Our Story: Part 4
Here it is - the final post of our timeline series detailing the extraordinary efforts of the Vahana team to take the vehicle from a napkin sketch to the tremendous achievement of full-transition flight. As a reminder, these updates were pulled from the internal monthly updates circulated throughout Airbus as the Vahana was built and tested. We’re thrilled to be able to share those updates publically with everyone who has followed so closely along during this journey.
For those who are up to date - enjoy 2019!
- With the completion of the 40-knot and 50-knot flight tests, the total number of flights now stands at 48. These tests include flights to perform the basic maneuver and separate ones for performance and flight controls evaluation.
- The subscale aircraft completed all autonomous transition testing and moved on to performing autonomous maneuvering flights comprising of turns and climbs. Several hundred subscale flights have been completed to date including validation of the motor failure mitigation strategy at various points in the flight envelope.
- Some bad weather caused a delay in flight testing, so during the down time, the team performed a few maintenance tasks and resolved motor performance issues.
- More weather issues (snow in February - groundbreaking!) further delayed flight testing this month.
- The downtime allowed for the team to work on resolving software issues in the ground control station related to real-time data plotting and fix some minor wiring issues.
- The weather finally cleared up which meant the restart of flight testing. After resolving the ground control station issues, the team performed three more 60 knot flights, including system identification for each, followed by three 70 knot flights.
- No significant aero-performance issues were noticed at either transition point and all measurements indicate that the expected values are in close alignment from those that are seen in subscale testing. In parallel to this, the flight controls and software teams have presented and passed the Flight Readiness Review for the next flight a 90-knot full transition.
- The team also spent the month preparing Alpha Two for its debut at the Paris Air Show. This includes updating the livry of the aircraft for it to be more in line with other Airbus projects.
- The month of April led up to the first successful transition flight in early May. This occurred after 58 full scale flights and more than 1000 subscale flights. The full transition flight started from a hover at 240 feet and transitioning to full wingborne flight at 90-knots.
- However, this triumph did not come without challenges as, in the month leading up to full transition flight, the team discovered that the first batch of propeller blades had manufacturing defects that required us to replace and rebalance all rotors within just one week.
- Post full transition flight the team completed two additional flights to further tune our flight control gains and one other flight at 100-knots.
- Once full transition flight was completed, the team focused on using flight testing for noise measurements and performance.
- Overall noise testing went very well:
- First, due to Vahana’s autonomous capabilities, the noise flight tests themselves went smoothly. The reason for this is that unlike piloted aircraft that typically have to re-fly the same test point multiple times, Vahana flew a near-perfect path each time.
- Second, the noise measurements during the cruise phase were about 5-7 dB less than the lighter-weight Cabri G2 and about the same as the heavier Bluecopter during hover.
- By this time we’ve flown 81 flight tests, logged 10.1 hours (5.8 of which were airborne), and flown about 85 nautical miles (157 km) -- all completely autonomously.
- The month of June marked the start of Vahana Alpha Two’s “world tour” with the Paris Air Show as stop number one:
- At the show the vehicle was proudly located amongst other amazing aircraft such as A350-1000, MRTT, and VSR700. It received a large amount of press and many visitors including the officials from European Commissioner for Transport Violeta Bulc and Mayor of Miami-Dade Florida Carlos Giménez.
- Vahana had the honor of being the backdrop to the Airbus-Paris partnership announcement photo including representatives from RATP, Groupe ADP, French Civil Aviation Authority DGAC, Région Île de France, and our CEO Guillaume Faury.
- Once Vahana wrapped up at the Paris Air Show it headed off to the Oshkosh Air Show in Wisconsin.
- The team also tested several new flight paths in software and subscale to prepare for full-scale envelope expansion. These include some improvements to the transition trajectory to improve smoothness.
- After its triumphant time spent at the Paris Air Show, Vahana Alpha Two made its way over to the Oshkosh Airshow in Wisconsin, US.
- Meanwhile, on Vahana Alpha One, the team implemented a few small improvements and prepared to complete the last batch of flight tests before concluding the Vahana project. These tests include:
- maneuvering flights
- motor out tests
- additional system identification tests
- These tests are designed to improve our understanding and analysis tools to help inform future vehicle designs.
- To date, Vahana Alpha One has flown 92 flights and flown over 100 nautical miles
- The month of August was focused on performing various maneuvering flights to finalize Vahana’s flight test campaign.
- In addition to our typical stability margin and bare airframe chirp flights, these flights have included those shown in the below images. All flights were performed successfully with no significant issues.
25° Banked Turns at 40 kts (left). 20° Banked Turns at 90 kts (middle). “Racetrack” at 90 kts (right).
- To date, Vahana Alpha One has flown 106 flights and 161 nautical miles (about 300 km).
- In the month of September Vahana hit a milestone with the longest racetrack flight path at 45kms. Several tests were also completed that focused on pirouette. Image of that flight pattern below:
- As of the last flight test of September, which took place on the 27th, Vahana Alpha One has flown 114 flights and 206 nautical miles (about 382 km). The total flight time for Alpha One’s flight test campaign stands at 9.39 hrs.
- Vahana Alpha Two made the journey to NBAA in Las Vegas this October and received a lot of positive attention. In fact, it made the cover of the daily NBAA magazine and was visited by Magic Johnson. Overall a great success!
- For Alpha One, testing this month focused on motor out cases and battery efficiency as the team prepares to close out flight testing in November.
- While we’re planning a special post to commemorate the culmination of flight testing, we did want to note that our last test flight was in mid-November. In the end we couldn’t be more proud of the stats we put up on the board with this project:
- Total flights: 138
- Total flight time: 13.41 hr
- Distance flown: 487 nautical miles (903 km)
- Farthest flight: 27.13 nautical miles (50.24 km)
- Longest flight duration: 19 minutes 56 seconds