Tier 1 in flight

Robinson R44
Tier 1
Santa Ana, California, USA

The Tier 1 Robinson R44 was built under contract from Lung Biotechnology PBC as an Electrically-Powered Semi-Autonomous Rotorcraft for Organ Delivery (EPSAROD). The idea is that the Tier 1 will be able to quickly transport manufactured organs to those that need them at nearby hospitals. The modification of the R44 took six months with Tier 1’s nine-person team. The aircraft utilizes lithium-polymer batteries for power, which were provided by American company Brammo.

The first flight of the aircraft was on September 21, 2016, where it flew for five minutes and still had 80% of its reserve power. With better batteries, the Tier 1 Robinson R44 will be expected to fly for 150 minutes and lift a payload of 600 lbs (272 kg).

Tier 1 in flight
Tier 1 in flight
The tail of the Tier 1
The tail of the Tier 1
The batteries of the Tier 1
The batteries of the Tier 1


Passengers 2
Gross Weight 2500 lb 1134 kg
Estimated Max Flight Time
20 min
Estimated Range 30 NM 55.56 km
Desired Flight Time
150 min
Desired Payload 600 lbs 272 kg
Battery Weight
1100 lbs 499 kg



Tier 1, Electric HelicoptersFlight Testing2 PassengerElectric/Batteries, Piloted