Posts in category: Infrastructure

There are more solutions than obstacles, Nicolas Zart

If we’ve been fairly quiet the past few weeks it’s not for lack of wanting to educate and talk about advanced air mobility (AAM). It’s because we’ve been busy redefining a core strategy, as should be done often in any industry and business life.

AAM Will Happen, Not How We Thought it Would

There’s a fine line between keeping your strategy close to the heart and away from prying eyes, and then there comes a time when the white elephant needs to be addressed. While we’re bombarded with how electric vertical take-off and landing (eVTOL) will start to conquer the world ushering in an era of clean areal mobility, more and more reasoned voices question the viability of eVTOL. Don’t get us wrong. We’re 100% behind eVTOLs and we will see them fly. however, practicality dictates we must first access electric flight in the most efficient ways. Electric short take-off and landing (eSTOL) offer two irrefutable pros, their better energy usage and smaller vertiport approach footprint.

Why are we using helicopter executive

eSTOL’s Unbeatable TLOF & FATO

Essentially, eSTOLs have no transitions from vertical to horizontal flight. This not only maximizes their energy use but also means they have shallower FATOs and TLOFs. What are FATos and TLOFs? According to the US Federal Aviation Agency (FAA), the TLOF of a heliport is the touchdown and lift-off area surrounded by a final approach and takeoff area (FATO). The TLOF is a load-bearing, usually paved, area at a heliport (helipad) where the helicopter is permitted to land. The TLOF can be located at ground or rooftop level, or on an elevated structure. The TLOF is normally centered in the FATO and is the safety area provided for VTOL aircraft to touch down. Final Approach and Takeoff Area (FATO). The FATO is a defined heliport area over which the final approach to a
hover or a departure is made. The touchdown and lift-off area (TLOF) where the helicopter is permitted to land is normally centered in the FATO. A safety area is provided around the FATO.

The relationship of the TLOF to the FATO and the Safety Area is shown in Figure 3-2. A FATO may NOT contain more than one TLOF.

Why are we using helicopter terms? Because vertiports are defined using many heliport executive briefs since their operations are similar. Vertiports are essentially modernized heliports with one difference, not all heliports can become vertiports due to space and original design constraints.

From Helicopter to eVTOLs to eSTOLs

The second reason why eSTOLs will most likely take off first, pun intended is their fairly more conservative use of energy. Since eVTOL will need to use vertical lift before being wing-borne, they will consume more energy than winged aircraft, especially those with blow-lift designs such as the Electra. This energy discrepancy will tally up at the end of the year and shareholders and municipalities will these uncomfortable questions to vertiport owners and operators.

Essentially, a blow-wing eSTOL will blow air under its wings smoothly establishing enough airflow to retract its flaps and allow portance, whereas an eVTOL will need to fly up fast enough for enough flow under the wings to give it portance.

Electric Air Mobility Marches Forward with eSTOLs

After mulling over the practicality of eVTOL over eSTOL operations, it became apparent that eSTOLs can achieve shorter FATOs. We redesigned our vertipad concepts to capture eSTOL’s potential longest landing and found it would be no bigger than a small to medium-sized vertiport. The other benefit to this is we automatically added extra landing pads or vertipads on top of creating eSTOL ports.

Further reading:

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_150_5390_2D_Heliports.pdf

https://www.faa.gov/sites/faa.gov/files/eb-105-vertiports.pdf

https://www.faa.gov/sites/faa.gov/files/regulations_policies/handbooks_manuals/aviation/instrument_procedures_handbook/FAA-H-8083-16B_Glossary.pdf