DN Specifications
B. Runner Plank
IDNIYRA OFFICIAL SPECIFICATIONS
REVISED MAY 2023
Note: Dimensions are given in inches in the English System (except as noted) and in millimeters (MM) in the metric system.
| B. Runner Plank | English | Metric | ||
| Max | Min | Max | Min | |
| 1. Length overall (including hardware except pivot bolt): |
96 | 94 | 2438 | 2388 |
| 2. Width at centerline | 7-1/2 | 6-1/2 | 190.5 | 165.2 |
| 3. Thickness at centerline | 1-5/8 | 1-1/8 | 41.2 | 28.6 |
| 4. Width at ends | 7-1/2 | 5-1/2 | 190.5 | 139.5 |
| 5. Thickness at ends | 1-5/8 | 1 | 41.2 | 25.5 |
| 6. Cross section is optional | ||||
| 7. Runner plank shall be constructed of wood. Number of laminations is optional. Fiberglass may be added. See Interpretations-General. | ||||
| 8. The underside of the runner plank shall be higher at the centerline than the underside of the outside ends. The profile of the plank lamination must assume a reasonable fair and continuous curve. Cutouts or hollow depressions are not permitted. | ||||
| 9. The runner plank, including all hardware and pivot bolts, may not weigh less than 20 lbs. (9.0 kg.). | ||||
INTERPRETATIONS OF THE OFFICIAL SPECIFICATIONS BY THE TECHNICAL COMMITTEE
Effective May 31, 2020
B. Runner plank
1/30/88: The overall length of the runner plank (including hardware except pivot bolt) is measured in a straight line from end to end without the skipper in the cockpit.
11/14/88: Gull wing runner plank: In the profile curve of the runner plank lamination, the curve must not reverse direction and in an unloaded condition no part of the curve may be lower than the ends.
7/01/92: The interpretation dated 1/30/88 is changed to read: The overall length of the runner plank (including hardware except pivot bolt) is measured in a straight line from end to end with the runner plank separate from the fuselage.
11/30/98 amended 10/6/2011: The runner plank must be constructed of wood and meet all minimum dimensions in specifications B.1., 2., 3., 4., 5. before the application of external reinforcement and coatings; and meet all the maximum dimensions in specifications B. 1., 2., 3., 4., 5. after the application of any external reinforcement and coatings. Internal fiberglass reinforcement is not allowed. Foam, honeycomb, and other non-wood core materials are not allowed.
1/15/2010: When the use of the reinforcement bar or stiffening element that is associated with the “Kent” style chock does not comply with interpretations I. Fittings dated 1/15/2010, and E. Runners dated 1/15/2010, the bar will be considered part of the chock and must comply with the materials as specified in I. 13. and will be included as hardware in determining the overall length of the runner plank as specified in B.1.