Mid-air Collisions

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Mid-airCollisions
Simon Stuart
Squadron 80
San Jose, CA
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Presentation Overview

• What defines a near mid-air collision (NMAC)?
• How often do they occur?
• At what stages of flight are they most likely to
  occur?
• Recent examples
• How to avoid them
• Hot spots for traffic in our local area
• Equipment to help minimize collision risks
• ATC Your second set of eyes
• Gliders
• References for further reading

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Near Mid-air Collision Defined

• b. Definition. A near mid-air collision is
  defined as an incident associated with the
  operation of an aircraft in which a possibility
  of collision occurs as a result of proximity of
  less than 500 feet to another aircraft, or a
  report is received from a pilot or a flight crew
  member stating that a collision hazard existed
  between two or more aircraft.

Source FAA AIM 7-6-3
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NMAC Statistics
a A situation where collision avoidance was due
to chance, rather than an act on the part of the
pilot. Less than 100 feet of aircraft separation
would be considered critical. b An
incident that would probably have resulted in a
collision if no action had been taken by either
pilot. Less than 500 feet would usually be
required in this case. c When direction
and altitude would have made a mid-air collision
improbable, regardless of evasive action
taken. d No determination could be made
due to insufficient evidence or unusual
circumstances, or because incident is still under
investigation.
Source US DOT
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NMAC Reporting

• NASA Aviation Safety Reporting System (ASRS)
• Generally speaking, a Voluntary submission
  system
• All NMACS thoroughly investigated by local FSDO
• ATC Reporting Be specific. I wish to report a
  near mid-air collision.
• New rules as of March 30, 2010 Mandatory ACAS
  reporting
• May increase the frequency of incidents being
  reported

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NMAC When Do They Occur?

• AOPA Study
• 49 in the pattern, approaching or departing an
  airport (AOPA)
• 26 in en-route climb, cruise or descent
• 25 during hazardous activities, e.g. Formation
  flight
• National Guard Study
• 75 involve general aviation aircraft
• 4 in 5 below 3000 AGL

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Mid-air Collisions (MAC)

• 93 were operating under Part 91
• 39 took place on the approach, 27 in cruise and
  17 while maneuvering
• Most approach collisions at non tower airports
• All occurred below 6000 feet
• 50 occurred below 1000 feet
• 35 were head on collisions
• All were in VMC
• Fatality rate 50. Higher in cruise collisions
  due to impact speed

The FAA recommends looking outside of the
aircraft 75 of the time. Pilots estimate they
look outside the aircraft 35 of the time.
Source NTSB 1994-9
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Mid-air Collisions 2008 Events

• Non-commercial collisions in 2008 11
• Fatal 4 (14 fatalities)
• Between two aircraft 9
• Commercial 2 A crop duster and a glider its
  tow plane
• 3 of the 8 planes involved in fatal mid-air
  collisions were under instruction
• The other 5 were on personal flights

In summary, actual collisions are rare but
serious.Far more common, but equally unnerving,
are the close calls.
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Examples

• Glider tow http//www.youtube.com/watch?vwTemKnL
  8X30
• Mid-air Collision over the Hudson river
  http//www.youtube.com/watch?v2oHRBMs2qQQ
• NMAC during a San Francisco Bay Tour United 889
  Cessna 182, March 2010. Cause Controller error.

Many close calls and collisions can be avoided by
simply looking out the window more of the time.
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Avoiding NMACS

• Consider the area in which you are flying
• Think about the presence, density and type of
  traffic
• Take extra precautions during certain stages of
  flight
• Make effective use of the equipment on board

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Hot Spots San Francisco Bay Area Airports
Average Daily Operations

• SFO 1075
• OAK 738
• RHV 630
• SJC 533
• PAO 516
• SQL 425

• LVK 375
• CCR 257
• CVH 180
• HAF 165
• TCY 164
• E16 117
• NUQ Nominal

Perspective SFO ranks 24th in the world in
terms of aircraft movement.
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Hot Spots San Francisco Bay Area

• Non tower airports / Marine layer
  w/Questionable VFR activity Watsonville, Half
  Moon Bay
• Paragliding Mission Peak
• Soaring Hollister, Minden, Truckee
• Parachuting Byron, Marina, Lodi
• Aerobatics South County, Watsonville, Livermore
• Training South County
• Bay Tours Alcatraz, Helicopter tours, banner tows

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Stages of Flight Additional Risks

• Climbing, descending and maneuvering
• Nose high obscuration. High / low wings in turns
• Programming the GPS, especially the G1000
• Low visibility scenarios
• Descent between East / West altitudes

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Equipment

• Eyeballs. Include your passengers, especially CAP
  observers scanners.
• Primary radar. ATC can detect the position of
  aircraft without transponders. Altitude is
  unknown.
• Mode C transponders. Provides ATC with position
  and altitude.
• Mode S transponders. Provides pilot with ground
  based traffic location and altitude. Limited
  radar coverage (lt50nm from source). Mainly West
  coast radar facilities.
• TCAS (Traffic collision avoidance system).
  Independent of ATC. Detects other transponders.
  Mainly large A/C.
• ADS-B. The future. Replaces radar. ADSB Out
  mandatory by 2020. Independent of ground systems.
  Only ADSB In provides pilot benefits.

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Avoiding NMACS

• Flight following, flight following, flight
  following
• Appropriate cruise altitudes
• Advantages of IFR under VMC
• Get all passengers to scan while you work the
  avionics / have the right seat fly the aircraft
  and scan for traffic
• Avoid the sinister G1000 head-in-cockpit syndrome
• Low level routes Track an offset

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Avoiding NMACS

• Flight planning
• Use VFR sectionals to review Glider and
  parachute areas
• Call flight services for NOTAMS
• En-route ATC Traffic Notifications
• Acknowledge notification. Confirm with initial
  Looking for traffic.
• Follow up. Negative contact, In sight, Not a
  factor, Will maintain visual separation etc.

In the end, See and Avoid is the guiding
principal. Even when VMC under IFR.
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Flight Following Dont Leave Home Without It

• ATC may provide
• Vectors around active drop zones
• Advisories for restricted areas when they are hot
• TFR advisories
• Remember These are by courtesy only Get a
  briefing and check NOTAMS

ATC often provides CAP flights with flight
following while maneuvering in and out of radar
coverage. Help them help you, e.g. Norcal
Approach, CAP 483, we will be maneuvering for the
next 30 minutes below 5000 on the Panoche 233
radial at 12 miles within a 5 mile
radius. Roger CAP 483, let me know when youre
done.
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Hazards Gliders

• Often not equipped with transponders or a radio
• Even those equipped with both may not have either
  turned on, to conserve power for landing calls.
  An example of why this is bad

Reno ASG-29 vs. Hawker XP800. 300kt impact
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Consider Ourselves Lucky

• No class Echo in the United Kingdom
• Soaring IMC without a transponder or radio is
  permitted
• In this scenario, IFR traffic separation is
  provided by
• Primary radar (If available)
• Big Sky theory, i.e. Luck

The US provides a superior airspace structure and
free ATC services. Use them to your advantage.
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References

• Analysis of mid-air collisions in civil aviation
  http//www.narcap.org/reports/misc/HumanfactorsMAC
  .pdf
• Near Mid-air collision statistics
  http//www.bts.gov/publications/national_transport
  ation_statistics/2002/html/table_02_15.html
• FAA Definition http//www.faa.gov/air_traffic/pub
  lications/atpubs/aim/Chap7/aim0706.html
• ASRS http//asrs.arc.nasa.gov/
• NTSB 830 Rules http//edocket.access.gpo.gov/2010
  /E9-30398.htm
• CAP Las Vegas Crash http//www.ntsb.gov/ntsb/brie
  f.asp?ev_id20071121X01832key1
• ADSB for beginners http//www.freeflightsystems.c
  om/docs/ADS-B_For_Beginners.pdf
• Reno glider collision http//jeremy.zawodny.com/b
  log/archives/007288.html
• National Guard NMAC MAC statistics
  www.pittsburgh.afrc.af.mil/shared/media/document/A
  FD-070820-011.doc

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• End of Presentation