A.DELTA~~ 

November 5, 2012 

Docket Operations, M-30 

Kirk Thornburg 

Managing Director - Aviation Safety & Assurance 

Corporate Safety, Security, & Compliance 

U.S. Department of Transportation (DOT) 

1200 New Jersey Avenue, SE 

Room W12-140, West Building Ground Floor 

Washington, DC 20590-0001 

Re: Docket Number FAA-2012-21826 Comments 

Dear Sir: 

Delta Air Lines, Inc. 

1020 Delta Blvd 

Department 041 

Atlanta, Georgia 30320 

404-773-9913 

Kirk.Thornburg@delta.com 

... ,.;. 

Delta Air Lines submitted information on October 30, 2012 against Docket FAA-2012-0752 

that may be useful to the FAA in its rulemaking interest regarding the use of cell phones in 

flight. In the attached letter, Delta provides information from a survey of 1462 customers 

on their preferences for expanded use of cell phones in flight and outlines a Safety 

Management System (SMS) approach to address potential interference with aircraft 

systems. 

Delta Air Lines supports expanded use of cell phones and PEDs in flight but takes a position 

that voice cellular calls should be limited to ground operation only. 

Sincerely, 

l&1c <; J 

Kirk Thornburg 

Managing Director, Aviation Safety Assurance 

Attachment: Delta submittal to Document FAA-2012-0752 
~.DELTA~-~ 

October 30, 2012 

Docket Operations, M-30 

Kirk Thornburg 

Managing Director- Aviation Safety & Assurance 

Corporate Safety, Security, & Compliance 

U.S. Department of Transportation (DOT) 

1200 New Jersey Avenue SE, Room W12-140 

West Building Ground Floor 

Washington, DC 20590-0001 

Re: Docket number FAA-2012-0752 Comments 

Dear Sir: 

Delta Air Lines, I,nc. 

1020 Delta Blvd 

Department 041 

Atlanta, Georgia 30320 

404-773-9913 

Kirk.Thornburg@delta.com 

Delta Air Lines is supportive of the FAA's review of current policy regarding the use of 

Portable Electronic Devices (PED) on aircraft. PEDs are now widely accepted into our 

society and are integral devices to most American's daily lives. It should be the joint 

responsibility of the aviation industry and the FAA to plan future air travel such that aircraft 

operating systems are compatible with PED operation. An Aviation Rulemaking Committee 

(ARC) comprised of technical and operational experts in the aviation community, technical 

and operational experts in the PED community, the FAA, and the FCC can be an effective 

vehicle to accomplish this objective. Delta believes that strict oversight of the ARC with 

specific deliverables and completion timelines is essential for the effort to be successful. 

As technology has developed in the last 30 years, the industry has worked similarly with the 

FAA to develop acceptable system standards and operational guidelines for In Seat Power 

Systems, Wireless Internet Systems (Wi-Fi), and many on board server based Passenger 

Entertainment Systems. Airline travel must adapt to the needs of the traveling public, but it 

must do so with a plan that ensures critical aircraft systems will not be affected by these 

devices .. 

Delta Customer Input 

In support of the FAA's efforts via this docket, Delta recently surveyed 1462 customers over 

the issue of expanded PED usage on flights. Our customers responded as follows: 

o When asked to pick which device they would like to use the most below 10,000 feet, 

cell phone is the top choice followed closely by tablet computer. 

o Reading e-books, text messaging, listening to music, watching movies and playing 

games are the top activities that customers would like to do below 10,000 feet 

Note: Of the activities available on today's smart phones, making cellular calls is only 

the 6t11 priority 

o Most customers feel that being able tp use electronic devices below 10,000 feet 

would have a positive impact on the onboard experience 

o The ability to make phone calls is seen to have a negative impact on the onboard 

experience for 64% of customers; however, 36% of customers believe it would be 

positive indicating that phone calls in flight can be polarizing. 
Impact on Onboard Experience is allowed to use PED's 

Below 10,000 Feet 

100% l 

80%1 

60%-; 

' 40%-; 

20% l 

0% 

-20%-: I 

-40% 1 

-60%] 

-80% J 

·100% 

Delta Ooerations View 

• Very Positive 

• Somewhat Positive 

• Somewhat Negative 

• Very Negative 

An important objective of expanded PED usage should include assurance that the safety 

function duties assigned to our Flight Attendants are not diminished due to an additional 

requirement to police on board PED usage to a greater degree than today. In the last 12 

months, data available to Delta from our in flight reporting systems show an increase in 

passenger non compliance to current PED usage policy with no corresponding increase in 

safety events. Our data shows the following: 

o 99% of passenger PED non compliance occurs in the taxi out portion of the flight 

o 95% of passenger PED non compliance were related to cell phone usage 

o No increase in actual operational safety events 

The ARC Is urged to recommend rulemaking that assures that flight attendants continue to 

devote their time to in-flight safety assurance functions and that the industry finds other 

means to satisfy compliance with expanded PED operation on aircraft. As opposed to an 

effort to require flight attendants to ask passengers to put their PED down for important 

safety briefing announcements, benchmarking of other industries should be examined to 

determine if there is a better way to ensure safety briefings are communicated to all. If not 

addressed, too much of our flight attendants time is focused on PED operational compliance 

of cabin readiness and not balanced across the greater need to assure that the cabin is 

properly prepared for each phase of flight. 

It should be the objective of the ARC to confirm PED usage is safe within today's Safety 

Management Systems Risk Acceptance guidelines. Once PED operation is confirmed safe for 

all phases of flight, flight attendant duties for PED usage should be similar to monitoring 

passenger's usage of a book or newspaper. 

' 

Safetv Management System (SMS) Data Availability 

Delta has implemented a Safety Management System which allows identified hazards to our 

operation to be collected across a number of safety reporting systems. To respond to the 

agency's request to comment on the current PED usage policy, Delta canvassed our 

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Maintenance defect reports and Pilot Aviation Safety Action Program (ASAP) reports. Since 

January 1, 2010 at Delta Air Lines, representing 2.3 Million flights, Delta pilots mentioned 

PED as a potential source of an observed flight equipment discrepancy on only 3 occasions. 

A review of maintenance defect reports during the same time period revealed 24 reports 

where Delta mechanics mentioned the possibility of PED interference when resolving 

avionics system irregularities. However, in each of the 24 mechanical defect reports, Delta 

was not able to confirm a PED was the cause of the anomaly, only that our mechanics felt 

that It was a possibility for the defect. When combined, 27 pilot and maintenance reports 

out of 2.3 million departures during this period that suggested the possibility of PED 

interference exist at Delta but none were able to be confirmed by any operational or 

maintenance methodology. 

Use of Safety Management System (SMSl Principles 

The FAA has regulation pending requiring US airlines to implement a safety management 

system to identify hazards and implement mitigation to operate aircraft at an acceptable 

risk level. As a part of this effort, SMS assessment tools are now available which define risk 

across a matrix of likelihood versus severity. Each carrier either has, or will be, adopting a 

system that meets the pending rule. Each carrier will demonstrate its assessment tools are 

in place to its FAA Flight Standards oversight organization. 

Delta believes that advances in technology both in the PED and aircraft system designs have 

reduced the likelihood of an Interference condition occurring in all phases of flight to a level 

that can be accepted with mitigation. The July 2012 FAA study on the use of cell phones on 

passenger aircraft cites information from several International civil aviation authorities that 

have approved installation of onboard cellular telephone base stations that cell phones and 

base stations have not interfered with aircraft systems. 

Anecdotally, Delta passengers and crew will confirm that on numerous flights some number 

of passengers inadvertently leave their PED on and as reported above, we have only three 

flights where a Delta flight crew thought a PED could possibly have caused interference. In 

the July 2012 FAA study, the French D~AC noted that approximately 10 percent of cell 

phone users forgot to turn their cell phone off even when the onboard cellular base station 

was not operating. 

Traditionally, airlines have used on board testing to confirm in-flight Wi-Fi systems and 

ground usage of cell phones have not interfered with aircraft systems. However, continued 

reliance on testing of every PED against every potential aircraft system Is an untenable 

task. The industry must look to other methods to identify hazards and mitigate risk. Delta 

encourages the ARC to look to the SMS methodology for alternative means to demonstrate 

acceptable expanded use of PED in flight. An acceptable SMS model may include: 

1. Acceptance or validation of the anecdotal data available that suggests aircraft have 

flown for the last 15 years with a variety of PED with an extremely remote likelihood 

of interference occurring. 

2. A mitigation strategy that examines existing pilot abnormal procedures for 

inaccurate/inop avionics equipment and determines if an additional procedure for 

PED interference may be warranted for one or more systems 

3. A safety assurance function that continuously examines mechanic and flight crew 

reports where PED interference is mentioned. 

Also of note are Boeing studies reported in a March, 2000 Boeing commercial publication 

where Boeing purchased PED from passengers that were confirmed to have caused 

interference on 737 and 767 aircraft. Boeing tried to recreate the interference with the 

PED with subsequent testing of the known devices on other aircraft but could not duplicate 

3 
the anomaly. Boeing concluded "As a result of these and other investigations, Boeing has 

not been able to find a definite correlation between PEDs and the associated reported 

airplane anomalies." 

Delta urges the FAA to have the ARC assess the role of interference testing in expanding the 

use of PEDs on aircraft. In addition to the complexity involved in testing combinations of 

PEDs against the many aircraft systems in service, the reliability of onboard testing to 

actually detect a potential anomaly appears remote. For these reasons, Delta promotes a 

risked base SMS assessment as a stronger methodology to safely expand the use of PED on 

aircraft. As is standard in our industry, Delta Flight Crews are trained to handle system 

interruptions and inaccurate display information today. An assessment of these non normal 

instructions against those interruptions and inaccurate displays that could be caused by PED 

interference should be accomplished. Where additional or supplemental procedures are 

called for, airlines should enhance their non normal instructions and training. 

If the industry comes to the conclusion that interference must be addressed, Delta suggests 

the focus center around the need to protect air travel against intentional electrical signal 

jamming devices. Delta is encouraged by Network Control Unit (NCU) devices available in 

the market today that prevent on board CMRS Mobile Stations (MS) from transmitting and 

therefore registering with terrestrial base stations. These NCU devices prevent mobile 

stations from transmitting by masking all possible cellular channels with an RF signal 

powerful enough to overcome possible signals received in the cabin from terrestrial base 

stations. 

Our Operations area suggests that the threat of an onboard intentional jamming device be 

assessed in this effort such that harmful RF signals generated from on board the aircraft are 

prevented from interfering with ships equipment as well. We believe the technology exists 

today to achieve this and should be examined and weighed as one possible mitigation 

strategy that could be made available to an operator. 

Examine Other Industries 

The expanded use of PEDs in today's society is a question not reserved for the commercial 

airline industry. We believe that many industries have examined this issue and could offer 

similar risk based approaches that we suggest above or alternate strategies to be 

considered. 

Delta notes relaxed cell phone policies in local hospitals are in place today. Interference 

between PED and medical devices (pacemakers, image/scan equipment, etc) draw a good 

comparison for the on board aircraft environment and we recommend that the ARC examine 

other safety sensitive industries for approaches to PED operation in their facilities. 

Technical Recommendations 

Delta believes that technical challenges are solvable in and regulatory changes are the key 

element in expanding PED use on the aircraft. That said, the ARC should address the 

following areas as part of a long term strategy to ensure compatible operation of PED and 

aircraft avionics systems: 

o Delta supports adoption of standards for PED and aircraft system designs 

Examine harmonizing PED FCC part 15 emission limits with D0-160 part 21 Cat M 

standards. 

Develop a database similar to the PMA process, to access data on all PED's that 

have passed D0-160 part 21 Cat M emissions tests 

Recommend the ARC assess all new aircraft designs to be PED tolerant 

4 
- Assess new installations on existing aircraft to be PED tolerant. 

- Assess that TC or STC applicants demonstrate that PED operation is not 

compromised by the submitted design changes. 

- Define "Airplane mode'' as used to describe device operation and attain 

agreement between aviation and PED Industries as to that definition. 

o Delta supports clarity of PED article retention risks 

- Seek a definition of projectiles, which do not require stowage during takeoff and 

landing (such as a book), in terms of current PED form factors. 

- Certification of literature pockets should be evaluated to allow carriers to approve 

larger PEDs (up to and including laptops for example) to remain stowed in 

literature pockets during takeoff and landing operations. 

o Delta supports efforts to find effective deterrents for Intentional harmful interference 

detection. Key elements of this area should include 

- Application of technology to block on board as well as terrestrial based signal 

acquisition on aircraft such as the Network Control Unit (NCU) devices. 

o Delta supports a specific effort to broaden the scope of 14 CFR 382 which requires 

medical respiratory devices to meet FAA electromagnetic and radio frequency 

emission standards. Key factors to consider: 

- Inclusion of other critical medical devices being brought on board aircraft today. 

Delta recommends that the DOT or FAA provide recommended labeling of devices 

meeting FAA electromagnetic and radio emission standards. 

- Many medical devices only meet medical IEC/EN specification or other nonaircraft level test standards so are not allowed during taxi, takeoff, and landing. 

- Devices may meet FAA/IEC/EN specifications and still not be recommended for 

use in aircraft due to lack of battery or accuracy of device on aircraft. 

Delta Position and Recommendations 

After review of PED usage With our customers and Delta Operations personnel, Delta comes 

to the conclusion that it is time that portable electronic devices are fully integrated into air 

travel. Technology in use on aircraft and in the PED industry has advanced such that 

interference events are extremely rare. The benefits of expanded in-flight PED usage 

outweigh the extreme low risk of an actual interference event occurring based on the data 

Delta has assembled. 

Delta supports the formation of an Aviation Rulemaking Committee to expand the use of 

PED during all phases of flight operations. We see the following objectives in such an 

effort: 

1. Expand the use of cellular telephone communication (voice calls) to all phases of 

ground operation. as determined practical by each airline operator. Most of Delta's 

passengers (64%) have told us that the ability to make phone calls in flight would 

have a negative impact on the onboard experience. 

5 
2. Use SMS Risk Based Methodology to ensure safe PED operation. This approach 

should replace the untenable task of testing every PED against all aircraft type 

designs and type design variants. 

3. Expand the use of all non voice/non sound PED during all phases of flight. Continue 

to allow the air carriers to make the determination what PED are authorized in flight. 

Encourage the Industry to develop standards that PED will be qualified against in the 

future. When these standards are available, the burden of authorization of devices 

can be removed from the air carrier. 

Further we desire the commercial environment of onboard equipment manufacturers to stay 

competitive. These systems should only be required to meet standards determined by the 

FAA for non interference to aircraft avionics systems. We urge the FAA to allow airlines to 

choose from a broad selection of onboard entertainment and communication systems and 

products in the future. 

Delta appreciates the opportunity to comment on this FAA initiative. In addition to 

providing a position of support to the agency through this letter, Delta will dedicate 

personnel, technical information, and in flight data to help the ARC effort move forward. 

Should you have any questions on our comments, please contact Kirk Thornburg, Managing 

Director, Aviation Safety Assurance at 404-433-6903 or kirk.thornburg@delta.com. 

Sincerely, 

~0:~fhs Managing Director, Aviation Safety Assurance 

.6