Author Topic: Glideslope unuseable  (Read 10898 times)

Offline mk223

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Glideslope unuseable
« on: February 23, 2006, 10:27:51 AM »
When i was listening to KLAX yesterday, i heard Glideslope unuseable for about 15 or so minutes. What does this mean exactly, as i thought you always need to the glideslope to land.



Offline dave

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Glideslope unuseable
« Reply #1 on: February 23, 2006, 10:40:20 AM »
Glideslope unusable means that the glideslope is either out of calibration or out of service.

An ILS approach usually reverts to a localizer only approach, with typically higher minimums.  "Minimums" refer the lowest altitude an aircraft can descend to on the approach.  They must get the runway (or runway approach lighting system) in sight before landing, otherwise they must execute a missed approach at the missed approach point.

Dave

Offline tedbyrne

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glideslope
« Reply #2 on: February 23, 2006, 10:47:58 AM »
Dave, you took the words out of my mouth! (or keyboard as the case might be)  Here's what I wrote:

It means the glideslope component of the ILS is out of service, so the approach must be flown with only the localizer.  This type of approach would more closely approximate a VOR approach, with the exception of the sensitivity of the localizer, which is 4 times more sensitive than a VOR.

Also, generally the decision height or minimum descent altitude is raised - without a glideslope indication, the approach will terminate higher above the ground, considering a localizer approach is not a precision approach, whereas an ILS is.

Here's a link to an explanation of an ILS:

http://en.wikipedia.org/wiki/Instrument_Landing_System

Offline mk223

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Glideslope unuseable
« Reply #3 on: February 23, 2006, 01:14:38 PM »
Thanks

Offline n57flyguy

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Glideslope unuseable
« Reply #4 on: February 23, 2006, 05:26:28 PM »
wow, I never knew any of that! I read the whole wikapedia explanation and it was kind of confusing, although I "flew" two ILSs into JFK in a simulator, some key things the pilot told me really stuck out in that explanation. Thanks guys.

Offline PHL Approach

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Glideslope unuseable
« Reply #5 on: February 23, 2006, 06:07:42 PM »
I remember back in the summer, M98 (Minneapolis Tracon) was issuing "Glideslope unuseable" for 30R approach clearances. They did that for about 2-3 months and there was a Notam out during the time.

Offline n57flyguy

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Glideslope unuseable
« Reply #6 on: February 23, 2006, 06:18:00 PM »
um....another stupid question. whats a NOTAM???

Offline Jason

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Glideslope unuseable
« Reply #7 on: February 23, 2006, 06:21:41 PM »
Quote from: n57flyguy
um....another stupid question. whats a NOTAM???


Quote from: Pilot/Controller Glossary
NOTAM-

(See NOTICE TO AIRMEN.)

NOTAM [ICAO]- A notice containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations.

a. I Distribution- Distribution by means of telecommunication.

b. II Distribution- Distribution by means other than telecommunications.

NOTICE TO AIRMEN- A notice containing information (not known sufficiently in advance to publicize by other means) concerning the establishment, condition, or change in any component (facility, service, or procedure of, or hazard in the National Airspace System) the timely knowledge of which is essential to personnel concerned with flight operations.

a. NOTAM(D)- A NOTAM given (in addition to local dissemination) distant dissemination beyond the area of responsibility of the Flight Service Station. These NOTAMs will be stored and available until canceled.

b. NOTAM(L)- A NOTAM given local dissemination by voice and other means, such as telautograph and telephone, to satisfy local user requirements.

c. FDC NOTAM- A NOTAM regulatory in nature, transmitted by USNOF and given system wide dissemination.


The Pilot/Controller glossary is but a click away....

Pilots are required to and should check NOTAMs applicable to their intentions and intended route of flight under FAR §91.103: "Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight."

Jason

Offline KMSY

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Glideslope unuseable
« Reply #8 on: February 23, 2006, 07:32:55 PM »
The 28 g/s at MSY has been out since Katrina. Been watching out my window alot recently with the "noculars" and seeing alot of iffy approaches.

Offline w0x0f

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Glideslope unuseable
« Reply #9 on: February 23, 2006, 07:36:35 PM »
You'll notice that the controller will still issue the clearance by saying "Cleared ILS Rwy XX approach, glide slope unusable."  Controllers are often asked why they just don't clear the pilot for the localizer approach.  The reason for that is there is no published localizer approach.  There is an ILS appraoch showing the higher minimums for localizer only.  This eliminates the confusion of a pilot looking through his charts or database for the localizer approach and not finding it.  And yes, it's a pain in the rear to have to say "Glide slope unusable" on initial contact and during the approach clearance to every aircraft.

w0x0f

Offline n57flyguy

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Glideslope unuseable
« Reply #10 on: February 24, 2006, 10:01:02 AM »
Quote from: Jason
Quote from: n57flyguy
um....another stupid question. whats a NOTAM???


Quote from: Pilot/Controller Glossary
NOTAM-

(See NOTICE TO AIRMEN.)

NOTAM [ICAO]- A notice containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations.

a. I Distribution- Distribution by means of telecommunication.

b. II Distribution- Distribution by means other than telecommunications.

NOTICE TO AIRMEN- A notice containing information (not known sufficiently in advance to publicize by other means) concerning the establishment, condition, or change in any component (facility, service, or procedure of, or hazard in the National Airspace System) the timely knowledge of which is essential to personnel concerned with flight operations.

a. NOTAM(D)- A NOTAM given (in addition to local dissemination) distant dissemination beyond the area of responsibility of the Flight Service Station. These NOTAMs will be stored and available until canceled.

b. NOTAM(L)- A NOTAM given local dissemination by voice and other means, such as telautograph and telephone, to satisfy local user requirements.

c. FDC NOTAM- A NOTAM regulatory in nature, transmitted by USNOF and given system wide dissemination.


The Pilot/Controller glossary is but a click away....

Pilots are required to and should check NOTAMs applicable to their intentions and intended route of flight under FAR §91.103: "Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight."

Jason


Thanks Jason, You're always there for me!!! :D

Offline Jason

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Glideslope unuseable
« Reply #11 on: February 24, 2006, 03:53:19 PM »
Quote from: n57flyguy
Thanks Jason, You're always there for me!!! :D


...and so are the other thousands of resources on the web (including the FAAO 7110.65R and the P/C Glossary).

No problem, but please bookmark the links I provide so you can turn back to them and find out yourself.  :lol:  :wink:

Jason