Basic instruments (lesson 2)

Question 1

Position errors increase…although…

Answer 1

With speed, although generally cancelled out by computer

Question 2

P errors reduced likelihood by having

Answer 2

A port on the other side

Question 3

Height is above

Answer 3

Airfield QFE

Question 4

ALT is above

Answer 4

Sea level QNH

Question 5

FL is above

Answer 5

SPS (1013.25)

Question 6

At transition altitude you switch from

Answer 6

Alt to FL

Question 7

At transition level you switch from

Answer 7

FL to ALT

Question 8

Transition altitude is given in the

Answer 8

Charts

Question 9

The transition level is given by

Answer 9

The ATC

Question 10

Barometric error

Answer 10

Differences of pressure in area, despite the QNH area being the same

Question 11

Time lag / hysteresis is … & is mainly due to

Answer 11

Time it takes for pressure to go from port to instrument.Mainly due to friction of the gears and the linkages

Question 12

Altimeter source is blocked….(altimeter still thinks it’s at altitude it was at before block.

With static pressure on decent / climb what happens?
With pitot pressure on decent /climb what happens?

Answer 12

SOD
SUC

PUD
POC

Question 13

Simple altimeter consists of

Answer 13

One capsule. One pointer hand.
Rough scale. Typically 0 to 10,000ft.
No setting a reference pressure

Question 14

The sensitive altimeter

Consists of

Answer 14

More accurate than the simple altimeter
Can set reference pressure = calibrate option
More than one capsule

Question 15

Servo altimeter

Consists of

Answer 15

More accuracy & sensitive than the sensitive altimeter bc capsule stack only has to overcome lag of the capsule.
Lag is virtually eliminated.
E & I shaped things (transducer).

Question 16

Mode C

Answer 16

_transmits to ATC => gives height info

Question 17

Mode S

Expensive…

Answer 17

Allows a/c to coordinate for avoidance

Question 18

Mode a

Answer 18

“There’s an aircraft” indication

Question 19

How mode c works

Answer 19

• Sensitive altimeters with an encoding system, supply info to a/c’s transponder.
• This then transmits to ATC when mode C is selected on transponder.

Question 20

Density altitude is

Answer 20

Air density given as a height above mean sea level .

Question 21

Density altitude = formula

Answer 21

Pressure altitude + (ISA dev x120ft)

Question 22

VSI
If blocked?
What else?
How work?

Answer 22

Will slowly return back to zero. (As no change in pressure)
⚫️Sensitive to lag
⚫️Not partially evacuated
Compares actual static pressure immediately with a delayed value of actual static pressure.

Question 23

What does IVSI do?

Answer 23

Cancels out the time lag

Question 24

From the table in the book, what two instruments don’t need a pitot source?

Answer 24

Altimeter & VSI