Welcome Guest. Sign in or Signup

2 Answers

Why is not required to check for RAIM with a WAAS GPS?

Asked by: 1944 views Instrument Rating

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.

2 Answers



  1. Bryan on Jun 08, 2022

    John Collins gave a great answer to this in March 2020: https://www.askacfi.com/34817/lose-raim-but-we-have-waas-can-you-shoot-the-gps-approach.htm

    In short, the two systems monitor integrity differently. Checking RAIM tells you nothing about WAAS integrity and vice-versa.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  2. John D Collins on Jun 09, 2022

    The WAAS signal includes the integrity information. The standard GPS signal does not include the integrity information, so RAIM is an algorithm that uses additional satellites to determine integrity of the position. Integrity is a measure of the trustworthiness of the position.

    0 Votes Thumb up 0 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.