Minibee TRL2

TRL 2 – Mini-Bee | Technology Concept Formulated

At TRL 2, the Mini-Bee project moved from basic principles to a first formulated aircraft concept. This stage focused on transforming the original VTOL idea into a more structured configuration, supported by academic studies, preliminary simulations, mock-ups, usage analysis, structural work and early technical assumptions. This page documents the collaborative work carried out during the TRL 2 phase and the historical Mini-Bee configuration studied at that stage.

Mini-Bee TRL2 concept visual

Quick project summary

Project Mini-Bee

TRL stage TRL 2 – Technology Concept Formulated

Main objective Formulate a first VTOL aircraft concept

Main outputs Studies, mock-ups, simulations and first configuration data

Visual introduction

Taxi concept Visual representation of the Mini-Bee TRL2 configuration. Open image

3-view layout Three-view representation used to clarify the aircraft configuration. Open image

3D mock-up Digital mock-up supporting concept formulation and communication. Open image

Project overview

TRL 2 – Technology Concept Formulated corresponds to the stage where the Mini-Bee project started to define a credible technical concept from the initial TRL 1 observations.

At this stage, the goal was not yet to validate a prototype. The objective was to describe a possible aircraft configuration, identify the main technical domains to study, and distribute work between academic contributors.

TRL 2 objective: formulate a first coherent Mini-Bee aircraft concept, supported by preliminary technical studies, mock-ups, simulations and mission assumptions.

Work done during TRL 2

During TRL 2, the Mini-Bee project benefited from a broad collaborative effort involving universities, engineering schools and technical contributors.

The work covered several technical and operational domains:

• aeronautical simulation;
• use cases and mission analysis;
• propulsion and engine assumptions;
• structural design;
• mechanical mock-up development;
• aerodynamic optimisation;
• equipment studies;
• human-machine interface;
• seats and safety;
• sensors and electromagnetic compatibility;
• rotor and power-chain optimisation;
• landing gear studies.

Academic and technical contributions

Contributor	Main contribution	Documents
Centrale Supélec	Aeronautical simulation	File:201706 pres ECP aero.pdf File:Suivi code 2017 3.0.pdf File:Guide fonction code Version 1.0 ECP2016.pdf
Estaca	Usages and engines	File:Rapport projet 5A Mini Bee intérieur.pdf File:Masse Coûts approx Mini-Bee version ambulance.xlsx File:2017 01 24 Planches VIP.pdf File:Rapport projet Mini-Bee.pdf File:BEE-PLANE REPORT 2016-2017 ISIEB v2.pdf
Estaca SQY 4A	Structure	File:RapportdeProjet structure estaca 4A 2017.pdf File:RapportdeProjet1ersemestre.pdf File:Soutenance 132F01.pdf File:Soutenance du 2ème semestre (21F042F2017).pdf
Supmeca	Structural and mechanical mock-up	File:SUPMECA FINAL 201706Bourget.pdf File:Supmeca MotorisationMiniBee 201706Bourget.pdf File:Mini-Bee Project 2017 - Aerodynamic optimisation.pdf File:Présentation Mini-Bee optimisation aérodynamique 2017.pdf File:Mini-bee soutenance2302 final.pdf File:Rapport Mini-Bee v5-finale.pdf
ENSTA Bretagne	Scale flying mock-up and project presentation	File:ENSTA Bretagne 201706Bourget.pdf
Polito	Equipment studies	File:Final Report Polito 23 02 17.pdf File:Polito Supmeca presentation 23 02 17.pdf
ENSEA	Human-machine interface	File:ENSEA 201706Bourget.pdf
INSA	Seat and occupant integration	File:INSA pres NAE.pdf
IUT Le Havre	Tilt mechanism studies	File:IUT LeHavre 201706Bourget.pdf
IUT Rouen	Sensors and electromagnetic compatibility	File:CEM IUT Rouen 201706Bourget.pdf File:IUT Rouen Capteur 201706Bourget.pdf File:Présentation24-06-17-2 IUT ROUEN 201706Bourget.pdf
IUT Caen	Rotors and power-chain optimisation	File:IUT CAEN PstBgt 201706Bourget.pdf
Esitech	Technical contribution	File:ESITECH 201706Bourget.pdf
Lycée Diderot	Rear landing gear	File:Projet Personnelle Mini Bee Sagithan DEVAKUMARAN.pdf File:Rapport de projet partie personelle SZASZ.pdf File:DIDEROT 201706Bourget.pdf

Mock-up display

A digital 3D mock-up was created to support the understanding of the Mini-Bee configuration during the TRL 2 phase.

3D mock-up: Mini-Bee 3D mock-up by Hamza Fouatih.

Mini-Bee TRL 2 configuration visuals

• 

  Taxi concept

• 

  Three-view layout

• 

  Early TRL2 visual

• 

  Front view

• 

  Side view

• 

  Top view

• 

  3D mock-up by Hamza Fouatih

Concept formulation at TRL 2

At TRL 2, the Mini-Bee concept was described as a hybrid VTOL aircraft intended to combine vertical take-off capability, distributed propulsion and mission flexibility.

The configuration studied at this stage included a larger aircraft concept than later versions of the Mini-Bee.

Important note: this page documents the historical TRL 2 configuration. Later TRL levels may describe updated Mini-Bee configurations, including revised rotor architecture, propulsion choices, mass assumptions and mission scope.

General characteristics

Parameter	TRL 2 configuration
Crew	2 pilots
Capacity	From 1 passenger and 1 patient to 3 passengers and 2 patients with central module
Length	6.01 m / 19 ft 9 in
Height	2.3 m / 7 ft 7 in
Empty weight	850 kg / 1,873 lb
Maximum take-off weight	1,200 kg / 2,643 lb
Powerplant	Piston engine for 250 kW at take-off and electric motors
Central rotor area	12.6 m² / 41.5 sq ft
Wing rotor area	10.6 m² / 35 sq ft
Wing area	8.66 m² / 28.5 sq ft
Airfoil	Davis basic B-24
Fuel capacity	150 l

Performance assumptions

Parameter	TRL 2 assumption
Cruise speed	250 km/h / 155 mph / 135 kn
Maximum speed	300 km/h / 186 mph / 162 kn
Range	500 km / 311 mi / 270 nm
Service ceiling	4,000 m / 13,000 ft
Rate of climb	6.45 m/s / 1,270 ft/min

Additional concept visual

Mini-Bee concept image used during the early configuration studies

Open image

TRL 2 outputs

TRL 2 produced a first structured basis for the Mini-Bee aircraft concept.

Concept definition A first aircraft configuration was described, including dimensions, mass assumptions, rotor areas and performance targets.

Collaborative studies Several academic teams contributed to simulation, structure, equipment, HMI, sensors, rotors and mechanical studies.

Visual and mock-up support The TRL 2 stage included 3D mock-ups, three-view layouts and visual representations to clarify the aircraft concept.

What TRL 2 clarified

Clarified during TRL 2 first Mini-Bee aircraft configuration; initial mission and use-case logic; preliminary performance assumptions; early propulsion and energy direction; first structural studies; mock-up and 3D representation; distribution of work between academic contributors.

Still open after TRL 2 validated propulsion architecture; final rotor configuration; detailed structural sizing; complete flight control architecture; power-chain validation; certification strategy; experimental proof of concept.

TRL 2 maturity logic

The TRL 2 phase helped transform the Mini-Bee from an early idea into a project with a visible concept structure.

1. Formulate	2. Assign studies	3. Model	4. Compare	5. Prepare TRL 3
First aircraft concept	Academic work packages	Mock-ups and simulations	Mission and technology assumptions	Toward proof of concept

Questions to solve before TRL 3

Before moving from TRL 2 to TRL 3, several questions had to be addressed:

• Which aircraft configuration should be retained for proof-of-concept work?
• Which propulsion architecture is realistic for vertical flight?
• What rotor distribution provides enough lift and redundancy?
• What structure can support the rotor system and mission loads?
• How should the flight control logic be tested?
• What mock-up or demonstrator is required to validate the main assumptions?
• Which mission should drive the next stage of development?

Image files used on this page

Wiki file name	Use in page	Link
MiniBee_Taxi.jpg	Hero image, visual introduction and gallery	Open image
Minibee 3view.jpg	Visual introduction and gallery	Open image
1.jpg	Gallery	Open image
Minibee 3view - front.jpg	Gallery	Open image
Minibee 3view - side.jpg	Gallery	Open image
Minibee 3view - top.jpg	Gallery	Open image
Mini-Bee TRL2 by Hamza Fouatih.jpg	Visual introduction and gallery	Open image
Minibeev14_image.png	Additional concept visual	Open image

Why TRL 2 mattered

TRL 2 was a key step because it gave the Mini-Bee project its first formulated technical identity.

It created a common concept basis for academic partners, contributors and project coordination. It also allowed the project to move from early intuition toward structured design studies and future proof-of-concept work.

Transition to the next stage

Next maturity step: TRL 3 – Experimental Proof of Concept.

At TRL 3, the project moves from concept formulation to first analytical or experimental evidence supporting the main technical assumptions.

See also

• General page - TRL 1
• Minibee TRL1
• Minibee TRL3
• Mini-Bee project