# 14 CFR 27.725 - Limit drop test.

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There are 3 Updates appearing in the Federal Register for 14 CFR 27. View below or at eCFR (GPOAccess)
§ 27.725 Limit drop test.
The limit drop test must be conducted as follows:
(a) The drop height must be—
(1) 13 inches from the lowest point of the landing gear to the ground; or
(2) Any lesser height, not less than eight inches, resulting in a drop contact velocity equal to the greatest probable sinking speed likely to occur at ground contact in normal power-off landings.
(b) If considered, the rotor lift specified in § 27.473(a) must be introduced into the drop test by appropriate energy absorbing devices or by the use of an effective mass.
(c) Each landing gear unit must be tested in the attitude simulating the landing condition that is most critical from the standpoint of the energy to be absorbed by it.
(d) When an effective mass is used in showing compliance with paragraph (b) of this section, the following formula may be used instead of more rational computations:
where:
W e=the effective weight to be used in the drop test (lbs.);
W=W M for main gear units (lbs.), equal to the static reaction on the particular unit with the rotorcraft in the most critical attitude. A rational method may be used in computing a main gear static reaction, taking into consideration the moment arm between the main wheel reaction and the rotorcraft center of gravity.
W=W N for nose gear units (lbs.), equal to the vertical component of the static reaction that would exist at the nose wheel, assuming that the mass of the rotorcraft acts at the center of gravity and exerts a force of 1.0g downward and 0.25g forward.
W=W T for tailwheel units (lbs.), equal to whichever of the following is critical:
(1) The static weight on the tailwheel with the rotorcraft resting on all wheels; or
(2) The vertical component of the ground reaction that would occur at the tailwheel, assuming that the mass of the rotorcraft acts at the center of gravity and exerts a force of lg downward with the rotorcraft in the maximum nose-up attitude considered in the nose-up landing conditions.
h=specified free drop height (inches).
L=ration of assumed rotor lift to the rotorcraft weight.
d=deflection under impact of the tire (at the proper inflation pressure) plus the vertical component of the axle travels (inches) relative to the drop mass.
n j=the load factor developed, during impact, on the mass used in the drop test (i.e., the acceleration dv/dt in g's recorded in the drop test plus 1.0).

Title 14 published on 2014-01-01

The following are only the Rules published in the Federal Register after the published date of Title 14.

For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.

• 2014-08-19; vol. 79 # 160 - Tuesday, August 19, 2014
1. 79 FR 48946 - Special Conditions: Robinson Model R66 Helicopter, § 27.1309, Installation of HeliSAS Autopilot and Stabilization Augmentation System (AP/SAS)
GPO FDSys XML | Text
DEPARTMENT OF TRANSPORTATION, Federal Aviation Administration
Final special conditions; request for comments.
The effective date of these special conditions is August 7, 2014. We must receive your comments on or before October 3, 2014.
14 CFR Part 27

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United States Code

Title 14 published on 2014-01-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 14 CFR 27 after this date.

• 2014-08-19; vol. 79 # 160 - Tuesday, August 19, 2014
1. 79 FR 48946 - Special Conditions: Robinson Model R66 Helicopter, § 27.1309, Installation of HeliSAS Autopilot and Stabilization Augmentation System (AP/SAS)
GPO FDSys XML | Text
DEPARTMENT OF TRANSPORTATION, Federal Aviation Administration
Final special conditions; request for comments.
The effective date of these special conditions is August 7, 2014. We must receive your comments on or before October 3, 2014.
14 CFR Part 27