Ac 61-107B Chg 1
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U.S. Department Advisory of Transportation Federal Aviation Administration Circular Subject: Aircraft Operations at Altitudes Date: 9/9/15 AC No: 61-107B Above 25,000 Feet Mean Sea Level Initiated by: AFS-800 Change: 1 or Mach Numbers Greater Than .75 1. PURPOSE. This advisory circular (AC) alerts pilots transitioning from aircraft with less performance capability to complex, high-performance aircraft that are capable of operating at high altitudes and high airspeeds. In particular, this AC stresses special physiological, equipment, and aerodynamic considerations involved in these kinds of operations. It also provides information to aid pilots in becoming familiar with the basic phenomena associated with high-altitude and high-speed flight. 2. PRINCIPAL CHANGES. Individual variability in hypoxia tolerance was the basis of discussions between the National Transportation Safety Board (NTSB) Chief Medical Officer and the Federal Aviation Administration (FAA) about whether to continue to include information in this AC relating to time of useful consciousness (TUC) (a measure of hypoxia tolerance) with increasing operational altitudes. TUCs are based on data that represent average values and reflect wide variation among pilots in terms of time to incapacitation. There was concern that this table was misleading because of the considerable ranges in TUCs given. Rather than delete the table from the AC, we agreed to augment it with more specific information on why hypoxia tolerances vary among individuals. This is in the form of a CAUTION statement presented underneath the original table. This change also incorporates editorial corrections throughout the document. PAGE CONTROL CHART Remove Pages Dated Insert Pages Dated Page ii 3/29/13 Page ii 9/9/15 Pages 1 thru 3 3/29/13 Pages 1 thru 3 9/9/15 Page 8 3/29/13 Page 8 9/9/15 Page 10 3/29/13 Page 10 9/9/15 Page 24 3/29/13 Page 24 9/9/15 Page 31 3/29/13 Page 31 9/9/15 Page 34 3/29/13 Page 34 9/9/15 Pages 40 thru 45 3/29/13 Pages 40 thru 45 9/9/15 John S. Duncan Director, Flight Standards Service U.S. Department Advisory of Transportation Federal Aviation Administration Circular Subject: Aircraft Operations at Altitudes Date: 3/29/13 AC No: 61-107B Above 25,000 Feet Mean Sea Level Initiated by: AFS-800 Change: or Mach Numbers Greater Than .75 This advisory circular (AC) alerts pilots transitioning from aircraft with less performance capability to complex, high-performance aircraft that are capable of operating at high altitudes and high airspeeds. In particular, this AC stresses special physiological, equipment, and aerodynamic considerations involved in these kinds of operations. It also provides information to aid pilots in becoming familiar with the basic phenomena associated with high-altitude and high-speed flight. Title 14 of the Code of Federal Regulations (14 CFR) part 61 prescribes the knowledge and skill requirements for the various airman certificates and ratings, including category, class, and type ratings authorized to be placed thereon. The civil aircraft fleet consists of numerous aircraft capable of high-altitude flight. Certain knowledge elements of high-altitude flight are essential for the pilots of these aircraft. As required by part 61, § 61.31, pilots who fly at altitudes at or above flight level (FL) 250 in a pressurized aircraft must receive training in the critical factors relating to safe flight operations under those circumstances. These critical elements include knowledge of the special physiological and/or aerodynamic considerations that should be given to high-performance aircraft operating in the high-altitude environment. High-altitude flight has different effects on the human body than those experienced during lower-altitude flight. An aircraft’s aerodynamic characteristics displayed in high-altitude flight may differ significantly from those experienced when penetrating at a lower altitude. Knowledge of and skill in operating high-performance aircraft will enhance the pilot’s ability to easily transition into aircraft capable of high-speed, high-altitude flight. It is beyond the scope of this AC to provide a more definitive treatment of this subject. Pilots should recognize that they need greater knowledge and skills for the safe and efficient operation of state-of-the-art turbine and turbocharged powered aircraft. We strongly urge pilots to pursue further study from the many excellent textbooks, charts, and other technical reference materials available through industry sources. Pilots will obtain from these sources a detailed understanding of both physiological and aerodynamic factors that relate to the safe and efficient operation of the broad variety of high-altitude aircraft available today and forecast for the future. 9/9/15 AC 61-107B CHG 1 CONTENTS Paragraph Page CHAPTER 1. GENERAL INFORMATION 1-1. Purpose ...........................................................................................................................1 1-2. Cancellation ...................................................................................................................1 1-3. Related Regulations .......................................................................................................1 1-4. Definitions......................................................................................................................1 1-5. Related Reading Material ..............................................................................................3 1-6. Warning, Caution, and Note ..........................................................................................3 1-7. Background ....................................................................................................................4 1-8. Discussion ......................................................................................................................4 CHAPTER 2. RECOMMENDATIONS FOR HIGH-ALTITUDE TRAINING 2-1. Purpose ...........................................................................................................................5 2-2. Outline............................................................................................................................5 2-3. Ground Training.............................................................................................................7 2-4. The High-Altitude Flight Environment .........................................................................7 2-5. Weather ..........................................................................................................................8 2-6. Flight Planning and Navigation .....................................................................................9 2-7. Physiological Training .................................................................................................12 2-8. FAA Physiological Training ........................................................................................30 2-9. High-Altitude Systems and Equipment .......................................................................31 2-10. Aerodynamics and Performance Factors .....................................................................35 2-11. Emergencies and Irregularities at High Altitudes ........................................................35 2-12. Flight Training .............................................................................................................38 CHAPTER 3. MACH FLIGHT AT HIGH ALTITUDES 3-1. Purpose .........................................................................................................................41 3-2. Critical Aspects of Mach Flight ...................................................................................41 3-3. Aircraft Aerodynamics and Performance ....................................................................43 LIST OF TABLES Table 2-1. Gas Laws and Their Effect on the Human Body ....................................................12 Table 2-2. Trapped Gas Issues .................................................................................................16 Table 2-3. In-Flight Treatment of Trapped Gas Emergencies .................................................17 Table 2-4. Hypoxia Types........................................................................................................18 Table 2-5. Common Hypoxia Signs and Symptoms ................................................................20 Table 2-6. Common Emergency Procedures for Hypoxia .......................................................22 Table 2-7. Types of Evolved Gas Decompression Sickness....................................................27 Table 2-8. Aircraft Cabin Volume Ratios ................................................................................36 LIST OF FIGURES Figure 2-1. Standard High-Altitude Service Volume ..............................................................12 Figure 2-2. Blood Cells and Alveoli ........................................................................................14 Figure 2-3. Times of Useful Consciousness Versus Altitude ..................................................24 Page ii (and iii) 9/9/15 AC 61-107B CHG 1 CHAPTER 1. GENERAL INFORMATION 1-1. PURPOSE. This advisory circular (AC) alerts pilots transitioning from aircraft with less performance capability to complex, high-performance aircraft capable of operating at high altitudes and high airspeeds of the special physiological, equipment, and aerodynamic considerations involved in these kinds