Interpretation ID: 77-1.48

TYPE: INTERPRETATION-NHTSA

DATE: 03/18/77

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your February 9, 1977, letter asking whether 10 described intersections of bus body components qualify as "body panel joints" subject to the requirements of Standard No. 221, School Bus Body Joint Strength.

The terms which establish the applicability of the requirements of the standard to a particular section of a school bus body are defined in S4 of the standard. Read together, they establish the following test. If the edge of a surface component (body panel) that encloses occupant space comes into contact or close proximity with any other body component, the requirements of S5 apply, unless the area in question is designed for ventilation or another functional purpose or is a door, window or maintenance access panel. Applying this test to the 10 intersections of bus body components you describe, it appears that none of them are required to comply with the standard.

The joints numbered 1 through 4 on page 1 of your letter refer to hanger straps, panels and pads involved in the installation of overhead storage racks. These items of equipment are not considered to have a function in enclosing occupant compartment space and, therefore, are excluded from the standard's requirements.

The exterior roof luggage rack described in paragraphs 5 and 6 is not considered to have a function in enclosing occupant space and, therefore, is not considered a body component for purposes of the requirements. For purposes of testing the complex joints to which the rack is fastened, it should be modified as necessary to prevent it from affecting testing of the underlying joint.

The NHTSA agrees that the joints described in paragraphs 1 through 4 on page 2 of your letter, relating to the installation of air conditioning units, involve the type of ventilation space that is not subject to the requirements for joint strength.

SINCERELY,

BLUE BIRD BODY COMPANY

February 9, 1977

Frank Berndt Chief Counsel National Highway Traffic Safety Administration

SUBJECT: FMVSS 221

We would appreciate a ruling that FMVSS 221 does not apply to the following joints because of the definition of "body panel joint": Book Racks - Fig. 1

1. Hanger strap to headlining to bow 2. Panel (tray) to panel to hanger strap

Parcel Racks - Fig. 2

3. Hanger bracket to headlining to bow 4. Pad to hanger bracket

Roof Luggage Rack - Fig. 3

5. Panel to panel to roof sheet 6. Rail assembly to panel to roof sheet

We would appreciate a ruling that FMVSS 221 does not apply to the following joints because of the "ventilation clause" in the definition of "body panel joint".

Air Conditioner Joints

1. Saddle assembly to roof structural members - Figs. 4, 5, 6 2. Saddle assembly, structural joints - Figs. 7, 8 3. Duct section to duct section - Fig. 9 4. Duct assembly to roof sheet - Fig. 9

Thanks for your help in this matter.

W. G. Milby Manager, Engineering Services

cc: LARRY HANSON

BODY TO SADDLE TRIMS

FIGURE #7

FIGURE #8

(Illegible Word) DUCT TO DUCT JOINTS

(Illegible Word) DUCT TO ROOF

FIGURE #9

(Illegible Word) AIR CONDITIONER COVER TO DUCT TRANSITION

(Illegible Word) AIR CONDITIONER COVER TO ROOF

(Graphics omitted)

Figure 1

Hanger Strap Tray

Overhead book rack available for conventent storage.

Figure 2

Pad

Hanger Bracket

Deluxe tubular steel parcel racks shown with upholstered aisel rail.

Figure 3

Rail Assembly

Panels

Roof luggage rack available in various lengths.

(Graphics omitted)

FIGURE #4

AIR CONDITIONER SADDLE SUPPORTIVE STRUCTURE TO BODY STRUCTURE

FIGURE $5

AIR CONDITIONER SADDLE TO SUPPORTIVE STRUCTURE

FIGURE #6

BODY PANELS TO SUPPORTIVE STRUCTURE

SADDLE

(Graphics omitted)