From 2fcb4fb3d911a5eb6ee57d0e9195252c05505248 Mon Sep 17 00:00:00 2001 From: Matthias Nott <mnott@mnsoft.org> Date: Mon, 23 Mar 2026 13:34:05 +0100 Subject: [PATCH] feat: anatomy sailplane diagrams, wikilink cleanup, orphan removal --- SPL Exam Questions EN/80 - Principles of Flight.md | 70 ++++++++++++++++++++++++++++++---- 1 files changed, 61 insertions(+), 9 deletions(-) diff --git a/SPL Exam Questions EN/80 - Principles of Flight.md b/SPL Exam Questions EN/80 - Principles of Flight.md index 11342f0..7d9df91 100644 --- a/SPL Exam Questions EN/80 - Principles of Flight.md +++ b/SPL Exam Questions EN/80 - Principles of Flight.md @@ -126,6 +126,8 @@ CG = Centre of Gravity ### Q7: What purpose does the vertical tail fin (rudder assembly) serve? ^t80q7 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q7) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q7) - A) Providing roll stability @@ -378,6 +380,8 @@ The minimum sink rate speed is the speed at the lowest point of the speed polar. Any speed change — faster or slower — from this point increases the sink rate. Accelerating beyond minimum sink speed increases parasite drag faster than induced drag decreases, resulting in a higher total drag and therefore a greater rate of descent. This is the trade-off in cross-country flying: flying faster covers more ground but at the cost of increased sink rate. ### Q20: What is the effect of extending airbrakes (spoilers) on a glider? ^t80q20 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q20) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q20) @@ -1290,7 +1294,7 @@ > **Speed Polar:** -> ![[figures/t80_q66.png]] +>  > *A = tangent from the origin → best glide speed (best L/D ratio, best glide)* > *B = tangent from a point shifted to the right on the V axis → best glide with headwind* @@ -1475,7 +1479,7 @@ [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q75) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q75) -![[figures/t80_q75.png]] + - A) The air mass flows through a larger cross-section at a higher speed - B) The air mass flows through a smaller cross-section at a lower speed @@ -1509,6 +1513,8 @@ ### Q77: When the frontal area of a disc in an airflow is tripled, drag increases by: ^t80q77 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q77) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q77) - **A)** 9 times @@ -1518,13 +1524,28 @@ #### Answer -B) +C) #### Explanation -Stall occurs at a critical angle of attack (stall angle), regardless of airspeed. At this angle, airflow separation on the upper surface causes a sudden drop in lift. +The drag equation is D = ½ × rho × V² × Cd × A, where A is the frontal (reference) area. Drag is directly proportional to frontal area: if A triples, drag triples. + +- **A (9 times)** is wrong — that would apply if drag were proportional to A² (it is not). +- **B (1.5 times)** is wrong — there is no ½ factor when scaling area. +- **D (6 times)** is wrong — no physical basis for this multiplier. +- **C (3 times)** is correct because D is linearly proportional to A. + +#### Key Terms + +- **D** — Drag force +- **rho** — ρ (rho) — air density +- **V** — Velocity / Airspeed +- **Cd** — Drag Coefficient — dimensionless shape-dependent factor +- **A** — Frontal Area — cross-sectional area perpendicular to the airflow ### Q78: Aerodynamic wing twist (washout) is a modification of: ^t80q78 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q78) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q78) @@ -1539,7 +1560,24 @@ #### Explanation -Airflow separation occurs at a determined angle of attack (critical angle), specific to each airfoil. It is not related to the nose attitude relative to the horizon. +There are two types of wing twist (washout): + +- **Geometric washout** changes the angle of incidence of the SAME aerofoil from root to tip (the wing is physically twisted so the tip has a lower angle). +- **Aerodynamic washout** changes the AEROFOIL PROFILE from root to tip (different cross-sections are used so the tip section has a lower zero-lift angle or stalls at a higher local angle of attack). + +The question specifically asks about "aerodynamic wing twist," which is the aerofoil profile change (B). Both types aim to make the wing root stall before the tip, preserving aileron effectiveness during stall. + +- **A** describes geometric washout, not aerodynamic washout. +- **C** is wrong — ailerons change angle of attack dynamically, not as a permanent design feature. +- **D** is wrong — dihedral is a separate concept (wing angled upward for lateral stability). + +#### Key Terms + +- **Washout** — wing twist that reduces lift at the tip to delay tip stall +- **Geometric washout** — same profile, twisted to lower incidence at the tip +- **Aerodynamic washout** — different profiles from root to tip +- **Dihedral** — upward angle of the wing from root to tip for lateral stability + ### Q79: What is the average value of gravitational acceleration at the Earth's surface? ^t80q79 @@ -1579,6 +1617,8 @@ Airspeed indicator reading is based on the difference between static pressure and total pressure (dynamic pressure). The ASI measures this difference via the Pitot tube and static port. ### Q81: The horizontal and vertical stabilisers serve in particular to: ^t80q81 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q81) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q81) @@ -1690,7 +1730,7 @@ [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q87) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q87) -![[figures/t80_q87.png]] + - **A)** Fowler - **B)** Split Flap @@ -1748,7 +1788,7 @@ [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q90) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q90) -![[figures/t80_q90.png]] + - **A)** M - **B)** K @@ -1863,7 +1903,7 @@ [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q95) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q95) -![[figures/t80_q95.png]] + - A) H - B) B @@ -2029,7 +2069,7 @@ [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q102) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q102) -![[figures/t80_q102.png]] + - A) Plain Flap - B) Split Flap @@ -2363,6 +2403,8 @@ ### Q117: The elevator causes the aircraft to rotate around the ^t80q117 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q117) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q117) - **A)** Longitudinal axis @@ -2407,6 +2449,8 @@ CG = Centre of Gravity ### Q119: What benefit does differential aileron deflection provide? ^t80q119 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q119) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q119) @@ -2721,6 +2765,8 @@ - **CL_max** — Maximum Lift Coefficient — highest CL the wing can produce before stalling ### Q133: What is the aerodynamic effect of deploying airbrakes? ^t80q133 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q133) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q133) - A) Both drag and lift increase @@ -2877,6 +2923,8 @@ ### Q140: What happens when the rudder is deflected to the left? ^t80q140 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q140) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q140) - **A)** The aircraft pitches to the right @@ -3011,6 +3059,8 @@ - Pilots experience ground effect as a floating sensation during the landing flare. ### Q146: Rudder deflections rotate the aircraft around the ^t80q146 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q146) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q146) @@ -3170,6 +3220,8 @@ ### Q153: If the right aileron deflects upward and the left aileron deflects downward, how does the aircraft react? ^t80q153 + + [DE](../SPL%20Exam%20Questions%20DE/80%20-%20Grundlagen%20des%20Fliegens.md#^t80q153) · [FR](../SPL%20Exam%20Questions%20FR/80%20-%20Principes%20du%20vol.md#^t80q153) - **A)** Rolling to the right with yaw to the left -- Gitblit v1.3.1