## Fovea Aero Systems LLC

60 Fostertown Road  Medf ord, New Jersey 08055 Phone: 888

- 623

- 4623  E

- Mail: jeff@foveaaero.com  Web: www.FoveaAero.com

Date: May 13 , 2015

U.S. Department of Transportation UAS Integration Office (AFS

- 80) Federal Aviation Administration 800 Independence Avenue, SW Washington, DC 20591

Dea r Sir or Madam :
Fovea Aero Systems LLC (“Fovea Aero”) has submitted for a Section 333 exemption pursuant to the FAA Modernization and Reform Act of 2012 (the “Reform Act”) and 14 C.F.R. Part 11, to allow for the commercial operation of its sUASs (docket FAA

- 2015

- 0545 ) . A s of the date of this letter, Fovea Aero is awaiting the FAA’s decision.

In anticipation of that decision, and based on past exemptions granted by the FAA for the commercial operation of sUASs in the national airspace, Fovea Aero hereby requests the FAA to allow the included
alterna te method of compliance for the condition and limita tion often referred to in granted exemptions
as “Condition and Limitation 26” (hereafter “Limitation 26”)

.

It states:

26. All Flight operations must be conducted at least 500 feet f rom all nonparticipating persons, vessels, vehicles, and structures unless:

a. Barriers or structures are present that sufficiently protect nonparticipating persons from the UA and/or debris in the event of an accident. The operator must ensure that nonparti cipating persons remain under such protection. If a situation arises where nonparticipating persons leave such protection and are within 500 feet of the UA, flight operations must cease immediately in a manner ensuring the safety of nonparticipating person s; and

b. The owner/controller of any vessels, vehicles or structures has granted permission for operating closer to those objects and the PIC has made a safety assessment of the risk of operating closer to those objects and determined that it does not present

an un due hazard. The PIC, VO, operator trainees or essential persons are not considered nonparticipating persons under this exemption.
The purpose of this condition is to protect nonparticipating persons, vessels, vehicles and structures
from harm in the even t of an accident during UA flight operations. Fovea Aero Systems LLC is dedicated to safe operations while providing a significant public benefit through the commercial operation of its sUASs. In order to achieve this, Fovea Aero hereby proposes the foll owing alternate method of compliance for Limitation 26 and contend s it meets or exceeds the intended purpose of this
limitation

.Page 2



## I. The Effect of Weight, Speed and Kinetic Energy on Accidents

The co nditions and limitations in most approved S ection 333 exe mptions were written to provide for the safe operation of UASs across a wide variety of designs and activities. These include UASs of weights up to 5 5 pounds, of various categories includ ing rotorcraft and fixed winged and of various technology levels from simple to technically advanced

. However, when taking into account the operational characteristics of specific UAS designs, as well as specialized safety devices available for those UASs, an equivalent or greater level of safety can be
maintained with reduced minimum distances to nonparticipating person, vessels, vehicles and

structures

.

A. UAS Characteristics as a Function of Safety

Limitation 26 applies to UASs weighing up to 55 pound s with a top speed of 100 mph.

The DJI S1000+ has a maximum takeoff weight of approximately 25 pounds (specifically 11 Kg). This
is less than half the we ight of other UASs approved under Limitation 26. Additionally, because the
S1000+ is a rotorcraft, it can be flown at airspeeds as low as 0 mph (ho ver) , allowing the operator to safely fly at reduced speeds . This is unlike fixed winged aircraft covered by Limitation 26 that will have a minimum flyable speed (stall speed) and may become more difficult to control as the airspeed reaches
this value.

Th is reduction in gross weight over other UASs

, as well as by implementing a maximum allowable speed

, significantly reduces the energy available during a crash. Thi s, by pure physics, reduces , or in some cases even eliminates, potential damage to persons, v essels, vehicles and structures in the event of
an accident

.

B. Kinetic Energy Example

A UAS covered by Limitation 26 can weight up to 55 pounds (24.95 Kg) and travel at a speed up to 100 mph (44.7 m/s)

. The S1000+ has a maximum takeof f weight of 11 Kg and c an have a maximum speed of 30 mph (13.41 m/s) imposed during operations. The kinetic energy available in each of these aircraft
is as follows. 1

Aircraft Weight Speed Energy

UAS covered by Limitation 26. 55lbs (24.95Kg) 100mph (44.7m/s) 24,926 Joules

S1000+ with maximum speed of 30 mph. 25lbs (11Kg) 30mph (13.41m/s) 989 Joules

The S1000+ at its maximum gross weight and at an imposed speed restriction of 30 mph has less than 4% of the energy available in other UASs covered by the conditions and limitat ions of Limitation 26. This is a 96% reduction in energy available.

1 Kinetic energy equation: = !

! !

.Page 3

The kineti c energy available during a crash has a direct physical effect on the work that can be done by that energy. Less energy available means that potential debris volume and distance will be reduced as well as potential damage to vessels, vehicles and structures in the event of an accident. The 96% reduction in energy in an S1000+ at gross weight and at the maximum imposed speed restriction would be expected to result in much less damage and smaller debris fields during a crash as compared to the previously approved UAS s operating under Limitation 26

.

C. Limitation 26 and Accident Energy

The distance limitation of 500 fe et set forth in Limitation 26 applies to the wide variety of aircr aft covered by the limitation . Aircraft, “... when weighing less than 55 pounds including payload ,” and
when not , “... operated at a speed exceeding 87 knots (100 miles per hour) ” 2 are permitted to operate at a distance of 500 feet from nonparticipating p ersons, vessels, vehicles and structures.

Fovea Aero Systems LLC contends that with appropriate speed restrictions and with lighter aircraft, these limitations can be safely reduced while meeting or exceeding the safety afforded to nonparticipating persons as compared to operations as approved in previously issued exemptions. The

11 Kg gross weight of the S1000+ and a speed limitation of 30 mph would significantly reduce the kinetic energy of the aircraft resulting in less damage in the event of an acciden t. This allows the
aircraft to safely operate with a lower distance restriction than that set forth in Limitation 26.



## II. Advanced Safety Features Specific UAS designs can be equipped with additional features and systems that further enhance the safety of the aircraft and reduce the risk of injury and damage to participating and nonparticipating persons, vessels, vehicles and structures in the event of an accident. These features can provide several advantages over non

- equipped aircraft and can allow operatio n of the aircraft with alternative conditions and limitations while meeting or exceeding the prote ctions afforded by the current S ection
333 limitations.

A. “DJI DropSafe” Airframe Parachute System

The S1000+ can be equipped with the “DJI DropSafe” full airfr ame parachute system. This system is automatically and / or manually deployed in the event of a malfunction, an imminent accident, a flyaway, main battery malfunction, or other anomaly that may result in a crash.

The DropSafe system monitors its own healt h and system status and provides the operator with a visual “READY” indication when the system is properly initialized and has passed its internal checks. The DropSafe system also connects to the aircraft’s flight control system and monitors aircraft heal th and flight parameters. The parachute will automatically deploy if the system detects fatal malfunction. 3

The operator can also manually deploy the parachute. When configured as described in the user manual, activation is per formed using a two

- switch combination on the operator’s ground station. One switch is a safety

- switch and the other is the activation switch. First the safety switch is triggered

2 FAA exemption number 11467.

3 DJI website, http://www.dji.com/product/dropsafe

.Page 4

followed by the activation switch. The safety

- switch and activation switch combination guards against accidental manual deployment of the parachute.

DropSafe uses its own backup battery and receiver and can be deployed even in the event of a total power loss on the aircraft due to a main battery malfunction

. The DJI DropSafe p ar achute deploys in 0.5 seconds and can be activated as low as 6 meters. A t a vehicle weight of 11 K g, the system lowers the entire aircraft to the ground in a controlled descent at the reduced speed of approximately 7.8 m/s ( 17.5 mph) 4

. Using the equation for kinetic energy, this results in 335 Joules of available kinetic energy at a gross weight of 11Kg. This is a 66% further reduction of available energy in the event of an accident as compared to an S1000+ at gross weight traveling at the imposed 30 mph speed limitation. Additionally,
it is only 1.3% of the energy available in the FAA allowed UAS weighing 55 pounds and traveling at 100 mph. This is a 98.7% reduction in energy

.

Aircraft Weight Speed Energy

UAS covered by Limitation 26. 55lbs (24.95Kg) 100mph (44.7m/s) 24,926 Joules

S1000+ with maximum speed of 30 mph. 25lbs (11Kg) 30mph (13.41m/s) 989 Joules

S1000+ descending under DropSafe parachute. 25lbs (11Kg) 17.5mph (7.8m/s) 335 Joules

This further reduction in available kinetic energy will res ult in significantly less damage or debris, or even no damage or debris, in the event of an accident when compared to previously approved aircraft subject to the 500 foo t limitation of Limitation 26.

The trajectory of a n aircraft descending under parachute can also be significantly different than a non

protected aircraft traveling horizontally when a malfunction occurs. Should a malfunction occur while the aircraft is traveling horizontally and the airframe parachute is deployed, the majority of the
horizontal momentum will be reduced or eliminated. A n aircraft descending under a parachute will ultimately be travelling in a generally straight down direction. This can further limit debris, if any is created, to a localized area around the final l anding point of the aircraft.

Furthermore, the DropSafe system when activated automatically disables the motors on the S1000+. 5 This causes the rotors on the aircraft to stop spinning within seconds of deployment. The disabled motors and stopped rotors wi ll significantly reduce or even eliminate potential injury or damage to nonparticipating persons, vessels, vehicles or structures when compared to an aircraft under power with spinning rotors or propellers.

4 Data obtained from “DJI DropSafe User Manual v1.2”.

5 When installed using compatible equipment and according to the directions cont ained in the “DJI DropSafe User Manual v1.2”.Page 5

B. Limitation 26 and the DJI DropSafe Airframe Parac hute System

The distance limitation of 500 feet set forth in Limitation 26 applies to the wide variety of aircraft often covered by the condition. Aircraft, “... when weighing less than 55 pounds including payload ,” and when not, “... operated at a speed exceeding 87 knots (100 miles per hour) ” 6 are permitted to operate at a distance of 500 feet from nonparticipating persons, vessels, vehicles and structures.

Fovea Aero Systems LLC contends that with the DJI DropSafe system, when maintained and enabled

acc ording to the instructions in the DJI DropSafe User Manual, these limitations can be safely reduced while meeting or exceeding the safety afforded to nonparticipating persons as compared to operations as approved in previously issued exemptions. The furth er reduction in available kinetic energy (only 1.3% of energy available in a 55 pound aircraft traveling at 100 mph)

, the downward controlled descent of a n aircraft landing under a parachute and the automatic motor cutoff, provides additional safety margin s over previously approved sUAS operations

. This allows the Fovea Aero Systems LLC’s aircraft to safely operate with a lesser distance restriction than that set forth in Limitation 26.



## III. Current Operations Using Manned Aircraft

Many of the operations for wh ich Fovea Aero Systems LLC has requested an exemption are currently performed by manned aircraft; often helicopters. Manned helicopters contain a pilot and often crewmembers, carry flammable fuel and c an have a gross weight of 5,000 pounds or more. 7

A. Feder al Aviation Regulation 91.119 and Helicopter Operations

14 C

. F

. R

. 91.119 states the following:

91.119 Minimum safe altitudes: General. Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes: (a) Anywhe re. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface. (b) Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft. (c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure. (d) Helicopters, powered parachutes, and weight

- shift

- control aircraft. If the operation is conducted without hazard to persons or property on the surface

— (1) A helicopter may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section, provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA; and

6 FAA exemption number 11467.

7 Airbus Helicopters AS350 according to data obtained from http://airbushelicoptersinc.com/products/AS350B2

- specifications.asp

.Page 6

(2) A powered parachute or weight

- shift

- control aircraft may be operated at less than the minimums prescribed in paragraph (c) of this section.

14 C

. F

. R

. 91.119(d)(1) permits a helicopter to operate lower than, “...500 feet above the surface...” and
closer than “...500 feet to an person, vessel, vehicle, or structure...” when, “ ...the operation is conducted without hazard to persons or property on the surface.”

Helicopters performing the duties Fovea Aero Systems LLC intends to perform with sUASs will often operate at these reduced limitations. 8 The helicopter may be in the general area, or even over, nonparticipating persons, vessels, vehicles, or structures at distances less than 500 feet. An accident with a helicopter at these distances could be catastrophic with significant damage or destruction of property and fatal to aircraft occupants or persons on the ground.
This is mostly due to the kinetic ener gy available in the aircraft and often the flammable
fuel carried onboard.

B. Helicopter vs. sUAS Operations

14 C

. F

. R

. 1.1 defines a helicopter as:
Helicopter means a rotorcraft that, for its ho rizontal motion, depends princ ipally on its engine

- driven rotors.
A certified helicopter may operate at distances less than 500 feet from nonparticipating persons, vessels,
vehi cles or structures according to 14 C

. F

. R

. 91.119(d)(1). Fovea Aero Systems LLC contends that an
sUAS using the additional safety measures outlined in this document and when operated at reduced minimum distances as compared to Limitation 26, meets or signi ficantly exceeds the safety provided by a manned helicopter performing the same operations and operating at the FAA allowed reduced
distances described in 14 C

. F

. R

. 91.119(d)(1)

.



## IV. Proposed Conditions and Limitations Given the information provided in this document and the additional limitations proposed below, Fovea Aero Systems LLC hereby petitions the FAA for the following alternate conditions and limitations

.

Alternate Conditions and Limitations

Fovea Aero Systems L LC proposes the following conditions and limitations:

8 A helicopter operating in the immediate vicinity o f an RV park while performing power line inspections. Photo from “Electric Co

- op Today”: http://www.ect.coop/weather

- effects/preparedness/troubleshooting

- in

- deep

water/12631

.Page 7

26. All Flight operations must be conducted at least 500 feet from all nonparticipating persons, vessels, vehicles, and structures unless:

a. Barriers or structures are present that sufficiently protect nonpa rticipating persons from the UA and/or debris in the event of an accident. The operator must ensure that nonparticipating persons remain under such protection. If a situation arises where nonparticipating persons leave such protection and are within 500 fe et of the UA, flight operations must cease immediately in a manner ensuring the safety of nonparticipating persons; and

b. The owner/controller of any vessels, vehicles or structures has granted permission for operating closer to those objects and the PIC ha s made a safety assessment of the risk of operating closer to those objects and determined that it does not present an undue hazard.

These limitation s may be reduced from 500 feet to 200 feet when:

a. The aircraft operated is a DJI S1000+;

b. The aircraft is at or below its maximum takeoff weight of 11Kg (25 pounds);

c. The aircraft does not exceed a maximum speed of 30 mph;

d. The S1000+ is equipped with the DJI DropSafe aircraft parachute system;

e. The DropSafe system is installed, maintained and inspected according t o the DJI DropSafe User Manual v1.2;

f. The DropSafe system is active and ready for deployment;

g. The PIC is familiar with the operation of the DropSafe system;

h. The DropSafe manual is available to PIC during operation;

i. The PIC discontinues the flight should it become apparent the DropSafe system is no longer active and ready for deployment; and j. The PIC has made a safety assessment of the risk of operating at the reduced distance limitation and determined that it does not present an undue hazard. The PIC, VO, ope rator trainees or essential persons are not considered nonparticipating persons under this exemption.
Fovea Aero Systems LLC contends, given the size , weight and speed limitation of the sUASs i n operation and the added protections and safety afforded by the DJI DropSafe system , the proposed
alternate conditions and limitations meet or exceed the safety of those set forth by the FAA in previously granted Section 333 exemptions.

The applicant is thankful for the Federal Aviation Administration’s time and co nsideration.

Respectfully yours,

Jeffrey Sassinsky President, Fovea Aero Systems LLC