David M. McDonald

VP Operations

7765 Northwest 54th Street

Miami, Florida 33166 U.S.A.

Phone 305.594.5802

Fax 305.594.5804

www.aeronautical-engineers.com

dmm@aeronautical-engineers.com

November 21, 2013

U.S. Department of Transportation Comment tracking number

Docket Management System 1jx-85ce-2vdr

400 7th Street SW 

Room PL 401

Washington, DC 20591-0001

Attention Transport Airplane Directorate

RE: Request For Exemption From FAR §25.785(b) For Freighter Aircraft

(STC # ST01827LA)

To Whom It May Concern,

Aeronautical Engineers, Inc. (AEI) has been granted an exemption from certain Federal Aviation 

Regulations (FAR) pursuant to 14 CFR Part 11, via Exemption No. 9722, allowing the carriage of 

up to 4 non-crewmembers (commonly referred to as supernumeraries). In addition to the 

exemptions requested and granted in Exemption 9722, AEI also seeks an exemption from the 

requirements of FAR §25.785, amendment 72, and §25.562. Finally, AEI seeks an amendment of 

Exemption 9722 to increase the total number of persons on board from 6 to eight.

The petitioner requests relief from the following regulations:

§25.785(b), Amendment 25-88, incorporates by reference FAR §25.562. FAR§25.562, 

Amendment 25-64 requires, among other things, seats be able to withstand up to a 14G vertical 

and 16G horizontal load. This requirement exceeds the certification basis for the original flight 

attendant seats. In order to provide additional supernumerary seating, AEI relocates the aft flight 

attendant seat (a dual seat) to the front of the 9G barrier. AEI seeks approval to use §25.785(b), 

Amendment 25-32 as there is no appreciable improvement in the safety level provided to the 

supernumeraries. All of the seats in the aircraft otherwise remain at amendment level 20, which is 

the certification basis for the aircraft.

The petitioner supports its request with the following information: 

AEI holds numerous Supplemental Type Certificates for modification of transport aircraft. With 

regard to this petition, AEI holds STC ST01827LA which allows conversion of Boeing 737-

300/400 aircraft to a freighter with a Class E main deck cargo compartment. Over 200 Boeing 

aircraft have been converted by AEI to freighters. Some operators of AEI freighters need to be able 

to carry supernumeraries to assist with special cargo such a valuable cargo requiring security 

and/or perishable, fragile, or live cargo requiring special attention to ensure its safe delivery. The 

interest of the petitioner is in providing a level of safety for the crew, supernumeraries, cargo and 
David M. McDonald

VP Operations

7765 Northwest 54th Street

Miami, Florida 33166 U.S.A.

Phone 305.594.5802

Fax 305.594.5804

www.aeronautical-engineers.com

dmm@aeronautical-engineers.com

aircraft that will allow operators of AEI converted 737 freighters to meet the needs of their 

clientele.

In this case, the supernumeraries are limited to a maximum of 4 persons which occupy the existing 

aft facing flight attendant (F/A) seats on the lavatory bulkhead and the relocated forward facing 

F/A seat mounted on the front of the 9G bulkhead. See diagram below.

The Boeing 737 certification basis is 14 CFR Part 25. Amd. 25-20. The certification basis for 

AEI’s STC for the freighter conversion is 14 CFR Part 25, Amd. 25-117. The seats used on the 9G 

bulkhead are the original forward facing F/A seats located in the F/A station in the rear of the 

aircraft. During conversion, these seats are relocated from the rear of the aircraft to the forward 

side of the 9G bulkhead. 

Petitioner seeks to maintain equivalent safety for all supernumeraries. It makes little sense to have 

the entire aircraft designed to one certification basis but to require the seat moved to the 9G 

bulkhead to meet a different certification basis. Similar relief has been granted in Exemption 9487.

AEI B737-300/400 Freighter Supernumerary Area
David M. McDonald

VP Operations

7765 Northwest 54th Street

Miami, Florida 33166 U.S.A.

Phone 305.594.5802

Fax 305.594.5804

www.aeronautical-engineers.com

dmm@aeronautical-engineers.com

9G Barrier and Forward Facing Supernumerary Seat

Increase Of Total Persons On Board

AEI’s current exemption from 14 CFR 25.855 and 25.857 (Exemption 9722) allows a maximum of 

6 persons onboard, including crew. Many of the subject 737 aircraft have an existing OEM 

observer’s seat in the cockpit and some include a second observer’s seat, for a total of 4 seats on 

the flight deck. AEI’s current exemption allows a total of six persons onboard, including crew, 

which limits the use of existing cockpit seating and/ or supernumerary seating. Increasing the 

number of persons onboard from 6 to 8 will not adversely affect safety as all occupants will be in 

seats already approved for use in the aircraft. AEI requests approval of using the observer seats on 

the flight deck for supernumerary seating as well.

Request for Waiver of Public Comment

AEI requests waiver of the normal public comment process since this request is substantially 
David M. McDonald

VP Operations

7765 Northwest 54th Street

Miami, Florida 33166 U.S.A.

Phone 305.594.5802

Fax 305.594.5804

www.aeronautical-engineers.com

dmm@aeronautical-engineers.com

similar to those already granted to other freighter STC holders and because the granting of this 

petition will not create new precedent.

2. Public Interest

An exemption from 14 CFR 25.855 and 25.857 to allow the carriage of an appropriate number of 

attendants aboard an aircraft to monitor and to attend to the special requirements of valuable, 

fragile, perishable, or live animal cargo, serves the public interest in raising the level of safety of 

the cargo, the airplane, the flight crew, and consequently, the public in general. In addition, a grant 

of an exemption from the requirements of FAR §25.785, amendment 72, and §25.562 providing 

equivalent safety for all persons on board an aircraft, both crew and supernumerary, also serves the 

public interest by ensuring consistent and equivalent safety standard for all occupants of the 

aircraft. 

AEI respectfully requests that this petition be granted.

Sincerely,

David M. McDonald, 

Vice President