Free tool

LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

Alien Flyer

Checking

7729 Alien Flyer

19 pieces in 11 part and color combinations, plus 1 minifigure.

The official piece count includes the 2 parts inside the set's minifigures, which this inventory lists separately. Spare parts are counted in neither figure.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Show

Piece checklist

Bricks Round and Cones 4 pieces

  • Cone 1 x 1 [No Top Groove] Trans-Neon Green Part 4589 Element 618849 or 458949 ×4

Hinges, Arms and Turntables 4 pieces

  • Hinge Brick 1 x 2 Top Plate Thin Black Part 3938 Element 393826 ×1
  • Hinge Plate 1 x 4 Swivel Top / Base - Solid Clip [Complete Assembly] Black Part 73983 Element 6102782 or 74011 ×2
  • Hinge Brick 1 x 2 Base Dark Bluish Gray Part 3937 Element 4211066 ×1

Bricks Sloped 3 pieces

  • Brick Sloped 2 x 2 No Studs, with 3 Side Pistons Raised Edges Black Part 30603 Element 4163524 ×1
  • Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope) Lime Part 54200 Element 4504372 or 4298015 ×2

Plates Round Curved and Dishes 2 pieces

  • Plate Round Corner 4 x 4 Lime Part 30565 Element 4504705 ×2

Plates Special 2 pieces

  • Plate Special 1 x 2 with Handles [Flat Ends / Low Attachment] Black Part 3839b Element 383926 ×2

Plates Wedged 2 pieces

  • Wedge Plate 4 x 4 with 2 x 2 Cutout Black Part 43719 Element 6275401 or 4561035 ×2

Bricks 1 piece

  • Brick 2 x 2 Dark Bluish Gray Part 3003 Element 4211060 ×1

Plates 1 piece

  • Plate 2 x 8 Dark Bluish Gray Part 3034 Element 4210997 ×1

Minifigures 1 figure

  • Martian Minifigure, checked as a whole figure ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.