U.
S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: General Aviation Controlled Flight Into Terrain Awareness Date: 4/1/03 AC No: 61-134 Initiated by: AFS-800 Change:
1. PURPOSE OF THIS ADVISORY CIRCULAR (AC). This AC highlights the inherent risk that controlled flight into terrain (CFIT) poses for general aviation (GA) pilots. This AC includes the Federal Aviation Administration’s (FAA) common definition of the term CFIT; identifies some, but not all, of the risks associated with GA CFIT accidents; and provides some recommendations and strategies to combat CFIT within the GA community. This AC is not an all-inclusive document on CFIT; rather, this AC is designed to help flight instructors, FAA Aviation Safety Program Managers, and other trainers develop CFIT training materials by identifying some of the factors involved in GA CFIT accidents. Some common references are included to aid instructors in preparing CFIT presentations. Pilots can benefit from reading this AC to check their own knowledge of CFIT and factors involved to avoid having a GA CFIT accident. This AC will break the study of GA CFIT into three broad categories. One will focus on visual flight rules (VFR) pilots without an instrument rating operating in marginal VFR weather conditions (visual meteorological conditions (VMC)) or instrument flight rules (IFR) weather conditions (instrument meteorological conditions (IMC)) commonly known as scud running. The second category will focus on GA IFR operations in IMC conditions on an IFR flight. The third category will focus on low-flying aircraft operating in VFR conditions. This AC does not address CFIT in Title 14 of the Code of Federal Regulations (14 CFR) part 121 or part 135 operations. 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. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.
2. BACKGROUND.
a. According to FAA information, GA CFIT accidents account for 17 percent of all GA fatalities. More than half of these CFIT accidents occurred during IMC. The FAA is working in partnership with industry to develop an action plan and revise guidance material to reduce the incidence of CFIT within the GA segment of aviation. However, one of the problems in reviewing GA CFIT accidents is the lack of data, particularly human factors data. Since many of the pilots involved in GA CFIT accidents are fatalities and most GA aircraft are not equipped with data recording systems, the lack of GA CFIT accident data will continue to remain a problem for investigators.
b. Although many CFIT accidents have some common factors that are applicable for all types of aircraft, we want to stress the difference between a crewed aircraft with two pilots in the cockpit and a single-pilot aircraft. In crewed cockpits, the second pilot may make the difference between a safe flight and a CFIT accident. Conversely, a second pilot can also be a distraction in certain circumstances unless the crew has been trained to work well together and is following
Par 2 Page 2 good crew resource management (CRM) techniques. As a general rule of thumb, whether an air carrier type aircraft or a GA aircraft, the crewed aircraft is generally better equipped with more safety equipment, such as an autopilot, radar altimeter, or ground proximity warning system (GPWS) on board, than a typical single-pilot, small GA aircraft.
c. Because a single-piloted, small GA aircraft is vulnerable to the same CFIT risks as a crewed aircraft but with only one pilot to perform all of the flight and decision-making duties, that pilot must be better prepared to avoid a CFIT type accident. In some cases, a GA pilot may be more at risk to certain CFIT type accidents because the pilot does not have the company management or government oversight that a corporate or commercial operator may be exposed to. Without such oversight, such as detailed standard operating procedures and higher mandatory safety requirements, it is the responsibility of the single pilot to ensure they are well-trained, qualified for the intended flight, meet all regulatory requirements for the flight, and have the self-discipline to follow industry recommended safety procedures that can minimize CFIT type accidents.
3. RELATED 14 CFR REFERENCES.
a. Part 91, §§ 91.103, 91.119, 91.121, 91.123, 91.155, 91.175, 91.177, 91.179, 91.181, and 91.515.
b. Part 97, Standard Instrument Procedures.
4. RELATED PUBLICATIONS.
a. ACs. The current editions of the following ACs are available online at https://www.faa.gov/regulations_policies/advisory_circulars/.
(1) AC 90-105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace.
(2) AC 120-51, Crew Resource Management Training.
b. Manuals and Handbooks. The current editions of the following documents may be obtained online at https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/.
(1) Aeronautical Information Manual (AIM), especially paragraph 7-6-3, Obstructions to Flight.
(2) Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25).
(3) Rotorcraft Flying Handbook (FAA-H-8083-21).
(4) Airplane Flying Handbook (FAA-H-8083-3).
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c. Checklists.
(1) Personal Minimums Checklist, https://www.faa.gov/training_testing/training/fits/guidance/media/personal%20minimums%20ch ecklist.pdf.
(2) Flight Safety Foundation, CFIT Checklist, Appendix 1, and https://flightsafety.org/wp-content/uploads/2016/09/cfit_check.pdf. To order a laminated copy, send a written request to The Director of Programs, Flight Safety Foundation, 701 N. Fairfax Street, Suite 250, Alexandria, VA 22314-2058. A fillable Microsoft Excel spreadsheet version of this checklist is available at https://flightsafety.org/wp-content/uploads/2016/09/FSF-CFIT- Checklist-Worksheet.xls.
d. Airman Certification Standards and Practical Test Standards. The current versions of these documents are available online at https://www.faa.gov/training_testing/testing/.
e. Controlled Flight Into Terrain Education and Training Aid. Historically, most of the research related to CFIT accidents and the development of recommended safety practices have been done for air carrier type operations. The Controlled Flight Into Terrain Education and Training Aid is a good example of such research done by industry and government. Produced by the Flight Safety Foundation, the International Civil Aviation Organization (ICAO), and the FAA, the aid provides a good history, lists common dangers, and provides some recommended means of combating CFIT accidents for air carrier operations. In addition, the document is a valuable resource for anyone developing a CFIT training course. The document is available online at https://skybrary.aero/sites/default/files/bookshelf/2507.pdf.
5. DEFINITIONS.
a. Controlled Flight Into Terrain (CFIT). CFIT occurs when an airworthy aircraft is flown, under the control of a qualified pilot, into terrain (water or obstacles) with inadequate awareness on the part of the pilot of the impending collision.
b. Loss of Control. Loss of control refers to emergency situations from which a pilot may have been able to recover but did not, such as problems with situation awareness, recovery from wind shear, mishandling of an approach, and recovery from a stall.
c. Situational Awareness. As used in this AC, situational awareness means the pilot is aware of what is happening around the pilot’s aircraft at all times in both the vertical and horizontal plane. This includes the ability to project the near term status and position of the aircraft in relation to other aircraft, terrain, and other potential hazards.
d. Crewed Aircraft. In this AC, crewed aircraft refers to an aircraft or flight operation in which more than one pilot is required by aircraft certification or type of operation.
e. Single-Pilot Aircraft. In this AC, “single-pilot” means only one pilot is required by the aircraft certification. Normally, only one pilot flies such an aircraft.
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6. SCOPE.
a. In VMC, the pilot in command (PIC) is responsible for terrain and obstacle clearance (See and Avoid) whether operating under VFR or IFR. Although this AC addresses the issue of pilots operating under VFR in marginal VMC or IMC conditions, the FAA does not endorse or approve of pilots operating under VFR in IMC. The paragraphs dealing with such operations are only designed to highlight the risks of such operations. The FAA expects pilots to comply with the appropriate flight rules for all flight operations.
b. This AC addresses CFIT operations in the United States only. Flight operations outside of the United States have added risks that can contribute to a CFIT accident. These risks include air traffic control (ATC) instructions from controllers for whom English is a second language or controllers with a limited ATC vocabulary. Other international factors include different types of altimeter settings, terrain elevation, runway data in units other than feet, and a general lack of knowledge with the ICAO standards and country specific operating standards. U.S. pilots planning on operating outside the United States need to carefully review the appropriate international requirements and operating procedures to ensure that an inadvertent mistake or failure to comply with local procedures does not result in a GA CFIT accident.
7. TOP 10 RECOMMENDED INTERVENTION STRATEGIES.
a. The following is a list of 10 safety recommendations from the FAA’s and industry’s Safer Skies: A Focused Safety Agenda, General Aviation Controlled Flight Into Terrain Joint Safety Implementation Team Report, February 2000. The list was derived from 55 ideas the CFIT Joint Safety Analysis Team (JSAT) developed after reviewing 195 GA CFIT accidents from 1993 and 1994. As the report noted, GA includes everything from pilot training, corporate, agricultural and external-load operations, fire-fighting, airborne surveillance, air shows, aircraft maintenance related flights, to personal and recreational flying. Types of aircraft vary from single-place home-builts to helicopters to business jets. GA aircraft also include gliders, balloons, and aerial application aircraft. As the report says, GA is “...basically everything except the military and scheduled air carriers.” Although some of the safety recommendations go beyond the capability of instructors or trainers interested in developing training materials for GA CFIT safety presentations or CFIT lesson plans, they all contain information that will improve CFIT safety in flight on or near airports and obstructions.
b. The CFIT JSAT’s Top 10 Recommended Intervention Strategies.
(1) Increase pilot awareness on accident causes.
(2) Improve safety culture within the aviation community.
(3) Promote development and use of a low cost terrain clearance and/or a look-ahead device.
(4) Improve pilot training (i.e., weather briefing, equipment, decision making, wire and tower avoidance, and human factors).
(5) Improve the quality and substance of weather briefs.
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(6) Enhance the flight review and/or instrument competency check.
(7) Develop and distribute mountain-flying technique advisory material.
(8) Standardize and expand use of markings for towers and wires.
(9) Use high visibility paint and other visibility enhancing features on obstructions.
(10) Eliminate the pressure to complete the flight where continuing may compromise safety.
8. VFR-ONLY PILOTS OPERATING IN MARGINAL VFR/IMC CONDITIONS.
a. Operating in marginal VFR/IMC conditions is more commonly known as scud running.
According to National Transportation Safety Board (NTSB) and FAA data, one of the leading causes of GA accidents is continued VFR flight into IMC. As defined in 14 CFR part 91, ceiling, cloud, or visibility conditions less than that specified for VFR or Special VFR is IMC and IFR apply. However, some pilots, including some with instrument ratings, continue to fly VFR in conditions less than that specified for VFR. The result is often a CFIT accident when the pilot tries to continue flying or maneuvering beneath a lowering ceiling and hits an obstacle or terrain or impacts water. The accident may or may not be a result of a loss of control before the aircraft impacts the obstacle or surface. The importance of complete weather information, understanding the significance of the weather information, and being able to correlate the pilot’s skills and training, aircraft capabilities, and operating environment with an accurate forecast cannot be emphasized enough.
b. Continued flight in reduced visual conditions compounded by night operations and/or overwater flight poses some risks. VFR pilots in reduced visual conditions may develop spatial disorientation and lose control, possibly going into a graveyard spiral or descend to an unsafe altitude while trying to maintain visual contact with the surface. The pilot then impacts terrain, the surface, or an obstacle while trying to maneuver. The following are some of the CFIT risks associated with such flight.
(1) Loss of aircraft control.
(2) Loss of situational awareness.
(3) Reduced reaction time to see and avoid rising terrain or obstacles.
(4) Inability of the pilot to operate the aircraft at its minimum controllable airspeed.
(5) Getting lost or being off the preplanned flightpath and impacting terrain or obstacle.
(6) Reduced pilot reaction time in the event of an aircraft maintenance problem because of a low or lowering altitude.
(7) Failure to adequately understand the weather conditions that resulted in the reduced conditions.
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(8) Breakdown in good aeronautical decision making.
(9) Failure to comply with appropriate regulations.
(10) Failure to comply with minimum safe altitudes.
(11) Increased risk of hitting one of many new low altitude towers installed for cellular telephones and other types of transmissions. This risk is especially great along major highways if VFR pilots try to follow a highway when lost or trying to stay under a lowering ceiling.
(12) Failure to turn around and avoid deteriorating conditions when first able.
9. GA IFR OPERATIONS IN IMC CONDITIONS ON AN IFR FLIGHT. These operations also pose special risks. Whether it is failure to follow safe takeoff and departure techniques, recommended en route procedures ― which includes loss of situational awareness ― or failure to maneuver safely to a landing, IFR operations can be dangerous for those not prepared to operate or not current and proficient in the IMC and IFR environments. Many of these accidents result in fatalities. Techniques or suggestions for avoiding some of these IFR risk factors include:
a. Importance of the PIC being qualified, current, and proficient for the intended flight.
b. Importance of the aircraft being properly equipped for the intended flight.
c. Having the proper charts and approach plates for the intended flight. VFR charts, although not required, should be on board because they can provide important obstacle and terrain data for an IFR flight.
d. Knowing the planned procedure well enough to know if air traffic is issuing an unsafe clearance or if the pilot flying, when a crewed aircraft, is not following the published procedure.
e. If in a crewed aircraft, both pilots have adequately briefed the flight and operation of the aircraft, including shared responsibilities.
f. Having complete weather data for the flight, including knowing where VMC exist or a safe alternative is since many GA aircraft flown IFR have limited range or speed to fly out of unforecasted weather conditions.
g. Importance of maintaining situational awareness, both horizontal and vertical, throughout the flight to avoid flying into hazardous terrain or known obstacles.
h. Complete knowledge on how to operate all equipment on board the aircraft. This includes the limitations and operations of new types of navigation equipment.
i. If a crewed aircraft, the crew is aware of and follows FAA and industry recommended CRM principles. If a single-piloted flight, the pilot knows to use all available resources including ATC to help ensure a safe flight as well as any onboard resource such as passenger or onboard charts or manuals.
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j. PIC follows the rules for making a missed approach and is prepared to make a missed approach when conditions fall below minimums as specified in the regulations, company policy, pilot’s personal minimums checklist, or the approach becomes destabilized.
k. Knowledge of minimum safe or sector altitudes and of the highest terrain in the area.
l. PIC is aware of the risks involved when transitioning from visual to instrument or from instrument to visual procedures on takeoff or landing.
m. PIC uses all available safety equipment installed in the aircraft and on the ground.
n. PIC is aware of the risks involved in setting the aircraft’s altimeter including inherent limitations of barometric altimeters.
o. Knowing the ATC system well enough to be proficient in it.
p. Knowing when not to fly.
q. Properly using an installed autopilot, if so equipped, to reduce pilot workload.
r. Proper use of checklists as outlined in the aircraft manual or if not listed, before reaching 1,000 feet above ground level (AGL) to minimize any distractions when operating close to the ground.
s. The importance of flying a stabilized approach. A common definition of a stabilized approach is maintaining a stable speed, descent rate, vertical flightpath, and configuration throughout the final segment of the approach. Although originally designed for turbojet aircraft, a stabilized approach is also recommended for propeller-driven aircraft. The idea is to reduce pilot workload and aircraft configuration changes during the critical final approach segment of an approach. The goal is to have the aircraft in the proper landing configuration, at the proper approach speed, and on the proper flightpath before descending below the minimum stabilized approach height. The following are recommended minimum stabilized approach heights.
(1) 500 feet above the airport elevation during VFR weather conditions.
(2) Minimum descent altitude (MDA) or 500 feet above airport elevation, whichever is lower, for a circling approach.
(3) 1,000 feet above the airport or touchdown zone elevation during IMC.
t. The increased CFIT risk of nonprecision approaches.
u. The increased CFIT risk of high descent rates near the ground.
v. The importance of good communications between the pilot and ATC concerning any flight instruction or clearance. The old rule of asking for clarification whenever in doubt about any instruction or clearance applies.
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w. The dangers of complacency for the single pilot, as well as multipiloted crews, when making routine flights.
x. The dangers of misunderstanding ATC instructions or accepting an incorrect clearance.
y. The dangers of not knowing the safe altitudes for your en route as well as your terminal area.
10. LOW-FLYING AIRCRAFT OPERATING IN VFR CONDITIONS. Although many of the factors listed previously apply to low-flying aircraft operating in VFR conditions, this is a special category for those pilots flying below minimum safe altitudes. Such operators include agriculture applicators and helicopter pilots who routinely operate near trees, telephone lines and power lines, or other such obstacles. In many cases, the pilot was aware of the obstacles but environmental factors such as time of day, minimal light, shadows, darkness, sun glare, cockpit blind spots, fatigue, or other such factors resulted in the pilot losing situational awareness and hitting an obstacle or impacting the ground. In some cases, pilots may have been aware of an obstacle, but because of some of these environmental factors, they were unable to avoid a collision because they did not see the danger in time or they saw the danger but failed to react in time to avoid an accident. Density altitude and aircraft performance limitations may also pose risk factors for such flights. These same factors can also result in a CFIT accident for someone flying in mountainous terrain. Some common low altitude CFIT factors are:
a. Wind shear and loss of flying speed.
b. Density altitude.
c. Failure to operate aircraft within operating limitations.
d. Failure to check an area from a safe altitude before descending into it (high reconnaissance and low reconnaissance).
e. Flying between hills or over rivers below hill tops can result in a CFIT accident if a power line or cable is strung between the hills. Not all such lines are marked or charted.
f. Flying up a box canyon and not being able to fly up and out of it before impacting terrain.
g. Flying over rising terrain that exceeds an aircraft’s ability or performance to climb away from the terrain.
h. Errors in pilot judgement and decision making.
i. Diversion of pilot attention.
j. Buzzing.
k. Crew distractions or a breakdown in CRM.
l. Operating in an unsafe manner.
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m. Failure to maintain control of the aircraft when taking off or landing.
n. Failure to properly preplan the flight.
o. Operating in unfamiliar areas or depending upon untrained people to provide important flight data.
p. Not having an objective standard to make go/no-go decisions for launching.
q. Failure to review all available data for the flight (particularly applicable to medical evacuation flights).
r. Lack of terrain knowledge and elevation of the highest obstacles within your immediate operating area.
s. Failure to properly plan your departure route when departing from unprepared areas such as helicopters or aircraft operating off an airport. Such factors include weight and balance, aircraft performance, height of obstacles, wind direction, trees, density altitude, rising terrain, length of takeoff area, and safe abort areas.
11. AERONAUTICAL INFORMATION MANUAL (AIM), CHAPTER 7, SECTION 6.
Potential Flight Hazards, paragraph 7-6-1, Accident Cause Factors, lists the following 10 most frequent cause factors for general aviation accidents that involve the PIC. The following list contains many of the same factors listed for CFIT accidents. This listing of major reasons why GA pilots continue to have accidents has remained constant over time. With the possible exception of subparagraph f, these factors can all be CFIT factors.
a. Inadequate preflight preparation and/or planning.
b. Failure to obtain and/or maintain flying speed.
c. Failure to maintain directional control.
d. Improper level off.
e. Failure to see and avoid objects or obstructions.
f. Mismanagement of fuel.
g. Improper in-flight decisions or planning.
h. Misjudgment of distance and speed.
i. Selection of unsuitable terrain.
j. Improper operation of flight controls.
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12. DECIDE MODEL. Many CFIT accident reports discuss the lack of good decision making on the part of the pilot or flight crew. The following D-E-C-I-D-E model is included in many manuals and books on decision making.
a. Detect change (or identify problem).
b. Estimate significance (of the change).
c. Choose the (best) objective or outcome.
d. Identify options (that meet objective or desired outcome).
e. Do best option.
f. Evaluate (the outcome—if the outcome is not what is desired then do a new DECIDE model).
13. TECHNICAL SOLUTIONS.
a. The development of the first GPWS has contributed to a marked decline in CFIT accidents in air carrier operations. The use of GPWS and the newer generation Terrain Awareness and Warning Systems (TAWS) in GA aircraft have the potential to provide a similar savings in lives and loss of GA aircraft. As noted in various CFIT documents, the proper use of TAWS is important to their effectiveness. Pilots are expected to execute the proper emergency escape maneuvers when their ground warning system activates.
b. Sections 91.223, 121.354, and 135.154 mandate the installation of TAWS in turbine-powered aircraft as outlined in the appropriate section. The type of operation also includes specific passenger seat requirements/limitations for the operations involved as well as the required type of equipment.
c. As digital-mapping systems combined with satellite positioning data become less expensive, GA pilots may soon be able to graphically see their horizontal and vertical location at all times. Expanded situational awareness should help pilots avoid some types of CFIT accidents.
Then the challenge will be to eliminate descent type CFIT accidents during the landing phase of flight.
14. SUMMARY.
a. CFIT normally occurs at speed with the result that many such accidents are fatal. A common thread throughout this AC is the importance of proper planning, good decision making, and being able to safely operate the aircraft throughout its entire operating range. Since CFIT implies that the aircraft is operating properly, the main reason for such accidents is what is commonly called pilot error. Therefore, it is the pilot’s responsibility to ensure that they are qualified for the flight, that the aircraft is properly equipped for the flight, and that the flight is flown according to the appropriate regulations and aircraft operating limitations. According to the CFIT Education and Training Aid, about 25.0 percent of all accidents occur during the takeoff and initial climb segment of flight. Approximately 7.0 percent of the accidents occur
Par 14 Page 11 dur ing the climb portion. Only about 4.5 percent occur during cruise. About 19.5 percent occur during descent and initial approach. But 41.4 percent of the accidents occur during final approach and landing. Takeoff, initial climb, final approach, and landing represent only about
6.0 percent of the total flight time of a given flight. But as these numbers point out, that
6.0 percent of a flight’s total time can be deadly. GPWSs and the newer TAWS using GPS have the potential to reduce CFIT accidents on takeoffs and landings. These systems provide one more tool for pilots to use to increase their safety margin when operating close to terrain and obstacles.
However, every pilot must know the limitations of their database and what objects are included in the database.
b. The solution to combating CFIT accidents starts on the ground. Pilots need to properly prepare to safely execute the maneuvers required during takeoff, initial climb, final approach, and landing phases of flight. Whether VFR or IFR, each flight has critical flight segments. How the flight segments are planned for and handled determines, to a great extent, the safety of the flight. Appendix 1, Flight Safety Foundation’s CFIT Checklist, provides one example of how to calculate CFIT risk. It states, “Use the checklist to evaluate specific flight operations and to enhance pilot awareness of the CFIT risk.” Page 4 of the checklist tells how pilots can obtain copies of the checklist or reproduce it.
c. Recommendations.
(1) Noninstrument rated VFR pilots should not attempt to fly in IMC.
(2) Know and fly above minimum published safe altitudes. VFR: Fly a minimum of 1,000 feet above the highest terrain in your immediate operating area in nonmountainous areas.
Fly a minimum of 2,000 feet in mountainous areas.
(3) If IFR, fly published procedures. Fly the full published procedure at night, during minimum weather conditions, or operating at an unfamiliar airport.
(4) Verify proper altitude, especially at night or over water, through use of a correctly set altimeter.
(5) Verify all ATC clearances. Question an ATC clearance that assigns a heading and/or altitude that, based upon your situational awareness, places the aircraft in a CFIT environment.
(6) Maintain situational awareness both vertically and horizontally.
(7) Comply with appropriate regulations for your specific operation.
(8) Don’t operate below minimum safe altitudes if uncertain of position or ATC clearance.
(9) Be extra careful when operating outside the United States or in an area which you are not familiar.
(10) Use current charts and all available information.
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11) Use appropriate checklists.
(12) Know your aircraft and its equipment.
15. AC FEEDBACK FORM. For your convenience, the AC Feedback Form is the last page of this AC. Note any deficiencies found, clarifications needed, or suggested improvements regarding the contents of this AC on the Feedback Form.
ORIGINAL SIGNED by /s/ Louis C. Cusimano for James J. Ballough Director, Flight Standards Service