Radio Altimeter Flashcards Preview

Advanced Instruments > Radio Altimeter > Flashcards

Flashcards in Radio Altimeter Deck (17):
1

Radio altimeter tells you

Absolute height from the main landing gear

2

When the main wheels are on the ground it will indicate

0 or sometimes a negative number

3

How does a radio altimeter work

Transmits a continuous wave at a variable freq

Measures the freq difference

The difference of the freq transmitted to the freq received = time - can use speed = distance/time to find distance

4

Variable freq of a radio altimeter wave



4200 - 4400 MHz

5

Radio altimeter indications

Indicates 2,500 to 0

6

Accuracy of a radio altimeter

With a bank angle it becomes less accurate as it indicates slant range

Normal accuracy = within +- 2ft below 500ft or +- 1.5% whichever is the greater

7

When does mach no appear on PFD

After mach .5

8

ISIS

Integrated standby instrument system

9

Symbol generator

Receives a signal from the EFIS computer and converts it into symbols for the PFD

10

Flight mode annunciators

Top of the PFD, tells you what the a/c is doing

11

Different colours and their indications

Green = active mode
Red = limitation
Amber = caution
Blue = sky
Brown = ground
Magenta = selected parameter/target
Cyan = other info

12

ND displays

Current heading
Track line
Selected heading
Selected course

13

CRT display

Cathode ray tube

Old type of screen

Poor resolution

14

LCD display

Liquid crystal display

New type
Decent resolution/bright

15

Radio altimeter modulation

Freq modulated

16

Precession of radio altimeter

+/- 2ft between 0 and 500ft and +/- 1.5% whatever is the greater

17

Radio altimeter supplies data to

TCAS, GPWS and the auto land systems