Welcome Guest. Sign in or Signup

1 Answers

ILS Y vs. ILS Z

Asked by: 14020 views , , , ,
Commercial Pilot, Flight Instructor, Instrument Rating

What is the main difference between a ILS Y vs. a ILS Z ?  I know there are differences but what's the biggest difference?

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

1 Answers



  1. John D Collins on Mar 24, 2019

    In most cases, the difference is the method for joining the approach. For example at my airport KUZA, Rock Hill, SC, there is an ILS Y or LOC Y RWY 2 which uses a TAA and GPS to join the approach and fly the missed approach. The ILS Z or LOC Z RWY 2 approach uses conventional ground based Navaids of VOR and DME for that purpose and has an MSA. Anytime the same navigation facility is used for the final approach, but there are multiple versions for whatever reason, an index letter starting at Z, Y, X .. is used to name the variations. There are other reasons than the one cited above, for example, the DA might be lower on one version, but require a higher than standard climb rate on the missed approach than the 200 ft/NM. You should be able to inspect the variations and choose the one that best fits your mission and the aircraft’s equipment and performance capabilities.

    +7 Votes Thumb up 7 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.