Radar

Question 0

2 main types (radar)

Type one PRIMARY RADAR

Answer 0

1. Primary radar
   - completely ground based system used by ATC
   - uses a synchronized radio transmitter and receiver to emit radio waves and process their reflection for display
   - no additional equipment required in A/C (no pilot participation)
   - transmits radio waves in a narrow beam by a rotating antenna
   - when the radio waves strike an aircraft, some of the waves are reflected back to the antenna
   - the reflected waves are displayed as echoes on a screen for ATC
   PROBLEMS:
   - temperature inversions can bend the radio waves and make the readouts less accurate
   - small aircraft can be hard to see
   Screen can be noisy because many things can cause a return signal (ground obstacles, clouds with precipitation and birds

Question 1

Radar (radio detection ranging)

Answer 1

• operates by line of site
• converts elapsed time to distance (d=speed x time) the range of the aircraft is determined by measuring the amount of time it takes for the echo to return to the antenna
• the azimuth, or angle of your aircraft is also measured to pinpoint where you are

Question 2

2 types

2. Secondary radar

Answer 2

• overcome most of the limitations of primary radar
• signal is sent out by ground (interrogator signal)
• transponder in aircraft responds with a separate signal of its own (transponder reply)
  EQUIPMENT
• antenna
• transponder
• decoder (on aircraft and on ground)
  PROBLEMS
• relies on pilot participation

Question 3

Radar services provided (guaranteed under IFR)

Answer 3

• traffic alerts
• radar vectoring
• ATC will provide bearings to pilot, known as vectors
• can help you if you are lost by locating a fix - how far you are from something

Question 4

Facilities providing these services

Answer 4

• ASR (ATC) immediate airport environment (CHD)
• TRACON - terminal radar approach control (PHX approach)
• cover RADAR services in airport vicinity
• usually in class B and C within 30 NM
• directs traffic to local airports
  ARTCC - air route traffic control center (ABQ center)
• 20 centers across the U.S.
• found on en-route chart or AFD
• used to monitor aircraft on en-route phase of flight
• provide continuous coverage over most of the continental US

Question 5

Radar approaches - 2 types (require approach plates) FT huachuca

Answer 5

AIRPORT SURVEILLANCE RADAR (ASR) NON- precision approach
- relatively short range
- ATC can use radar to help you to come in on an approach
- ATC will give you vectors to keep you on course
- ATC can tell you when to make your final decent
- ATC will tell you when you are at your missed approach fix
PRECISION APPROACH RADAR: (PAR) (precision approach)
- can keep you on vertical course the entire way to the ground
- requires special equipment for each runway
very expensive (military use)
- provides vertical and horizontal guidance
- inform you if you are above or below glide slope
BOTH APPROACHES HAVE PUBLISHED CHARTS

Question 6

No GYROS approach

Answer 6

• airport must have ASR or PAR equipment
• an emergency approach; when a gyro becomes unreliable or fails
• make a malfunction report to ATC (91.187)
  1. Aircraft ID
  2. Equipment affected
  3. Degree the pilot is affected to fly under IFR
  4. Type of help needed from ATC
• ATC will tell you when to start and stop turns, use standard rate turns until on final approach course then use 1/2 standard rate turns once on final approach course
• ATC provides: may provide discrete radio frequency. When it is needed they will give radar vectors, tell you when to descend, what altitude, distance from the runway or the missed approach point at each mile along the final approach course. Can tell you when you arrive at the missed approach point

Question 7

Transponder operations

Answer 7

• normally found in the radio stack
• IFR uses a digital style
  FUNCTION SELECTOR
• controls the mode of operation
• off
• on
• ALT - transmits pressure altitude
• STBY - used for warm up does not reply to requests
• TEST - transmits reply without a query
  IDENT button:
• highlights your position on the ATC screen so they can easily find you
  CODE SELECTOR:
• can be set to display numbers 0-7
• 4096 possible codes
  CODES:
• SQUAWK codes
• 1200 VFR traffic
• 7500 hijacked
• 7600 lost comms
• 7700 - emergency

Question 8

Types of transponders

Answer 8

MODE A:
- no altitude reported
MODE C:
- reports altitude automatically
MODE S:
- provides altitude, tail #, and aircraft type
- can also receive weather information and clearances
- less of a workload for controller
- relieves communications frequency congestion