Controlled Flight Into Terrain (CFIT)

Introduction

Picture embedded from Gruber-Aviation on 8 Oct 09	Picture embedded from Wikipedia on 18 Aug 11

CFIT is defined as "one in which an otherwise serviceable aircraft under the control of the crew, is flown (unintentionally) into terrain, obstacles or water, with no prior awareness on the part of the crew of the impending collision" [1]

Statistics in 2006 have shown that over a 10 year average, 34% of all aviation accidents are due to CFIT. [2]

Statistics from the Pie Chart below also depict that the large proportion of CFIT accidents are caused by private General Aviation pilots, followed by commercial pilots. [3]

Picture embedded from AmericanFlyers on 10 Oct 09

Causes

• Loss of Situational Awareness

• Spatial Disorientation

• Equipment Malfunction
  • If the aircraft's navigational equipment is unserviceable or malfunctioned, this could mislead the pilots in reading the wrong data and wrongly fly the plane into terrain.

• Adverse Meteorological Conditions
  • Pilots flying in IMC conditions may try to seek visual reference of land and descend below the specified safe altitude resulting in collision with terrain.

• Unclear Instrument Approach Templates
  • Unclear approach templates may cause pilots to deviate from them or misread them hence taking them close to unsafe areas especially if the airfield is near mountainous regions; this is exacerbated especially if pilots are unfamiliar or are first time patrons into the airfield in a night environment. [4]

Accidents involving CFIT

• Crash of Korean Air Flight 801 in Guam due to pilots flying an ILS approach with an outdated flight map specifying a wrong Minimum Safe Altitude in inclement weather conditions.
• For a more comprehensive analysis of the incident, please refer to Korean Air Flight 801

(Image embedded from NSGOV on 10 Oct 2009)

• Crash of American Airlines Flight 965 in Colombia due to erroneous input of navigational waypoints into the computer Flight Management System.
• For a more comprehensive analysis of the incident, please refer to American Flight 965

(Image embedded from AirportWebcam on 10 Oct 2009)

• Crash of Air New Zealand Flight 901 in Antarctica due to a combination of factors including (but not limited to) 'Whiteout' conditions, deviation from SOP's and a change in programmed waypoints in the Flight Management Computer that was not advised to the crew.
• For a more comprehensive analysis of the incident, please refer to Air New Zealand Flight 901

(Image embedded from Wikipedia on 18 Aug 2011)

Prevention of CFIT

• Ground Proximity Warning Systems
  • These are systems installed on board the aircraft which provide oral warnings to the flight crew, alerting them there they are potentially in dangerous proximity to terrain. For example, the Enhanced Ground Proximity Warning System (EGPWS) compares aircraft position vis-a-vis GPS maps taking reference with the aircraft's forward flight path with terrain, enabling pilots to take avoidance actions.

• Training
  • With proper and realistic training, flight crew will be well prepared to know the hazards of flying close to terrain, to recognize the symptoms of spatial disorientation. Many airlines use past CFIT accidents during training courses to emphasis points and help pilots to understand their own limitations and recognise when a an undersireable situation is developing.

• Proper documentation in flight charts
  • Airline companies and pilots must ensure that they are always carrying the most up to date flight instrument charts so that they fly the correct instrument charts and do not fly into terrain mistakingly. [5]

References

1. Wiener.E.L.(1977) Controlled Flight Into Terrain: System-Induced Accidents, Human Factors 19

2. ASN(2006). ASN Airliner Accident Statistics 2006. Retrieved from the World Wide Web on 10 Oct 09. http://www.scribd.com/doc/2460587/ASN-Airliner-Accident-Statistics-2006

3. NAFTA(2002). Prevention of Controlled Flight Into Terrain In General Aviation Operations. Retrieved from the World Wide Web on 10 Oct 09. https://www.americanflyers.net/library/Medical%20Brochures/CFIT.htm

4. Skybrary(2009) CFIT. Retrieved from the World Wide Web on 10 Oct 09.http://www.skybrary.aero/index.php/CFIT

5. Ladkin.P.B. Controlled Flight Into Terrain: What is Being Done. Retrieved from the World Wide Web on 10 Oct 09. http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/Research/Rvs/Misc/Additional/Reports/CFIT.html

Want to know more?

TERPS, CFIT and Me

This article provides details on considerations of instrument flying vis-a-vis CFIT.

CFIT

This article provides details on how CFIT can occur in either an IFR or VFR scenario.

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