Petition for Exemption - (FAR) §91.9(a) 

Delta Air Lines, Inc. December 4, 2015 

Page 1 

BEFORE THE 

FEDERAL AVIATION ADMINISTRATION 

WASHINGTON D.C. 

Petition of: 

DELTA AIR LINES, INC. 

OPERATING CERTIFICATE DALA026A 

For exemption of certain requirements of 

14 C.F.R. §91.9{a) 

Docket FAA-2015-

PETITION OF DELTA AIR LINES, INC. 

FOR AN EXEMPTION 

Delta Air Lines, Incorporated, operating certificate DALA026A, hereby petitions the Federal 

Aviation Administration (FAA), pursuant to 14 C.F.R. Part 11 for partial relief from Federal 

Aviation Regulation (FAR) §91.9(a), provided certain conditions and limitations are met. 

Section of the FAR Affected: 

Section §91.9(a), Civil aircraft flight manual, marking, and placard requirements, states in 

pertinent part: 

"(a) Except as provided in paragraph (d) of this section, no person may operate a civil 

aircraft without complying with the operating limitations specified in the approved Airplane 

or Rotorcraft Flight Manual, markings, and placards, or as otherwise prescribed by the 

certificating authority of the country of registry." 

Background: 

Delta has operated successfully for the last 18 months utilizing Wi-Fi and a web-based 

turbulence application on the 8737 aircraft during non-critical phases of flight while 

conducting research for the FAA. This was conducted under exemption 10818. 

During this time Delta has also deployed and validated a tablet device EFB for use by all 

pilots across all fleets. The EFB is now approved for use by Delta pilots through all phases of 

flight as documented in operations specifications paragraph A061. The EFB has proven to be 

a useful tool to supplement information required by regulation to include weather 

observations and forecasts. 

It is Delta's intention to allow pilots to use FAA approved web-based applications. To do this, 

access and connectivity to Wi-Fi on the aircraft is required. 

As previously discussed in the docket for exemption 10818, when Boeing transitioned to an 

upgraded display unit (Phase 2 to Phase 3) on the B737, it was discovered under some 

conditions that the phase 3 display unit was susceptible to RF interference. 
Petition for Exemption- (FAR) §91.9(a) 

Delta Air Lines, Inc. December 4, 2015 

Page 2 

When the FAA issued an STC to "GoGo" for installation of Wi-Fi connectivity on the B737 

a limitation was added. The following textual excerpt was taken from the Additional 

Limitations and Conditions section of the FAA Approved Model List of ST02541CH: 

"Honeywell Display Unit (DU), PIN 4091900-xxx (Example P/Ns 4091900-931, 

4091900-932,4091900-933 and 4091900-934), exhibited susceptibility during 4 watt 

EIRP Personal Electronic Devices (PEDs) wireless emission tests. Installation of the 

AirceiJ ABS on aircraft with these displays requires prohibition of use of Wi-Fi devices 

on the flight deck when engines are operating for the purposes of flight." 

As a result of this STC, a placard to prohibit the use of Wi-Fi devices on the flight deck 

when engines are operating for the purposes of flight has been installed in all B737-

700/800/900 aircraft to ensure compliance. The placard wording is as follows: 

"USE OF WI-Fl DEVICES ON THE FLIGHT DECK PROHIBITED WHEN ENGINES 

OPERATING FOR PURPOSE OF FLIGHT" 

In July 2009, several qualification tests with respect to display unit flickering were 

conducted by Boeing. The qualification tests were conducted to determine the different 

frequencies, wattage, device type, and distance that would cause flickering of the display 

units. During these tests of the Phase 3 Display Unit (DU), some flickering was observed 

when the max power of the testing equipment (4 watts) was introduced. However, the 

typical Wi-FI transmission power in laptops is 32 mill watts, well below the 4 Watts that 

caused the flickering. 

Further, when Boeing performed Electro-Magnetic Interference/Radio Frequency 

Interference (EMI/RFI) tests of the Honeywell Phase 3 Display Units (DU) they developed 

recommended distances from the DUs for safe use of wireless radiating devices. At a 

measured transmitter output of 100 mw, the safe distance determined by Boeing's test is 

no closer than 7 inches from the DU. 

Delta has validated Boeing's testing by taking the proposed tablet devises and operating 

them at the recommended distances from the display while on the ground. There have 

been no display issues even when placing the device within 1 inch of the display. 

However, to account for the possible spike in wattage, Delta will maintain a distance of 18 

inches from the display units while in flight. This is easily trained and recognizable by not 

bringing the devices forward of the control column. 
Petition for Exemption- (FAR) §91.9(a) 

Delta Air Lines, Inc. 

December 4, 2015 

Page 3 

Extent of Relief and Reason 

In order to proceed with both providing FAA approved web-based information to the pilots 

(not for operational control decision making), and provide turbulence data information to 

the FAA, DAL is seeking a Petition for Exemption from CFR Title 14, Part 91.9(a), as it 

relates to the placard on the flight deck associated with a Supplemental Type Certificate 

(ST02541CH) issued to GoGo LLC. 

DAL is requesting relief for Delta 8737 pilots' use of the approved Surface Tablets EFB 

devices to access FAA approved web-based applications using the existing aircraft Wi-Fi 

connection. The relief requested would allow for use of the Wi-Fi only during non-critical 

phases of flight outside of Sterile Flight Deck. 

The tablet devices approved for EFB use in opspec A061 that exhibit Wi-Fi connections of an 

Effective Radiated Power of approximately 40 mill watts (mw); far below those powers and 

frequencies that prompted the STC. 

The subject STC states that the display units only "exhibited susceptibility during 4 watt EIRP 

Personal Electronic Devices (PEDs) wireless emission tests". The normal radiating power of 

the proposed demonstration tablet PC is approximately 100 times less than the value 

identified to cause the display unit anomaly. The manufacturer of the tablet's transmitting 

device does state the possibility of spike wattage of 350 mw which equates to only 0.35 

watts. 

The 8737 are the only aircraft type within Delta's fleet that have the cockpit display units 

and STC that are in question. Because of the number of display units in service and 

Honeywell's ability to update the existing units, the process of replacement could take two 

to three years. This modification or replacement of the Phase 3 displays is impractical and 

would unnecessarily delay benefits to the public and potentially impact the schedule for the 

weather integration in the NextGen planning cycle. NextGen has been identified as being 

critical to our nation's infrastructure and its schedule is critical to the benefits anticipated 

from a timely implementation. 

Request for expedited consideration: 

DAL is also requesting that, as part of this Petition for Exemption request, the public 

comment phase be waived as per Title 14 CFR Part 11.87(a) and (c), which states: 

"The FAA may not publish a summary of your petiUon for exemption and request 

comments if you present or we find good cause why we should not delay action on your 

petition. The factors we consider in deciding not to request comment include: 

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

(c) Whether our delaying action on your petition would affect you adversely." 
Petition for Exemption- (FAR) §91.9(a) 

Delta Air Lines, Inc. 

December 4, 2015 

Page 4 

It is the opinion of Delta that since the mitigating actions remove the operational threat, 

there is no precedent being set with our request. Further, during the testing & 

demonstration period conducted under exemption 10818, there were no reported incidents 

of flickering or blanking of the display unit. The purpose of this petition is to continue to 

provide data to the FAA while also providing safety tools via FAA approved web based 

applications for the pilots while maintaining significant procedures in place to mitigate any 

safety issues. 

It is also the opinion of Delta that the use of this information available via these applications 

will result in useful information to the cockpit that will ultimately increase safety to the 

flightcrews, cabin crews, and the traveling public, such as turbulence information and weather 

updates. Turbulence is the leading cause of inflight injuries in commercial aviation. For 

example; pilots currently have limited turbulence and real time weather information at their 

disposal during flight. Their information is limited to either their preflight information 

briefing material or the information they receive via the ATC frequency. The intent of use of 

FAA approved web based applications is to provide near real-time information to the cockpit to 

enable the pilot to engage dispatchers and ATC to make proactive decisions. These proactive 

decisions would enhance aviation safety. 

Continued Research 

The FAA Aviation Weather Division (AWD} has requested that Delta continue to provide 

turbulence data in a research effort to attempt to increase safety within the National 

Airspace System (NAS) by reducing passenger and cabin crew injuries due to unexpected 

turbulence encounters. The initial research with the FAA and Delta demonstrated that 

providing enroute turbulence information to dispatchers improved safety, fewer capacity 

constraints, and lower aircraft emissions. This new phase of research would provide the 

same information to flightcrews as is currently being provided to the dispatchers at Delta. 

Safety would be enhanced through improved knowledge of turbulence events to the 

flightcrews. 

The proposed effort will quantify the benefits of providing enhanced turbulence forecast and 

near real-time aircraft derived turbulence reports to the aircraft. The pilots, through the use 

of the approved tablet device EFB and the onboard Wi-Fi connection, will be able to access 

and display turbulence information during non-critical phases of flight. An enhanced 

turbulence forecast model via an FAA approved application will provide the flightcrew with 

relevant turbulence information that is currently unavailable to the cockpit. Having this 

information at their disposal will allow the flightcrew to better manage their flight while 

reducing cockpit workload. It is anticipated that access to enhanced turbulence information 

wilt result in better flight management, cabin management and overall safety of the 

operation. 
Petition for Exemption- (FAR) §91.9(a) 

Delta Air Lines, Inc. 

December 4, 2015 

Page 5 

Public Benefit 

With improved tools and knowledge, the flightcrews can better coordinate with controllers 

and dispatchers regarding weather and other flight safety related information. This will result in 

better coordination with their cabin crews to provide advance warning of upcoming areas of 

turbulence and other significant events. 

The most significant impact resulting from inflight turbulence encounters during commercial 

operations is injury to the passengers and cabin crew. The use of one of the anticipated 

applications, the turbulence viewer application for example will provide aircrews with 

atmospheric turbulence information prior to an actual turbulence encounter; thus increasing 

their situational awareness. Provisioning of better turbulence information on the flightdeck 

will lead to improved mitigation or avoidance procedures resulting in far fewer cabin injuries 

to passengers and cabin crew members. 

Delta's expectation is the programs and applications available to the pilots will enhance the 

experience of the traveling public which will benefit the total air transportation system. The 

implementation and continued data flow will provide the FAA important information on how 

to validate the improvements in the system and quantify operational and NAS benefits based 

on lessons learned from the data collected. 

No Adverse Affect on Safety: 

Delta is seeking to allow 8737 pilots to use the approved tablet device EFB and Wi-Fi 

connection to access a FAA approved web-based applications on the flight deck during noncritical phases of flight. 

The web-based applications will enhance situational awareness. A well-defined and approved 

risk mitigation strategy will be in place during this operation. Delta will put in a place a risk 

mitigation strategy very similar to those approved by the FAA via the previously issued 

exemption 10818 that includes the following as a minimum: 

a. The approved tablet device EF8 will not be used to view the applications below 

10,000 feet. 

b. The approved tablet device EFB will not be used forward of the control column at 

any time during flight, This will ensure a separation of at least 18 inches between the 

EFB and Display Units. 

d. If any Display Unit anomalies occur, the pilot will immediately disable any Wi-Fi 

connection on the approved EFB for the duration of the flight. 

e. This exemption applies to use of approved EFB Wi-Fi enabled devices for viewing 

FAA approved applications. No other Wi-Fi devices shall be used on the flight deck of 

placarded 8737 aircraft, Further, this relief does not extend to any other placard or 

marking beyond the 8737 flight deck placard which reads "USE OF WI-FI DEVICES ON 

THE FLIGHT DECK PROHIBITED WHEN ENGINES OPERATING FOR PURPOSE OF 

FLIGHT." 
Petition for Exemption- (FAR) §91.9(a) 

Delta Air Lines, Inc. 

December 4, 2015 

Page 6 

DAL conducted an internal Safety Review Analysis of this proposal as part of their FAA 

approved Safety Management System (SMS) program. Based upon information obtained 

from Boeing, the FAA, GoGo, and Delta's technical operations' group, DAL's internal Safety 

Analysis concluded that, with the risk mitigation plan in place during the use of the web 

based Wi-Fi applications, there is no risk to the aircraft, the crew, or the passengers. 

During the previous docket petition, the FAA also considered the discussion between Delta 

and Boeing. Delta requested a No Technical Objection (NTO) from Boeing and on October 

24, 2012, Boeing responded to DAL's request with the following statement: "Boeing 

engineering has No Technical Objection (NTO) to Delta's proposed plan of action." 

Please contact Charles M. Schramek, General Manager Quality Assurance and Compliance, 

at (404) 715-1112 or e-mail at chuck.schramek@delta.com, if you have and questions or 

need additional information. 

Sincerely, 

Step en M. Dickson 

Senior Vice President Flight Operations 

Delta Air Lines, Inc. 

cc: James T. Giles, Jr, Principal Operations Inspector, Delta Certificate Management Unit- FAA 

Attachments: 
Petition for Exemption~ (FAR) §91.9(a) 

Delta Air Lines, Inc. 

December 4, 2015 

Page 7 

Summary for Federal Register 

• Rule from which you seek the exemption 

o DAL is petitioning for a two year exemption from CFR Title 14, Part 91.9(a), as 

it relates to the placard on the flight deck associated with a Supplemental Type 

Certificate (ST02541CH) issued to GoGo LLC. 

• Brief description of the exemption 

o The current placard on the B737NG flight deck prohibits the use of Wi-Fi 

while the engines are operating for the purpose of flight. 14 CFR Part 

91.9(a) requires compliance with all aircraft markings and placards. In 

order to allow use of Wi-Fi and FAA approved web-based applications and also 

to continue to provide turbulence information to the FAA, DAL is requesting 

relief for 8737 pilots to access a Wi~Fi during non-critical phases of flight 

using the existing aircraft Wi-Fi connection. The pilots will be using a low 

wattage Wi-Fi enabled FAA approved tablet device EFB.