Blended Wing Body X-48B Flight Test

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Blended Wing Body X-48B Flight Test R. H.

X-48B Being Installed in ODU 30x60 Tunnel

of All Boeing rights Management reserved.

1 Blended Wing Body X-48B Flight Test R. H. Liebeck BWB Chief Scientist April 2015 X-48B Being Installed in ODU 30x60 Tunnel BOEING is a trademark of Boeing Management Company. BOEING Copyright is a 2009 trademark Boeing. of All Boeing rights Management reserved. Company. Copyright 2004 Boeing. All rights reserved. EOT_RT_Sub_Template.ppt 1/6/2009 1

2 Concept Genesis Is there an Aerodynamic Renaissance for the long-haul transport? -Dennis Bushnell, December years 45years EOT_RT_Sub_Template.ppt 2

3 Early BWB Concept (NASA / Douglas Aircraft 1993) Batwing Span Loading with Circular Pressure Vessels EOT_RT_Sub_Template.ppt 3

4 Structural Efficiency Conventional Aircraft Blended Wing Body Aerodynamic Lift Pressure Loads Span loading Non-lifting vs lifting fuselage Independent vs integrated wing box Payload distributed normal vs parallel to wing Ideal circular vs flat pressure vessel EOT_RT_Sub_Template.ppt 4

5 Structural Layout Exaggerated Cabin Skin Deflection at 2X Pressure EOT_RT_Sub_Template.ppt 5

6 Initial Performance Comparison (1993) EOT_RT_Sub_Template.ppt 6

7 Boeing BWB-450 Baseline EOT_RT_Sub_Template.ppt 7

8 Interior Volume Comparison Frontal Cross Section Side Cross Section A EOT_RT_Sub_Template.ppt 8

Aerodynamically Smooth 450 350 Common Cockpit,

9 Growing a BWB 250 Fuel volume available in wing Adds payload Adds wing area Adds span Balanced Aerodynamically Smooth Common Cockpit, Wing and Centerbody Parts EOT_RT_Sub_Template.ppt 9

10 OML Commonality BWB-5-250G BWB-5-450G EOT_RT_Sub_Template.ppt 10

11 Definition of Common/Cousin Parts Between BWB-250 and % Unique 33% Cousin Gauge Changes 39% Common Total Aircraft by Weight Non-Recurring Commonality Benefit 23% Non- Recurring Fleet Cost Payloads - 80% Common - 14% Cousin Wing Inner Spars & Bulkheads - 100% Common Recurring Commonality Benefit 12% Recurring Fleet Cost Unique OML for Stretch EOT_RT_Sub_Template.ppt 11

Greener than A Green Giant* Quieter Lower thrust Engine noise shielded by body Not reflected down by the wing No multi-segment flaps producing air

8,700 nm range each Lower Emissions Lower thrust Lower fuel burn Lower Material Waste Composite construction Lower structural weight Longer airframe

12 Greener than A Green Giant* Quieter Lower thrust Engine noise shielded by body Not reflected down by the wing No multi-segment flaps producing air noise Aircraft Comparison Shown to Same Scale Approx. 480 passengers each Approx. 8,700 nm range each Lower Emissions Lower thrust Lower fuel burn Lower Material Waste Composite construction Lower structural weight Longer airframe life Operators Empty Weight Maximum Takeoff Weight Total Sea-Level Static Thrust Fuel Burn per Seat BWB A3XX-50R BWB A3XX-50R BWB A3XX-50R BWB A3XX-50R 19% 32% 19% 18% * A3XX Briefing 2000 EOT_RT_Sub_Template.ppt 12

13 Why flight test? Flight test is justified when required data cannot be obtained via ground-based analyses and testing. Sub-scale, low-speed flight test requires that the vehicle is dynamically scaled. High-speed requires Mach scaling. Dynamic scaling assures that the angles between the 6 force and moment vectors are independent of scale. EOT_RT_Sub_Template.ppt 13

14 Vehicle Scaling Laws Example: Low Speed Vehicle High Speed Vehicle K = Scale Factor = Dynamic Scaling Mach Scaling Length, L K K for Vehicle, 1 for Motion Area, S = L 2 K 2 K 2 Volume, V = L 3 K 3 K 3 Density, ρ = m/v 1 1/K for Vehicle, 1 for Atmosphere Mass, m K 3 (Wt = 525 lb) K 2 (Wt = 6,176 lb, Wing loading preserved) Moment of Inertia, I = ml 2 K 5 K 3 to K 4 (Impossible to obtain K 3 ) Time, T K 1/2 1 Velocity, U K 1/2 1 Mach Number K 1/2 1 (Must be 1) Force, F = ρu 2 S K 3 K 2 Acceleration, F/m 1 1 Moment, M = ρu 2 SL K 4 K 3 Angular Acceleration, M/I 1/K 1 to 1/K (Motion too fast due to MOI < K 3 ) Angular Rate or Frequency, ω 1/K 1/2 1 to 1/K (Response is not correct) Angle, θ 1 1 to 1/K Reynolds Number, ρlu/µ K 3/2 K (Similar to pressurized wind tunnels) EOT_RT_Sub_Template.ppt 14

15 Critical Flight Control Technology C L Performance gain reduced wing area and weight B-2 pre-stall α limit Controllable in post-stall region BWB post-stall α limit High-rate large control surfaces create large secondary power demands α BWB Elevon #1 C M Stable Unstable Increased challenge to maintain control in unstable post-stall region Need to Prove that the BWB is as Robust as a C-17 EOT_RT_Sub_Template.ppt 15

16 Flying Wing Spin & Tumble Departures Then... Flying wing dynamics dominated by minimal aerodynamic pitch and yaw damping Post-stall, this could lead to unrecoverable spin and tumble modes Air Flow Model BWB-450-1L Now Spin testing shows that the BWB potentially has unrecoverable spin and tumble modes Need to prove that an advanced flight control system will prevent entry into departure regions EOT_RT_Sub_Template.ppt 16

17 Flying Wing Spin & Tumble Departures Then... Flying wing dynamics dominated by minimal aerodynamic pitch and yaw damping Post-stall, this could lead to unrecoverable spin and tumble modes Air Flow Model BWB-450-1L Now Spin testing shows that the BWB potentially has unrecoverable spin and tumble modes Need to prove that an advanced flight control system will prevent entry into departure regions EOT_RT_Sub_Template.ppt 17

BWB X-48B Overview Two X-48B Vehicles #1: Wind Tunnel & Flight Test #2: Primary Flight Test Two Configurations Slats extended & retracted Dynamically Scaled Maximum Weight: 525 lb Wing Span: 21 ft

18 BWB X-48B Overview Two X-48B Vehicles #1: Wind Tunnel & Flight Test #2: Primary Flight Test Two Configurations Slats extended & retracted Dynamically Scaled Maximum Weight: 525 lb Wing Span: 21 ft Max Equiv Airspeed: 118 kts Max Altitude: 10,000 ft MSL Vertical Load Factor Limits: +4.5 to -3.0 g s Flight Duration: 30 to 50 min Emergency Recovery System (Drogue, Parachute, and Air Bags) System Fabricated by Cranfield Aerospace in the UK EOT_RT_Sub_Template.ppt 18

19 X-48B Configuration Top View Triple JetCat P200 Engines Drogue Boom Clean top surface Interchangeable slat assemblies Pilots View Camera Air Data Booms EOT_RT_Sub_Template.ppt 19

20 X-48B Configuration Underside View Fixed Landing Gear Triple Airbags for Impact Attenuation Split Drag Rudders 20 Flying Control Surfaces Drogue Boom Access Hatches for Avionics, Fuel Tank, Actuator access, etc. EOT_RT_Sub_Template.ppt 20

X-48B Configuration Internal View Laser Height Sensor (Under) Main Chute Drogue Ejector Control Panel Drogue Chute Lines (Under Boom) Drogue Boom Drogue Ejector Air Data Interface Fuel Pumps &

21 X-48B Configuration Internal View Laser Height Sensor (Under) Main Chute Drogue Ejector Control Panel Drogue Chute Lines (Under Boom) Drogue Boom Drogue Ejector Air Data Interface Fuel Pumps & ECUs Air Bag Inflation System Batteries Fuel Tank Control Surface Actuators IMU (Rear of Bulkhead) Air Data Boom Transponder GPS Antennae Avionics Crate BIT Panel Antennae EOT_RT_Sub_Template.ppt 21

22 Air Vehicle Configuration Basic Construction Details Center Body Slat Wing Joint Wing Control Surfaces EOT_RT_Sub_Template.ppt 22

23 Air Vehicle Configuration Major Components Systron Donner C-MIGITS III IMU / GPS JetCat P200 Drogue Ejector Avionics Crate & Cards ATL Fuel Tank Laser Height Sensor Kearfott K2000 & Volz Actuators Air Data Probe Hitachi Camera Nose & Main Landing Gear EOT_RT_Sub_Template.ppt 23

24 Ground Vibration Test & Inertia Measurement EOT_RT_Sub_Template.ppt 24

25 GCS Trailer EOT_RT_Sub_Template.ppt 25

26 GCS Pilot Station EOT_RT_Sub_Template.ppt 26

27 Edwards Air Force Base EOT_RT_Sub_Template.ppt 27

28 Recovery System Drogue Main Airbags EOT_RT_Sub_Template.ppt 28

with flight control hardware active Data used by Boeing for

29 X-48B 30x60 Wind Tunnel Test ODU Langley Full-Scale Tunnel Wind tunnel test completed April / May hours of testing with flight control hardware active Data used by Boeing for X-48B simulation and flight control software EOT_RT_Sub_Template.ppt 29

30 X-48B Flight Test Summary 92 Flights completed (as of May 2011) 55 Flights w/ Slats Extended 37 Flights w/ Slats Retracted (12 Flights conducted to stall/deep stall) Test Highlights: Test Maneuvers Real-Time Stability Margins Envelope Expansion Automated Parameter Identifications (PID) Freq Sweeps/Doublets Steady Heading Sideslips - Simulate Cross-winds Lazy-8s and Wind-up Turns Airspeed Calibrations (Triangle method) Successful Approach to Stalls & Beyond Trim in Ground-Effect at 10 feet AGL Engine-out RTB and normal landing Operations from Hard Surface Runway vs. Lakebed Runway Edwards AFB North Base 6/24 3,000 Feet (Eastern End) EOT_RT_Sub_Template.ppt 30

31 6:00 am July 20, 2007 EOT_RT_Sub_Template.ppt 31

32 7:00 am EOT_RT_Sub_Template.ppt 32

33 8:30 am EOT_RT_Sub_Template.ppt 33

34 8:45 am EOT_RT_Sub_Template.ppt 34

35 First Flight Video EOT_RT_Sub_Template.ppt 35

36 EOT_RT_Sub_Template.ppt 36

37 9:20 am EOT_RT_Sub_Template.ppt 37

38 9:20 am EOT_RT_Sub_Template.ppt 38

39 10:30 am EOT_RT_Sub_Template.ppt 39

X-48B Primary Flight Test Result I. Unique tailless configuration required development of special flight control laws. II. Flight simulator developed to evaluate control laws and train pilots. III.

40 X-48B Primary Flight Test Result I. Unique tailless configuration required development of special flight control laws. II. Flight simulator developed to evaluate control laws and train pilots. III. Following first flight, test pilot reports that flying the simulator and flying the airplane are equivalent. IV. Test pilot reports that the X-48B exhibited no unusual characteristics, and is a very nice airplane to fly. Copyright 2007 Boeing. All rights reserved. EOT_RT_Sub_Template.ppt 40

X-48B Lessons Learned COTS Design approach Initial Equipment Cost Low, But Integration Cost may be High Original planned Engine Design not COTS large impact to Flight Duration Waypoint Nav Design /

41 X-48B Lessons Learned COTS Design approach Initial Equipment Cost Low, But Integration Cost may be High Original planned Engine Design not COTS large impact to Flight Duration Waypoint Nav Design / Software V&V testing Test Limits - Windshear, Gusts / Weather Balloon Data Flight Simulator invaluable for Successful Tests Very good match for flight Excellent flight rehearsal / pilot training tool Braking PIO potential High No Decel Feedback to Pilot / Brake Spring or Ground Models inaccuracies Robust Flight Control System can Mask some Control Law Deficiencies Lessons Re-Learned Copyright Boeing. All rights reserved. EOT_RT_Sub_Template.ppt 41

X-48B What s Next for the Future COTS Design approach Flight Duration Flight control logic (Beta Switching) Waypoint Nav Design / testing Test Limits (windshear, gusts) 2-D view soda

42 X-48B What s Next for the Future COTS Design approach Flight Duration Flight control logic (Beta Switching) Waypoint Nav Design / testing Test Limits (windshear, gusts) 2-D view soda straw limitations Braking PIO potential Testing planned to continue thru FY2012 Modified Geometry for Lower Noise Copyright Boeing. All rights reserved. EOT_RT_Sub_Template.ppt 42

43 BWB X-48C EOT_RT_Sub_Template.ppt 43

44 X-48C Low Noise Configuration in 30x60 Wind Tunnel EOT_RT_Sub_Template.ppt 44

45 Innovation: Before & After Initial Goal: Create a concept for a subsonic transport that may be distinct from tube & wing (DC-8, B707). Initial Result: BWB that offered reduced fuel burn via a very high Lift/Drag ratio and large wingspan. Developed Result: BWB that offers breakthrough fuel efficiency and noise reduction. Unplanned Features: Natural family, low noise, low part-count and low cost. Unplanned Liability: As a disruptive technology, the BWB may be regarded as a threat to existing airplanes. EOT_RT_Sub_Template.ppt 45

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