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June 12 , 2012

2 /5 **•** API has reviewed the Falcon 50 design with respect to the above configurations, . Multiple failures of the flight control and hydraulic systems were examined as well as particular risks such as uncontained engine failure, bird strike, tire and wheel failures and flailing shafts. In
all cases, the installation o f API winglets has no effect on the probability of the event(s) occurring or the severity of the resulting hazard

.

**•** In addition, API has determined that flight control and hydraulic system failures that could potentially result in the above configurations are extremely improbable, and that these configurations will not result from bird strike, tire or wheel failures, or flailing shafts.

**•** A potential exposure identified is from an uncontained failure of engine 1 or engine 3 with one of two specific tr ajectories

. As previously noted, the installation of winglets has no effect on this failure. The probability of occurrence has been calculated to be 1.1 x 10 -8 per flight hour which is quite low when compared to the est imated 1.4 x 10 7 maximum total fleet

hours for the entire F alcon 50 production run (352 airplanes with a design service life of 20,000 flights of 2 hours average duration ). Therefore, this event is not anticipated to occur during the entire operational life of all airplanes of this type.

**•** An other potential exposure is a structural failure of the maintenance c ontrol valve manifold

for the engine 2 hydraulic system electric motor pump, which could allow leakage o f fluid

from both engine 1 and 2 system reservoirs

. T he installation of winglets has no effect on

this failure. Th is failure rate is on the order 1 x 10 -8 per flight hour , a nd this event is also not anticipated to occur during the entire operational life of all airplanes of this type.

A llowing this exemption will have no material effect on the level of safety of the Falcon 5 0 airplane s

.

Allowing this exemption would be in the public interest. The winglets installation improves the fuel mileage of the airplane by about 5%, reducing fue l burn by that amount on every flight. Thus

, the winglets reduce the demand on crude oil from the world’s supply. Therefore, t h ey also reduce the

environmental effects of CO 2 and NO X emissions. Additionally, it does not impact the level of safety

relativ e to the current airplane.

The current Falcon 5 0 series airplanes already operate extensively outside the United States , and about thirty per cent of the airplanes are registered outside of the United States. The exemption requested would allow the Falco n 50 airplanes to continue to be operated outside the United States after the installation of winglets.

AIRPLANE MODEL

This petition is specifically proposed for the Dassault Falcon 5 0 series airplanes (Mystere

- Falcon 50 and Falcon 50EX) when equipped wi th Aviation Partners Inc (API) blended winglets.

SPECIFIC RELIEF REQUESTED

It is requested that the identified airplane configuration be exempted from certain parts of:

14 CFR 25.671 (c)(2) requiring consideration of dual hydraulic system failures with l oss of all hydraulic fluid from both systems

, and any single failure in combination with any probable hydraulic

failure with loss of fluid.API

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3 /5 BACKGROUND

Aviation Partners, Inc. (API) has a project underway with the Federal Aviation Administration (FAA)

for the certification of the installation of blended winglets on Falcon 5 0 series airplanes by a Supplemental Type Certificate (STC). API’s blended w inglets will significantly reduce the fuel burned on each flight co mpared to the baseline Falcon 5 0 air craft

.

The Falcon 50 series air craft were manufactured by Dassault

- Aviation of France , with the last airplane delivered in 2008

. Dassault has a European Aviation Safety Agency (EASA) type

certificate ( TCDS EASA.A.062) and an FAA type certificate ( TCDS A46EU) f or the basic Falcon 5 0 family.

API and Dassault have a business agreement regarding technical data about the basic Falcon 5 0

series . With this agreement

, API can re ceive from Dassault any information that API may require to develop and certify the wingle ts STC. Dassault provides certification data about their basic airplane which API then uses to determine the effects of the winglets. API prepares drawings, analysis reports and test reports for submittal to the FAA to support the FAA approval of the

win glet STC.

T he FAA has asserted its position that the winglet equipped airplane cannot meet the continued safe flight and landing (freedom from flutter) requirements of § 25.671(c)(2)

. The FAA has guidance

, in the form of issue papers, that the dual hydraulic failure referred to in § 25.671(c)(2) means loss of both hydraulic systems’ pressure s and both systems’ hydraulic fluid must be considered not to be extremely improbable. With the loss of all fluid in both systems

, or with a single disconnect combined with a hydraulic failure that includes loss of fluid, API cannot show that

the winglet air craft will be free from flutter due to the ailerons having low stiffness and damping for

this failure scenario

.

Both the baseline Falcon 50 and the airplane equipped with winglets have aileron surfaces that are

not mass

- balanced. The baseline airplane was shown to be free from flutter after loss of pressure in both hydraulic systems; the assumption of both systems also being drained of fluid was not used in the original certification. The aileron actuators do not include design features that can be shown

to positiv ely trap hydraulic fluid in order to ensure the flutter damping values used in original certification. Consequently, w ith a complete loss of fluid from bo th hydraulic systems, or with the single failure combined with hydraulic failure scenario with loss of fluid, API is unable to show the

baseline Falcon 50 compliant with the latest FAA requirements or with the original certification basis and, therefore, A PI cannot show the winglet airplane compliant.

§ 25.671(c)(2) Combination of failures (for example, dual hydraulic system failures)

The rule states, “Any combination of failures not shown to be extremely improbable, excluding jamming (for example, dual e lectrical or hydraulic system failures, or any single failure in combination with any probable hydraulic or electrical failure).”

EXEMPTION REQUESTED

That the Falcon 50, when equipped with blended winglets be exempted from certain elements of

14 CFR § 25 .671(c)(2) with respect to aileron flutter . This regulation requires the airplane to be capable of continued safe flight and landing following a dual hydraulic system failure, as well as any single failure in combination with any probable hydraulic failure. These failure conditions mustAPI

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4 /5 be considered regardless of numerical probability. The FAA does not consider hydraulic failures including loss of fluid to be extremely improbable. API proposes to exempt the dual hydraulic

failure scenario with loss of fluid , and the single failure combined with hydraulic failure scenario

with loss of fluid

.

JUSTIFICATION

Rationale for the exemption is based on the following points that show the winglet equipped airplane retains the same level of safety as the baseline airplane in these aspects:

**•** The installation of winglets does not degrade the flutter characteristics of the baseline airplane in the potential aileron flutter configurations noted above.

**•** The airplane with winglets installed meets the aeroelastic stability requirements of the original certification basis for all other cases which is the same certification standard as the unmodified Falcon 50 series of airplanes is capable of meeting.

**•** API has reviewed the Falcon 50 design with respect to the above c onfigurations

. Multiple failures of the flight control and hydraulic systems were examined as well as particular risks such as uncontained engine failure, bird strike, tire and wheel failures, and flailing shafts. In
all cases, the installation of API wi nglets has no effect on the probability of the event(s) occurring or the severity of the resulting hazard.

**•** In addition, API has determined that flight control and hydraulic system failures that could potentially result in the above configurations are extremely improbable, and that these configurations will not result from bird strike, tire or wheel failures, or flailing shafts.

**•** A potential exposure identified is from an uncontained failure of engine 1 or engine 3 with one of two specific tr ajectories

. As previously noted, the installation of winglets has no effect on this failure. The probability of occurrence has been calculated to be 1.1 x 10 -8 per flight hour which is quite low when compared to the est imated 1.4 x 10 7 maximum total fleet

hours for the entire F alcon 50 production run (352 airplanes with a design service life of 20,000 flights of 2 hours average duration ). Therefore, this event is not anticipated to occur during the entire operational life of all airplanes of this type.

**•** An other potential exposure is a structural failure of the maintenance c ontrol valve manifold

for the engine 2 hydraulic system electric motor pump, which could allow leakage o f fluid

from both engine 1 and 2 system reservoirs

. T he installation of winglets has no effect on

this failure. Th is failure rate is on the order 1 x 10 -8 per flight hour , a nd this event is also not anticipated to occur during the entire operational life of all airplanes of this type.

Allowing this exemption will have no material effect on the level of safety of the Falcon 50 airplanes.

A review by the FAA of available NTSB, AIDS and SDR databases shows that there have been no reported incidents for the Falcon 50/50EX fleet involving loss of both hydraulic systems’ pressure

and fluid. This fl eet of airplanes has been flown successfully since 1979, demonstrating that the original certification basis and failure scenarios have been safe for these airplanes.

Allowing this exemption would be in the public interest. While not decreasing the level of safety,

t he winglets installation improves the fuel mileage of the airplane by about 5%, reducing fuel burn