Lesson 3h - Spirals, Descents, Unusual Attitude Recovery

Lesson Objective

The student will learn typical modes of entry into, and methods of recovery from, unusual attitudes including spins and spiral dives. The student will also learn the concept and limitations of the "benign spiral" descent mode.

Regulatory Requirement

Student Pilot Candidates: (Maneuvers and procedures for pre-solo flight training in a glider)§61.87(i)(15)

Content

Instructor demonstration:

• Overbanking tendency into spiral dive entry
• Spiral dive entry from spin or departure (from controlled flight) conditions
• Initial slow-speed aft-stick-limited spiral dive
• Transition to high-speed g-limited spiral dive
• Spiral dive recovery procedure
• Nose-high slow airspeed recovery procedure
• Initiation of benign spiral descent mode

Student practice:

• Nose-low steep bank unusual attitude recovery
• Nose-high low-speed unusual attitude recovery
• Initiation of benign spiral descent mode

Completion Standards

The student must be able to explain:

• How spiral dives might develop from a nose-low overbanking turn, or following a spin recovery
• The differences between spiral dives and spins
• The recovery technique from a spiral dive, and hazards of incorrect techniques
• How spins might develop, and the general recovery technique from a spin
• The recovery technique from a nose-high low-airspeed unusual attitude
• The benefits and limitations of a benign spiral descent mode

The student must be able to perform:

• Recovery from a nose-low steeply banked attitude, including spiral dive (relax aft stick pressure, roll wings level, stick smoothly aft until nose above horizon)
• Recovery from a nose-high low-airspeed unusual attitude (neutral elevator and ailerons, rudder to minimize yaw, roll wings level after nose falls to horizon)
• Initiation of an intentional benign spiral descent mode (full spoilers, trim slightly aft, hands off stick, feet off rudders)

Prerequisite Study

Glider Flying Handbook (2013), Chapter 8, page 8-15 "Spiral Dives" and "Spins"
Soaring Safety Foundation, Flight Safety Videos, "Stall/Spin" (2) and "Spiral Dive", including pop-up "Instructor Guides"

Recommended Study

Airplane Flying Handbook, Chapter 4, "Maintaining Aircraft Control: Upset Prevention and Recovery"
Pilot's Handbook of Aeronautical Knowledge, page 5-20, "Spiral Instability"
Skylines, June 2005 "Stay Safe in Wave", article about benign spirals
Benign Spirals forum reference to Knauff glider transition book
Unload for Control forum reference to Rutan article
SSA Video: Spiral Dive

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Previous Lesson: 3g -- Turning Stall, with and without airbrakes
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