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CFI Practical Test Standards: Technical Subject Areas

AC 90-48E – Pilots' Role in Collision Avoidance

This AC is issued to assist pilots with their regulatory obligation to see and avoid other aircraft. Specifically, this AC looks to alert pilots to human contributors to midair collisions and near midair collisions (NMAC), and recommend improvements to pilot education, operating practices, procedures, and improved scanning techniques to reduce midair conflicts. This AC is not mandatory and does not constitute a regulation. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way, and the document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.

This AC is intended to provide guidance to certificated pilots, flight instructors, student pilots, training providers, and pilot examiners to mitigate the risk of a midair collision or NMAC during flight operations.

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For Visual Scanning and Collision Avoidance, AC AC 90-48 is the key text to bring to the oral exam. Proper scanning technique also is discussed in Chapter 1 of the Pilots Handbook of Aeronautical Knowledge (for some reason, the FAA front-loads this content in a chapter that's otherwise introductory.)

AC 90-48 notes that "efficient use of visual techniques and knowledge of the eye's limitations will help pilots avoid collisions."

The AC includes a helpful table describing different kinds of reaction times in seconds.

Typical mid-air collision scenarios are explained, including:

  • Approaching Head-On (During Cruise Flight)
  • Overtaking (During Cruise Flight)
  • Landing at Non-Towered Airports
  • Landing at Towered Airports
  • Avoiding Collisions With Unmanned Aircraft Systems (UAS)

The AC also cautions against maneuvering flight and formation flight.

Effective scanning is reviewed, as well as night operations.

Section 17.2, "Flight Instructor and Safety Pilot Responsibilities," should be emphasized during the oral exam. Flight instructors and persons acting as safety pilots can contribute to reducing the risk of aircraft collisions by:

  • Guarding against preoccupation during flight instruction to the exclusion of maintaining a constant vigilance for other traffic.
  • Being particularly alert during the use of advanced flight deck/cockpit technology and the conduct of simulated instrument flight, where there is a tendency to "look inside" excessively and forget see-and-avoid responsibilities.
  • Taking the time to teach new and advanced flight deck/cockpit technology on the ground. Thoroughly review features as well as limitations of the equipment and the pitfalls of fixation and overreliance on technology.
  • Placing special training emphasis on those basic problem areas of concern mentioned in this AC. Improvements in pilot education, operating practices, conflicts, procedures, and techniques are needed to reduce midair conflicts.
  • Student pilots communicating at towered or non-towered airports. Student pilots are advised to inform ATC at a towered airport, and at a non-towered airport announce over the CTAF that they are a student pilot solo.

And take note of 17.3: "Pilot Examiner and Certificated Flight Instructor (CFI) Actions. Pilot examiners and CFIs play an integral role in ensuring pilots have the collision avoidance skills necessary to satisfy their regulatory see-and-avoid obligations. For example, the Private Pilot–Airplane Airman Certification Standards (FAA-S-ACS-6), Appendix 6, Safety of Flight, requires that the evaluator assess an applicant's use of visual scanning and collision avoidance procedures throughout the entire test. Other FAA guidance also encourages CFIs to train and assess an applicant or certificated pilot's knowledge and skill in their use of visual scanning and collision avoidance techniques."

Practical Test Standards: Flight Instructor

II. Technical Subject Areas
Task C: Visual Scanning and Collision Avoidance


  1. AC 90-48
  2. Aeronautical Information Manual (AIM)
  3. Airplane Flying Handbook (FAA-H-8083-3)
  4. Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25)

Objective: To determine that the applicant exhibits instructional knowledge of the elements of visual scanning and collision avoidance by describing:

  1. Relationship between a pilot's physical condition and vision.
  2. Environmental conditions that degrade vision.
  3. Vestibular and visual illusions.
  4. "See and avoid" concept.
  5. Proper visual scanning procedure.
  6. Relationship between poor visual scanning habits and increased collision risk.
  7. Proper clearing procedures.
  8. Importance of knowing aircraft blind spots. Relationship between aircraft speed differential and collision risk.
  9. Situations that involve the greatest collision risk.

Flight Instructor Test Questions

Which technique should a student be taught to scan for traffic to the right and left during straight-and-level flight? Systematically focus on different segments of the sky for short intervals.

What is an effective way to prevent a collision in the traffic pattern? Maintain the proper traffic pattern altitude and continually scan the area.

Most midair collisions occur during clear days.

Oral Exam Questions

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Robert Wederquist   CP-ASEL - AGI - IGI
Commercial Pilot • Instrument Pilot
Advanced Ground Instructor • Instrument Ground Instructor

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