terrain..." is a legal one. It's a release. It's ATC telling you that they are not responsible, and that you are. It also puts the burden on you...you must be able to maintain your own terrain and obstacle separation.

Not enough information has been provided to answer your question. Have you received your clearance, yet? If ATC won't clear you until getting you on radar and radar-identifying/accepting responsibility, and you're in controlled airspace, then no, you can't enter the cloud. If ATC has cleared you, then you can maintain your own terrain by means of IFR routing/methedology, or visually.

You said that ATC debated something with you. What was the debate, and what was ATC's point?

 

[minitour]

Where is that located about class G. I read it in that everything explained book but I don't have it on me.

91.173...it's in the regs.

-mini

 

[ToiletDuck]

not debate. They called and asked the question. We are debating it here lol. what was ment by class G you can punch through cloud?

 

[minitour]

not debate. They called and asked the question. We are debating it here lol. what was ment by class G you can punch through cloud?

Well what do you need to go into clouds?
Flight plan and ATC clearance right? Yes, if you're in controlled airspace.

The regs don't say "in uncontrolled airspace you need.....".

So...the way I read it, if you want to operate IFR in uncontrolled airspace, you can.

I still can't figure out a "why would you want to"...but there it is...and remember Victor airways are class E...

-mini

PS
If you're doing your -II after your CFI, know these regs by heart! You will probably be asked about them on your oral...just a heads up.

 

[DC8 Flyer]

I used to get this quiet often at my old flight school. My student and I would be out VFR and the weather would push in or vis would go down. We would call approach and get a clearance like this:

XYZ maintain own obstruction clearance to 2500 feet, cleared direct, sqauwk XXXX.

Basically, it meant we were cleared direct and given an IFR clearance once we reached 2500 feet.

Where it could get "hairy" is when the weather got bad enough that the clearane to 2500 would put us in IMC before getting there and we would be in Class E airspace.

 

[minitour]

DC - Love the avatar!

-mini

 

[aucfi]

I still can't figure out a "why would you want to"

"Legal Stupid"

 

[Vector4fun]

What's the field elevation? That often confuses some folks, ATC clearances are in MSL, while ceilings are in AGL. If the field elevation is 1000', then the base of the ceiling is at around 3500'.


In any case, if there is a published departure procedure, or you can otherwise insure your own terrain clearance, then you're good to go. The controller didn't say "Maintain VFR to 3000'", they asked if you could provide your own terrain separation.