University of Maryland Blitzen (concept design)

Blitzen (concept design)
University of Maryland
College Park, Maryland, USA
www.umd.edu

The Vertical Flight Society's (based in Fairfax, Virginia, USA) annual Student Design Competition began in 1984 and challenges students at colleges and universities around the world to design a vertical lift aircraft that meets specified requirements, provides a practical exercise for engineering students and promotes student interest in vertical flight technology. Each of the winning teams is awarded a cash stipend, while each of the first-place winning teams are invited with complimentary registration, to the Vertical Flight Society's Annual Forum and Technology Display to present the details of their designs.

In August 2021, the Vertical Flight Society announced its 39th Annual Student Design Competition. The student objective was to design an electric vertical takeoff and landing (eVTOL) air taxi aircraft for to accommodate all passengers, including passengers with reduced mobility. This would include designing an aircraft to accommodate people with any type of disability, including hidden disabilities. The competition was sponsored by Bell (based in Fort Worth, Texas, USA). The winners of the 39th Annual Student Design Competition were announced on August 22, 2022.

“These are the leaders of the future vertical lift industry,” said Mike Hirschberg, executive director of the Vertical Flight Society. “We hope this experience will change them and, through the visibility of this competition, also change people who are in the eVTOL industry today.” To date, eVTOL concepts have focused on feasibility, safety, airworthiness and efficiency. But as developers clear those hurdles, the goal is to ensure electric aircraft can transport anyone and everyone, including persons with reduced mobility, visible or hidden disabilities.

A student design team from University of Maryland in College Park, Maryland, USA won 1st Place in the undergraduate category of the competition for their Blitzen all-electric helicopter. The team's Executive Summary is here online. The electric helicopter, made for advanced air mobility (AAM), was designed specifically for passengers with reduced mobility, including hidden disabilities.

Blitzen’s name was inspired by the German word "blitz" which translates to lightning and is also the name of the mythical flying reindeer. The team sees Blitzen as a helicopter that everyone can enjoy in the future for fast, comfortable, non-polluting and provides convenient air taxi transportation.

The helicopter is flown by one pilot and can carry between two and four passengers. The helicopter will carry a maximum of two passengers in wheelchairs or a maximum of four passengers without wheelchairs. The interior seats are removable to allow space for wheelchairs. In addition to wheelchair accessibility, there is storage for large medical devices and the aircraft has resources for those with impaired hearing.

The helicopter can cruise at 150 mph (241 km/h) and has a range of over 100 miles (161 km). The empty weight of the helicopter is 4,485 lb (2,034 kg), has a maximum payload of 1,232 lb (559 kg) and has a maximum takeoff weight of 5,717 lb (2,593 kg). The helicopter has one main rotorblade (with five blades) and has one rear pusher propeller. In addition, the helicopter has one high main wing, to extend the range of the helicopter. The rotorcraft has the typical look of a helicopter with the exception of having a large wing and rear pusher propeller, the helicopter has one main rotorblade, a cabin, a tail boom and fixed skid landing gear.

The electric helicopter uses six electric motors to power the main rotorblade and uses four electric motors to power the rear pusher propeller. The main rotorblade has a semi-articulated rotor hub. Both the main rotorblades and the pusher propeller can have two electric motors fail and the helicopter can still land safely under its own power. All electrical and propulsion systems have redundancies to prevent single point failures. In the event of a total electric motor failure, the helicopter can autorotate and land safely on the ground.

For the ingress and egress of wheelchaired passengers, the design team recommends that retractable motorized lifts would be stored at all helipads. The lift can also help to load or unload medical equipment, luggage and cargo. There is also a luggage compartment in the rear of the helicopter.

The design team also states the helicopter's interior is easily reconfigurable and the rotorcraft could additionally be used for medical emergency evacuation missions, combat search and rescue, and for air cargo. The student team estimates the cost to purchase the helicopter is $1,926,700.00 USD and the cost of charging the batteries for the helicopter is $35.00 USD.

Specifications:

• Aircraft type: eVTOL passenger helicopter
• Piloting: 1 pilot
• Capacity: 4 passenger, 2 passengers with disabilities
• Cruise speed: 150 mph (241 km/h)
• Range: Over 100 m (161 km)
• Empty weight: 4,485 lb (2,034 kg)
• Maximum payload: 1,232 lb (559 kg)
• Maximum takeoff weight: 5,717 lb (2,593 kg)
• Rotorblade: 1 main rotorblade
• Tail propeller: 1 pusher tail propeller
• Electric motors: 10 electric motors (6 electric motors for the main rotorblade, 4 electric motors for the tailrotor)
• Power source: Batteries
• Fuselage: Carbon fiber composite
• Windows: Large helicopter type windows
• Wings: 1 high main wing
• Tail: 1 rear standard helicopter tail with with rear horizontal stabilizers
• Landing gear: Fixed skid landing gear
• Safety features: Distributed Electric Propulsion (DEP), provides safety through redundancy for its passengers and/or cargo. DEP means having multiple propellers (or ducted fans) and motors on the aircraft so if one or more propellers (ducted fans) or motors fail, the other working propellers (or ducted fans) and motors can safely land the aircraft. There are also redundancies in the sub-systems of the aircraft. The helicopter can autorotate in case all electric motors fail.

Resources:

• University of Maryland website
• Article: The Vertical Flight Society Announces the Winners of the 39th Annual Student Design Competition, Vertical Flight Society, Aug. 22, 2022
• Article: VFS Announces the Winners of the 39th Annual Student Design Competition, eVTOL Insights, Aug. 24, 2022