X0306 4 2018-03-20 0 0001418819 Iridium Communications Inc. IRDM 0001473963 Baralonco Ltd P.O. BOX 71, ROAD TOWN TORTOLA D8 VG1110 VIRGIN ISLANDS, BRITISH 0 0 1 0 0001473960 bin Abdullah bin Abdulrahman Khalid P.O. BOX 71, ROAD TOWN BRITISH VIRGIN ISLANDS TORTOLA D8 VG1110 VIRGIN ISLANDS, BRITISH 0 0 1 0 Common Stock 2018-03-20 4 C 0 530110 A 12930110 D 7.00% Series A Cumulative Perpetual Convertible Preferred St 2018-03-20 4 C 0 50000 0.00 D 2012-10-03 Common Stock 530110 0 D The Issuer caused the mandatory conversion of 7.00% Series A Cumulative Perpetual Convertible Preferred Stock into shares of Common Stock on March 20, 2018, at a conversion price of approximately $9.43 per share (equivalent to a conversion rate of 10.6022 shares of Common Stock for each share of 7.00% Series A Cumulative Perpetual Convertible Preferred Stock). Upon the mandatory conversion of such Convertible Stock, accrued and unpaid dividends were paid in cash by the Issuer. These securities have no stated expiration date. This Form 4 is a joint filing with the sole owner of Baralonco Limited, Khalid bin Abdullah bin Abdulrahman, at the same business address. The joint filer is the indirect owner of the same shares as to which Baralonco Limited is the direct owner. /s/ Larry G. Franceski, Attorney-in-Fact 2019-04-15