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 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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