A combustor liner for a gas turbine engine, the combustor liner comprising: a heat shield (50; 350; 450) including: a shield hot side (74; 374; 474); and a shield cold side (72; 372; 472); and a shell (42; 342; 442) attached to the heat shield, the shell including: a cold side (64; 364; 464); a hot side (66; 366; 466); a row of cooling holes (68; 368;468) in the shell (42; 342; 442); and a jet wall (70; 370; 470) projecting from the shell hot side (66; 366; 466) nearly to the shield cold side (72; 372; 472) such that there is a gap between the jet wall (70; 370; 470) and shield cold side (72; 372; 472), the jet wall (70; 370; 470) for creating a wall shear jet of increased velocity cooling flow (Fc) through the gap between the jet wall (70; 370; 470) and the shield cold side (72; 372; 472) in a tangential direction away from the row of cooling holes (68; 368; 468) and along an adjacent heat shield cold side wall (72; 372; 472), wherein the shell hot side (66; 366; 466) faces the shield cold side (72; 372; 472) and the shell cold side (64; 364; 464) faces away from the shield cold side (72; 372; 472), wherein the combustor liner is arcuate in shape defining an axis and a circumferential direction, and the jet wall (70; 370; 470) runs in a circumferential direction, characterised in that the heat shield (350; 450) further includes: a plurality of first linear film cooling slots (392; 492) through the heat shield (350; 450), the first linear film cooling slots (392; 492) angled in a first axial direction and disposed in a row running in the circumferential direction; and a plurality of second linear film cooling slots (394; 494) through the heat shield (350; 450), the second linear film cooling slots (394; 494) angled in a second axial direction opposite to the first axial direction, and alternating with first linear film cooling slots (392; 492) in the row; the first and second linear film cooling slots (392; 394; 492; 494) connected to form a single, multi-cornered film cooling slot (390; 490) downstream from the jet wall (370; 470). a heat shield (50; 350; 450) including: a shield hot side (74; 374; 474); and a shield cold side (72; 372; 472); and a shield hot side (74; 374; 474); and a shield cold side (72; 372; 472); and a shell (42; 342; 442) attached to the heat shield, the shell including: a cold side (64; 364; 464); a hot side (66; 366; 466); a row of cooling holes (68; 368;468) in the shell (42; 342; 442); and a jet wall (70; 370; 470) projecting from the shell hot side (66; 366; 466) nearly to the shield cold side (72; 372; 472) such that there is a gap between the jet wall (70; 370; 470) and shield cold side (72; 372; 472), the jet wall (70; 370; 470) for creating a wall shear jet of increased velocity cooling flow (Fc) through the gap between the jet wall (70; 370; 470) and the shield cold side (72; 372; 472) in a tangential direction away from the row of cooling holes (68; 368; 468) and along an adjacent heat shield cold side wall (72; 372; 472), wherein the shell hot side (66; 366; 466) faces the shield cold side (72; 372; 472) and the shell cold side (64; 364; 464) faces away from the shield cold side (72; 372; 472), a cold side (64; 364; 464); a hot side (66; 366; 466); a row of cooling holes (68; 368;468) in the shell (42; 342; 442); and a jet wall (70; 370; 470) projecting from the shell hot side (66; 366; 466) nearly to the shield cold side (72; 372; 472) such that there is a gap between the jet wall (70; 370; 470) and shield cold side (72; 372; 472), the jet wall (70; 370; 470) for creating a wall shear jet of increased velocity cooling flow (Fc) through the gap between the jet wall (70; 370; 470) and the shield cold side (72; 372; 472) in a tangential direction away from the row of cooling holes (68; 368; 468) and along an adjacent heat shield cold side wall (72; 372; 472), wherein the shell hot side (66; 366; 466) faces the shield cold side (72; 372; 472) and the shell cold side (64; 364; 464) faces away from the shield cold side (72; 372; 472), wherein the combustor liner is arcuate in shape defining an axis and a circumferential direction, and the jet wall (70; 370; 470) runs in a circumferential direction, characterised in that the heat shield (350; 450) further includes: a plurality of first linear film cooling slots (392; 492) through the heat shield (350; 450), the first linear film cooling slots (392; 492) angled in a first axial direction and disposed in a row running in the circumferential direction; and a plurality of second linear film cooling slots (394; 494) through the heat shield (350; 450), the second linear film cooling slots (394; 494) angled in a second axial direction opposite to the first axial direction, and alternating with first linear film cooling slots (392; 492) in the row; the first and second linear film cooling slots (392; 394; 492; 494) connected to form a single, multi-cornered film cooling slot (390; 490) downstream from the jet wall (370; 470). a plurality of first linear film cooling slots (392; 492) through the heat shield (350; 450), the first linear film cooling slots (392; 492) angled in a first axial direction and disposed in a row running in the circumferential direction; and a plurality of second linear film cooling slots (394; 494) through the heat shield (350; 450), the second linear film cooling slots (394; 494) angled in a second axial direction opposite to the first axial direction, and alternating with first linear film cooling slots (392; 492) in the row; the first and second linear film cooling slots (392; 394; 492; 494) connected to form a single, multi-cornered film cooling slot (390; 490) downstream from the jet wall (370; 470).