Transponder Technicalities

[MCM]

When you are in IMC, this generally means you are in touch with ATC, squawking and being followed on radar and on a flight plan that will define your location and separate you from other aircraft that would be legally operating in IMC...

Thats clearly from someone lives in a country with total (or near total) Radar coverage . The vast majority of IFR flying down here was (until ADSB came along), procedural. Much of it still is.

You do require comms with ATC, you would be on a flight plan, but you do not need to be followed on Radar if it doesn't exist! Separation would be procedural rather than radar.

If you're leaving Radar coverage, or not going near it, you would squawk IFR (2000) as SnyderSS pointed out earlier, but if there's no Radar where you are or where you're going, then it doesn't really doesn't matter what you put there as no one will see it! If your pilot had left radar airspace, and wasn't reentering it, then while technically incorrect, he hasn't done anything that is going to cause any problems on that flight.

[3WE]

Thats clearly from someone lives in a country with total (or near total) Radar coverage .

Please note that I was careful to use the word "generally" and avoid overly-bold, absolute statements....so for us tunnel-visioned Americans, I stand by my comment.

That being said- what do you think??? Is it appropriate and legal to turn your transponder from an assigned code to 1200 while hauling paying passengers in the clouds between San Jaun and Ponce Puerto Rico?

I do not need your opinion as to whether it's appropriate to turn your transponder form an assigned code to 1200 while hauling paying passengers in the clouds between Big Rock and Chickendale, Arkansas.

[3WE]

Ok, let me try again; is a transponder absolutely, always required for IFR flight, espeically an instance where there is no radar.

Fixed (by a singificant reduction in wordiness)

Answer: No.

Indeed it would be moot if there is no radar coverage.

However, generally, you are going to be squawking in US and related territories.

I also belive that one may obtain special permission to move ones transponderless, tail dragging, toilet-paper-laden biplane from Sweet Monkey River, Texas, even though you are in proximity to a big Class B airspace terminal airport.

[MCM]

That being said- what do you think??? Is it appropriate and legal to turn your transponder from an assigned code to 1200 while hauling paying passengers in the clouds between San Jaun and Ponce Puerto Rico?

I do not know the airspace or Radar coverage in that part of the world (I struggle enough in this part of the world :P), but if the ATC said "Radar services terminated" (or the local to that effect), and there is no further controlled airspace on his route, then there's no problem changing from a discrete code. It really should be to an IFR code, but its not exactly life threatening.

If you're not going back into Radar, then there's no reason to be on a discrete code.

If, however, he changed his plan to VFR when he was IMC, then thats not very clever.

I'd prefer to think it was the first option first!

[Gabriel]

Fixed (by a singificant reduction in wordiness)

Maybe, but I was thinking in a broader question, which, for the sake of wordiness reduction, could be phrased as:

Is it legal (in certain airspaces and without resorting to the "emregency" wild card) to fly IFR in IMC in conditions where separation is porvided by statistics only?

[MCM]

Is it legal (in certain airspaces and without resorting to the "emregency" wild card) to fly IFR in IMC in conditions where separation is porvided by statistics only?

No.

[3WE]

I'd prefer to think it was the first option first!

As stated earlier in this thread, the Ponce area has radar coverage so I don't think you can prefer to think anything.

And yes, this is the second time, I have seen someone switch to 1200 while well up in thick clouds to break out 10 to 20 miles later to good visibility and not overly low ceilings where the a nice normal VFR pattern and visual landing was flown.

...and live to post about it on obscure aviation fora.

[Gabriel]

Is it legal (in certain airspaces and without resorting to the "emregency" wild card) to fly IFR in IMC in conditions where separation is porvided by statistics only?

No.

Then what hapens with airspace classes F and G? IFR allowed in VMC only?

Class..Controlled?..IFR..SVFR.VFR..ATC Clearance....Separation...................Traffic Information
A......Controlled...Yes..Yes..No...Required.........Provided for all flights.....N/A
B......Controlled...Yes..Yes..Yes..Required.........Provided for all flights.....N/A
C......Controlled...Yes..Yes..Yes..Required.........For all IFR/SVFR.............Provided for all VFR
D......Controlled...Yes..Yes..Yes..Required.........For IFR/SVFR vs IFR/SVFR.....Provided for all flights
E......Controlled...Yes..Yes..Yes..Req for IFR/SVFR.For IFR/SVFR vs IFR/SVFR.....For all flights if poss.
F......Uncontrolled.Yes..No...Yes..Advisory only....IFR/SVFR vs IFR/SVFR if poss.Prov if requested & poss
G......Uncontrolled.Yes..No...Yes..Not provided.....Not provided.................Prov if requested & poss

[3WE]

Maybe, but I was thinking in a broader question, which, for the sake of wordiness reduction, could be phrased as:

Is it legal (in certain airspaces and without resorting to the "emregency" wild card) to fly IFR in IMC in conditions where separation is porvided by statistics only?

In non-Radar environments (and we have a lot of those in the USA that are a few hundred feet deep at outlying airports), your IFR activities are restricted in space and time. You want to take off, but someone is inbound...your clearance times will be adjusted!

Holding and "expect further clearance"...some of that happens at uncontrolled airports to allow someone to make an approach, land, phone in, or to get out of the vicinity to the missed approach hold fix, etc.

Now, what folks sometimes discuss is that some of the cloud clearance distances for VFR may not be of too much value for someone flying IFR and popping out of the clouds at just the wrong place.

That separation may depend heavily on probability and statistics.

[MCM]

In Class G airspace you don't require an ATC clearance, but will ask for traffic information, as well as arrange your own separation. A lot of it is "self separation" over the radio.

So say I'm flying from point L to point P. Both are uncontrolled aerodromes within Class G airspace, and there is only Class G between them.

Before you depart aerodrome L, you will make broadcasts on the aerodrome frequency, telling people where you are going. Any other aircraft within the area should reply, particularly if there is a conflict. You will also advise ATC on the radio what you are doing. They will pass traffic information on known flights (which should be all IFR). You won't get told about VFR flights if they don't know about them - but thats where see and avoid comes in. Enroute, you'll be told about other IFR aircraft that may be a threat. The ATC won't separate you, thats not their job, but they'll pass information. Invariably there will be no conflict at cruising levels, or someone will adjust theirs.

At the other end, P, pilots will be told about aircraft known to be operating in the aerodrome area, and will make broadcasts advising that you are arriving, when other aircraft will similarly report their positions.

So, basically, it is self separation between the pilots, with ATC chipping in information about who you should be self separating from.

If the aerodrome is controlled, then it works like 3WE has said - its just procedural separation based on time or lateral distance.

[Gabriel]

Thanks for the replay MCM. I guess there will be some "extreme" cases where ATC is not even available or reachable.

Last two questions:

Is the procedure that you describe above "required"? (I mean, it makes a lot of sense and I don't see why somebody would not comply with it, but still).
Is a comm radio a required equipment for IFR period? Even in class G airspace?

I guess the answer to the above is "yes". But I am asking because the procedures you mention above look similar to the "good practices" when operating VMC in uncontrolled airspace and non-controlled fields, however reporting your position is not required, and even a radio is not required to begin with. Of course, "see and avoid" IS required in VMC (even if flying IFR in controlled airspace), and not required or even possible in IMC.

[3WE]

...Is a comm radio a required equipment for IFR period?...

It may not be an absolute requirement.

For practical purposes, you can't neccesarily call the center when sitting on the ground at an outlying, uncontrolled airport.

So, you call them on the telephone, file a flight plan, take off on time and start flying with no radio (and I guess no transponder) contact.

("Start" and "Contact" are critical words because generally you will report in as soon as reasonable after you get high enough for radio reception).

So...the next question...could you file an IFR flight plan from one place to another where you will be out of radio range? I dunno- sounds tough...I believe you need to have official clearance to do the approach at your destination and I'm not sure they will offer that to you over a land-line telephone.

...and all of this has the final twist if ITS needs to move his transponderless, radioless cub from Sweet Monkey River to Waco Texas, can he get special permission to do so under IFR and be compliant with some sub chapter of the FAR's that only Flyboy5234M can recite?

[atc_av8er]

The issue is that you generally don't go flying in the clouds with zero visibility while sqawking VFR.

If you are flying in the clouds with zero visibility you need to be doing something special to not crash into another plane flying in the coulds with zero visibility.

Now, I'm sure there's ways that can be done without radar, sqawking and talking to ATC...but that is sort of the first choice if at all possible.

And, the interesting ironing, is that you- as a controller- don't really know if the plane is in the clouds or not.

Yes you are absolutely correct. There have been times where I can't see the aircraft on 5 mile final, but he can see the field, and vice versa. I was speculating and if I had to pick any of the options I proposed, I am almost willing to bet that the pilot had personal knowledge of the area, probably knew enough where he could determine when he could proceed visually, and informed Center he was in VMC, then completed the flight from there. Without seeing the radar feed or hearing the voice recordings, that is, unfortunately, the best I can do.

[3WE]

I am almost willing to bet that the pilot had personal knowledge of the area, probably knew enough where he could determine when he could proceed visually, and informed Center he was in VMC, then completed the flight from there.

PR is a small, mountanous island. There was ~80 cover of towering cumulus. I didn't have to be super familiar with the area- but with breif glimpses of the Southern flank of the mountans, 'flatter ground' below and the ocean ahead it was clear that with flying straight ahead with a reaonsable descent would eventually place us safely under the clouds where we could land "VFR-style".

...that being said, I still have a legal concern and the slight paranoia of the one in a zillion chance of another plane being out in the clouds- not out to report anything to authorities...but fodder for the fora.