UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 16) Mine Safety Appliances Company ------------------------------ (Name of Issuer) Common Stock, No Par Value -------------------------- (Title of Class of Securities) 602720 10 4 ------------- (CUSIP Number) Check the following box if a fee is being paid with this statement [ ]. 1. Name of Reporting Person Helen Ruth Henderson ------------------------------------- 2. Check the Appropriate Box if a Member of a Group (a) [ ] (b) [X] 3. SEC Use Only ----------------------------------- 4. Citizenship USA ------------------------------------------------------------ Number of 5. Sole Voting Power 308,895 ------------------------------------------ Shares Beneficially 6. Shared Voting Power 120,392 ---------------------------------------- Owned by Each 7. Sole Dispositive Power 308,895 ------------------------------------- Reporting Person With 8. Shared Dispositive Power 74,840 ----------------------------------- 9. Aggregate Amount Beneficially Owned by Each Reporting Person 429,287 -------------------------------------------------------------------------- 10. Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares -------------------------------------------------------------------- 11. Percent of Class Represented by Amount in Row 9 7.1% ------ 12. Type of Reporting Person IN ------------------------------------ ITEM 1(A) NAME OF ISSUER: --------------- Mine Safety Appliances Company ITEM 1(B) ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES: ------------------------------------------------ P. O. Box 426 Pittsburgh, Pennsylvania 15230 ITEM 2(A) NAME OF PERSON FILING: ---------------------- Helen Ruth Henderson ITEM 2(B) ADDRESS OF PRINCIPAL BUSINESS OFFICE, OR IF NONE, RESIDENCE: ------------------------------------------------------------ 728 Fairview Road Pittsburgh, Pennsylvania 15238 ITEM 2(C) CITIZENSHIP: ------------ USA ITEM 2(D) TITLE OF CLASS OF SECURITIES: ----------------------------- Common Stock, No Par Value ITEM 2(E) CUSIP NO.: ---------- 602720 10 4 ITEM 3 IF THIS STATEMENT IS FILED PURSUANT TO RULE 13D-1(B), OR 13D-2(B), ------------------------------------------------------------------ CHECK WHETHER THE PERSON FILING IS A: ------------------------------------- Inapplicable. This statement is filed pursuant to Rule 13d-2(b) by a person described in Rule 13d-1(c). ITEM 4 OWNERSHIP: ---------- See Items (5) through (9) and Item (11) of cover page. ITEM 5 OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS: --------------------------------------------- Inapplicable. ITEM 6 OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON: ---------------------------------------------------------------- Inapplicable. ITEM 7 IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE ---------------------------------------------------------------------- SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY: --------------------------------------------------------- Inapplicable. ITEM 8 IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP: ---------------------------------------------------------- The undersigned is not a member of any group of two or more persons who have agreed to act together for the purpose of acquiring, holding, voting or disposing of any equity securities of Mine Safety Appliances Company. ITEM 9 NOTICE OF DISSOLUTION OF GROUP: ------------------------------- Inapplicable. ITEM 10 CERTIFICATION: -------------- Inapplicable. SIGNATURE --------- After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. ------------------------------- Date ------------------------------- Signature Helen Ruth Henderson -------------------------------- Name/Title