U.S. Deportment 

of Transportation 

Federal Aviation 

Administration 

MAR 1 4 2016 

Mr. Paul Hudson 

President 

FlyersRights.org 

Aircraft Certification Service 

441 I Bee Ridge Road, #274 

Sarasota, FL 34233 

Dear Mr. Hudson: 

800 Independence Avenue, SW. 

Washington, DC 20591 

Thank you for your February 21 letter regarding the Federal Aviation Administration's 

(FAA) February I decision to dismiss your petition for rulemaking on seat size reductions, 

Docket No. FAA-2015-4011. 

In your letter, you point out that the docket had not been updated to include the FAA's 

February 1 decision by the time you received our February 1 decision. Prior to making this 

decision, we fully reviewed your petition as well as the comments submitted to the docket. 

In your letter, you request additional clarification on emergency evacuation tests. The FAA 

works directly with the airplane manufacturers to conduct the full-scale evacuation 

demonstrations required to justify the maximum passenger occupancy. The FAA is fully 

involved in these demonstrations, including approval of the test plan, inspecting and 

configuring the test article (airplane), and witnessing the tests. 

Multiple manufacturers have performed evacuation demonstrations below 30-inch seat 

pitch, down to 28-inch seat pitch. The extensive data we have indicates seat pitch and width 

does not adversely affect evacuation times. As requested, references regarding seat and 

evacuation studies, as well as potential health issues, are enclosed. 

We understand your concern for the safety of the traveling pubiic. The FAA is firmly 

committed to passenger safety. We will continue to monitor seat designs and effects on 

safety and health. 

Sincerely, 

Dorenda D. Baker 

Director, Aircraft Certification Service 

Enclosure 
List of References 

Passenger demographics: 

1. FAA Report DOT/FAA/AM-01/2 "Access-to-Egress: A Meta-Analysis Of the 

Factors That Control Emergency Evacuation Through The Transport Airplane TypeIII Overwing Exit" 

http:/ /v..rwvv. faa. gov I data research/research/med humanfacs/oam techreQot1s/2000s/m 

edia/0 1 02.pdf 

2. FAA Report DOT/FAA/AM-03115 "Access-to-Egress II: Subject Management and 

Injuries in a Study of Emergency Evacuation Through the Type-III Exit" 

http://www.faa.gov/data research/research/med humanfacs/oamtechreports/2000s/m 

edia/0315.pdf 

3. FAA Report DOT/FAA/AM-04/2 ''Access-To-Egress III: Repeated Measurement of 

Factors That Control the Emergency Evacuation of Passengers Through the 

Transport Airplane Type-Ill Overwing Exit" 

http://www.faa.gov/data research/research/rned humanfacs/oamtcchrcports/2000s/m 

edia/0402.pdf 

Deep vein thrombosis: 

1. American College of Chest Physicians. Anti thrombotic Therapy and Prevention of 

Thrombosis, 9th ed: ACCP Evidence--Based Clinical Practice Guidelines. 6.1.1 -

6.1.3. Chest february 2012, Vo1141, No. 2_suppl. 

http://journal.publications.chestnet.org/article.aspx?articleiD= II59399. 

2. Tsai J, Grant AM, Beckman MG, Grosse SO. YusufHR. Richardson LC. (2015) 

Determinants of Venous Thromboembolism among Hospitalizations of US Adults: A 

Multilevel Analysis. PLoS ONE 10(4): e0123842. 

doi: 1 O.l371/journal.pone.0123842. 

http://www.cdc.gov/ncbddd/clvt/features/existing-condition-hospital.html. 

3. Mayo Clinic. Patient Care and Health Information. Deep vein thrombosis (DVT). 

Risk Factors. http://www.mayoclinic.org/diseases-conditions/dccp-veinthrombosis/basics/tisk-tactors/con-2003 1922. 

4. Boyles S. New guidelines debunk 'Economy Class Syndrome.' WcbMD. Feb. 7. 

2012. http://www. webmd.com/dvt/news/20 120?07 /new-guide! ines-debunkeconomy-class-syndrome. 

5. Farber D. Does cancer cause blood clots? Dana-Farber Cancer Institute. April 4, 

2014. http://blog.dana-farber.org/insight/20 14/04/does-cancer-causc-blood-clots/. 

6. James A. Women's health. National Blood Clot Alliance. 

https://www.stoptheclot,org/learn more/womens health i~1q.htm. 

7. Cruickshank J, Gorlin Rand Jennett B. Air travel and thrombotic episodes: the 

economy class syndrome. Lancet. 1988 Aug 27;2(8609):497-8.