449 Eisenhower Boulevard, Suite 300 

Harrisburg, PA 17111-2302 

Phone: 717-232-0593 

800-892-6532 

E-mail: skellyloy@skellyloy.com 

Internet: www.skellyloy.com 

Fax: 717-232-1799 

June 8, 2015 

Ms. Brenda Robeson 

Program Analysis, Airmen and Airspace Rules Division 

Federal Aviation Administration 

800 Independence Avenue 

Washington, D.C. 20591 

Re: Public Docket Number FAA-2015-

1364 

Dear Ms. Robeson: 

In response to your June 1, 2015, letter, Skelly and Loy, Inc. is providing the following 

supplemental information to Public Docket FAA-2015-1364. 

Skelly and Loy is seeking relief from the following regulations. 

14 C.F.R. §45.23(b): Marking of the Aircraft 

The regulation provides: 

When marks include only the Roman capital letter "N" and the registration 

number is displayed on limited, restricted or light-sport category aircraft or 

experimental or provisionally certificated aircraft, the operator must also display 

on that aircraft near each entrance to the cabin, cockpit, or pilot station, in letters 

not less than 2 inches nor more than 6 inches high, the words "limited," 

"restricted," "light-sport," "experimental," or "provisional," as applicable. 

The UX5 has no entrance to the cabin, cockpit, or pilot station on which the word 

"Experimental" can be placed. Given the size of the UAV, two-inch lettering will be impossible. 

The word "Experimental" will be placed on the forward fuselage in compliance with §45.29(f). 

The equivalent level of safety will be achieved by having the UX5 marked on its forward 

fuselage as required by §45.29(f) where the pilot, observer, and others working with the UAV 

will see the identification of the UAS as "Experimental." The FAA has issued the following 

exemptions to this regulation to Trimble, Exemption No. 10700, and to others, including 

Exemption Nos. 8738, 10167 and 10167A. 

14 C.F.R. Part 21, Subpart H: Airworthiness Certificates 

14 C.F.R. § 91.203(a)(1) 

Section 91.203(a)(1) requires all civil aircraft to have a certificate of airworthiness. 

Part 21, Subpart H, entitled Airworthiness Certificates, establishes the procedural requirements 

for the issuance of airworthiness certificates as required by FAR §91.203(a)(1). Given the size 

Office Locations: Pittsburgh, PA Morgantown, WV State College, PA Hagerstown, MD Hunt Valley, MD 
Ms. Brenda Robeson 

Page 2 

June 8, 2015 

of the aircraft (5.5 lbs.) and the limited operating area associated with its utilization, it is 

unnecessary to go through the certificate of airworthiness process under Part 21 Subpart H to 

achieve or exceed current safety levels. 

Such an exemption meets the requirements of an equivalent level of safety under 

Part 11 and Section 333 of the Reform Act. The Federal Aviation Act and Section 333 of the 

Reform Act both authorize the FAA to exempt aircraft from the requirement for an airworthiness 

certificate, upon consideration of the size, weight, speed, operational capability, and proximity to 

airports and populated areas of the UAS involved. 

In this case, an analysis of these criteria demonstrates that the UX5 operated without an 

airworthiness certificate, under the conditions proposed herein, will be at least as safe, or safer, 

than a conventional aircraft (fixed wing or rotorcraft) with an airworthiness certificate. The UX5 

weighs less than 6 lbs. fully loaded. It will not carry a pilot or passenger, will not carry 

flammable fuel, and will operate exclusively within an area pre-disclosed and in compliance with 

conditions set forth herein. Operations under this exemption will be tightly controlled and 

monitored by both the operator, pursuant to the conditions set forth above, and by local public 

safety requirements. The FAA will have advance notice of all operations through the filing of 

NOTAMs. Receipt of the prior permission of the land owner, the size of the aircraft, the lack of 

flammable fuel, and the fact that the aircraft is carried to the location and not flown there all 

establish the equivalent level of safety. The UX5 construction with absorbent material provides 

at least an equivalent level of safety to that of such operations being conducted with 

conventional aircraft that would be orders-of-magnitude larger and would be carrying 

passengers, cargo, and flammable fuel. 

14 C.F.R. §61.113(a) & (b); 61.133(a): Private Pilot Privileges and Limitations; Pilot in 

Command; Commercial Pilot Privileges and Limitations 

Section 61.113(a) and (b) limit private pilots to non-commercial operations. Unlike a 

conventional aircraft that carries a pilot, passengers, and cargo, the UX5 in this case is remotely 

controlled with no passengers or property of others on board. Section 61.133(a) requires an 

individual with a commercial pilot's license to be pilot in command of an aircraft for 

compensation or hire. Trimble respectfully proposes that operator requirements should take 

into account the characteristics of the particular UAS. Trimble's UX5 has a high degree of preprogrammed control and various built-in technical capabilities that strictly limit the potential for 

operation outside of the operating conditions set forth in the exemption application. 

The UX5 has a semi-autonomous navigation and control system comprised of a Ground 

Control Station (GCS) and auto-pilot system. All flights are pre-programmed with precision GPS 

guidance and do not require human intervention. Flight mission area and routing cannot be 

changed after launch. Flights are not directed by positive manual control nor are evasive 

maneuvers. In the case of unplanned events, the operator inputs pre-programmed evasive 

maneuvers from the control unit, and the control unit executes that maneuver. Pre-programmed 

operator interventions include diversion to the right; initiation of holding at present position; 

suspension of mission; fly back to launch point; fly to point and hold; abort mission and land; 

and emergency power cut off and land (Flight Termination System). 
Ms. Brenda Robeson 

Page 3 

June 8, 2015 

Additional automated safety functions and safety enhancing features of the UX5 include 

the following. 

• Auto-pilot detection of lost GPS or of insufficient satellites initiates an 

immediate spiral landing. 

• Low power on the aircraft triggers escalating alarms at GCS at 35% and 

10% levels. 

• If the auto-pilot detects a lost-link to the GCS for longer than 30 seconds, 

landing procedure begins. 

• The UX5 is inherently unstable, so auto-pilot fail will result in very rapid 

exit from flight. 

• Aircraft has an on-board failsafe that limits speed in the event of dive to 

approximately 14 mis. 

• The aircraft, weighing less than 6 lbs. fully loaded, is constructed of EPP 

foam or similar material which is intended to absorb impact energy. 

• The motor is driven by a pulse width modulated signal, not an analog 

signal. 

Given these safety features, Trimble proposes that operators of the UX5 should not be 

required to hold a commercial or private pilot certification. Instead, operators should be required 

to 

• have successfully completed, at a minimum, FAA private pilot ground 

instruction and passed the FAA Private Pilot written examination or FAArecognized equivalents and 

• have completed the manufacturer's training program for operation of the 

UAS. The manufacturer's training program will have been satisfactorily 

reviewed through the SAC process. 

Trimble notes that the FAA has found that safety factors permitted operation of UASs by 

operators with these qualifications in the case of operations pursuant to public COAs where the 

mandatory operating conditions specified above are present. See Federal Aviation 

Administration, Notice N-8900.227, Unmanned Aircraft Systems (UAS) Operational Approval, at 

20-21 (July 30, 2013). The FAA has the statutory authority, granted at 49 U.S.C. §44701 (f) to 

waive the pilot requirements for commercial operations. 
Ms. Brenda Robeson 

Page 4 

June 8, 2015 

Given these conditions and restrictions, an equivalent level of safety will be provided by 

allowing operation of the UX5 without a private pilot's certificate or a commercial pilot's 

certificate, under the conditions set forth herein. 

The risks associated with the operation of the UX5 (given its size, speed, operational 

capabilities, and lack of combustible fuel) are so diminished from the level of risk associated 

with private pilot operations or commercial operations contemplated by Part 61 with 

conventional aircraft (fixed wing or rotorcraft}, that allowing operations of the UAS as set forth 

above meets or exceeds the present level of safety provided under 14 C.F.R. § 61.113(a) and 

(b) and does not rise to the level of requiring a commercial pilot to operate the aircraft under 

§61.133(a). 

14 C.F.R. § 91.7(a): Civil Aircraft Airworthiness 

This regulation requires that no person may operate a civil aircraft unless it is in 

airworthy condition. Should the exemption be granted allowing commercial operation of the 

UX5 without an airworthiness certificate, no standard will exist for airworthiness of the UX5. 

Given the size of the aircraft and the requirements that have presumably already been met in 

the SAC approval process for the UX5 (for instance, the UX5's Maintenance and Inspection 

Manual and Safety Checklist), an equivalent level of safety will be achieved by insuring 

compliance with the Trimble manuals prior to each flight. 

14 C.F.R. §91.9(b)(2): Civil Aircraft Flight Manual in the Aircraft 

The regulation provides the following. 

No person may operate a U.S.-registered civil aircraft ... 

(2) For which an Airplane or Rotorcraft Flight Manual is not required by 

§21.5 of this chapter, unless there is available in the aircraft a current 

approved airplane or Rotorcraft Flight Manual, approved manual material, 

markings, and placards, or any combination thereof. 

Given the size and configuration of the UX5, it has no ability or place to carry such a 

flight manual on the aircraft, not only because there is no pilot on board, but because there is no 

room or capacity to carry such an item on the aircraft. 

The equivalent level of safety will be achieved by keeping the flight manual (e.g., User 

Guide, Exhibit 4) at the ground control point where the pilot flying the UAS will have immediate 

access to it. The FAA has issued to Trimble and others the following exemptions to this 

regulation: Exemption Nos. 8607, 8737, 8738, 9299, 9299A, 9565, 95658, 10167, 10167A, 

10602, 32827, and 10700. 
Ms. Brenda Robeson 

Page 5 

June 8, 2015 

14 C.F .R. §91.109(a) and 91.319(a)(1 ): Flight Instruction 

These regulations provide that no person may operate a civil aircraft (except a manned 

free balloon) that is being used for flight instruction unless that aircraft has fully functioning dual 

controls. 

The UX5 is a remotely piloted aircraft and, by design, does not have fully functional dual 

controls. Flight control is accomplished through the use of a control box that communicates with 

the aircraft via radio communications. The flight plan is pre-programmed into the autopilot 

before flight and only in unusual circumstances will the pilot input control functions to alter the 

pre-programmed flight. If instruction is accomplished through a training program, as set forth in 

Exhibit 2, an equivalent level of safety will be assured. The FM has approved exemptions for 

flight training without fully functional dual controls for a number of aircraft and for flight 

instruction in experimental aircraft. See Exemption Nos. 5778K and 9862A. The equivalent 

level of safety will be achieved by the manufacturer providing training and through the use of 

experienced and qualified pilots familiar with the UX5. 

14 C.F.R. §91.119: Minimum Safe Altitudes 

Section 91.119 establishes safe altitudes for operation of civil aircraft. Specifically, 

§91.119( c) limits aircraft flying over areas other than congested areas to 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. 

As set forth herein, the UX5 will never operate at higher than 400 feet AGL. It will, 

however, be operated to avoid congested or populated areas that are depicted in yellow on VFR 

sectional charts. Because aerial survey work must be accomplished at relatively low altitudes 

and at altitudes less than 500 feet AGL, an exemption from Section 91.119(c) is needed. 

The equivalent level of safety will be achieved given the size, weight, speed, and 

material with which the UX5 is built. Also, no flight will be taken without the permission of the 

landowner or those who control the land. Because of the advance notice to the landowner, all 

affected individuals will be aware of the survey flights. Compared with aerial survey operations 

conducted with aircraft or rotorcraft weighing far more than 5.5 lbs. and carrying flammable fuel, 

any risk associated with these operations will be far less than those currently allowed with 

conventional aircraft operating at or below 500 feet AGL. Indeed, the low-altitude operations of 

the UAS will maintain separation between these small-UAS operations and the operations of 

conventional aircraft that must comply with Section 91.119. 

14 C.F.R. §91.151(a): Fuel Requirements for Flight in VFR Conditions 

This regulation prohibits an individual from beginning "a flight in an airplane under VFR 

conditions unless (considering wind and forecast weather conditions) there is enough fuel to fly 

to the first point of intended landing and, assuming normal cruising speed - (1) During the day, 

to fly after that for at least 30 minutes; or (2) At night, to fly after that for at least 45 minutes." 
Ms. Brenda Robeson 

Page 6 

June 8, 2015 

The UX5 batteries provide approximately 50 minutes of powered flight. Without an 

exemption from 14 C.F.R. §91.151, the UAS's flights would be limited to approximately 20 

minutes in length. Given the limitations on its proposed operations and the location of those 

proposed operations, a longer time frame for flight in daylight VFR conditions is reasonable. 

Trimble believes that an exemption from 14 C.F.R. §91.151 (a) is safe and within the 

scope of a prior exemption. See Exemption 10673 [allowing Lockheed Martin Corporation to 

operate without compliance with 91.151 (a)]. Operating the small UAS without 30 minutes of 

reserve fuel does not engender the type of risks that Section 91.151 (a) was meant to prevent 

given the size and speed at which the UAS operates. The fact that it carries no pilot, 

passenger, or cargo also enhances its safety. Additionally, limiting UX5 flights to 20 minutes 

would greatly reduce their utility. In the unlikely event that the UX5 should run out of fuel, it 

would simply land. Given its weight and construction material, the risks are less than 

contemplated by the current regulation. 

Trimble believes that an equivalent level of safety can be achieved by maintaining 1 O 

minutes of reserve fuel, which, allowing 40 minutes of flight time, would be more than adequate 

to return the UAS to its planned landing zone from anywhere in its operating area. 

Trimble holds an Exemption from this FAR, Exemption No. 10808 for its X-100 UAS and 

has applied for such an exemption for the UX5 as part of its SAC application. Similar 

exemptions have been granted to others, including Exemptions 2689F, 5745, and 10673. 

14 C.F.R. §91.203 (a} and (b}: Carrying Civil Aircraft Certification and Registration 

This regulation provides as follows. 

(a) ... no person may operate a civil aircraft unless it has ... an appropriate and 

current airworthiness certificate. 

(b) No person may operate a civil aircraft unless the airworthiness certificate 

required by paragraph (a) of this section or a special flight authorization issued 

under§ 91.715 is displayed at the cabin or cockpit entrance so that it is legible to 

passengers or crew. 

The UX5 fully loaded weighs no more than 6 lbs. As such, there is no ability or place to 

carry certification and registration documents or to display them on the UAS. In addition, there 

is no pilot on board the aircraft. 

An equivalent level of safety will be achieved by keeping these documents at the ground 

control point where the pilot flying the UAS will have immediate access to them. The FAA has 

issued numerous exemptions to this regulation. A representative sample of other exceptions 

includes Exemption Nos. 9565, 9665, 9789, 9789A, 9797, 9797A, 9816A, and 10700. 
Ms. Brenda Robeson 

Page 7 

June 8, 2015 

14 C.F.R. §91.405(a); 407(a)(1); 409(a)(2); 417(a): Maintenance Inspections 

Section 91.405(a) requires that an aircraft operator or owner "shall have that aircraft 

inspected as prescribed in subpart E of this part and shall between required inspections, except 

as provided in paragraph (c) of this section, have discrepancies repaired as prescribed in part 

43 of this chapter .... "Section 91.407 similarly makes reference to requirements in Part 43; 

Section 91.409(a)(2) requires an annual inspection for the issuance of an air worthiness 

certificate. Section 91.417(a) requires the owner or operator to keep records showing certain 

maintenance work that has been accomplished by certificated mechanics, under Part 43, or 

licensed pilots and records of approval of the aircraft for return to service." 

Maintenance of the UX5 will be compleated by the owner/operator pursuant to the 

manuals provided by Trimble. An equivalent level of safety will be achieved because the UAS is 

small in size, will carry no external payload, will operate only in restricted predetermined areas, 

and is not a complex mechanical devise. As provided in the attached Maintenance Manual and 

the Safety Checklist, which were reviewed as part of Trimble's SAC application, the operator of 

the UX5 will ensure that the UAS is in working order prior to initiating flight, perform required 

maintenance, and keep a log of any maintenance that is performed. Moreover, the operator is 

the person most familiar with the aircraft and is best suited to maintain the aircraft in an 

airworthy condition and to ensure an equivalent level of safety. 

The UX5's Maintenance Manual provides for replacement of the airframe every 50 hours 

of flight. This will ensure an equivalent level of safety to the maintenance requirements in 

Part 91. In addition, between such air frame replacements, should a mechanical issue arise, 

the aircraft will either return to its launch site or immediately land. 

Public Interest 

The requested exemption would permit commercial operation of Trimble's UX5, which 

weighs 5.5 lbs. and performs precision aerial surveys that consist of still photographs taken by 

onboard cameras. The UX5 takes a series of high quality, still digital images that are used to 

produce precision digital point clouds, triangulated models, and contour maps of the surveyed 

area. Applications for these UAS devices and associated data processing functions include 

agriculture, mining, and professional surveying. Use of the UX5 for aerial surveys reduces the 

need to operate conventional aircraft for the same purpose and provides very high quality 

imagery at a fraction of the cost of surveys using conventional aircraft. These savings result in 

enhanced efficiency and productivity for the affected activities, as well as environmental 

benefits. 

Equivalent Level of Safety 

The applicant respectfully submits that because this small, unmanned aerial vehiclethe UX5-will be used in lieu of comparatively hazardous operations now conducted with fixed 

wing and rotary conventional aircraft, the FAA can have confidence that the operations will 

achieve at least an equivalent level or greater level of safety. Approval of this exemption would 

thereby enhance safety and fulfill the Secretary of Transportation's (the FAA Administrator's) 
Ms. Brenda Robeson 

Page 8 

June 8, 2015 

responsibilities under Section 333(c) of the Reform Act to "establish requirements for the safe 

operation of such aircraft systems in the national airspace system." 

Pilot Information 

Richard S. Johnston 

FAA Certificate Number: 3374141 

Trimble UX5 Aerial Imaging Remote Pilot Certificate Number: 3722467 

If you have further questions or need additional information please contact us. 

Sincerely yours, 

SKELLY and LOY, Inc . 

John W. Gunnett 

. ~ P.G. 

Chief Operating Officer, President 

cc: Rick Johnston 

File: ROBESON_JWG.docx