Lost comm -- what would you do?

Michael wrote: I find it just a
bit surprising you got that clearance in the first place - around
here, short IFR legs in the close vicinity of a class B are almost
always by RADAR vectors.

Yes, it's pretty typical. Sometimes you get cleared "radar vectors
direct", but much more often you get something like what I got. In
fact, this particular clearance is common enough that I use as an
exercise for people learning our GPS. Something like "CMK CMK275R
intercept SAX039R SAX" is one of the few things that's actually easier
to execute with dual VORs than with a GPS.

I agree with you that if you lost comm right off the ground, direct
CMK then as cleared would make sense. The more interesting scenario
is what happens if you check in with Departure (as we did) and he just
leaves you on the SID heading with no further instructions for a
while. At some point, you're 5 miles from SAX and 30 miles from CMK,
and it obviously doesn't make any sense to double back any more. It's
unclear where the dividing line is between those two extremes.

I don't think there's any right answer to this, it's just an
interesting exercise in PIC decision making ability to figure out what
the right thing to do is.

Roy Smith wrote:

I don't think there's any right answer to this, it's just an
interesting exercise in PIC decision making ability to figure out what
the right thing to do is.

At least you've a fix towards which you can fly. A common clearance out of
CDW towards the west is "180 vectors Lanna V30...". This is even given to
aircraft /U...which would find it tough to fly direct to Lanna.

In practice, we'd fly "SBJ Lanna..." but I still find it an odd clearance.
In fact, I'd go so far as to call it one of my pet peeves regarding
routing.

Similarly odd is a clearance like "STW direct KCDW" or "COATE direct KCDW".
Neither STW nor COATE are initial approach fixs, so what should be done?
In RADAR and COMM, one is vectored to final. But in a communication
failure? Fly to SAX (which is an IAF for CDW's LOC22)?

[Assuming IMC, of course.]

- Andrew

At some point, you're 5 miles from SAX and 30 miles from CMK,
and it obviously doesn't make any sense to double back any more.

I'm not sure it ever made sense to double back to CMK. That's not
really the point. The regulation is clear - your next fix is CMK. I'm
not saying that going to CMK is the right thing to do, especially if
you are 5 miles from SAX - merely that it's what the regulation calls
for. Sometimes the regulation is just wrong.

I don't think there's any right answer to this, it's just an
interesting exercise in PIC decision making ability to figure out what
the right thing to do is.

Well, I sort of agree. There really isn't one exact right answer, but
there are reasonable answers and unreasonable ones. One of those
unresonable answers involves actually following the rules when you're 5
miles from SAX. Part of PIC decision making in the real world is
knowing when to bend the rules in a non-emergency situation, and
knowing what you can get away with.

If you talk to an actual practicing center or approach controller, he
will tell you that in the event of lost comm, the best thing for
everyone is for you to get on the ground by the most expeditious route,
since they can't count on you doing anything in particular (more likely
than not your lost comm is associated with a more serious emergency)
and are going to sterilize the airspace around you anyway. In the age
of RADAR capable of seeing primary targets, that's the sensible course
of action. 91.185 hasn't kept pace. It doesn't need to. Lost comm
due to equipment failure is a rare event these days, and lost comm due
to equipment failure not associated with another emergency in IMC has
got to be so rare it's not worth the effort of rewriting the rules. We
torment our instrument students with the minutiae of lost comm rules,
but in reality that's strictly a checkride exercise.

So forget about following the letter of the rules - do something
sensible. Remember - no action is foolproof. A fed who wants to get
you will get you. One who isn't after your hide will accept that you
did something reasonable. Backtracking 40 miles and tying up the
system with your NORDO self for an extra 45 minutes isn't reasonable,
even if that's what the rule calls for (and clearly it does).

Let's say you're changing radios on your audio panel, and due to crappy
soldering and decades of vibration, the switch comes off in your hand.
Everything else still works, but with no audio panel you can't use
either comm. No real emergency - the fan is still turning, the juice
is still flowing, and the nav is still pointing.

If you've established comm with ATC, climbed to your final altitude,
and were left on your DP heading, there's very little chance the
controller had any intention of ever sending you back to CMK. He's
either going to send you direct by RADAR vectors, or have you join the
route somewhere in the middle (or reroute you). I would suggest that a
reasonable thing to do is look at your position relative to your
cleared route, and draw a reasonable intercept course from your present
position to your route. We generally consider 30 degrees to be a
reasonable intercept. If you can make that work, that's what makes
sense. If you're too close to SAX to make that work, you need to go
direct SAX. That's how the controller would put you back on the route
if he had to (due to transponder problems, for example) and that's what
you ought to do.

However, if there's a flight restriction area that prompted the
circuitous clearance, be damn sure your course for getting back on the
cleared route avoids it. If the only way you can assure this is by
backtracking to CMK, well, that's what you do.

It's not an exact right answer, but it does give you some reasonable
guidance on what to do. It's what makes sense in the real world. It
may not play so well on an IFR oral.

Michael