Clear to intercept localizer

I want out to play last week. I requested clearance from EMT to RAL
for ILS to rwy 9. Shortly after I was level at 4000, I was cleared to
intercept localizer. As I tracked localizer, the glideslope started
down and I started down with it. At 3,700, ATC called to ask me to
remain 4000. I climbed back to 4000 and about 30 seconds later, was
cleared to decent.

I did not think about it at the time, but does clear to intercept
localizer mean I cannot decent until I am clear to decent? BTW, the
glideslope was functioning.

" wrote:
I want out to play last week. I requested clearance from EMT to RAL
for ILS to rwy 9. Shortly after I was level at 4000, I was cleared to
intercept localizer. As I tracked localizer, the glideslope started
down and I started down with it. At 3,700, ATC called to ask me to
remain 4000. I climbed back to 4000 and about 30 seconds later, was
cleared to decent.

I did not think about it at the time, but does clear to intercept
localizer mean I cannot decent until I am clear to decent? BTW, the
glideslope was functioning.

An approach clearance lets you descend to the altitudes published on the
approach plate. A clearance to intercept the localizer is not an approach
clearance, so you can't descend yet.

That being said, it's strange that you would get to GS Intercept and not be
cleared for the approach yet. As I noticed the GS starting to come off the
top peg, I would have asked the controller if I was cleared approach yet.
If not (or I didn't get a response), I would continue to track the
localizer at my last assigned altitude.

If, as you said, you were not cleared to descend until more than 30 seconds
past GS intercept, I would have refused the approach clearance and
requested vectors back around for another try. Divebombing to intercept
the GS from above is not a good plan.

"Roy Smith" wrote in message
...
If, as you said, you were not cleared to descend until more than 30
seconds
past GS intercept, I would have refused the approach clearance and
requested vectors back around for another try. Divebombing to intercept
the GS from above is not a good plan.

Definitely. Just as excessive descent rates are not something you want in
real IMC (gently does it), the whole point of intercepting a glideslope from
below is to be sure you're following the real one, not a phantom one induced
by the oddities of radio-based navaids.

D.

David Cartwright wrote:



Definitely. Just as excessive descent rates are not something you want in
real IMC (gently does it), the whole point of intercepting a glideslope from
below is to be sure you're following the real one, not a phantom one induced
by the oddities of radio-based navaids.


ATC is required to put you in a position to intercept the glideslope
from below.

"Newps" wrote in message
...
ATC is required to put you in a position to intercept the glideslope from
below.

By a strange coincidence, I was reading a recent CHIRP publication this
morning, and this very subject came up. The response, if I'm understanding
it correctly, is a little concerning - it implies that there are places
where a glideslope intercept from above is regarded as normal.

The text of the report is reproduced here.

********
Report Text
On several occasions at AAA (UK major airport), I have been vectored to the
ILS, on both the easterly and westerly runways, such that the aircraft is
above the glidepath at localiser intercept.

I have discovered that this is not an unknown occurrence; colleagues within
my Company and from other airlines have suffered similar problems. I
understand that representations have been made to the Duty Supervisor, but
the practice continues sporadically.

As far as I am aware, no aircraft are equipped to intercept the glidepath
automatically from above.

My next course of action will be an MOR, but CHIRP might just highlight the
issue such that an MOR is unnecessary.

CHIRP Comment
It is sometimes the case that height restrictions associated with airspace
structure or particular traffic conditions can result in intercepting the
localiser above the glidepath.

Also, the use of Continuous Descent Approaches (CDAs), required by the
Department for Transport for environmental reasons at some UK airports, is
also considered to be 'best practice' at other locations for the reduction
of noise, nuisance and emissions (UKAIP ENR 1-1-3-1 Para 2.3.1 refers).

One of the principal objectives of CDAs is for an aircraft to join the
glidepath without recourse to level flight. Where the use of CDAs are
promulgated in the appropriate AIP AD2 Section, the detailed procedure
permits the pilot to descend at a rate he judges will be best suited to the
achievement of continuous descent and thus avoid the problem described in
this report. However, no standard RTF phraseology currently exists to cover
CDA procedures and it is not clear that pilots are always aware when a CDA
procedure is being conducted. In view of the important environmental
contribution of CDAs; it would be perhaps appropriate to review this
particular aspect.

If you are positioned significantly above the glidepath at localiser
intercept, submit an MOR to permit the reasons to be investigated.

*****

Regards,

David C

"David Cartwright" wrote in message
...

By a strange coincidence, I was reading a recent CHIRP publication this
morning, and this very subject came up. The response, if I'm understanding
it correctly, is a little concerning - it implies that there are places
where a glideslope intercept from above is regarded as normal.


What is CHIRP? In the US, ATC is required to vector aircraft to intercept
the localizer at an altitude not above the glideslope or below the minimum
glideslope intercept altitude specified on the SIAP.

"David Cartwright" wrote in message =
...
=20
=20
As far as I am aware, no aircraft are equipped to intercept the =
glidepath=20
automatically from above.
=20
David C


It strains my FAA-trained imagination even to call that a "glidepath =
intercept".

wrote in message
oups.com...

I want out to play last week. I requested clearance from EMT to RAL
for ILS to rwy 9. Shortly after I was level at 4000, I was cleared to
intercept localizer. As I tracked localizer, the glideslope started
down and I started down with it. At 3,700, ATC called to ask me to
remain 4000. I climbed back to 4000 and about 30 seconds later, was
cleared to decent.

I did not think about it at the time, but does clear to intercept
localizer mean I cannot decent until I am clear to decent? BTW, the
glideslope was functioning.


An instruction to intercept the localizer means intercept the localizer and
nothing more. You cannot descend until you receive either an approach or
descent clearance.

On 2 Oct 2005 17:17:13 -0700, "
wrote:

I want out to play last week. I requested clearance from EMT to RAL
for ILS to rwy 9. Shortly after I was level at 4000, I was cleared to
intercept localizer. As I tracked localizer, the glideslope started
down and I started down with it. At 3,700, ATC called to ask me to
remain 4000. I climbed back to 4000 and about 30 seconds later, was
cleared to decent.

I did not think about it at the time, but does clear to intercept
localizer mean I cannot decent until I am clear to decent? BTW, the
glideslope was functioning.

Once you have an approach clearance, you can descend to the altitudes
shown on the chart.

However...

It is very common for the controller to give you a vector to the
localizer and an altitude restriction until you are established on the
localizer. Typically, this would be something like: "N123, fly 130
to intercept localizer, maintain 4000 until established, cleared ILS 9
@ RAL."

Perhaps that happened, and you just missed the altitude restriction?

-Nathan

On 10/3/2005 06:16, Nathan Young wrote:

On 2 Oct 2005 17:17:13 -0700, "
wrote:

I want out to play last week. I requested clearance from EMT to RAL
for ILS to rwy 9. Shortly after I was level at 4000, I was cleared to
intercept localizer. As I tracked localizer, the glideslope started
down and I started down with it. At 3,700, ATC called to ask me to
remain 4000. I climbed back to 4000 and about 30 seconds later, was
cleared to decent.

I did not think about it at the time, but does clear to intercept
localizer mean I cannot decent until I am clear to decent? BTW, the
glideslope was functioning.

Once you have an approach clearance, you can descend to the altitudes
shown on the chart.

However...

It is very common for the controller to give you a vector to the
localizer and an altitude restriction until you are established on the
localizer. Typically, this would be something like: "N123, fly 130
to intercept localizer, maintain 4000 until established, cleared ILS 9
@ RAL."

Perhaps that happened, and you just missed the altitude restriction?

No... he said that he was established on the localizer and was still
told not to descend. It sounds like, as he said, he had not received
an approach clearance yet.

I remember two or three times during my IFR training when I was
established on the FAC but had not received my approach clearance
and had to ask for it.




-Nathan



--
Mark Hansen, PP-ASEL, Instrument Airplane
Sacramento, CA