TransDigm UK Holdings plc

Notice of Effectiveness

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Registration statement under Securities Act of 1933

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Registration statement under Securities Act of 1933

Notice of Effectiveness

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933 (amendment)

Registration statement under Securities Act of 1933

Letter from the SEC

Letter from the SEC

Letter from the SEC

Correspondence with the SEC

Correspondence with the SEC

Letter from the SEC