Row44

Exemption Request

B767-300

820 Springer Drive

Lombard, IL 60148

Page 1

U.S. Department of Transportation

Docket Operations

West Building, Room W12-140

1200 New Jersey Avenue, SE

Washington, D.C. 20590-0001

June 17, 2014

Re: Petition of Row 44 for Time Limited Exemption from § 25.571(e)(1) of Title 14, Code of Federal 

Regulations (CFR). Project ODA-GED-P066, Row 44 Wireless Broadband System Antenna 

Provisions Installation in Boeing 777-200 Series Aircraft

In accordance with 14 CFR Part 11, Row 44 hereby petitions for an exemption from 14 CFR § 25.571(e)(1) 

(Amendment 25-132) as it relates to the above referenced certification project. For the reasons detailed 

below, Row 44 requests an immediate exemption from this rule and that it remain in effect for a period of 

one year from the date of Supplemental Type Certificate (STC) issuance. This twelve-month exemption 

from the FAA bird-strike damage tolerance requirements is required to ensure that Row 44 has time to 

develop a means of full compliance with § 25.571(e)(1) that is acceptable to the FAA.

The specific regulation, § 25.571(e)(1) is as follows:

Section 25.571(e)(1) – Damage tolerance (discrete source) evaluation. 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 0.85 Vc at 8,000 feet, whichever is more critical.

This section defines required structural requirements for damage to the airframe from a bird strike.

Safety and the Public Interest

This petition for exemption would not adversely affect safety because of two primary factors. First, there have 

never been any documented bird strikes for large fuselage mounted satellite antenna radomes installed on 

Part 25 Transport Category Aircraft. Secondly, in the normal operational flight envelope, the fuselage 

shadows the radome and a bird strike is not possible due to the positive angle of attack of the airplane.

Row 44 currently has approximately 460 satellite antenna radomes installed on Southwest’s 737 aircraft fleet. 

These aircraft are accumulating over 1 million flight hours per year with no reported bird strikes to the radome. 

Additionally, the following table below lists all the exemptions granted for § 25.571(e)(1) for calendar year 

2013. 
Row44

Exemption Request

B777-200

820 Springer Drive

Lombard, IL 60148

Page 2

Exemption No. Applicant Aircraft type Regulatory Docket No.

10760 Live TV Airbus A321 Series FAA-2013-0373

10761 Live TV Boeing 757-300 Series FAA-2013-0372

10762 Live TV Airbus A320 Series FAA-2013-0336

10763 Live TV Boeing 737-100 thru -900 Series FAA-2013-0338

10814 Plane Antennas and 

Security Systems

Boeing 737-900 Series FAA-2013-0433

10817 Gogo LLC Boeing 767-200 thru -400 Series FAA-2013-0562

10845 Standard Aero Airbus A330 Series FAA-2013-0563

10847 Standard Aero Boeing 757-200, -300 Series FAA-2013-0564

10848 Gogo LLC Boeing 767-200 thru -400 Series FAA-2013-0567

10849 Gogo LLC Boeing 777-200, -300, F Series FAA-2013-0569

10850 DRB Aviation 

Consultants

Boeing 777-200, -300, F Series FAA-2013-0660

10851 Star Aviation Airbus A320 Series FAA-2013-0570

In each exemption case listed above, the applicant has presented data that indicates on satellite antenna 

radome installations, which are similar to the satellite radome installed by Row 44 in both size and installation 

location, there has never been a documented bird strike to the radome. This includes over 10 million flight 

hours with satellite antenna radomes installed on all types of Part 25 Transport Category Aircraft. 

In previous efforts to substantiate the Row 44 satellite antenna radome installation for bird strike, it was 

shown analytically that for normal flight operations below 10,000 feet, the fuselage shadows the radome 

and a bird strike was not possible. Per 14 CFR 91.117(a), aircraft are not to fly beyond 250 Knots at an 

altitude below 10,000 feet. This project expected to use this “normal flight envelope” velocity when showing 

compliance to § 25.571(e)(1). It has recently been clarified by the FAA that the cruise velocity should be 

used for the flight envelope when investigating the potential for bird strike. This increased the speed used 

in the analysis from 250 Knots to Vc (Aprox.360 Knots). This clarification changes the attitude of the aircraft 

when investigating the radome for bird strike potential. Under the operational rule for max velocity below 

10,000 feet (§ 91.117(a)), the aircraft would fly in a “nose up” attitude thus shielding the satellite antenna 

radome from a bird strike. However, under the language of § 25.571(e)(1), the aircraft design speed at sea 

level is used. This changes the attitude of the aircraft to level thus exposing the satellite antenna radome to 

a potential bird strike. This project’s STC modification is expected to be complete in October 2014 and the 

updated analysis and/or testing or design changes required to show compliance to § 25.571(e)(1) may not 

be in place.

The public interest is served in granting this exemption for the following reasons. There is keen interest, by 

the flying public, in having connectivity services while flying, particularly on long domestic and international 

flights. These services enable business travelers to remain engaged in their trade while flying, thus

enhancing efficiency and productivity. The connectivity services are also of great benefit to the leisure 

traveler by providing valuable connectivity and entertainment options. 

Bird Strike Substantiation: 

Row 44 has been reviewing § 25.571(e)(1) compliance options with the Chicago Aircraft Certification Office 

(ACO) and the Transport Aircraft Directorate (TAD) for the past seven months. A coordination meeting held 

in early November resulted in a method of showing compliance to § 25.571(e)(1) that was tentatively 

agreed to by all parties present and is summarized below. 
Row44

Exemption Request

B777-200

820 Springer Drive

Lombard, IL 60148

Page 3

Row 44 is developing an analytical model to predict the effects of bird strikes on our satellite antenna 

radome and antenna installation methodology. The model will be developed by creating a modeled (digital 

simulation) and performing an actual bird strike test on a satellite antenna radome and antenna installed on 

a rigid instrumented test fixture. After testing, the digital model response will be updated to incorporate the 

results obtained from the physical test. Next, the updated model will be validated by performing a bird strike 

analysis on a second (simulated) satellite antenna radome and antenna installation (different from the initial 

testing) and comparing this result with actual results of a second physical test of the actual structure with 

the satellite antenna radome and antenna mounted. 

Once the model is validated, the simulation data will be used in the future to show compliance to §

25.571(e)(1) on new FAA STC projects employing this particular satellite antenna radome and antenna 

installation methodology. 

At this time the digital test simulations have been completed, providing guidance on the highest potential 

impact zone vs. antenna position. The initial physical test fixture is complete, required to validate/predict the 

composite response characteristic, however during installation of the validation fixture on a physical section 

from a B767-300 aircraft, a problem was encountered on the B767 adapter ring. This problem was identified 

as a tooling error on the mold for adapter ring. The fix for this tooling error has been identified and corrective 

action is underway. The corrected parts will not be available until late July with test and validation schedule 

completion until late September or early November 2014. 

International Operations:

Per § 11.81(h), Row 44 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. The Boeing 777-200 aircraft is intended for the global marketplace.

The initial aircraft to be modified has China registration. However, they are insistent that the United States 

airworthiness standards along with the CAAC airworthiness standards be followed for all modifications.

Commercial Impact:

Row 44 will incur significant loss of revenue as a result of a delay in obtaining FAA approval of the Satellite 

System Installation on Boeing 777-200 series aircraft operated by China Airlines.

Good Cause Exists to Issue the Exemption without Notice and Comment:

Row 44 requests that the FAA issue the exemption without publication for comment in the Federal Register. 

Section 11.87 lists four factors considered by the FAA in deciding whether or not to publish a summary of 

the petition and request comments. Row 44’s response to each condition is shown below in italics.

(a) Whether granting the petition would set a precedent.

According to the FAA’s Exemption database, 12 exemptions have been granted to § 25.571(e)(1) in 

calendar year 2013 which allows aircraft to operate for a limited period of time pending the 

successful resolution of a compliance issue discovered late in the certification process.
Row44

Exemption Request

B777-200

820 Springer Drive

Lombard, IL 60148

Page 4

(b) Whether the relief requested is identical to exemptions granted previously.

The majority of the exemptions granted in 2013 were for the same reason as stated in requesting 

this exemption. The applicant, Row 44 needs additional time to analyze and/or test and/or modify 

the existing radome to be fully compliant with the provisions of § 25.571(e)(1). This exemption 

request is identical to a previous (granted) exemption request by Row44 based on FAA Project

ST08257CH-T.

(c) Whether our (FAA) delaying action on your (Row 44) petition would affect you (Row 44) 

adversely.

The importance of the SATCOM Antenna radome installation to Row 44’s core business cannot be 

overstated. Due to the rapidly changing technology involved in this modification, coupled with the 

project’s advanced stage and the disruption to operators that have contracted for the Row 44

system, any delay would adversely affect Row 44.

(d) Whether you (Row 44) filed your petition in a timely manner.

The petition is timely filed. Row 44 and our agent have had discussions on this subject with the 

New York ACO and are planning additional discussions with the ACO and Transport Airplane 

Directorate over the next several months.

In light of the above considerations, Row 44 submits that good cause exists not to delay action on this 

request.

Summary of Exemption Request:

In accordance with 14 CFR § 11.81(f), Row 44 offers the following summary suitable for publication in the 

Federal Register in the event the FAA believes that good cause to waive publication has not been 

established.

Row 44 petitions the FAA for an exemption from the discrete source damage tolerance (bird strike) 

requirements of 14 CFR § 25.571(e)(1) for a period of one year based on data that a bird strike encounter 

on a fuselage mounted satellite antenna radome is extremely remote.

Please feel free to contact me by phone or email if additional information is required.

Respectively,

Mr. Kreg Doerr

Manager, Aircraft Installation Design and Certification

Row 44

(732)-710-6414

kdoerr@row44.com