Jay Carter, Founder & CEO CAFE Electric Aircraft Symposium July 23 rd, 2017

CARTER AVIATION TECHNOLOGIES An Aerospace Research & Development Company www.cartercopters.com Wichita Falls, Texas Jay Carter, Founder & CEO CAFE Electric Aircraft Symposium July 23 rd, 2017 2015 CARTER AVIATION TECHNOLOGIES, LLC SR/C is a trademark of Carter Aviation Technologies, LLC 1

A History of Innovation Built first gyros while still in college with father s guidance Led to job with Bell Research & Development Steam car built by Jay and his father First car to meet original 1977 emission standards Could make a cold startup & then drive away in less than 30 seconds Founded Carter Wind Energy in 1976 Installed wind turbines from Hawaii to United Kingdom to 300 miles north of the Arctic Circle One of only two U.S. manufacturers to survive the mid 80s industry decline 2015 CARTER AVIATION TECHNOLOGIES, LLC 2

SR/C Technology Progression 1998 1 st Gen First flight 2009 License Agreement with AAI, Multiple Military Concepts 2005 1 st Gen L/D of 7.0 2013-2014 DARPA TERN Won contract over 5 majors 2011 2 nd Gen First Flight Later Demonstrated L/D of 12+ 2017 Find a Manufacturing Partner and Begin Commercial Development 1994-1997 Analysis & Component Testing 1994 Company founded 22 years, 22 patents + 5 pending 11 key technical challenges overcome Proven technology with real flight test 2015 CARTER AVIATION TECHNOLOGIES, LLC 3

SR/C Technology Progression Quiet Jump Takeoff & Flyover at 600 ft agl Video also available on YouTube: https://www.youtube.com/watch?v=_vxoc7xtfrm 2015 CARTER AVIATION TECHNOLOGIES, LLC 4

Profile HP SR/C vs. Fixed Wing SR/C rotor very low drag by being slowed 600 500 400 300 200 100 0 Profile HP vs. Rotor RPM, PAV Rotor @ 250 kts @ SL 54 5.7 0 100 200 300 400 Rotor RPM 299 155 HPo - Full HPo - Rot Only Drag per WADC TR 55-410: 3 2 R 1 4.6 0 8 D b 0 SR/C wing very small because rotor supports aircraft at low speeds wing can be sized for cruise Fixed-wing wing must be sized for low speed/landing SR/C slowed rotor & small wing equivalent to fixed-wing s larger wing 2015 CARTER AVIATION TECHNOLOGIES, LLC 5 HP O C A 550

SR/C Electric Air Taxi Ø34 54 Cabin Width 36 2015 CARTER AVIATION TECHNOLOGIES, LLC 6

High inertia, low disc loaded rotor acts as built-in parachute, but safer because it works at any altitude / speed, and provides directional control SR/C Electric Air Taxi Features Lightweight, low profile, streamlined tilting hub greatly reduces drag. No spindle, spindle housing, bearings or lead-lag hinges Slowed rotor enables high speed forward flight, low drag, low tip speed/noise, no retreating blade stall 10 diameter scimitar tail prop rotates to provide counter torque for hover or thrust for forward flight Tall, soft mast isolates airframe from rotor vibration for fixed-wing smoothness Tilting mast controls aircraft pitch at low speeds & rotor rpm for high cruise efficiency at high speeds Battery pack in nose to balance tail weight Extreme energy absorbing fail safe landing gear up to 30 ft/s improves landing safety Simple, light, structurally efficient wing with no need for high lift devices Mechanical flight control linkages to optional pilot in parallel with actuators for true redundancy High aspect ratio wing with area optimized for cruise efficiency 2015 CARTER AVIATION TECHNOLOGIES, LLC 7

Empty Weight, lbs Range, miles 2250 2200 2150 2100 2050 2000 Performance Parameters Drag coefficients based on actual achieved data, not expected improvements 3200 lb empty weight with batteries 4000 lb max gross weight (800 lb max payload) 300 W-hr/kg battery energy density Assumed margin for 0.5 Empty Weight Fraction at 600 ft/s tip speed Mission: 30 sec HOGE for takeoff, Climb at Vy to 5k ft, Cruise at 175 mph, Descend at Vy, 2 min HOGE at landing (no reserve) Empty Wt (w/o batteries) vs. Rotor Hover Tip Speed 1950 400 450 500 550 600 650 700 Rotor Hover Tip Speed, ft/s 2213 lbs D=213 lbs 2000 lbs 2015 CARTER AVIATION TECHNOLOGIES, LLC 8 200 180 160 140 120 100 80 60 40 20 0 Range at 175 mph vs. Payload for Various Hover Tip Speeds 0 200 400 600 800 1000 Payload, lbs Figure 1 Figure 2 159 miles D=46 miles 113 miles 600 ft/s 550 ft/s 500 ft/s 450 ft/s Note: 150 mph cruise will extend range by ~10% at 800 lb payload

L/D Air Taxi Concept Comparison Compared three different configurations SR/C Hex Tilt Rotor T Tilt Rotor Used common assumptions and methods for all three concepts Based drag coefficients and parameters on measured flight data from PAV SR/C Carter PAV L/D vs. IAS 14 12 10 8 6 4 Meas'd Model Hex Tilt Rotor 2 0 0 50 100 150 200 250 IAS, mph Actual Measured Flight Data Note: Data scatter mostly attributable to gathering data when developing rotor rpm / mast control algorithms and varying rotor rpm considerably T Tilt Rotor 2015 CARTER AVIATION TECHNOLOGIES, LLC 9

Analysis Methods & Assumptions Parameter Assumptions Gross Weight 4000 lbs Pilot/Pax Weight 200 lbs per person 4 people max Empty Weight Calc d with same method for all modified Raymer Battery & Drive Efficiency 0.92 Useable Battery Capacity Motor + Inverter Weight Wiring Weight Drag Coefficients Hover Typical Mission Planning Mission 80% (top 10% unuseable with rapid charge, bottom 10% unuseable to avoid current spike) Scaled Linearly with Max Continuous Power 0.4 lb/hp Assumed motor could be overloaded 1.87x for 30 sec for OEI Limited current to 40 amp per wire, running multiple wires per leg to reach full current required. Per N.E.C., used AWG-10 with Class C Insulator Used same coefficients on all concepts & appropriately scaled misc drags as derived from calibrating model to actual flight data from PAV Hover Out of Ground Effect (HOGE) at 6k ft with 1.1x margin 30 sec hover, climb, cruise, descent, 30 sec hover 120 sec hover, climb, cruise, descent, 120 sec hover +Reserve: 120 sec hover, 2nm divert, 120 sed hover 2015 CARTER AVIATION TECHNOLOGIES, LLC 10

34 width 34 ft Common Footprint Footprint driven by interface with vertiports If certain size footprint can be justified, justification is applicable to all technologies Single Rotor SR/C & Hex Tilt Rotor have similar disc loadings T tilt rotor has very high disc loading T TR Hex TR SR/C Rotor Area, ft² 144.9 791.5 907.9 Disc Loading, lb/ft² 27.6 5.1 4.4 Total Hover HP 774.0 368.4 424.0 30 sec OEI HP 1869.6 467.8 N/A Cruise HP at 175 mph 240 240 207 Total Installed Cont HP 1099.2 390.1 612.8 39 ft T TR Rotor Area only includes 4 lifting rotors (tails rotors for trim control only) SR/C Total Hover HP includes tail rotor power to counter torque All Hover HPs include 10% lift margin 2015 CARTER AVIATION TECHNOLOGIES, LLC 11

L/D Empty Weight, Excluding Batteries, lb Comparison Preliminary Results Range, miles mile / kw-hr T Tilt Rotor has very high HP required due to disk loading higher empty weight for installed HP SR/C has better L/D @ 175 mph due to smaller wings & less wetted area from prop spinners, fuselage, & no LG sponsons Empty Weight vs. Width Range vs. Payload 2,100 2,050 2,000 1,950 1,900 1,850 1,800 1,750 1,700 32 34 36 38 40 42 Overall Width, ft SR/C Hex TR T TR 180 160 140 120 100 80 60 40 20 0 0 200 400 600 800 1000 Payload, lbs SR/C - 40 ft SR/C - 37 ft SR/C - 34 ft Hex TR - 40 ft Hex TR - 37 ft Hex TR - 34 ft 'T' TR - 40 ft 'T' TR - 37 ft 'T' TR - 34 ft L/D vs. Airspeed Mileage vs. Payload 16 14 12 10 8 6 4 2 0 0 50 100 150 200 True Airspeed, mph SR/C - 40 ft SR/C - 37 ft SR/C - 34 ft Hex TR - 40 ft Hex TR - 37 ft Hex TR - 34 ft 'T' TR - 40 ft 'T' TR - 37 ft 'T' TR - 34 ft 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 200 400 600 800 1000 Payload, lbs SR/C - 40 ft SR/C - 37 ft SR/C - 34 ft Hex TR - 40 ft Hex TR - 37 ft Hex TR - 34 ft 'T' TR - 40 ft 'T' TR - 37 ft 'T' TR - 34 ft 2015 CARTER AVIATION TECHNOLOGIES, LLC 12

Energy, kw-hr Comparison Preliminary Results SR/C has farthest range with least energy used in typical mission, due to better L/D at 175 mph T Tilt rotor has low useable energy because of high empty weight fraction. Has low percentage of energy available for cruise because of high HOGE power requirements for planning / reserve. 180 Useable Energy Budget, 800 lb payload, 34' width 160 140 120 100 80 60 40 R3. Reserve 2 min HOGE R2. 2 nm reserve at best endurance R1. Reserve 2 min HOGE P1. 90 sec + 90 sec add'l HOGE for planning 5. 30 sec HOGE 4. Descend to Ldg Altitude 3. Cruise at 5000 at 175 mph 2. Climb at Max ROC to Cruise Alt 1. 30 sec HOGE Reserve Add l HOGE for Planning Typical Mission 20 0 SR/C (123 mile) Hex TR (110 mile) 'T' TR (49 mile) 2015 CARTER AVIATION TECHNOLOGIES, LLC 13

Extreme energy absorbing 24 stroke for descent rates up to 24 ft/s at touchdown Responds to impact speed for near constant deceleration across full throw of gear No rebound no bouncing Proven technology used on all Carter prototypes Lightweight due to efficient energy absorption Energy Absorbing Cylinder Extreme Energy Absorbing Landing Gear PAV Single Strut Design Air Over Hydraulic for Energy Absorption Carter Smart Strut Belleville Stackup to control valve to keep pressure on piston near constant based on impact velocity Automatic Metering Valve Torque Tube Main Gear Trailing Arm Hydraulic Pressure in Lower Cylinder for Gear Retract 2015 CARTER AVIATION TECHNOLOGIES, LLC 14

Energy Absorbing Landing Gear Video Video also available on YouTube: https://www.youtube.com/watch?v=mntcejrl2ye 2015 CARTER AVIATION TECHNOLOGIES, LLC 15

Percentage of Max Energy Absorbing Landing Gear 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Note near constant pressure over full stroke Piston position (8.44" max) Valve position (.5" max) Pressure Top (3000 psi max) Pressure Bottom (3000 psi max) 0 0.5 1 1.5 2 Time (s) Data from drop test shown in previous slide 2015 CARTER AVIATION TECHNOLOGIES, LLC 16

Carter Scimitar Propeller Highly swept to reduce apparent Mach number Allows higher CL s, faster tip speeds, & thicker airfoils Swept tip reduces noise Twist a compromise between high speed cruise & static/climb Lightweight composites 1/2 to 1/3 the weight of conventional designs 100 diameter prop shown weighs 42 lb Tested at Mach 1 for cumulative 10 minutes Wide chord blade not stalled Spinner nearly flat at prop root Reduces decreasing pressure gradient, keeping good airflow on prop root Cruise efficiencies of 90+% Static/climb efficiencies on order of 30% better than conventional designs 2015 CARTER AVIATION TECHNOLOGIES, LLC 17

Scimitar Propeller Bearingless Design Pitch change accomplished by twisting the spar Eliminates spindle, spindle housing, and bearings used on conventional propeller simple & lightweight Similar design used on Carter rotors which further eliminates lead/lag and coning hinges Video also available on YouTube: https://www.youtube.com/watch?v=scrxvfwj7hy 2015 CARTER AVIATION TECHNOLOGIES, LLC 18

CARTER AVIATION TECHNOLOGIES An Aerospace Research & Development Company www.cartercopters.com Wichita Falls, Texas Jay Carter, Founder & CEO CAFE Electric Aircraft Symposium July 23 rd, 2017 2015 CARTER AVIATION TECHNOLOGIES, LLC SR/C is a trademark of Carter Aviation Technologies, LLC 19

Backup Slides 2015 CARTER AVIATION TECHNOLOGIES, LLC 20

Mission Definition Using same typical & planning missions as McDonald and German* Typical mission for operating cost only requires 30 sec hover for T.O. & landing Worst case mission for planning (i.e. charge required before taking off to fly a given mission) requires 120 sec T.O. & landing for given mission + 120 sec T.O. & landing for reserve + 2 nm reserve cruise For sizing, assuming 4 min continuous hover *McDonald, R. A., German, B.J., evtol Energy Needs for Uber Elevate, Uber Elevate Summit, Dallas, TX, April 2017. 2015 CARTER AVIATION TECHNOLOGIES, LLC 21

Cruise Performance Model L/D Analysis conducted with Carter s proprietary cruise analysis model For SR/C, developed mainly for cruise when rotor is unloaded Model calibrated to measured flight data for PAV. Inputs were scaled appropriately for these concepts. Had to estimate drag contributions from different elements, since the aircraft is only instrumented to measure overall thrust* Interference & separation drags can account for up to ~1/2 of total aircraft drag, and must be accounted for to allow accurate L/D prediction (based on flight test experience by Carter and Bell Helicopter / Ken Wernicke) Air taxi analysis breaks flight into short segments, incorporating climb, descent, and reserves 14 12 10 8 6 4 2 0 Carter PAV L/D vs. IAS 0 50 100 150 200 250 IAS, mph Meas'd Model Note: Data scatter mostly attributable to gathering data when developing rotor rpm / mast control algorithms and varying rotor rpm considerably * Overall drag is calculated based on thrust adjusted for rate of climb/descent report with methods is available 2015 CARTER AVIATION TECHNOLOGIES, LLC 22

Using same rationale as McDonald and German* for useable battery capacity Top 10% & Bottom 10% of capacity inaccessible 80% capacity accessible Ignoring internal resistance losses for this analysis Battery Assumptions DOD = Depth of Discharge Ignored for this analysis *McDonald, R. A., German, B.J., evtol Energy Needs for Uber Elevate, Uber Elevate Summit, Dallas, TX, April 2017. 2015 CARTER AVIATION TECHNOLOGIES, LLC 23

Time, sec Motor Overload Capacity Overload capacity very dependent on specific motor see examples below from various sources (only shown to illustrate behavior these aren t the motors being used) Model with a simple empirical curve that mimics those trends, where C is a constant 120 100 80 60 40 20 Thermal Limit assuming 90 sec @ 1.5x 0 1 1.5 2 2.5 3 I / I_rated Time = 2015 CARTER AVIATION TECHNOLOGIES, LLC 24 C I I rated 1 Based on text in Uber Elevate, assume a motor that can be overloaded 1.5x for 90 seconds (paper stated 1 2 min). Matching above formula to that data point, C = 22.5 2 t, sec I/Ir 15 2.22 30 1.87 45 1.71 60 1.61 90 1.50 120 1.43 240 1.31 480 1.22 Data from manufacturer needed to improve this estimate 1.87x for 30 sec OEI 1.31x for 4 min HOGE

Empty Weight Estimation Weight estimate for all concepts used same methodology Structures & Equipment Groups based on method in Chapter 15 of Raymer, Daniel P: Aircraft Design: A Conceptual Approach Structures weights multiplied by 0.50 to reflect gains from carboncomposite construction, with the exception of tilt rotor wings, which were multiplied by 0.625 to reflect the higher bending moments due to carrying lift from prop/rotor Landing Gear based on historical Carter data, not Raymer's method (same for all aircraft) Propeller weights based on historical Carter data All Equipment Group weights from Raymer included. Even if the system per se wasn t in the aircraft, the functions it would have done must still be performed by another system, so the weight must still be accounted for (e.g. hydraulics) All other weights based on best engineering practices and judgment 2015 CARTER AVIATION TECHNOLOGIES, LLC 25

Prop-Rotor Performance Conceptual design using a blade element model validated through previous Carter propellers calculates FOM & efficiency Includes induced velocity Airfoils design by John Roncz Uses CL & CD vs. alpha lookup tables for -20 < α < +20 Models CL & CD as sine functions for α < -20 or +20 < α Includes simple estimation of critical Mach & drag divergence Mach (Mcr & Mdd) based on CL, & increases CD accordingly Completed for both tilt rotor configurations (substantially different operating parameters due to disc loading) Different flight regimes in hover and cruise make prop-rotor less efficient than a conventional propeller Varied prop-rotor planform area to shift optimization from static (hover) performance to cruise performance Requires very low RPMs in cruise for best efficiency only possible with electric motors (Results shown next slide) 2015 CARTER AVIATION TECHNOLOGIES, LLC 26

FOM - cruise FOM - cruise Hex Tilt Rotor Hover Cruise Airspeed 0 175 mph RPM 820 422 ΩR 600 ft/s 310 ft/s HP per prop 66 HP 34 HP Dia 168 168 Spinner 15 15 T Tilt Rotor Hover Cruise Airspeed 0 175 mph RPM 1690 267 ΩR 600 ft/s 95 ft/s HP per prop 215 HP 34 HP Dia 81.5 81.5 Spinner 15 15 Prop-Rotor Performance 1.00 0.98 0.96 0.94 0.92 0.90 0.88 0.86 0.84 0.82 0.80 0.64 0.66 0.68 0.70 0.72 0.74 0.76 0.78 0.80 0.82 0.84 0.86 0.88 0.90 1.00 0.98 0.96 0.94 0.92 0.90 0.88 0.86 0.84 0.82 FOM - static 0.80 0.80 0.82 0.84 0.86 0.88 0.90 0.92 0.94 0.96 0.98 1.00 FOM - static Note different x-scales Cruise RPM is ratioed by HP cruise /HP hover, assuming constant torque from motor results in very low cruise rpm, especially for T Tilt Rotor T tilt rotor can achieve higher static FOM, but because of very high disk loading, actual HP requirement is still much higher 2015 CARTER AVIATION TECHNOLOGIES, LLC 27

Single Rotor SR/C Hover Performance Using slightly modified method from WADC TR 55-410* Rotor Induced HP: HP 0.03 W LW DiskLoading PlanformScaleFactor WingArea FuselageTopArea H Where HP ih = Induced horsepower in a hover W = weight L WH = Wing, fuselage, & horizontal stabilizer downforce in a hover A = Disk Area ρ = density ρ o = density at standard sea level Rotor Profile HP: o HPo CDb A R 8 Where HP o = Profile horsepower σ = Solidity ΩR = Tip speed µ = Advance ratio f pr = profile correction factor Tail Rotor HP: ih L WH W LW A o H 3 2 1 4.6 f 550 T k HP dia 3 2 1 o pr o HorStabArea *Foster, R. D., A Rapid Performance Prediction Method for Compound Type Rotorcraft, WADC TR 55-410, 1957. 2015 CARTER AVIATION TECHNOLOGIES, LLC 28

Wing Sizing Input from Ken Wernicke Former program technical manager of all Bell helicopter s tilt rotor programs from the XV-15 through the V-22 (now retired) Tilt rotors have a special consideration for avoiding stall during the transition between partial rotor supported flight and full lift on the wings Wing must be sized with appropriate margin. For 175 mph cruise, wing must support aircraft at 125 mph SR/C rotor is already in autorotation and can take over and provide the lift required to prevent wing stall For 175 mph cruise, wing must support aircraft at 150 mph 2015 CARTER AVIATION TECHNOLOGIES, LLC 29

Wing Sizing Concern Wing Sizing / Structural Integrity Required wing area combined with high wing spans yields very high aspect ratios High aspect ratio a concern for tilt rotors with prop-rotors mounted near wing tips AR with 34 span AR with 37 span AR with 40 span SR/C (S = 63 ft²) 18.4 21.7 25.4 Hex Tilt Rotor (S_main = 68 ft²)* 17.0 20.1 23.5 T Tilt Rotor (S = 83 ft²) 13.9 16.4 19.2 *Note, Hex Tilt Rotor has 3 wings. Fore & aft wings provide additional area Plan to do structural analysis to see if this will be an issue / how it will affect wing weight compared to historical trends from Raymer 2015 CARTER AVIATION TECHNOLOGIES, LLC 30

Electric Air Taxi SR/C Concept I 2015 CARTER AVIATION TECHNOLOGIES, LLC 31

Electric Air Taxi SR/C Concept I Features High speed & fixed wing smoothness from SR/C technology Tail prop rotates to provide counter torque for hover, or thrust for forward flight Scimitar prop for high cruise efficiency & high static thrust Battery pack in nose to balance tail weight Long tail boom reduces tail rotor required HP in hover, also reduces hor stab area 2015 CARTER AVIATION TECHNOLOGIES, LLC 32

Electric Air Taxi SR/C Concept Weight Component Weight Estimation (lbs) - CC-31A Hovering SR/C Concept I Gross Weight 34 37 40 Gross Weight 34 37 40 Structures Group Total Before Margins, no batteries W_wing 137.5 152.2 167.1 Total Empty Weight Before Margin 1,588.1 1,585.5 1,587.0 W_horizontal tail 8.9 8.9 8.9 Empty Weight Fraction Before Margin 0.397 0.396 0.397 W_vertical tail 5.9 5.9 5.9 W_fuselage 136.0 136.0 136.0 Margin W_main landing gear** 111.3 111.3 111.3 Margin % of Empty Weight 0.100 0.100 0.100 W_nose landing gear** 27.8 27.8 27.8 Margin, lbs 158.8 158.5 158.7 Total Structural 427.5 442.1 457.1 Total Empty Weight, no batteries Propulsion Group Total Empty Weight Including Margin 1,746.9 1,744.0 1,745.7 W_motors+inverters 245.1 228.3 214.8 Empty Weight Fraction Including 0.437 0.436 0.436 Margin W_wiring 10.3 9.6 9.0 W_prop 93.4 91.2 89.5 Batteries Total Propulsion 348.8 329.0 313.3 Battery Weight 1,453.1 1,456.0 1,454.3 Empty Weight, with batteries 3,200.0 3,200.0 3,200.0 Equipment Group W_flight controls 78.1 80.6 83.0 Other Weight W_hydraulics 4.0 4.0 4.0 Unusable Fuel 0.0 0.0 0.0 W_electrical 118.5 118.5 118.5 Oil 0.0 0.0 0.0 W_avionics 81.4 81.4 81.4 Oxygen 0.0 0.0 0.0 W_furnishings 167.8 167.8 167.8 Total Additions 0.0 0.0 0.0 W_air conditioning & anti ice 95.4 95.4 95.4 Total Equipment 545.3 547.8 550.2 Basic Weight 3,200.0 3,200.0 3,200.0 SR/C Unique Elements Gross Weight Rotor 200.0 200.0 200.0 Crew & Pax 800.0 800.0 800.0 Rotor Drive (Mechanical Only) 56.5 56.5 56.5 Gross Weight 4,000.0 4,000.0 4,000.0 Tail Rotor Pivot Mechanism 10.0 10.0 10.0 Total SR/C Elements 266.5 266.5 266.5 Structures & Equipment Groups based on method in Chapter 15 of Raymer, Daniel P: Aircraft Design: A Conceptual Approach Structures weights multiplied by 50% to reflect gains from carbon-composite construction Landing Gear based on historical Carter data, not Raymer's method. Includes hydraulic pumps to raise/lower gear W_hydraulics included to account for traditionally hydraulic systems, even though most of those will be electric on this aircraft All other weights based on best engineering practices and judgment Increasing structural weight from high aspect ratio wing offset by reduced motor weight due to lower hover power requirement 2015 CARTER AVIATION TECHNOLOGIES, LLC 33

Electric Air Taxi Hex Tilt Rotor Concept 2015 CARTER AVIATION TECHNOLOGIES, LLC 34

Electric Air Taxi Hex Tilt Rotor Features Carter propeller technology for light weight & best compromise between hover & cruise thrust Distributed Electric Propulsion (DEP) allows multiple rotors without weight & complexity of gearboxes & cross shafts Battery packs distributed along length of aircraft for reduced wire run lengths Lift sharing for 3 lifting surfaces optimized for lowest possible induced drag for configuration 2015 CARTER AVIATION TECHNOLOGIES, LLC 35

Motor Sizing for OEI Hover Sized motors to maintain hover even if one motor fails (One Engine Inoperative OEI) Must maintain balance around CG, not just total lift Two minimization strategies Minimize total horsepower while hovering Minimize horsepower increase of each individual motor results in lowest installed horsepower Solved with iterative solver to find min HP solutions Baseline Example Case Fail front left rotor Min Total HP Strategy keeps all remaining rotors providing lift. Total HP = 418.12, but rotor 2L must go to 2.18x the baseline (to balance moments about CG) Min Installed HP Strategy Drops opposite rotor (rear right). Total HP = 443.58, but 2L only must go to 1.75x the baseline 2L 1L 3L 1R 3R 2R normal hover 1L Fail, Min Total HP 1L Fail, Min Installed 1L Lift, lbs 682.23 0.00 0.00 1L Preq'd, HP 57.13 0.00 0.00 1L HP / HP Baseline 1.00 0.00 0.00 1R Lift, lbs 682.23 1070.24 988.89 1R Preq'd, HP 57.13 112.25 99.69 1R HP / HP Baseline 1.00 1.96 1.75 2L Lift, lbs 835.54 1404.31 1211.11 2L Preq'd, HP 69.96 152.45 122.10 2L HP / HP Baseline 1.00 2.18 1.75 2R Lift, lbs 835.54 808.04 1211.11 2R Preq'd, HP 69.96 66.54 122.10 2R HP / HP Baseline 1.00 0.95 1.75 3L Lift, lbs 682.23 705.93 988.89 3L Preq'd, HP 57.13 60.13 99.69 3L HP / HP Baseline 1.00 1.05 1.75 3R Lift, lbs 682.23 411.48 0.00 3R Preq'd, HP 57.13 26.76 0.00 3R HP / HP Baseline 1.00 0.47 0.00 Total Lift, lbs 4400.00 4400.00 4400.00 Total HP Req d 368.44 418.12 443.58 Max HP / HP Baseline 1.00 2.18 1.75 2015 CARTER AVIATION TECHNOLOGIES, LLC 36

Motor Sizing for OEI Hover Min installed power solutions will give best empty weight fraction / most battery capacity Summary of min installed power solutions: Small Rotor Motor Failure Large Rotor Motor Failure Failed Rotor Increase power to remaining rotors Failed Rotor Reduce to zero power Reduce to zero power Increase power to remaining rotors Motor HP Req d (4000 lb GW, 1.1 margin) Normal Hover Small Rotor Failure Main Rotor Failure Main Rotor HP Req d (each) 70.7 122.6 NA Small Rotor HP Req d (each) 56.4 97.7 117.0 2015 CARTER AVIATION TECHNOLOGIES, LLC 37

Hex Tilt Rotor Weight Component Weight Estimation (lbs) - CC-31C Hex Tilt Rotor Overall Width 34 37 40 Overall Width 34 37 40 Structures Group Total Before Margins, no batteries W_wings 189.6 193.4 208.1 Total Empty Weight Before Margin 1,587.3 1,573.5 1,572.9 W_horizontal tail 0.0 0.0 0.0 Empty Weight Fraction Before Margin 0.397 0.393 0.393 W_vertical tail 0.0 0.0 0.0 W_fuselage 126.5 126.5 126.5 Margin W_main landing gear** 111.3 111.3 111.3 Margin % of Empty Weight 0.100 0.100 0.100 W_nose landing gear** 27.8 27.8 27.8 Margin, lbs 158.7 157.3 157.3 Total Structural 455.2 459.1 473.8 Total Empty Weight, no batteries Propulsion Group Total Empty Weight Including Margin 1,746.0 1,730.8 1,730.2 W_motors+inverters 156.0 144.2 134.0 Empty Weight Fraction Including Margin 0.436 0.433 0.433 W_wiring 5.2 5.0 4.4 W_props 287.2 278.9 271.8 Batteries Total Propulsion 448.5 428.1 410.2 Battery Weight 1,454.0 1,469.2 1,469.8 Empty Weight, with batteries 3,200.0 3,200.0 3,200.0 Equipment Group W_flight controls 86.4 89.1 91.7 Other Weight W_hydraulics 4.0 4.0 4.0 Unusable Fuel 0.0 0.0 0.0 W_electrical 118.5 118.5 118.5 Oil 0.0 0.0 0.0 W_avionics 81.4 81.4 81.4 Oxygen 0.0 0.0 0.0 W_furnishings 167.8 167.8 167.8 Total Additions 0.0 0.0 0.0 W_air conditioning & anti ice 95.4 95.4 95.4 Total Equipment 553.6 556.3 558.9 Basic Weight 3,200.0 3,200.0 3,200.0 Other Systems Gross Weight BRS 100.0 100.0 100.0 Crew & Pax 800.0 800.0 800.0 Wing Tilt Mechanism 30.0 30.0 30.0 Gross Weight 4,000.0 4,000.0 4,000.0 Total Other Elements 130.0 130.0 130.0 Structures & Equipment Groups based on method in Chapter 15 of Raymer, Daniel P: Aircraft Design: A Conceptual Approach Structures weights multiplied by 50% to reflect gains from carbon-composite construction Landing Gear based on historical Carter data, not Raymer's method. Includes hydraulic pumps to raise/lower gear W_hydraulics included to account for traditionally hydraulic systems, even though most of those will be electric on this aircraft All other weights based on best engineering practices and judgment 2015 CARTER AVIATION TECHNOLOGIES, LLC 38

T Tilt Rotor 2015 CARTER AVIATION TECHNOLOGIES, LLC 39

Motor Sizing for OEI Hover Sized motors to maintain hover even if one motor fails (One Engine Inoperative OEI) Must maintain balance around CG, not just total lift To keep motors as light as possible (min empty weight), minimize power increase for each motor (not total power) strategy depends on which rotor fails Inboard Rotor Motor Failure Failed Rotor Failed Rotor Outboard Rotor Motor Failure Increase power Decrease power, but not to zero Tail Rotors don t provide significant lift Increase power Decrease to zero power Tail Rotors don t provide significant lift Motor HP Req d (34 overall width, 1.1 margin) Normal Hover Inboard Rotor Failure Outboard Rotor Failure Inboard Rotor HP Req d (L / R) 194 / 194 Fail / 388 547 / 547 Outboard Rotor HP Req d (L / R) 194 / 194 388 / 144 Fail / 0 2015 CARTER AVIATION TECHNOLOGIES, LLC 40

T Tilt Rotor Weight Component Weight Estimation (lbs) - CC-31F 'T' Tilt Rotor Overall Width 34 37 40 Overall Width 34 37 40 Structures Group Total Before Margins, no batteries W_wing 176.4 195.2 214.4 Total Empty Weight Before Margin 1,875.7 1,830.9 1,818.1 W_horizontal tail 21.3 21.3 21.3 Empty Weight Fraction Before Margin 0.469 0.458 0.455 W_vertical tail 0.0 0.0 0.0 W_fuselage 126.4 126.4 126.4 Margin W_main landing gear** 111.3 111.3 111.3 Margin % of Empty Weight 0.100 0.100 0.100 W_nose landing gear** 27.8 27.8 27.8 Margin, lbs 187.6 183.1 181.8 Total Structural 463.3 482.1 501.3 Total Empty Weight, no batteries Propulsion Group Total Empty Weight Including Margin 2,063.3 2,014.0 1,999.9 W_motors+inverters 439.7 392.8 365.7 Empty Weight Fraction Including Margin 0.516 0.503 0.500 W_wiring 26.8 23.8 22.0 W_prop 262.4 245.8 240.2 Batteries Total Propulsion 728.9 662.4 627.9 Battery Weight 1,136.7 1,186.0 1,200.1 Empty Weight, with batteries 3,200.0 3,200.0 3,200.0 Equipment Group W_flight controls 86.4 89.1 91.7 Other Weight W_hydraulics 4.0 4.0 4.0 Unusable Fuel 0.0 0.0 0.0 W_electrical 118.5 118.5 118.5 Oil 0.0 0.0 0.0 W_avionics 81.4 81.4 81.4 Oxygen 0.0 0.0 0.0 W_furnishings 167.8 167.8 167.8 Total Additions 0.0 0.0 0.0 W_air conditioning & anti ice 95.4 95.4 95.4 Total Equipment 553.6 556.3 558.9 Basic Weight 3,200.0 3,200.0 3,200.0 SR/C Unique Elements Gross Weight BRS 100.0 100.0 100.0 Crew & Pax 800.0 800.0 800.0 Wing Tilt Mechanism 30.0 30.0 30.0 Gross Weight 4,000.0 4,000.0 4,000.0 Total SR/C Elements 130.0 130.0 130.0 Structures & Equipment Groups based on method in Chapter 15 of Raymer, Daniel P: Aircraft Design: A Conceptual Approach Structures weights multiplied by 50% to reflect gains from carbon-composite construction Landing Gear based on historical Carter data, not Raymer's method. Includes hydraulic pumps to raise/lower gear W_hydraulics included to account for traditionally hydraulic systems, even though most of those will be electric on this aircraft All other weights based on best engineering practices and judgment 2015 CARTER AVIATION TECHNOLOGIES, LLC 41