PROJECT PT. 85

Jason Cornelius, Penn State University

SAE INTERNATIONAL

Objectives

• Emphasize a “gap” in the capabilities of modern aircraft

• Introduce the challenge Mr. Frank Harris posed in his

presentation, The V/STOL Performance Gap (VTOL-sf.org), to fill

this gap

• Explain the need for VTOL commercial transport

• Present a novel VTOL configuration

• Highlight how this design stands out from what currently exists

• Discuss a preliminary look into the technology

• Get people to start thinking of ways to close this gap

Objectives

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The complicated

problem called VTOL

• Fixed wing type

certificates issued at

a much greater rate

than VTOL

machines

The Complicated Problem Called VTOL

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THERE ARE A LOT OF CHALLENGES TO OVERCOME WITH VTOL

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The performance gap

• For the same ESHP

(equivalent shaft

horsepower) per unit

weight, fixed wing aircraft

are remarkably faster

• Setting ESHP aside,

there is an obvious

separation between the

cruise speed of fixed

wing and VTOL aircraft

The Performance Gap

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CURRENT VTOL DESIGNS INHIBIT HIGH CRUISE SPEEDS

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NASA-identified aviation

mega drivers

• Global mobility

• Accessibility

• Cost

• Speed

• Technological convergence

• Safety

• Comfort

• Noise reduction

• Environmental challenges

• Efficient

• Reduced fuel burn

NASA-Identified Aviation Mega Drivers

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DESIGN NEEDED TO FLOURISH CROSS CULTURAL

DEVELOPMENT

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Current concepts’

runway dependence

• Runway dependent

aircraft have a strong

relation between max

speed and landing

speed

• Higher landing speeds

require longer runways

Current Concepts’ Runway Dependence

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CURRENT COMMERCIAL DESIGNS MAKE TRANPORATION

VIABLE ONLY WITH LONG RUNWAYS

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Benefits of VTOL capability

• Gate-to-gate time reduced

• No taxiing leads to lower

fuel consumption

• Users can get from point A

to point B quickly without

needing a runway

• Vertiports can begin to

appear everywhere and

anywhere

• Reduces noise levels for

airport neighbors since the

aircraft’s ascent and

descent occur directly over

the LZ

Benefits of VTOL Capability

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FAST AND ACCESSIBLE MEANS OF TRANPORTATION

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Past and current concepts

• There have been many

ideas to bring increased

speed to the VTOL realm

• Majority of new concepts

lack enough benefits to

pursue commercially

Past and Current Concepts

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NEW CONCEPTS ARE COMMON AND POSSIBLE

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Making progress, but

we’re not there yet

• In recent years some

new VTOL concepts

have begun to close

the speed gap

• Still much room to

cover

Making Progress, but We’re Not There Yet

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A NOVEL APPROACH NEEDED TO SOLVE THE PROBLEM

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A novel concept: Project pt. 85

• VTOL capable runway independent aircraft

• High subsonic, low transonic cruise speeds

• Range of configurations possible

• Boeing 737 size shown below in hover configuration

A Novel Concept: Project pt. 85

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A POTENTIAL SOLUTION TO CLOSE THE SPEED GAP

Not To Scale

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Turbolift engine technology

• Lifting surface placed in fan exhaust stream

• End plate design used to combat low AR

• Controllable angle-of-attack

• Turbine exhaust directed above (away from) Turbolift wing

Turbolift Engine Technology

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USING THE EXHAUST ENERGY TO OUR ADVANTAGE

Rear Engine

Exhaust

Flow

Not To Scale

𝑉∞

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Conversion method/ VTOL

& cruise

• The 4 Turbolift engines

allow for a vertical ascent

from the terminal

• The thrust of the front

two engines is

decreased to provide a

net forward thrust

accelerating the aircraft

• Once adequate lift is

established on the wing,

the forward two engines

spool down and stow

Conversion Method/ VTOL & Cruise

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STOWED ENGINES ACT AS TIP MOUNTED TANKS FOR MAIN

WING AERODYNAMIC BENEFITS

Front Engine

Exhaust

Flow

𝑉∞

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Configuration size, speed,

range

• Regional or mainline

• Commercial transport

• 150 pax

• VTOL, high subsonic,

low transonic cruise

• 300-450 knots at

altitude

• Can be configured to

short, medium, or long

range

Configuration Size, Speed, Range

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TARGETS LARGE PERCENTAGE OF FLIGHTS TAKING OFF IN THE

U.S.

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Wing Sizing

BASIC ANALYSIS SHOWS PLAUSIBLE NUMBERS

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Metric Project pt. 85 Boeing 737-700

Runway Requirement 0 ft 5,520 ft

Seating Capacity 149 pax 149 pax

Max. Gross Weight 157,000 lbs 155,000 lbs

Wing Area 646 ft^2 1340 ft^2

Wing Loading (MGW) 244 lbs/ft^2 115 lbs/ft^2

Max. Cruise Speed 450 kts 450 kts

Cruise Altitude 35,000 ft 35,000 ft

Engine LEAP-1A CFM56-7B20

Performance Comparison

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A COMPETITIVE VERTICAL TAKE OFF AND LANDING CONCEPT

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Safety

• 1 engine out

considerations

• Option 1 (emergency

conversion): Accelerate forward to

establish lift, then fly to

nearest capable

runway

• Option 2 (emergency

landing): In the event

of being too low to carry

out option 1, a hard

landing is performed

Safety

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FAA TYPE CERTIFICATE POSSIBLE

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Conclusions

• There is obvious need for an efficient commercial VTOL vehicle

• New ideas and concepts continue to close in on the “Speed Gap”

between fixed wing and VTOL

• Project pt. 85 helps put into perspective what it would truly mean to

have a means of transportation as described

• Commercial V/STOL configurable for multiple airliner

configurations with flight envelope to Mach .85

• Zero length runway requirement

• Taxiing is essentially eliminated

• Creates the accessibility to open vertiports almost anywhere

• Decreased noise impact on surroundings during climb and

descent to/from cruise

• The design presented competes favorably with a 737 type transport

Conclusions

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Next steps/ vision

• Further develop

the current

configuration

• Continue thinking

of out of the box

ways to close the

speed gap

Next Steps/ Vision

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VISION: A WORLD WHERE EVERYONE FLIES EVERYWHERE

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Questions?

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