Vectoring to Join Glidepath/Glideslope

mwoyno55

Senior Member
Jan 7, 2010
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According to the 7110.65 5-9-1c, I have to vector an aircraft to intercept the final approach course for a precision approach at an altitude not above the glideslope/glidepath.

Setup the example, KAUS ILS RWY35L.

If I am vectoring an aircraft to join the final approach course in between LAMAS (at or above 5000') and CAMDY (at or above 4400'):

A. Can I still issue 5000' until established.
B. I now have to issue 4400' until established.

Do step down altitudes provide guidelines for glideslope/glidepath altitudes? I have researched and understand that a plane may capture the glideslope/glidepath many miles from the field, but a pilot still needs to comply with step down altitudes.

Take it a step further. I am vectoring an aircraft to join the final approach course inside of JOVSA. What would be the highest altitude that can be issued when intercepting?

Interested to see the responses.
 

Stinger

Epic Member
May 24, 2009
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Depends where at between LAMAS and CAMDY. Standard glideslope is about 300ft/mile. CAMDY at 4400 is on the glideslope if you work the math at 300'/mile from FUNNN. LAMAS to CAMDY is 4 miles...so 1200 feet. Glideslope altitude at LAMAS would be 5600. If you're intercepting no closer than 2 miles from CAMDY, your 5000 feet is going to be at or below the glideslope.

The stepdown altitudes are for LOC approaches, where once you pass one fix, you drop down to the next altitude. On an ILS, the stepdown altitudes are reference points so you can ensure everything is matching up as you follow the glideslope.

Vectoring to intercept inside of JOVSA, which is 1.7 miles from the FAF at FUNNN is going to need extremely precise vectors and a ceiling no lower than 500' above the MVA or asking the pilot and getting concurrence (in which case you can intercept right at the FAF.) Assuming you don't ask the pilot and you have good weather, you can vector to intercept at the approach gate (1 mile from the FAF), which would have you intercept .7 miles inside of JOVSA, and the glideslope altitude will be at 1900. The Austin MVA in that area is 2000. Which causes a problem when you're trying to vector inside of JOVSA at glideslope altitude. If you're vectoring at the MVA of 2000 you can't intercept closer than .4 miles inside of JOVSA and remain below the glideslope.
 
Last edited:

atcbrownie

Trusted Contributor
Jun 14, 2008
661
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Warrenton Va
A. Yes you can still use 5000 between LAMAS and CAMDY provided that you are not above glidpath.

B. Yes you can issue 4400 between LAMAS and CAMDY provided you are not below the mva.

The glideslope in this case is 3 degrees which is roughly 300 feet per mile. The lightning bolt by 1600 at FUNNN indicates glideslope intercept so do the math backwards.

For JOVSA the highest altitude that could be assigned would be dependent on how far inside JOVSA you are vectoring. But not higher than 2100. Remember 300 feet per mile so one mile inside JOVSA would be 1800 roughly.
 

mad1dizzle

Rookie
Jun 18, 2009
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I usually try to stick with numbers I know for sure. Since I I know what the minimum intercept altitude is I try to get close to the altitude as possible taking into consideration the MVA's. In your case 1600' is the minimum intercept altitude depicted by the lightning bolt. The aircraft doesn't start deciding on the glideslope until the FAF which is FUNNN. All the altitudes prior to that are to be adhered to by the pilot only if you clear them prior and or higher than those altitudes.