The Manoeuvring Envelope

1. The Manoeuvring Envelope Part 2 The placard, structure and flight limitations D S Puttock based on the work of WG Scull

2. 6 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

3. 6 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

4. 6 Stall Line 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

5. 6 5 FLIGHT NOT POSSIBLE 4 FLIGHT POSSIBLE 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

6. 6 Stall Line 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

7. 6 Stall Line 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

8. 6 Stall Line 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

9. 6 Stall Line 5 Vs=1g stall speed 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

10. 6 Stall Line 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 Typical cambered aerofoil, works poorly upside down -1 -2 -3 D S Puttock based on the work of WG Scull -4

11. 6 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

12. Design dive speed VD 6 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 Normal gravity -1 -2 -3 D S Puttock based on the work of WG Scull -4

13. Design dive speed VD 6 Several calculations to derive VD. Gliders built under JAR-22 are either utility or aerobatic category. VNE and not VD appears on the placard 5 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

14. Velocity never exceed VNE VD 6 . 5 VNE is usually 90% of VD 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

15. Demonstrated design speed VNE VD VDF 6 . 5 VDF is approximately 95% of VD During test flying, the glider is flown to the Demonstrated design Speed 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

16. VNE VD VDF 6 . n1 5 n2 4 3 LIMIT LOADS JAR-22 sets+4g As the limit load for Category “U” gliders at VD, and 5.3g at the stall line 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 n3 -2 n4 -3 D S Puttock based on the work of WG Scull -4

17. VNE VD VDF Limit load 6 . n1 5 n2 4 3 2 Load Factor,n 1 Kt 0 Envelope corners 20 40 60 80 100 120 140 160 -1 n3 -2 n4 -3 Limit load D S Puttock based on the work of WG Scull -4

18. 7 A Category 6 Limit load . n1 5 n2 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 Envelope corners -1 n3 -2 n4 -3 Limit load -4 D S Puttock based on the work of WG Scull -5

19. Failure! 8 Ultimate load 7 6 Damage . 5 Limit load Load Factor,n 4 3 2 The factor of safety required by JAR-22 is the limit load multiplied by1.5. 1 Kt 0 20 40 60 80 100 120 140 160 D S Puttock based on the work of WG Scull

20. 6 . 5.3 5 4 3 VA 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 The maximum manoeuvring speed VA, is where the 5.3g limit line crosses the stall line -1 -2 -3 D S Puttock based on the work of WG Scull -4

21. SUMMARY Failure 6 Flight not possible . Damage 5 4 3 Failure 2 Load Factor,n OK 1 Kt 0 20 40 60 80 100 120 140 160 -1 OK Flight not possible -2 Damage -3 Failure D S Puttock based on the work of WG Scull -4

22. The Gust Envelope Part 3 The placard, structure and flight limitations D S Puttock based on the work of WG Scull

23. Creation of the gust envelope A very sudden gust Will not instantly Stall the wing 6 Stall line revised . Briefly the wing can Produce 25% more Lift. 5 VNE VD 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 Load factors can Increase by 25% As a result -1 -2 -3 D S Puttock based on the work of WG Scull -4

24. Creation of the gust envelope JAR-22.333 At VB sailplane must be capable Of withstanding positive up and negative down gusts of 15 m/s 6 VB . 5 VNE VD 4 3 2 Load Factor,n 1 Kt This is defined As a strong gust And is about 30kts 0 20 40 60 80 100 120 140 160 -1 -2 -3 D S Puttock based on the work of WG Scull -4

25. Creation of the gust envelope Rough air is all air in lee-wave rotors, thunderclouds visible whirlwinds or over mountain crests 6 VB . 5 VNE Strong gust +15 m/s VD 4 3 2 Load Factor,n 1 Kt VA cannot be more Than VB In practice they are often very close. 0 20 40 60 80 100 120 140 160 -1 Strong gust +15 m/s -2 -3 D S Puttock based on the work of WG Scull -4

26. Creation of the gust envelope 6 VB . Strong gusts are not an issue up to VB (Max Rough Air) 5 VNE Strong gust +15 m/s VD 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 -1 Strong gust +15 m/s -2 -3 D S Puttock based on the work of WG Scull -4

27. Creation of the gust envelope 6 VB . Weak gust +7.5 m/s Strong gusts are not an issue up to VB (Max Rough Air) 5 VNE VD 4 3 2 Load Factor,n 1 Kt 0 20 40 60 80 100 120 140 160 Weak gusts are +7.5 m/s -1 Weak gust +7.5 m/s -2 -3 D S Puttock based on the work of WG Scull -4

28. Creation of the gust envelope Additional Effect of loop EXAMPLE 6 VB . Weak gust +7.5 m/s Sailplane at 110kts meets a weak gust. 5 VNE VD 4 Effect of gust 3 2 Load Factor,n Effect of Normal flight 1 Kt If the glider pulls 3g in a loop, at the same moment. The aircraft will be Outside the placarded Limits. 0 20 40 60 80 100 120 140 160 -1 Weak gust +7.5 m/s -2 -3 D S Puttock based on the work of WG Scull -4