. 

Robert Wagner Vice President 

402 Park Place Drive

Hewitt, TX 76643

P-13-00001

U.S. Department of Transportation

Docket Operations, M-30

1200 New Jersey Avenue, S.E.

Room W12-140, West Bldg. Ground Floor

Washington, DC 20590-0001

Subject:

Model:

FAA Project No.:

Reference(s): 

SpecialInstructions:

This letter submits:

Petition for 12 Month Exemption from 25.571 related

to “Normal Flight Envelope” for Birdstrike

737-900

ST09645SC-T

N/A

N/A

(X) Request for Exemption

This letter is sent for:

(X) Review and Approval

As one of the large antenna installation projects that are currently nearing completion, and 

this 12 months exemption being based on previously approved aircraft, Plane Antennas 

and Security Systems Inc (P.A.S.S.) respectfully requests that the public comment period 

be waved.

Please contact me if you have further questions:

Sincerely,

Robert Wagner

(812) 204-4616

Enclosure: Petition for Exemption from 14 CFR25.571(e)(1) at Amendment 25-

132
Enclosure to P-13-00001

Page 1 of 6

A. Name and Address of the Petitioner

Robert Wagner Park Place Dr Hewitt TX 76843

B. Section of the Code of Federal Regulations (CFRs) that are Affected

As provided for in §11.61(b), Boeing hereby petitions for exemption from the following 14

CFR for the model 737-900:

Regulation Amendment Requirement

25.571(e)(1) 25-132 the airplane is capable of successfully completing 

a flight following the impact with a 4-pound bird 

when the velocity of the airplane relative to the 

bird along the airplane’s flight path is equal to Vc 

at sea level or .85Vc at 8,000 feet, whichever is 

more critical. However, this requirement need 

not be considered if it can be demonstrated that 

a bird cannot strike the radome within the normal 

flight envelope up to the design speeds required 

by § 25.571(e)(1).

C. The Extent of Relief Being Sought

Regulation Requirement Why relief is necessary

25.571

(e)(1)

. Per the federal regulation 91,117(a) aircraft are not to fly 

beyond 250 knots at an altitude below 10,000 feet and 

this project expected to use the “normal flight envelope”

enlisting the 250 knot limit. It has recently been clarified 

by the FAA that the cruise velocity should be used for 

the normal flight envelope when looking at the potential 

for bird strike. This clarification takes the radome from a 

worst case condition where the aircraft would fly with a 

nose up attitude, thereby shielding the radome from a 

bird strike, to a 0 degree alpha in which the radome and 

antenna would be exposed to the bird. This antenna and 

radome are scheduled to be completed by the end of 

May, 2013, and therefore may not have the changes 

required to satisfy the bird strike 

The proposed configuration will therefore not comply 

with the requirement of 14 CFR 25.571(e)(1).

Description of relief sought: P.A.S.S respectfully 

requests that the FAA grant a 12 month exemption for

the bird strike clarification to ensure P.A.S.S has time to 

design, fabricate and install a net that will secure any 

large debris from hitting the empennage.
Enclosure to P-13-00001

Page 2 of 6

D. Description of the Issue

14CFR 25.571(e)(1) states “The airplane must be capable of successfully completing a 

flight during which likely structural damage occurs as a result of—

(1) Impact with a 4-pound bird when the velocity of the airplane relative to the bird along 

the airplane's flight path is equal to Vc at sea level or 0.85Vc at 8,000 feet, whichever is 

more critical”

The original FAA issue paper template stated the following:

“To meet this requirement, the applicant must show that a bird strike of the radome will not 

result in a catastrophic condition. However, this requirement need not be considered if it 

can be demonstrated that a bird cannot strike the radome within the normal flight 

envelope.”

14 CFR 91.117(a) states “no person may operate an aircraft below 10,000 feet MSL at an 

indicated airspeed of more than 250 knots (288 m.p.h.).”

Therefore 250 knots was used to generate a “normal flight envelope” which resulted in a 

nose up attitude sufficient to ensure the bird could not strike the radome. 

Recently the FAA became aware of the industry interpretation and notified this applicant of 

the clarification on the issue paper that requires the “normal flight envelope” consider 

velocities up to Vc. 

The revised issue paper template now states the following:

“The applicant must show that the airplane is capable of successfully completing a flight 

following the impact with a 4-pound bird when the velocity of the airplane relative to the 

bird along the airplane’s flight path is equal to Vc at sea level or .85Vc at 8,000 feet, 

whichever is more critical. However, this requirement need not be considered if it can be 

demonstrated that a bird cannot strike the radome within the normal flight envelope up to 

the design speeds required by § 25.571(e)(1). The applicant must consider all phases of 

climb-out, cruise, descent and approach, from sea level to 8000 ft, at the full range of 

certified design weights and CG limits.

Section 91.117 is not applicable to the bird strike requirement of § 25.571(e)(1), and may 

not be used as a means of altering the requirement of § 25.571(e)(1).”

At cruise velocity the aircraft will be flying at a zero degree angle of attack and therefore 

not shield the radome from a bird strike. P.A.S.S. is working diligently to provide design 

changes to ensure the regulation is met.

The notification of this change to the issue paper was provided on March 15, 2013, 2

months prior to the scheduled certification date. This may not allow time for the applicant 

to institute changes to the design that can be instituted prior to the expected certification 

date. Therefore P.A.S.S. respectfully requests a 12 month extension to allow for this 

regulation to be met. 
Enclosure to P-13-00001

Page 3 of 6

E. Statement of Public Interest

Timely completion of this STC will ensure delivery of a head of state aircraft to the 

nation of Kuwait and maintain harmonious relations, and have a positive impact on the 

trade balance with this nation thereby enhancing the social balance, the gross domestic 

product, and the economic health of the United States. 

Granting of this exemption serves the public interest by ensuring continued sales within 

the United States for this nations aircraft as well as the modifications performed after the 

initial sale. 

This serves the public interest by serving economic interests of the United States in general,

and welfare of residents, employment and improved tax revenues.

F. Statement of No Adverse Effect on Safety

The current design will have no adverse effect on safety and is designed to the same 

standards as previously certified antennas. At the FAA regulated speed of 250 knots, the 

antenna can not be hit with a bird due to the nose up attitude of the aircraft and will pose no 

additional risk. 

The FAA has indicated that aircraft currently certified to the original issue paper, will not 

currently be subject to an Airworthiness Directive, which supports the applicant position that 

an no adverse effect on safety exists.
Enclosure to P-13-00001

Page 4 of 6

G. Summary of Petition

In response to a customer request, P.A.S.S requests a 12 month exemption from 14

CFR 25.571(e)(1), Amendment 25-132, for the ability to complete a flight after a bird 

strike under a “normal flight envelope” that includes Vc at sea level. 

It is not envisioned that the aircraft will fly beyond 250 knots below 10,000 feet and will 

therefore not have any increase in risk from a bird strike.

H. Request for Reduced Public Comment Period

With the aircraft due for delivery in the near future, and with no increased risk to the public, 

P.A.S.S respectfully requests that the public comment period be waived.

I. Privileges of this Exemption Outside the United States

Per § 11.81(h), Boeing requests that the privileges of this Exemption be extended outside of 

the United States. This extension of privileges is necessary for operations based within 

foreign countries having bilateral agreements with the United States accepting FAA 14 CFR 

Part 25 as their airworthiness standards for transport category aircraft. This aircraft is

intended for the global market place.