AFS–10–162–E 

Exemption No. 10142 

UNITED STATES OF AMERICA 

DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRATION 

WASHINGTON, DC 20591 

In the matter of the petition of 

AL’S AERIAL SPRAYING, LLC Regulatory Docket No. FAA-2010-0134

for an exemption from § 137.51(b)(4)(i) 

of Title 14, Code of Federal Regulations 

DENIAL OF EXEMPTION 

By letter dated February 3, 2010, Mr. Michael D. Schiffer, Partner, 

Al’s Aerial Spraying, LLC (Al’s Aerial Spraying), 3473 North Shepardsville Road, 

Ovid, Michigan 48866–9667, petitioned the Federal Aviation Administration (FAA) on 

behalf of Al’s Aerial Spraying for an exemption from § 137.51(b)(4)(i) of Title 14, Code of 

Federal Regulations (14 CFR). The proposed exemption, if granted, would permit 

Al’s Aerial Spraying to use a single-engine turbopropeller-powered Air Tractor aircraft to 

takeoff and make turnarounds over congested areas in a loaded configuration. 

The petitioner requests relief from the following regulation:

Section 137.51(b)(4)(i) prescribes, in pertinent part, that for single-engine aircraft, 

except helicopters, no person may takeoff a loaded aircraft, or make a turnaround over 

a congested area. 

The petitioner supports its request with the following information:

The petitioner states that Al’s Aerial Spraying is a small disciplined agricultural 

operation that has been in business for 32 years. The petitioner adds that 

Al’s Aerial Spraying’s pilots have thousands of hours of agricultural application 

experience. The petitioner notes that Al’s Aerial Spraying only operates 

turbopropeller-powered Air Tractor aircraft, which are purpose-built for agricultural 

operations. 
2

The petitioner states the reason for seeking the exemption is that as owners, engineers, 

and highly experienced pilots, Al’s Aerial Spraying personnel have determined that 

flight operations will be safer operating a single-engine turbopropeller-powered 

Air Tractor aircraft for takeoff or to make turns over congested areas than operating a 

multiengine piston-powered aircraft for the same task. 

The petitioner asserts that a grant of exemption would be in the public’s interest and 

would benefit the public as a whole, as it is safer to operate a single-engine 

turbopropeller-powered Air Tractor aircraft than it is to operate a multiengine 

piston-powered aircraft currently allowed under § 137.51(b)(5). 

The petitioner states Al’s Aerial Spraying has contracts to treat trees for Federal, State, 

and local governments. The petitioner adds that under § 137.51(b)(2) and (3) 

Al’s Aerial Spraying submits a congested area plan that includes a public relations 

news media release informing the public that agricultural aircraft will be applying 

material to prevent pests from destroying the trees. The petitioner further states that 

the use of multiengine aircraft causes concern and complaints because when the 

average person sees a multiengine piston-powered aircraft flying low overhead, he or 

she assumes the aircraft is in trouble and a crash is imminent. 

The petitioner explains that Air Tractors have a distinctive look and the 

turbopropeller-powered engines are built to be quieter. The petitioner notes that when 

an average person sees bright yellow Air Tractors from Al’s Aerial Spraying in 

operation, that person is able to make the connection to the press release, resulting in 

significantly fewer 911 emergency calls. 

The petitioner states that Al’s Aerial Spraying operates Air Tractor aircraft powered by 

Pratt and Whitney PT–6 turbopropeller engines, which are significantly more reliable 

and quieter than multiengine piston-powered aircraft. The petitioner further adds that 

these engines reduce and/or eliminate noise complaints resulting from the use of 

multiengine piston-powered aircraft. 

The petitioner notes that the United States Forest Service has extensively researched 

the effective swath width of the Air Tractor and other aircraft and has found the 

average swath or spray pattern of a multiengine piston-powered aircraft is 100 feet or 

less. The petitioner states that the swath of an Air Tractor aircraft is 150 feet; 

therefore, it is more efficient and effective and will require fewer passes and fewer 

turns overhead during aerial applications. The petitioner further adds that fewer passes 

and fewer turns overhead will provide less annoyance to property owners and will 

be safer. 
3

The petitioner notes that multiengine aircraft are purpose-built to operate at higher 

speeds than aircraft purpose-built for agricultural operations. The petitioner explains 

that multiengine aircraft must be flown at higher speeds, which allows the pilot to 

retain control of the aircraft if an engine fails. However, because of these higher 

speeds there is less saturation and penetration of the agricultural material applied to the 

designated area. In comparison, the petitioner explains the Air Tractor’s high lift wing 

design allows the pilots to operate safely at lower speeds, and the wake vortices created 

by the wing ensure excellent coverage and penetration for the agricultural material. 

The petitioner states the customer, who is frequently the taxpayer, benefits by receiving 

the best results for the price paid for aerial application services. 

The petitioner states that granting the exemption would not adversely affect safety and 

would provide a higher level of safety than the existing regulations provided 

in § 137.51. 

The petitioner states that part 137 was promulgated in 1967, at a time when aircraft 

used for agricultural application were built for other purposes and modified to become 

restricted-category aerial applicators. The petitioner notes that Civil Aeronautics 

Manual (CAM) 8, the regulation in place at that time, lists aircraft such as 

Aeronca 7AC, Boeing 75 (Stearman), and the Piper J3 Cub as aircraft that could 

become restricted-category aerial applicators. The petitioner adds that in practice, 

many of these aircraft were “worn out, used up” trainers that gave the aerial application 

business a poor reputation. 

The petitioner states that since 1967, the technology of aerial application has advanced, 

but the law has remained the same. The petitioner notes that millions of dollars have 

been spent on research and computer modeling of the spray droplets exiting aircraft and 

the measurement of spray-drop spectrums produced by aircraft. The petitioner further 

adds that millions of dollars are spent each year to trap, survey, and delineate the exact 

areas that will be targeted by an application to control a specific pest. 

The petitioner explains that the use of differentially corrected global positioning 

systems provides the accuracy to target hundreds of smaller application blocks 

scattered within a city instead of blanket spraying the entire population. The petitioner 

adds that many products used to control pests are specific to one pest at only 

one growth stage, and the window for effective application may be less than 3 days. 

The petitioner further states the end result would provide (1) better control with less 

pesticide used, (2) infinitely less environmental damage, and (3) fewer aircraft turns. 

The petitioner adds that there are now aircraft specifically built for agricultural 

application, and premier among these is the turbopropeller-powered Air Tractor 

aircraft. The petitioner states more operators choose the Air Tractor because it is the 

most productive, highest quality, and most cost effective aircraft available. He adds 

that the Air Tractor provides pilots with superb visibility, light control forces, speed, 

and maneuverability. 
4

Modified versus Purpose-built 

The petitioner states the Air Tractor aircraft operated by Al’s Aerial Spraying are built 

for aerial application, and the wing design is focused on the ability to turn safely at 

very low altitudes. The petitioner explains, on the other hand, multiengine aircraft 

are built to be stable, allowing them to fly safely in instrument meteorological 

conditions and making them comfortable to fly on long trips. In addition, the petitioner 

states that multiengine aircraft resist being turned or made to climb as part of their 

inherent stability and have a built-in 2-second lag time from pilot control inputs to 

turn or climb. The petitioner explains that this 2-second lag time can be extremely 

crucial for a pilot when trying to avoid a collision with another aircraft or obstacle 

(see Advisory Circular (AC) 90–48, Pilots’ Role in Collision Avoidance, appendix 1). 

The petitioner explains the Air Tractor aircraft was deliberately built without this 

inherent control lag. The Air Tractor reacts immediately to pilot control input, thereby 

enhancing the pilot’s ability to avoid collision with another aircraft or the many 

obstacles encountered flying at 50 feet above tree top level. 

Regarding visibility, the petitioner states the principle of “see and avoid” is 

fundamental to all flight in visual meteorological conditions. The petitioner explains 

that the higher speeds multiengine aircraft must fly to retain control in the event of an 

engine failure diminishes the pilots’ time to “see and avoid.” 

In addition, the petitioner further explains that because multiengine aircraft are 

designed to fly high and fast, they may be pressurized and/or their windshields may be 

heated. The petitioner adds that as a result, window posts of a multiengine aircraft 

must be designed to be wide to accommodate systems wiring and structural loads, 

thereby creating blind spots for the pilots. (See FAA P–8740–51, How to Avoid a 

Midair Collision.) 

The petitioner states that in comparison, the Air Tractor provides superb visibility for 

the pilot, having larger and more windows and narrow window posts. The petitioner 

further adds that this outstanding visibility gives the Air Tractor pilot the edge in 

seeing and avoiding collision with other aircraft and the numerous obstacles 

encountered flying at 50 feet above tree top level. 
5

Reciprocating versus Turbopropeller–powered Engines 

The petitioner states that the piston (reciprocating) engine used when part 137 was 

promulgated in 1967 for aircraft modified into restricted-category agricultural aircraft 

has not changed in multiengine aircraft operations that can be legally used today for 

agricultural applications. 

The petitioner states, however, that restricted-category agricultural aircraft eventually 

were retrofit with turbopropeller-powered engines and manufacturers of purpose-built 

agricultural aircraft made the turbopropeller-powered engine standard equipment, as is 

the case with Al’s Aerial Spraying Air Tractors. The petitioner notes from the FAA’s 

Aircraft Flying Handbook (FAA–H–8083–3A) that the turbopropeller-powered engine 

offers several advantages over other types of engines, such as— 

 Light weight; 

 Mechanical reliability because of relatively few moving parts; 

 Simplicity of operation; 

 Minimum vibration; and 

 High power per unit of weight. 

The petitioner states that the mechanical reliability and simplicity of operation equate 

to safety and that statistics provided in the petition show that turbopropeller-powered 

engines are substantially less likely to fail than reciprocating engines. 

The petitioner adds that Al’s Aerial Spraying Air Tractors are powered by 

Pratt and Whitney PT–6 turbopropeller engines because these engines are built for high 

reliability. In addition, the petitioner states Al’s Aerial Spraying complies with 

manufacturers’ recommended overhaul periods or FAA-approved intervals and adds 

that its Pratt and Whitney PT–6 engines are operated on an inspection program to 

increase reliability, durability, and safety. Therefore, the petitioner states that 

Al’s Aerial Spraying Air Tractors are less likely to experience an engine failure than 

the multiengine piston-powered aircraft allowed under part 137. 

Single-Engine versus Multiengine 

The petitioner notes that the purpose of having two engines instead of one is that, in the 

event of an engine failure, the multiengine aircraft should be able to fly to an airport 

where it can land safely. The petitioner adds that this may or may not be achievable, 

depending on the situation. 
6

The petitioner quotes the following from FAA publication FAA–P–8740–19, 

Flying Light Twins Safely: 

The major difference between flying a twin engine and a 

single engine airplane is knowing how to manage the flight if 

one engine loses power for any reason. Safe flight with 

one engine-out requires an understanding of the basic 

aerodynamics involved as well as proficiency in engine-out 

procedures. 

Loss of power from one engine affects both climb performance and 

controllability of any light twin (emphasis added). 

The petitioner states that multiengine aircraft modified for aerial application have the 

additional burden of drag produced by spray booms and other agricultural appliances 

mounted on the exterior of the aircraft. He asserts that performance data provided by 

the multiengine aircraft manufacturer might show the aircraft can climb with an engine 

failure under ideal conditions, without pilot error, and no additional externally mounted 

equipment. 

The petitioner states the FAA clearly recognizes the danger an engine failure poses to 

the controllability of a multiengine aircraft operated at an altitude lower than 3,000 feet 

above ground level (AGL). He notes that aerial application requires these same aircraft 

be operated at 50 feet above tree top level. The petitioner references the 

FAA Commercial Pilot Practical Test Standards (PTS) FAA–S–8081–12B, 

Multiengine Aircraft Emergency Operations. The petitioner explains that for 

multiengine aircraft emergency operations, the PTS states that FAA examiners must 

ensure single-engine demonstrations are conducted at an altitude no lower than 

3,000 feet AGL. The petitioner states that aerial applications require the same aircraft 

to be operated at 50 feet above tree top level. According to the petitioner, the PTS 

delineates that the pilot of a multiengine aircraft that experiences an engine failure 

while involved in aerial application 50 feet above tree top level must accomplish the 

following: 

 Recognize an engine failure promptly, maintain control, and use appropriate 

emergency procedures; 

 Reduce drag by raising the landing gear or flaps as appropriate; 

 Identify and verify the inoperative engine; 

 Feather the propeller on the inoperative engine; 

 Establish VYSE (best rate of climb with one engine inoperative); if obstructions 

are present, establish VXSE (best angle of climb with one engine inoperative) or 

VMC (minimum control speed with critical engine inoperative) +5 knots, 

whichever is greater, until obstructions are cleared; then transition to VYSE; 
7

 Bank toward the operating engine as required for best performance; 

 Monitor the operating engine and make adjustments, as necessary; 

 Recognize the aircraft’s performance capabilities. If a climb is not possible at 

VYSE, maintain VYSE and return to the departure airport for landing, or initiate 

an approach to the most suitable landing area available; 

 Secure the inoperative engine; and 

 Complete an emergency checklist. 

The petitioner explains that these tasks must be accomplished without colliding with 

the ground, other aircraft, or obstacles encountered at 50 feet above tree top level, 

while the pilot attempts to continue to look inside the cockpit for an extended period. 

In comparison, the petitioner states in accordance with FAA H–8083–3, 

Airplane Flying Handbook, the pilot of a single-engine aircraft that experiences an 

engine failure while involved in aerial application at 50 feet AGL must— 

 Establish and maintain the recommended best glide airspeed, ± 10 knots; 

 Select a suitable landing area; and 

 Follow the appropriate checklist. 

The petitioner concludes the single-engine aircraft engine failure scenario is most 

likely to have a better outcome. The petitioner adds that Al’s Aerial Spraying’s 

Air Tractor will be operating at greater than best glide speed and the pilot will be able 

to climb, trading that speed for altitude and time. 

In addition, the petitioner states that Al’s Aerial Spraying’s congested area plans 

provide emergency landing areas to its pilots and these areas are reviewed before every 

day of operation so its pilots know where they are in relation to these emergency 

landing areas at all times. 

The petitioner states that despite a multiengine piston-powered aircraft having the 

second engine available, it is still more likely than the single-engine Air Tractor to 

crash in the event of an engine failure. The petitioner further adds that in the event of 

an engine failure using the Air Tractor, Al’s Aerial Spraying’s pilot will be able to use 

the stored energy of the airspeed to climb and fly according to manufacturer’s data 

(Air Tractor), in excess of 1.5 miles to a predetermined landing area and land. 

Current Multiengine Requirement 

The petitioner states that the FAA’s requirement under § 137.51(b)(5)(ii) for a climb 

with a critical engine inoperative is expressed as “a rate of climb of at least 50 feet per 

minute.” The petitioner adds that in accordance with 14 CFR part 23, small 

multiengine aircraft of 6,000 pounds or less maximum weight have no FAA 
8

certification requirement for a single-engine positive rate of climb, and the aircraft 

performance to comply with FAA certification standards is based on climb gradient. 

Therefore, the petitioner states this makes the agricultural operator and/or the 

FAA aviation safety inspector’s ability to determine whether a multiengine aircraft can 

comply with § 137.51(b)(5) improbable. 

In addition, the petitioner notes that § 137.51(b)(5) does not require multiengine 

aircraft used in agricultural operations flying 50 feet above tree top level to maintain 

engines within the manufacturer’s overhaul times. The petitioner further notes that 

there is no requirement for multiengine aircraft to have a low fuel warning system or 

systems that provide pilots with information while the pilot continues to look outside 

the aircraft. There also is no requirement that the pilots have additional training 

regarding engine failures low to the ground at low speeds in steeply banked turns. 

The petitioner again refers to the FAA’s Airplane Flying Handbook (FAA H–8083–3) 

and further notes that a major aspect of flying an agricultural application in a congested 

area is the need for multiple turns to be made in a very small radius, necessitating the 

multiengine aircraft required by this regulation to be flown at a low speed and turned at 

higher than standard bank angles. The petitioner states that recovery is unlikely when a 

multiengine aircraft in a slow steeply banked turn suffers an engine failure on the 

inside of that turn at 50 feet above tree top level. 

The petitioner comments that in 1967 the authors of part 137 believed that two engines 

are better than one, without knowledge of the physics involved, benefit of FAA training 

publications, or the next 43 years of development and operating statistics. 

Statistics 

The petitioner provides statistical information on single-engine turbopropeller 

powerplant aircraft reliability summarized from the contents of a report prepared by 

Robert E. Breiling Associates, Inc., Boca Raton, Florida, based on information 

available from National Transportation Safety Board (NTSB) and FAA sources. The 

petitioner asserts the statistics further prove Al’s Aerial Spraying’s use of a 

turbopropeller-powered Air Tractor over a congested area is safer taking off or turning 

than using multiengine piston-powered aircraft for the same tasks. 

The petitioner presents powerplant reliability comparative data that shows multiengine 

reciprocating-powered aircraft accounted for 5.68 percent of accidents per 100,000 

hours by major aircraft type based on a 5-year average, from 1992 through 1996, as 

compared to 1.46 percent for single-engine turbopropeller-powered aircraft during the 

same period. The petitioner also presents data to show that multiengine 

reciprocating-powered aircraft accounted for 27.6 percent of general aviation 

fixed-wing aircraft accidents attributed to power loss, all causes, based on a 5-year 

average, from 1992 through 1996, as compared to 0 percent for single-engine 

turbopropeller-powered aircraft during the same period. 
9

The petitioner states that based on the review and analysis of accident data involving 

single- and multiengine reciprocating- and turbopropeller-powered malfunctions, 

failures, and accidents, and an analysis of the available powerplant reliability data, 

Robert E. Breiling Associates., Inc. concluded that a single-engine 

turbopropeller-powered aircraft, with adequate backup systems provided in its design, 

will be more reliable, involved in fewer powerplant malfunction/failure-related 

accidents than single- or multiengine reciprocating-powered fixed-wing aircraft, and is 

comparable to the reliability of a multiengine turbopropeller-powered aircraft. 

Precedent 

The petitioner argues that at one time the FAA prohibited 14 CFR part 135 

single-engine operations under instrument flight rules (IFR) and night operations using 

reciprocating-powered engine and turbopropeller-powered aircraft. He added that the 

FAA revised part 135 in 1998 to allow single-engine operations provided certain 

maintenance, equipment requirements, and flight crewmember training and experience 

levels are met. The petitioner adds that Al’s Aerial Spraying Air Tractor aircraft are 

equipped with the same Pratt and Whitney PT–6 turbopropeller-powered engine as the 

Cessna C208 Caravan, which has an extremely reliable safety record. According to the 

petitioner, Cessna C208 Caravan fatal accidents in the United States between 1985 and 

1996 (2.6 million total flight hours) were 0.56 per 100,000 hours; fatal accidents 

caused by mechanical failures of the engine were zero. 

Al’s Aerial Spraying Maintenance, Equipment, and Flightcrew Experience Levels 

The petitioner notes that Al’s Aerial Spraying holds a part 135 certificate. 

The petitioner states that compared to the 100 hours of flight experience as pilot in 

command required under § 137.53(b)(2) to dispense agricultural materials or chemicals 

over congested areas, Al’s Aerial Spraying pilots have a minimum 2,500 hours of 

agricultural application flight time, minimum of 6,500 hours total flight time, and an 

average of 14,500 hours of total flight time. The petitioner adds that these pilots are 

career aerial application pilots who have worked with Al’s Aerial Spraying for several 

years and have conducted aerial application operations on thousands of acres over 

congested areas. 

The petitioner further states that Al’s Aerial Spraying fleet consists of only Air Tractor 

aircraft, as these aircraft are designed to provide the necessary visibility, 

maneuverability, reliability, and excellent glide distance that have made 

Al’s Aerial Spraying’s impeccable safety record possible. 

The petitioner states that Air Tractor, Inc., the aircraft manufacturer, provides proactive 

and superior product support, and Al’s Aerial Spraying complies with all 

FAA airworthiness directives and inspections, including the manufacturer’s 

recommended overhaul periods or FAA-approved intervals. In addition, the petitioner 

states that Al’s Aerial Spraying Air Tractors have a supplemental type certificate for 
10

single point refueling, and a SATLOC differentially corrected global positioning 

system that provides the pilot with the location of the closest noncongested area at 

all times. 

Finally, the petitioner states that Al’s Aerial Spraying conducts daily post-flight 

briefings as an important part of the company’s safety culture and for learning 

purposes. 

A summary of the petition was published in the Federal Register on May 26, 2010 

(75 FR 29602). The FAA received 12 comments from individuals, consisting of airline 

transport pilots, general aviation pilots, aviation maintenance technicians, and an engineer. 

In general, all 12 commenters support the granting of an exemption to Al’s Aerial Spraying 

based on the following three issues: 

(1) Outdated FAA regulations for agricultural aircraft operations. 

The majority of persons submitting comments on the petition for exemption have 

stated that part 137 is outdated and needs to be updated to account for the 

significant evolution of purpose-built agricultural application aircraft and 

agricultural and aviation technology. Six commenters specifically want the 

regulations to be updated. 

(2) Support the petition for exemption based on referenced FAA publications. 

Eight commenters support the petition for exemption based on the 

FAA publications, ACs, and statistical information that, in their opinions, prove a 

single-engine turbopropeller-powered aircraft is safer than a multiengine aircraft at 

the low altitudes necessary for aerial applications. 

(3) Higher level of safety. 

Eleven commenters state that granting the exemption to permit 

Al’s Aerial Spraying to operate single-engine turbopropeller-powered Air Tractor 

aircraft to takeoff and make turnarounds over congested areas in a loaded 

configuration will not adversely affect safety of flight and will provide a higher 

level of safety. 
11

The FAA’s analysis is as follows: 

The FAA has fully considered the petitioner’s supporting information, as well as the 

information provided by comments submitted to the docket supporting the Al’s Aerial 

Spraying petition for exemption, and determined that the circumstances presented by the 

petitioner do not justify a grant of exemption. The FAA finds the petitioner has not 

sufficiently shown that a grant of exemption would be in the public interest or that a level of 

safety equivalent to that provided by the regulations would be maintained for the following 

reasons: (1) Al’s Aerial Spraying operation is not unique or special in comparison to other 

agricultural aircraft operators who conduct aerial application operations over congested areas 

using single-engine aircraft so as to justify relief by way of an exemption; (2) The FAA does 

not agree with the petitioner that operating a single-engine turbine-powered aircraft for 

takeoff or to make turns over congested areas is safer than operating a multiengine piston 

powered aircraft for the same task. Furthermore, the petitioner’s arguments regarding the fact 

that the regulations are outdated indicate that this request is more appropriate for a petition for 

rulemaking. 

Title 14 CFR § 137.51 addresses three types of aircraft used in agricultural aircraft 

operations: helicopters, multiengine aircraft, and single-engine aircraft. Currently, takeoff or 

turnaround operations over congested areas are permitted for single-engine helicopters per 

§ 137.51(b)(4)(i) or for a multiengine aircraft per § 137.51(b)(5)(ii). Part 137 does not 

preclude the petitioner from conducting aerial application operations over congested areas 

with a single-engine aircraft. At issue are takeoff and turnaround single-engine aerial 

application operations while over congested areas. The safety concern is with respect to 

engine loss below the safe altitudes prescribed in part 91. Before an operator conducts any 

aerial application operations in any aircraft over congested areas, the FAA must approve a 

congested area plan in accordance with § 137.51(b)(3). Before approving any operator’s plan 

of operation using a single-engine aircraft over congested areas, the FAA requires the 

operator to coordinate safety measures with local officials. These measures may include 

blocking off streets and other areas that could be used as an emergency landing or similar 

precautionary measures required in the interest of public safety. The FAA then determines 

whether the aircraft to be used complies with the emergency landing requirements contained 

in § 137.51(b)(4)(iii) during the actual dispensing operation. 

The FAA, as a part of the approval of a congested area plan, requires an operator of a 

multiengine aircraft who intends to takeoff over a congested area to show in the plan that the 

aircraft can meet the accelerate-stop requirements of § 137.51(b)(5)(i). If the aircraft cannot 

meet these requirements, the operator must state in the written plan of operation that no 

takeoff will be made over a congested area during dispensing operations. In addition, the 

operator must show in the congested area plan that the aircraft can meet the climb 

requirements for a critical engine inoperative as specified in § 137.51(b)(5)(ii). Otherwise the 

FAA does not approve the plan for multiengine aircraft aerial application operations over 

congested areas. 
12

The FAA recognizes the unique flight characteristics of helicopters and performance 

characteristics of multiengine aircraft. By requesting to takeoff or make a turnaround in a 

loaded, single-engine aircraft, over a congested area, the petitioner must demonstrate that a 

singleengine aircraft has an equivalent level of safety comparable with the recognized 

maneuverability of helicopters and/or the climb capability required by this regulation in a 

multiengine aircraft with one-engine inoperative. 

The petitioner asserts, with supporting statistical data, that turbopropeller-powered engines 

are more reliable than piston-powered engines. Although the turbine-powered engine may be 

more reliable, it is the sole source of power for the aircraft. A powerplant failure of singleengine aircraft (regardless of engine type) while over congested areas, below the minimum 

altitudes prescribed in part 91, make the aircraft a potentially greater hazard than a singleengine helicopter or multiengine aircraft. Over congested areas, a helicopter has greater 

ability, at low altitudes, to maneuver to a safe landing area and to ensure the safety of persons 

or property on the surface. In addition, § 137.51(b)(5)(ii) requires “positive” climb 

performance capabilities of multiengine aircraft with one engine inoperative. The FAA 

reviewed Fiscal Year 02 – FY 09 NTSB data which showed 496 airplanes involved in part 

137 operator accidents. Of these accidents, none involved multiengine aircraft. A review of 

17 recent fatal agricultural accidents in single-engine turbines indicate that the 2 most recent 

involve catastrophic engine failures. In considering the data, the FAA assessed the petition 

on more than accident rates. Other issues were considered including potential long-term risk 

to the public due to unintended consequences from a significant change to the agricultural 

spraying market over congested areas. This preliminary accident analysis indicates that this 

petitioner’s request requires further study and consideration and is not appropriate for 

exemption relief. 

The petitioner claims that the FAA clearly recognizes the danger an engine failure poses to 

the controllability of a multiengine aircraft because the PTS requires single-engine 

demonstrations for emergency operations in multiengine aircraft be conducted at an altitude 

no lower than 3,000 feet AGL. The FAA reminds the petitioner that the PTS areas of 

operation are designed in this case for a pilot to demonstrate competency during emergency 

operations to obtain a commercial pilot certificate with a multiengine rating. The designation 

of 3,000 feet AGL is a safety precaution used during emergency operations testing and does 

not mean the FAA has determined that an engine failure in a multiengine aircraft cannot be 

successfully addressed at a lower altitude or that a certificated pilot’s competency during 

actual emergency operations in a multiengine aircraft would diminish at an altitude below 

3,000 feet AGL. Finally, the FAA recognizes that single-engine demonstrations for 

emergency operations in multiengine aircraft may take place at altitudes below 3,000 feet 

AGL and specifies that at altitudes lower than 3,000 feet AGL engine failure must be 

simulated by reducing throttle to idle and then establishing zero thrust. 
13

In addition, the petitioner argues that the part 135 rule change in 1998 is similar to what has 

been proposed in this request. The FAA does not agree that a comparison can be made 

between single-engine aircraft passenger-carrying operations under IFR and the hazards 

associated with low altitude aerial works. Part 135 was revised to allow single-engine aircraft 

passenger-carrying operations under IFR after almost 20 years of study and a notice and 

comment rulemaking period. The FAA’s decision included a review of operational data from 

Canada, accident data, Aviation Rulemaking Advisory Committee recommendations, and an 

NTSB study. In order to consider the petitioner’s request, a thorough review and analysis 

would need to be completed. Moreover, six commenters specifically stated the need for 

part 137 to be updated. These comments indicate that the petitioner’s request is not unique or 

special in comparison to other agricultural aircraft operators. Therefore, rather than a petition 

for exemption, this request is more appropriate for a petition for rulemaking. Although this 

request has merit as a petition for rulemaking, due to resource and time constraints as a result 

of the mandatory rulemaking projects in the Airline Safety and Federal Aviation 

Administration Extension Act of 2010 (Public Law 111-216) signed on August 1, 2010, we 

cannot address a possible change to part 137 at this time. 

The FAA’s Decision: 

In consideration of the foregoing, I find that a grant of exemption would not be in the 

public interest. Therefore, pursuant to the authority contained in 49 U.S.C. §§ 40113 

and 44701, delegated to me by the Administrator, the petition of Al’s Aerial Spraying, LLC 

for an exemption from 14 CFR § 137.51(b)(4)(i) is hereby denied. 

Issued in Washington, D.C., on Sep 20 2010. 

/s/ 

John W. McGraw 

Acting Director, Flight Standards 

 Service 
14

Project No.: AFS–10–162–E 

Project Officer: _______________ 

ARM-107:LBrunache:09/09/10:Doc# 30298 

ARM-1/100/107: AFS-800 

Statistics: Final Draft Als Aerial Spraying LLC.DOC, 4,800 words 

 Original, 10 Sep 2010 17:15 

 Style Index 66 Average for a Legal Document 

 Average Sentence Length 28 Poor

 Passive Index 26 Excellent

MR MICHAEL D SCHIFFER 

ALS AERIALSPRAYING LLC 

3473 NORTH SHEPARDSVILLE RD 

OVID MICHIGAN 48866