Interpretation ID: nht90-1.28

TYPE: INTERPRETATION-NHTSA

DATE: 01/29/90

FROM: TIMOTHY A. KELLY -- SALEM VENT INTERNATIONAL

TO: DAVID A GREENBURG -- NHTSA CHIEF COUNSEL

TITLE: SALEM BUS VENTILATOR/ESCAPE HATCH - FMVSS 217

ATTACHMT: ATTACHED TO LETTER DATED 05/30/90, FROM STEPHEN P WOOD -- NHTSA TO TIMOTHY A. KELLY; REDBOOK A35; STANDARD 217; LETTER DATED 01/29/90 FROM TIMOTHY A. KELLY TO DAVID A. GREENBURG -- NHTSA; RE SALEM BUS VENTILATOR/ESCAPE HATCH - FMVSS 217

TEXT: (Illegible Word) you for the courtesies extended to the writer during my visit with (Illegible Word) Thursday afternoon January 25th, following my previous discussions (Illegible Word) Delarm. As we discussed, Salem Vent International already manufactur es a roof ventilating panel as shown on print #4220-001 attached. As (Illegible Word), the 4220-001 lacks a mounting frame which is supplied as part (Illegible Word) bus. To complete our program, we will need to design our own mounting frame and also a method by which the cover can swing free to provide an (Illegible Word) hatch. My concern was that we design the proper size to conform FMVSS 217.

(Illegible Word) said that his reading of the spec was that the opening had to (Illegible Word) an ellipsoid having 20" as its major axis and 13" as its minor (Illegible Word) and that this ellipsoid had to be able to fit through the escape (Illegible Wo rd) in the horizontal position. It looks to me that our existing tool(Illegible Word) accomodate this ellipsoid with ease.

Further discussed the specification as to what type of busses 217 (Illegible Word) covers and you pointed out that school busses were specifically covered by 217. While a roof escape hatch/ventilator is undoubtedly a (Illegible Word) option, it is not m andatory and does not allow the builder to (Illegible Word) any other methods of egress by its presence.

(Illegible Word), on other types of busses (transit, inter-city, airport, etc.) if builder elects to use an escape hatch/ventilator in the roof, they are (Illegible Word) to delete the rear exit door.

(Illegible Word) I left you I began to wonder what would happen if a bus builder put (Illegible Word) than one ventilator/escape hatch in the roof. Would the builder be (Illegible Word) to delete other specified methods of egress other, than the rear (I llegible Word) or would the additional ventilator/escape hatches really only serve purpose of additional ventilation to the bus.

2

You said that if I wanted an official opinion from the Office of the Chief Counsel, that I ought to request it in writing. John Machey suggested the same thing when I talked with him this morning and so attached hereto is a formal request for your opini on on my questions. I have tried to make this as simple as possible and I would be happy to hear from you if you have any questions as to my request.

Again it was my pleasure to meet you.

Sincerely,

Enclosure