Welcome Guest. Sign in or Signup

2 Answers

Approach Categories

Asked by: 11960 views Airspace, FAA Regulations

I understand how the approach categories are computed (1.3  x Vs0)and understand the logic for the higher mins. as you move to higher categories for circling approaches but I would like more clarity for straight in approaches.

Assume straight in approach and assume a airplane is Cat. A ( using 1.3 Vso ) and I have elected to land straight in with a tailwind (although typically I would not approach or land with a tailwind) .My usual IAP speed is 85 KIAS.  The tailwind puts my ground speed at 95 knots yet my indicated is 85 knots. Based upon the categories,  95 knots ground speed puts me in category B but 85 KIAS puts me in category A.  Assume the IAP has higher mins. for Cat. B.

QUESTION: Do I use Cat. A or Cat. B mins?

Thank you for the feedback.

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. John D Collins on Jan 03, 2014

    The definition of approach categories can be found in 97.3:

    “As used in the standard instrument procedures prescribed in this part– Aircraft approach category means a grouping of aircraft based on a speed of VREF, if specified, or if VREF is not specified, 1.3 Vso at the maximum certificated landing weight. VREF, Vso, and the maximum certificated landing weight are those values as established for the aircraft by the certification authority of the country of registry. The categories are as follows–
    (1) Category A: Speed less than 91 knots.
    (2) Category B: Speed 91 knots or more but less than 121 knots.
    (3) Category C: Speed 121 knots or more but less than 141 knots.
    (4) Category D: Speed 141 knots or more but less than 166 knots.
    (5) Category E: Speed 166 knots or more”

    At VSo there is typically a significant difference between CAS and IAS, whereas at approach speeds these values are much closer together. 1.3 VSo is a calibrated airspeed that should be converted to an equivalent indicated airspeed.

    The category speeds are IAS/CAS and do not take winds into consideration. An aircraft is only in one category, but if operated at an IAS/CAS of a higher category, must use the minimums associated with the IAS/CAS of the higher category. You can read this in the Terminal Procedures Legend information.

    So to answer your question, if you use an approach speed of 85 Knots and the aircraft is a category A aircraft, then a GS of 95 knots does not change which category of approach minimums you are required to use, category A is still applicable. On the other hand if you are flying a category A aircraft and have a 10 knot headwind, but are flying the approach at an IAS of 95 Knots and therefore have an 85 Knot GS, you must use the category B approach minimums.

    +5 Votes Thumb up 5 Votes Thumb down 0 Votes



  2. Dan Chitty on Jan 04, 2014

    Thank you John for the feedback.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


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.