Altimeter Settings

Question 1

What are the three different altimeter settings

Answer 1

SPS, Standard - 1013,25 hp

QNH

QFE

Question 2

What is SPS

Answer 2

Standard Pressure Settings

Always 1013,25 hPa

Using for ensuring safe separation of aircraft on high altitudes over great distances

Uses Flight Level (FL x 100 = ft)

Question 3

What is QNH

Answer 3

NH is short for Nautical Height

QNH should be read as Pressure at Sea Level

Normally used when handling ROZ

Uses MSL

QNH uses Angels (Angels x 1000 = ft)

Question 4

What is QFE

Answer 4

FE is short for Field Elevation

The pressure setting for a specific point

Mainly used by civilian air traffic for landing

QFE is what you get from a normal weather station

QFE uses Above Ground Level (xxxxft AGL)

Question 5

What are the minimum safe separation of A/C

Answer 5

1000ft

2000ft (UAV)

Question 6

When to use what pressure setting

Answer 6

When a transition altitude is set for an area
We use QNH below and SPS above

Question 7

What is the normal size of a transition altitude

Answer 7

2000ft
Transition altitude + 1000ft

Question 8

When working inside a ROZ do you normally apply a transition altitude

Answer 8

No, normally it’s cancelled

Question 9

What is the calculation factor of 1 hPa

Answer 9

30ft

Question 10

What is the altitude and pressure relation

Answer 10

Higher altitude equals lower pressure

Lower altitude equals higher pressure

Question 11

Calculate and answer the following:

Your map tells you your elevation is 425m MSL

Your weather station reads 895 hPa

What is the QNH?

Answer 11

Elevation in ft = 425 x 3,28 = 1394ft

Pressure difference = 1394 / 30 = 46,5 hPa

QNH = 895 + 46.5 = 941 hPa (always rounded down)

Question 12

Calculate and answer the following:

An AC130 request QFE for landing

You lack a weather station

A METMAN gives you a valid QNH of 1008 hPa

Your Field Elevation is 585m

What is the QFE

Answer 12

Elevation in ft = 585 x 3,28 = 1919ft

Pressure difference = 1919 / 30 = 64 hPa

QFE = 1008 - 64 = 944 hPa

Question 13

HAMMER 16 is on FL160, SPADE 25 reports ANGELS15 on 1009

• Will this ensure safe separation between the A/C?
• How much will the actual separation
  be?
• How do you calculate the actual separation

Answer 13

• NO, not enough separation
• Actual separation is 872,5ft

FL160 = 1013,25 hPa

1013,25 - 1009 = 4,25

4,25 x 30 = 127,5

1000 - 127,5 = 872,5