C o n t i n u u m D y n a m i c s , I n c .

(609) 538-0444 (609) 538-0464 fax 34 Lexington Avenue Ewing, NJ 08618-2302

September 30th, 2015

U.S. Department of Transportation

Docket Management System

1200 New Jersey Ave. SE

Washington, DC 20590

Re: Exemption request under Section 333 of the FAA Reform Act and Part 11 of the Federal 

Aviation Regulations

Dear Sir or Madam:

Pursuant to Section 333 of the FAA Modernization and Reform Act of 2012 (the “Reform 

Act”) and 14 C.F.R. Part 11, Continuum Dynamics, Inc. (CDI) seeks an exemption from the 

Federal Aviation Regulations (“FARs”) listed below:

 14 C.F.R. Part 21

 14 C.F.R. Part 45.23

 14 C.F.R. Part 45.29

 14 C.F.R. Part 61.23

 14 C.F.R. Part 61.3

 14 C.F.R. Part 61.113(a) & (b)

 14 C.F.R. Part 61.133(a)

 14 C.F.R. Part 91.7(a)

 14 C.F.R. Part 91.9

 14 C.F.R. Part 91.109(a)

 14 C.F.R. Part 91.119

 14 C.F.R. Part 91.121

 14 C.F.R. Part 91.151(a)

 14 C.F.R. Part 91.203

 14 CFR Subpart E (91.401 – 91.417)

The requested exemption would authorize an unmanned aircraft demonstration of low altitude, 

precision, automated flight using a T-Rex 600 RC helicopter over the course of 1-2 days in a 

secluded rural research area of New Jersey to support a NASA-sponsored SBIR Phase I research 

and development effort. The demonstration flights will be subject to strict operating requirements 

and conditions as defined herein in order to ensure an equivalent or higher level of safety than

current authorized operations using manned aircraft.
Background and Motivation

NASA is involved in UAS research that would greatly benefit from advancing the ability of 

UAS to make real-time decisions based on sensor data with little human oversight. To pursue this 

goal, NASA has awarded Continuum Dynamics, Inc. (CDI) and our subcontractor Dragonfly 

Pictures, Inc. (DPI) an SBIR effort designed to develop and demonstrate autonomous operation

capability by installing and executing an onboard system on a UAS platform to provide an 

autonomous agricultural application process managed entirely by EPA-approved software. This 

is a high-value civilian application well-suited to autonomous UAS given the dangers posed by 

maneuvering manned aircraft at extremely low altitudes and the ability to operate in areas of low 

population density. This project is currently in the first phase of the SBIR effort. As part of this 

phase, CDI and DPI have obtained permission from the Rutgers Cooperative Research & 

Extension to perform a demonstration of automated flight technology using the T-Rex 600 RC 

helicopter in their agricultural research fields. This feasibility demonstration is the precursor to a

fully-autonomous flight demonstration to be performed with a larger aircraft in Phase II. CDI is 

seeking this Section 333 exemption to allow us to perform this demonstration flight as part of our 

NASA Phase I SBIR effort.

Continuum Dynamics, Inc., (CDI), is a small business of approximately 20 employees located 

in Ewing, NJ actively involved in the research and development of rotary-wing aircraft for over 

35 years. During this time, CDI has lead or participated in over 50 SBIR projects for NASA and 

the DoD related to rotorcraft R&D, analysis, design or simulation. CDI is currently partnering 

with Dragonfly Pictures, Inc. (DPI) to perform Phase I of the NASA SBIR effort described above 

and summarized in the figure below.

Figure 1. Phase I Project Summary
Dragonfly Pictures, Inc. (DPI) was founded in 1992, and has become an industry leader in the 

development and implementation of small rotary wing unmanned aircraft systems (UAS) in the 

U.S. (www.dragonflypictures.com). DPI UAS have successfully flown thousands of hours in 

military applications and DPI is now actively pursuing their deployment in commercial, industrial 

applications. DPI’s fleet of UAS, (some of which are shown in Figure 2), are designed to be easily 

tailored for specific applications and specialize in areas where stable precision flight, selflaunch/land, and high payload capability are critical required platform elements.

DP-5X Wasp DP-12 Rhino DP-14 Hawk

DP-6XT Whisper Modified T-Rex 600 RC - Test Vehicle

Figure 2. Dragonfly Pictures Inc. (DPI) Unmanned Aircraft Systems (UAS). The vehicle at the 

bottom right is the test vehicle for which we are seeking the 333 exemption.

In July 2014, Dragonfly Pictures, Inc. (DPI) and NASA launched a partnership in a landmark 

study of requirements for civil airworthiness certification for operation of the DPI DP-14 Field 

Hawk unmanned tandem helicopter in the national airspace. The goal of this joint effort is to 

develop UAS to study airworthiness requirements to support FAA commercial certification. The 

requirements developed are targeted specifically for precision agricultural application. It is 

intended that the airworthiness requirements developed for the DP-14 will help create a roadmap 

for other UAS developers to build safe systems that can be certified for commercial use in the U.S.

In June 2015, NASA awarded CDI and DPI a Phase I SBIR effort that supports the goals of 

this NASA/DPI initiative while also addressing specific needs described in the NASA SBIR 

solicitation topic A2.02 Unmanned Aircraft Systems Technology. NASA wishes to facilitate the 

process of introducing UAS into the national airspace for commercial purposes. The SBIR effort 

supports this goal by advancing technology in support of UAS platforms performing complex 

operations autonomously. In terms of safety and commercialization of UAS systems, 

advancements in autonomy are essential to expand beyond operations that can be performed 

through direct control by experienced pilots. The ultimate breakthrough in commercial UAS use 

will hinge on the ability for UAS systems to fly autonomously and safely, thereby eliminating the 

need for an experienced pilot to be assigned to each aircraft. If successful, this SBIR effort will 

see the development and demonstration of an entirely autonomous, UAS commercial operation –

agricultural application managed by software that guarantees safe airworthiness according to FAA 

requirements and safe chemical deposition according to EPA regulations.
The demonstration flight for which we are seeking the 333 Exemption

The demonstration flight for which we are seeking the exemption would be performed at the 

research cranberry fields located at 125 Lake Oswego Rd, Chatsworth, NJ owned and operated by 

the Rutgers University Cooperative Research & Extension (see Figure 3 below). The flights will 

be performed over the course of 1-2 days by a T-Rex 600 RC helicopter with a MicroPilot®

autopilot installed by DPI. The UAS to be flown weighs under 10 lbs. A lightweight, mock spray 

boom of roughly 6ft in length will be attached to the aircraft that contains LED lights that will turn 

on to represent when the aircraft spray nozzles are open. The UAS will be constrained from flying 

above 100 ft and above 40 kts. Flights will last less than 30 minutes and will take place within a 

5 acre rural area. The UAS will generally operate at low speed and very close to the ground. The 

flights may be repeated several times over 1-2 days.

 

Figure 3. Rutgers Cooperative Research & Extension cranberry fields where the demonstration 

flight is to be performed; 15 miles from Hammonton, NJ. On the ground (top) and 

Google Maps satellite image (bottom). 
The T-Rex 600 RC helicopter being tested is an off-the-shelf RC helicopter built and sold by 

Align. Given the small size and weight of this UAS, the low altitude, low flight speed, RC-industry 

standard autopilot, and the flight plan in a secluded field in rural NJ, CDI believes it is realistic 

that an equivalent or higher level of safety than for manned aircraft can be maintained throughout 

the demonstration flights. In making this determination, CDI has patterned our exemption request 

on similar requests found on the FAA WEBSITE, most notably an exemption request for a similar 

scenario that was approved for Precision Ag & Imagery, LLC, Regulatory Docket No. FAA-2015-

2726, dated September 22, 2015. CDI’s flight plans are considerably more limited in scope than 

this previous approved request – we are asking for exemption only for 1-2 days of demonstration 

flight tests as part of an experimental R&D project to be performed far from any population centers

or airports and with the vehicle never exceeding a height of 100 ft or a speed of 40 kts.

Aircraft Characteristics – T-Rex 600

The T-Rex 600 RC helicopter is built by Align. Details concerning this aircraft can be found 

on the Align WEBSITE at http://www.align.com.tw/helicopter-en/trex600e/ . Many videos of 

hobbyists flying the T-Rex 600 can be found on the internet.

 Length: 1160mm

 Height: 319mm

 Width: 210mm

 Main rotor diameter: 1347mm

 Tail rotor diameter: 260mm

 Weight: 2840gm (6.25lb)

DPI has added a MicroPilot (www.micropilot.com) UAS autopilot to perform precision flight 

using onboard GPS and related flight management software. This allows the operator to safely 

and efficiently plan a mission in 3D and monitor the UAS in real-time. The autopilot system 

continuously analyzes data from the inertial measurement unit and the onboard GPS and takes care 

of all the aspects of the flight under the supervision of the operator. Additionally, the UAS 

provides an override capability that allows the operator to take manual actions during the flight, 

(e.g. Go to Home, Go Land, Hold, Resume), or optionally to suspend automated operations and 

take manual control of the aircraft with the remote controller provided should it become necessary 

to respond to emergency situations.

Aircraft and Equivalent Level of Safety

The following operation limitations proposed are chosen to provide an equivalent or higher 

level of safety than that required for manned aircraft operations. The applicant agrees to adhere to 

the following limitations and conditions when conducting the proposed research operations under 

the FAA issued exemption:

1. The UAS will weigh less than 55 lbs.

2. The UAS will not fly above 100 ft. The flight ceiling of 100 ft will be pre-programmed so 

as to ensure the aircraft will not fly over 100 ft altitude AGL.

3. The UAS will not fly faster than 40 kts. This maximum speed will be pre-programmed so 

as to ensure the aircraft will not fly at speed in excess of 40 kts.
4. The UAS will only fly over a 5 acre area of rural farmland owned and operated by the 

Rutgers Cooperative Research & Extension near 125 Lake Oswego Road, Chatsworth, NJ. 

This area restriction will be enforced using a geo-fence capability of the autopilot.

5. No operations will be performed within 5 miles of an airport or populated area.

6. Maximum flight time for each flight will be 30 minutes.

7. Minimum crew for each operation will consist of the UAS Pilot in Command (PIC) and a 

Visual Observer (VO). Our most experienced UAS pilot does not hold a private pilot’s

license. Safest operation would be with our most experienced UAS pilot as the PIC and 

the holder of the private pilot’s license as the VO. If this is allowed under current law, this 

is the preferred method of operation for this exemption. If this is not allowed under current 

law, then the holder of the private pilot’s license will serve as the PIC and our most 

experienced UAS pilot will serve as the VO. 

8. A briefing will be performed regarding the planned UAS operations prior to the beginning 

of the day’s operations. The PIC and VO will review the safety of the planned operations 

and provide verbal/written approval for the plan.

9. The PIC will obtain verbal/written consent of all persons involved with the planned 

operation and ensure that only consenting persons will be allowed within 100 feet of the 

flight operation.

10. The PIC and VO will be able to communicate by voice at all times.

11. If the UAS loses communications or loses GPS signal, the UAS will be pre-programmed

to return to a pre-determined location and land autonomously.

12. The UAS will have the capability to abort a flight in case of unpredicted obstacles, weather 

or emergencies.

13. Operations will not interfere with manned aircraft operations.

14. Operations will be limited to Visual Flight Rules Meteorological Conditions (VMC) and 

daylight hours.

15. Operations will remain within Visual Line of Sight (VLOS) and will be visually monitored 

by the PIC and VO at all times.

16. Operations shall comply with required permissions and permits established by territorial, 

state, county or city jurisdictions; including local law enforcement, fire, or other 

appropriate governmental agencies.

17. Operations will compliant with existing safety procedures inherent to the activities of the 

Rutgers Cooperative Research & Extension facility where the flights are being performed.

Operator Requirements

The T-Rex 600 to be used in this research project is a light UAS (under 10 lbs) platform 

utilizing an industry standard MicroPilot autopilot. The UAS is characterized by a high level of 

pre-programmed controls and various built-in technical capabilities (programming of a geo-fence, 

automatic wind detection) that prevent the operator from doing a mission outside of the operating 

limits. All flights are pre-programmed with GPS guidance and do not require human intervention; 
nevertheless human override is possible by clicking on one of the multiple “action” buttons or by 

using the remote controller provided with the system. In the case of unplanned events, either the 

autopilot reacts immediately or the operator can choose between different pre-programmed or 

manual actions. Those procedures include a Flight Termination System (emergency landing 

procedure, triggered by the autopilot or the operator in charge.

Given these safety features, and the extreme limitations on the mission, (10 lb aircraft, low 

speed, low altitude, rural setting, privately-owned land), CDI requests an exemption from the 

airworthiness certification requirements in Part 21 and the concomitant requirements in 14 C.F.R. 

91.7(a) and 91.203 to operate an airworthy aircraft. CDI also seeks an exemption from certain 

requirements in Parts 45 and 91 that are impractical as well as unnecessary for UAS operations. 

Please see Appendix A for a detailed explanation of each regulation from which an exemption is 

sought and the equivalent level of safety.

Conclusion

It is hoped that Continuum Dynamics, Inc. and Dragonfly Pictures, Inc. have provided justification 

for the grant of the requested exemption by describing a safe, precision agricultural spraying 

demonstration to be performed by a small UAS, flying at low speed and low altitude as part of an 

important NASA SBIR project supporting NASA’s goals for future autonomous use of UAS in 

agricultural applications. The demonstration flights will be performed in a safe, controlled 

manner, well away from population centers, over a small 5-acre area of privately-held rural land 

owned and operated by the Rutgers Cooperative Research & Extension.

CDI believes a Section 333 exemption represents the most pragmatic approach to allowing this 

demonstration to be performed safely and in a timely manner, and we greatly appreciate your 

prompt attention to our request.

Sincerely yours,

Daniel Wachspress

Senior Associate

Continuum Dynamics, Inc.

34 Lexington Ave.

Ewing, NJ 08618

Email: dan@continuum-dynamics.com

Phone: (609)-538-0444 x114

www.continuum-dynmaics.com
Appendix A: Exemption Request and Equivalent Level of Safety Showings 

under Applicable Rules Subject to Exemption

Continuum Dynamics, Inc. requests an exemption from the following regulations as well as 

any additional regulations that may technically apply to the flight demonstration of the T-Rex 600 

RC as proposed:

14 C.F.R. Part 21, Subpart H: Airworthiness Certificates 14 CFR § 91.203(a)(1)

Section 91.203 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). Given the size of the T-Rex 600 its 

very light weight (maximum takeoff weight is 10 lbs) and the limited operating area associated 

with this demonstration flight, it is unnecessary to go through the certificate of airworthiness 

process under Part 21 Subpart H in order 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. An analysis of these different criteria demonstrates that the 

T-Rex 600 operated without an airworthiness certificate, under the conditions proposed will be at 

least as safe, or safer, than a conventional aircraft with an airworthiness certificate.

14 C.F.R. § 45.23 & 14 C.F.R. § 45.29: Display of marks; size of marks

These regulations provide that each aircraft must display "N" and the aircraft's registration number 

in letters at least 3 inches high. Additionally, the aircraft must display the word 

"EXPERIMENTAL" in letters at least 2 inches high near the entrance to the cabin, cockpit, or pilot 

station. Given the size of the T-Rex 600 (roughly one meter in length), this requirement is 

impossible to match. A greater level of safety will be achieved by closing the one vehicle entrance 

to the fields where the tests will occur when the UAS is airborne.

14. CFR §61.23 Medical certificates: Requirement and duration

Regulations provide that a person

(1) Must hold a first-class medical certificate:

 When exercising the pilot-in-command privileges of an airline transport pilot certificate;

 When exercising the second-in-command privileges of an airline transport pilot certificate in 

a flag or supplemental operation in part 121 of this chapter that requires 3 or more pilots; or 

 When serving as a required pilot flight crew member in an operation conducted under part 121 

of this chapter if the pilot has reached his or her 60th birthday.

(2) Must hold at least a second class medical certificate when exercising:

 Second-in-command privileges of an airline transport pilot certificate in part 121 of this 

chapter (other than operations specified in paragraph (a)(1)(ii) of this section); or

 Privileges of a commercial pilot certificate
Given the size of the T-Rex 600, its structure, the limited flight area, and the safety features 

integrated in the autopilot, (geo-fencing and automatic abort), Continuum Dynamics, Inc. and 

Dragonfly Pictures, Inc. believe that an Equivalent Level of Safety can be reached if the operator 

has a valid driver’s license.

14 C.F.R. § 61.3: Requirements for certificates, ratings and authorizations 14 C.F.R. § 

61.113(a) & (b); 61.133(a): Private Pilot Privileges and Limitations; Pilot in Command; 

Commercial Pilot Privileges and Limitations

This regulation provides that no person may serve as a required pilot flight crewmember of a civil 

aircraft of the United States, unless that person:

(1) Has a pilot certificate or special purpose pilot authorization issued under this part in that 

person's physical possession or readily accessible in the aircraft when exercising the privileges of 

that pilot certificate or authorization. However, when the aircraft is operated within a foreign 

country, a pilot license issued by that country may be used. The regulation provides also that no 

person that holds a private pilot certificate may act as pilot in command of an aircraft for 

compensation or hire. Subparagraph (b) allows a private pilot to act as pilot in command of an 

aircraft in connection with any business or employment if:

(a) The flight is only incidental to that business or employment;

(b) The aircraft does not carry passengers or property for compensation or hire.

Given the safety features of the T-Rex 600 and the fact that the demonstration flight is preprogrammed and monitored in real-time with specific flight management software (MicroPilot), 

CDI and DPI propose that operators of the T-Rex 600 should not be required to hold a commercial 

or private pilot certification. Instead, operators should be required to:

 Have completed an AMA affiliated small unmanned aircraft systems education and 

training program and achieved an AMA UAS endorsement, or have successfully 

completed a small UAS education and training program provided by any FAA qualified 

entity, and;

 Have passed DPI’s training program for operation of the UAS.

The equivalent level of safety will be achieved by having an operator who meets the above 

qualifications and a Visual Observer (VO) who has a private pilot’s license monitoring and 

participating in the flight test.

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 operation of the T-Rex 600 without an 

airworthiness certificate, no standard will exist for airworthiness of the T-Rex 600. An equivalent 

level of safety will be achieved by insuring compliance with the T-Rex 600 user manual prior to 

each flight. The T-Rex 600 is an off-the-shelf RC helicopter whose airworthiness has been 

demonstrated through many thousands of hobbyist hours of operation.

The equivalent level of safety will be achieved because the T-Rex 600 will only fly over private 

property with the permission of the landowner. Before every flight, the operator will define a 

working area of approximately five acres and a flight area ceiling below 100 ft, preventing the T-
Rex 600 from going beyond the designated flight area. The landowner, the Rutgers Cooperative 

Research & Extension, is a partner in this demonstration. All personnel who may be on the ground 

in the flight area will be briefed of the expected route of flight and the associated risks to people 

and property on the ground. Due to the small size of the T-Rex 600 and its specific safety 

procedures (among others ground detection), the hazard to persons, vessels, vehicles, and 

structures is not comparable to manned aircraft and should be considered in granting the 

exemption. Moreover, the aircraft will not be operated over congested areas or over any open-air 

assembly of persons.

14 CFR 91.121 – Altimeter settings

This section requires that each person operating an aircraft shall maintain the cruising altitude or 

flight level of that aircraft, as the case may be, by reference to an altimeter that is set, when 

operating below 18,000 feet MSL to:

 The current reported altimeter setting of a station along the route and within 100 nautical 

miles of the aircraft;

 If there is no station within the area prescribed in paragraph (a)(1)(i) of this section, the 

current reported altimeter setting of an appropriate available station;

 In the case of an aircraft not equipped with a radio, the elevation of the departure airport or 

an appropriate altimeter setting available before departure.

To provide an equivalent level of safety, the T-Rex 600 autopilot calculates the reference altitude 

(ground level) with the on-board GPS during the pre-flight tests. The GPS and barometer data are 

then used to calculate the altitude in-flight.

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

The regulation provides that no person may begin a flight in an airplane under day-VFR conditions 

unless there is enough fuel to fly to the first point of intended landing and to fly after that for at 

least 30 minutes. Given the limited area of operation for the demonstration flight test, Continuum 

Dynamics, Inc. believes that an equivalent level of safety is already achieved with the specific 

procedure preventing the T-Rex 600 to accept a take-off order if the battery level is below a given 

value. Moreover, the MicroPilot autopilot has integrated “low” and “critical” battery level 

warnings and a “return to Home ” (and “ Go Land ”) action in these situations.

14 C.F.R. § 91. 9: Civil aircraft flight manual, marking, and placard requirements.

This regulation provides that no person may operate an aircraft unless a current, approved flight 

manual is in the aircraft. We assume that the intent of this requirement is to ensure that flight 

manual information is available to the aircrew while operating the aircraft. We request an 

exemption to this requirement since the aircraft is not only too small to carry documentation, but 

the documentation would not be available to the crew, as there is no flight crew on board. The 

equivalent level of safety will be achieved by keeping a hard copy of the T-Rex 600 user manual 

in the T-Rex 600 transport box that will be within reach of the operator at all times.
14 C.F.R. § 91.109(a) & 91.319(a)(1): Flight Instruction

The regulation provides that "No person may operate a civil aircraft that is being used for flight 

instruction unless that aircraft has fully functioning dual controls." Flight instruction will not be 

performed as part of the proposed demonstration. The T-Rex 600 operator will have already 

accomplished the required training program as described in the user manual and will be an 

experienced and qualified pilot familiar with the T-Rex 600.

14 CFR § 91.119: Minimum Safe Altitudes

The regulation provides that over sparsely populated areas, the aircraft cannot be operated closer 

than 500 feet to any person, vessel, vehicle, or structure. Since the T-Rex 600 will be operating at 

a maximum of 100 feet AGL, CDI cannot comply with this requirement.

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

This regulation provides as follows:

 No person may operate a civil aircraft unless it has an appropriate and current airworthiness 

certificate.

 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 T-Rex 600 weighs less than 10 lbs. There is no place to carry certification and registration 

documents or to display them on the UAS. In addition, there is no pilot on board the aircraft. To 

obtain an equivalent level of safety and meet the intent of 91.203, we propose that documents 

deemed appropriate for this aircraft by the FAA will be co-located with the operator at the ground 

control station in the T-Rex 600 box and available for inspection upon request.

14 CFR Subpart E (91.401-91.417) - Maintenance, Preventive Maintenance, and Alterations

This regulation provides that the operator is primarily responsible for maintaining the aircraft in 

an airworthy condition, including compliance with Parts 39 and 43. Paragraphs 91.407 and 91.409 

require the aircraft to be "approved for return to service by a person authorized under 43.7" after 

maintenance and inspection. Section 91.409 requires an annual inspection for the issuance of an 

airworthiness certificate. Section 91.417 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.

CDI proposes that the maintenance of the T-Rex 600 will be accomplished by DPI according to 

the T-Rex 600 user manual. An equivalent level of safety will be achieved because the T-Rex 600 

is small in size, it is not a complex mechanical device and does carry any external payload. 

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. Finally, before 

every flight, the T-Rex 600 automatically runs a sequence of pre-flight tests to make sure that 

every sensor and every critical part is operating properly. If a problem is detected, the T-Rex 600 

will not be able to be switched-on and an error message is displayed to the operator. The owner or 

the operator can then refer to the T-Rex 600 user manual to troubleshoot any issue. Several parts 

of the T-Rex 600 are easily interchangeable (propellers, wings), which allows the operator to make 

sure the wings and propulsion system are always airworthy when a mission is initiated.