# Presentation: 095296

## Mission Aircrew CourseChapter 7: High Altitude and Terrain Considerations(Jul 2005)

**Mission Aircrew Course****Chapter 7: High Altitude and Terrain Considerations****(Jul 2005)**

## P-2011 DISCUSS THE EFFECTS OF DENSITY ALTITUDE ON AIRCRAFT PERFORMANCE (O)
P-2024 DISCUSS STRATEGIES TO COMBAT HIGH ALTITUDE EFFECTS (S)

**P-2024 DISCUSS STRATEGIES TO COMBAT HIGH ALTITUDE EFFECTS**** (S)**

**Aircrew Tasks**

## Discuss the symptoms and dangers of dehydration, and strategies used to combat its effects. {S; 7.3}
Discuss the symptoms and dangers of ear block, sinus block and hypoxia, and strategies used to combat their effects. {S; 7.3.1 – 7.3.3}

**Discuss the symptoms and dangers of ear block, sinus block and hypoxia, and strategies used to combat their effects. {S; 7.3.1 – 7.3.3}**

**Objectives**

## Review the effects of high altitude on aircraft performance 
Concerning atmospheric pressure: {O; 7.1}
State the pressure at sea level, and describe how to compensate for ‘other-than-sea level pressures’ when setting the altimeter
Discuss the three factors that affect the density of an air mass.
Define density altitude
State the phases of flight affected by a decrease in atmospheric pressure, and how aircraft performance is affected. {O; 7.2} 
Discuss strategies to compensate for high DA during searches. {O; 7.2.1}
Discuss mountainous terrain precautions and strategies. {O; 7.4}

**Concerning atmospheric pressure: {O; 7.1}**
**State the pressure at sea level, and describe how to compensate for ‘other-than-sea level pressures’ when setting the altimeter**
**Discuss the three factors that affect the density of an air mass.**
**Define density altitude**
**State the phases of flight affected by a decrease in atmospheric pressure, and how aircraft performance is affected. ****{O; 7.2} **
**Discuss strategies to compensate for high DA during searches. {O; 7.2.1}**
**Discuss mountainous terrain precautions and strategies. {O; 7.4}**

**Objectives**

## Human Performance: Dehydration

**The loss of water through the skin, lungs and kidneys never ceases**
**Loss increases as the humidity drops with increasing altitude**
**Symptoms are dryness of the tissues and resulting irritation of the eyes, nose and throat**
**Minimize intake of coffee, tea, cola or cocoa since they contain caffeine and other chemicals**
**Prevention Strategies**
**Drink plenty of hydrating fluids – WATER!**
**Increase air flow (vents and windows)**
**If the search objective allows, reduce temperature by climbing to higher altitude**

**Notes:**
7.3
Objective 7.4 – Discuss the symptoms and dangers of dehydration, and strategies used to combat its effects.
Hypoxia can be insidious.  It can affect you without your being aware.
The percentage of oxygen in the atmosphere is constant at about 21%, regardless of altitude.  Low atmospheric pressure at altitude prevents oxygen from being absorbed into the red blood cells at high altitude 
FAR’s require the pilot to breathe supplemental oxygen above 14,000.  
Flight at 12,500 is limited to 30 minutes.
Ear block usually occurs during descent.
Tell the pilot as soon as an ear or sinus block occurs.  It can be very painful and can cause permanent damage.
Can’t scan well while you are in pain.
Medications can affect your performance.

## Other Effects of Altitude

**Ear Block**
**Congestion around the Eustachian tube makes pressure equalization difficult**
**Can produce severe pain and a loss of hearing that can last from several hours to several days (can rupture eardrum)**
**Sinus Block**
**Sinus congestion makes pressure equalization difficult, particularly during descent**
**Can produce severe pain**
**Hypoxia**
**Normally not a concern for non-mountainous CAP operations (usually below 12,000 MSL)**
**Can have loss of night vision as low as 5,000 feet**
**Body has no built-in warning system against hypoxia**
**Everyone ’s symptoms are different**
**Onset altitude will vary depending upon individual**

**Notes:**
7.3.1 – 7.3.3
Objective 7.5 – Discuss the symptoms and dangers of ear block, sinus block and hypoxia, and strategies used to combat their effects.
Low atmospheric pressure at altitude prevents oxygen from being absorbed into the red blood cells at high altitude.
FARs require the pilot to breathe supplemental oxygen above 14,000; flight at 12,500 is limited to 30 minutes without supplemental oxygen.
Ear block usually occurs during descent.
Tell the pilot as soon as an ear or sinus block occurs.  It can be very painful and can cause permanent damage, and you can’t scan well while you are in pain.
Medications may affect your performance.

## Prevention Strategies

**Ear Block**
**Yawn, swallow, tense muscles in throat**
**Valsalva maneuver**
**Sinus Block**
**Don’t fly if you’re not well**
**Medication usually not effective and has side effects**
**Hypoxia**
**Avoid smoking, alcohol and depressants**
**Supplemental oxygen**

## A barometer is used to register changes in pressure; measured in inches of mercury
Standard sea-level pressure and temperature:
29.92 inches of mercury
59 degrees F (15 degrees C)
A change of 1000 feet in elevation makes a change of about one inch
To correct for local elevation, set altimeter to latest reading (ATIS/AWOS/ASOS/FSS) or enter field elevation

**Standard sea-level pressure and temperature:**
**29.92 inches of mercury**
**59 degrees F (15 degrees C)**
**A change of 1000 feet in elevation makes a change of about one inch**
**To correct for local elevation, set altimeter to latest reading (ATIS/AWOS/ASOS/FSS) or enter field elevation**

**Atmospheric Pressure**

**Notes:**
Demonstrate knowledge of atmospheric pressure: state the pressure at sea level, and describe how to compensate for ‘other-than-sea-level pressures’ when setting the altimeter.

## Three factors:
Pressure
Temperature
Humidity
Altitude and pressure combined to determine pressure altitude
Add non-standard temperature to get density altitude
Remember: Drag, lift, power available and true airspeed are all affected by density altitude

**Pressure**
**Temperature**
**Humidity**
**Altitude and pressure combined to determine *****pressure altitude***
**Add non-standard temperature to get ****density altitude**
**Remember: Drag, lift, power available and true airspeed are all affected by density altitude**

**Density Altitude**

**Notes:**
Discuss the three factors that affect the density of an air mass; Define density altitude, and compute density altitude for a given situation using a chart and a flight calculator.

## TAS vs. DA

## Density Altitude

**Notes:**
Compute density altitude for a given situation using a chart

## Flight Computer

**Circular slide rule**
**Density altitude**
**Nautical to statute miles**
**True airspeed**
**Other stuff**

**Notes:**
Compute density altitude for a given situation using a flight computer

## Density altitude and aircraft weight have a tremendous effect on aircraft performance
Both must be accurately calculated, especially for mountain flying missions

**Both must be accurately calculated, especially for mountain flying missions**

**Aircraft Performance**

**Notes:**
State the phases of flight affected by a decrease in atmospheric pressure, and how aircraft performance is

## As altitude increases pressure decreases; this decrease can have a pronounced effect on flight:
Engine (hp) and prop are less efficient
Take off distance, climb rate, and landing distance effected
Take off distance almost doubles with a 5000 foot elevation increase
Rate of climb slows with higher elevation
Landing distance increases with higher elevation
Higher Humidity, Heat or Height result in reduced aircraft performance

**E****ngine (hp) and prop are less efficient**
**Take off distance, climb rate, and landing distance effected**
**Take off distance almost doubles with a 5000 foot elevation increase**
**Rate of climb slows with higher elevation**
**Landing distance increases with higher elevation**
***Higher Humidity, Heat or Height***** result in reduced aircraft performance**

**Pressure vs. Performance**

## DA & ROC

## Reduced Performance

## Don’t fly at high elevation during the hottest part of the day
Carefully calculate DA and weight
Reduce load:
Less fuel
Crew of three instead of four
Less baggage
Remember “High to Low, Look out Below” (update altimeter setting hourly)
If you fly in the mountains, take the Mountain Fury Course

***Carefully***** calculate DA and weight**
**Reduce load:**
**Less fuel**
**Crew of three instead of four**
**Less baggage**
**Remember “High to Low, Look out Below” ****(update altimeter setting hourly)**
**If you fly in the mountains, take the *****Mountain Fury***** Course**

**Strategies**

**Notes:**
Discuss strategies to compensate for high DA during searches.
Briefly discuss “High to Low, Look out Below”

## Flight Near Mountainous Terrain

**Crews must be constantly careful that the search never takes them over terrain that rises faster than the airplane can climb.  Narrow valleys or canyons that have rising floors must be avoided, unless the aircraft can be flown from the end of higher elevation to the lower end, or the pilot is *****certain *****that the aircraft can climb faster than the terrain rises.  Careful chart study by the crew prior to flight will help identify this dangerous terrain. **
**If you fly in the mountains, take the *****Mountain Fury***** Course**

**Notes:**
Discuss mountainous terrain precautions and strategies.
Approach ridges at a 45 degree angle.  Cross at least 2,000 ft. above.

## Flight Near Mountainous Terrain

**Notes:**
Discuss mountainous terrain precautions and strategies.
Approach ridges at a 45 degree angle.  Cross at least 2,000 ft. above.

## Flight Near Mountainous Terrain

**Notes:**
Enter terrain from above and always have an escape route in mind.

## Flight Near Mountainous Terrain

**Notes:**
Take the Mountain Fury course.

## QUESTIONS?