Plane Facts: Surveillance

In aviation, surveillance methods are decidedly less sinister. Early on, surveillance was a way for controllers, who were few and far between, to know where the planes were. And it was all for the good. With controllers on the lookout, they could help planes get to their destinations and avoid colliding with terrain. And after a couple of tragic accidents, mostly notably the midair collision between a Lockheed Constellation and a Douglas DC-7 over the Grand Canyon, a tragedy in which all 128 people aboard the two planes perished, there was a hew and cry for new tools for controllers to use to help keep airplanes from running into each other. 

Indeed, tragic crashes have on several occasions led to the development of new surveillance systems, with ADS-B, a satellite-enabled dependent surveillance technology, being the latest and greatest of them all. 

First military use of ground controlled approach (GCA) radar: 1943

Range: 20 miles

Altitude range: 10,000 feet

First civilian use: 1945, LaGuardia Airport

Landing rate prior to implementation: 5 planes per hour

Landing rate after implementation: 15 planes per hour

Transponders introduced for aviation: World War II

Worst friendly fire incident of WWII: July 11, 1943

Occurred during: Operation Husky, the invasion of Sicily

Reason cited for incident: "Need for better preparation in aircraft identification"

Aircraft involved: C-47 Skytrains, C-53 Skytroopers

Planes shot down: 23 out of fleet of 144

American soldiers killed: 300+

Technology developed to prevent friendly fire: Identification, Friend or Foe (IFF) radar receivers/transmitters

IFF transponders: Transmit code signal when interrogated by military radar

Modernization of ATC began: 1956

Sparked by: Grand Canyon mid-air collision

Fatalities: 128

Civilian Aeronautics Authority (CAA) dissolved and became Federal Aviation Administration (FAA): 1958

GPS development project launched: 1973, U.S. Department of Defense

Goal: Overcome limitations of previous navigation systems

Satellites used: 24

Test flights location for project: Holloman Air Force Base

Military conflict first incorporating GPS tech: The Gulf War (1990-1991)

Operational GPS navigation satellites: 31

Satellites' altitude: 11,000 miles                                 

FAA-Grade Standard Positioning Service GPS (L1 band): <25 feet

DoD-Grade Precise Positioning Service (L1 & L2 bands): <19 feet

New L5 band GPS: <1 foot

Creation of Traffic Alert and Collision Avoidance System (TCAS): 1981

First aircraft installed with TCAS II: Piedmont Airlines Boeing 727

Interrogation-and-response cycle frequency: Multiple times per second

Crash attributed to TCAS II oversight: 2002 Überlingen mid-air collision

Cause: Conflicting TCAS and ATC commands

Seconds pilots had visual on each other: 2

Fatalities: 69

Children on board: 45

TCAS II system improvements: Issues reversal of warning, Alerts ATC of TCAS advisory

Kickstart of Next-Generation Air Transportation Plan: 2002

Task force created by: Commission on the Future of U.S. Aerospace Industry

Goal: Modernize U.S. National Airspace System

Rollout of changes: Between 2007 and 2025

Fuel savings estimated through 2030 through ADS-B: 2.8 billion gallons

Carbon emissions reduction estimated: >650 million metric tons

NextGen Airport Surveillance Radar (ASR): Fully digital ASR-1

Range: 60 miles

Altitude range: 25,000 feet

Frequency new system transmits positions: 1x per second

Previous system: 1x per 5-12 seconds