false horizons

FALSE HORIZONS

NICHOLAS SOTO

OVERVIEW• What is a False Horizon?

• Conditions • Hazards to Aviation

• Types of False Horizons• City Lights• Road Lights• Cloud Layers• Obscured Horizons

• Overcome a False Horizon• Proper Instrument Scan• Flight Planning

• NTSB Report

WHAT IS A FALSE HORIZON?• A False Horizon is when the natural horizon is obscured

or not readily apparent• Is not created due to an eye limitation!• Created from terrain features

• Rising terrain• Lights from a busy road• Calm water and clear skies• Sloping cloud layer• Low visibility or haze

• Day or night • Completely obscured horizon is also a false horizon

HAZARDS TO AVIATION• Controlled Flight into Terrain (CFIT)

• An airworthy a/c under pilot control is flow into the ground• Fixation• Not using CRM• Pilot levels a/c with false horizon

• False horizon can cause a hazardous attitude• Nose high attitude

• Cause a/c to stall• Break altitude restrictions

• Nose low attitude• Impact ground or obstacles• Break VNE• Break altitude restrictions

• Spatial Disorientation

CITY LIGHTS WITH RISING TERRAIN

CALM WATER AND CLEAR SKIES

LOW VISIBILITY

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CLOUD LAYER

OVERCOME A FALSE HORIZON ILLUSION• Flight Planning

• Known false horizon illusions • Proper Instrument Scan

• Relay what you see outside with a/c instruments• Trust your Instruments

• Spatial disorientation can occur• Attitude Indicator, Turn Coordinator, Altimeter, Airspeed

Indicator, Vertical Speed Indicator

NTSB REPORT• NTSB Identification: NYC99MA178• Friday, July 16, 1999 in VINEYARD HAVEN, MA• Aircraft: Piper PA-32R-301, registration: N9253N• 3 Fatal • Non instrument-rated pilot• Conditions: 4-10 miles vis due to haze, night flying• Flew over 30 mile stretch of water at 5,500• 7 miles from approaching shore began right turn descent to 2,200• Climbed back to 2,600 and entered a left turn with a 900 FPM

descent• Then entered a right turn with a descent of 4,700 FPM impacting

the water• Other pilots reported obscured or no visual horizon• The pilot's failure to maintain control of the airplane during a

descent over water at night, which was a result of spatial disorientation. Factors in the accident were haze, and the dark night.

REFERENCES• National Transportation Safety Board. Report No.

NYC99MA178, Published 07/16/1999, http://www.ntsb.gov/aviationquery/index.aspx

• Jeppesen. Rotorcraft Flying Handbook, City: Englewood, CO, Published 2007

• Aircraft Owners and Pilots Association, “Spatial Disorientation Confusion that Kills” http://www.aopa.org/asf/publications/sa17.pdf

• Jeppesen. Guided Flight Discovery Private Pilot, City: Englewood, CO, Published 2007

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