Part # 410 and 414 D-LOK (series) Owner's Manual


Instructions for Continued Airworthiness

(Document Control Date: April 28, 2021)


For LSC Part Numbers

Part # Sling Type
410-(series) D-LOK Hoist Hook (Fitments A1, F1, AF, E, H, G)
414-(series) NEW D-LOK Hoist Hook (Fitments A1, F1, AF, E, H, G)


(missing or bad snippet)




The D-LOK incorporates an automatic dual-lock latch gate design for ultimate safety. The double lock gate provides security to prevent accidental openings, while allowing the latch gate to be operated quickly and easily with one hand. The hoist hook features a large ring volume for multiple equipment rings, and will accept rings over one inch in diameter. Integral utility eye allows attachment of tag/guide line. Hook is constructed entirely of stainless steel for strength and corrosion resistance.

The D-LOK Hoist Hook eliminates all problems associated with the current double rescue hook, such as inadvertent engagement (including the snagging of fingers on the small hook), and self-release (ring roll-out). The LSC D-LOK Hoist Hook exceeds the load test requirement for the double rescue hook (MS-18027-2A), and is available with seven (7) attachment options to fit all current hoist installations.


  1. Install in accordance with all applicable hoist and helicopter installation & maintenance procedures by qualified personnel only.

  2. Verify the attachment fitment on the D-LOK is the same as the hook being replaced. Contact LSC if different.

  3. Inspect the hoist hook bumper/carrier assembly as per the manufacturer's instructions. Inspect the nut used to secure the D-LOK to the carrier assembly for excessive wear or worn threads and replace if necessary.

  4. Prior to installation of the hook, thoroughly clean and degrease the screw threads on the D-LOK hoist hook and on the attachment nut. Apply LOCTITE 243 or similar thread-locking material per material instructions and in sufficient quantity to fill all engaged threads of the hoist hook.

    Caution: Do not allow thread-locking material to penetrate the bearing assembly.

  1. Install the D-LOK into the carrier assembly as per the manufacturer's instructions. Follow the thread-locking material instructions and allow curing prior to use/flight. Check for free rotation of hoist hook in carrier assembly.


While LSC has designed and manufactured the D-LOK to be reliable, periodic testing and inspection are necessary to ensure functional reliability. The frequency of inspection should be determined by the frequency and condition of use. However, the period between inspections shall not exceed three (3) months.

Operational Inspection

Visually inspect the entire hook assembly for damage and proper function of the latch gate prior to each use.

Periodic Inspection - Monthly

Carefully inspect the D-LOK hook and latch gate assembly for cleanliness, cracks, distortion, broken or missing parts, unusual wear and corrosion.

Corrosion is most often a surface containment and can be removed with abrasive cloth or wire brush and fresh water. If corrosion persists, contact LSC for assistance.

On -G (swivel) fitments, inspect the swivel for free spin and security of attachment.

Check latches for proper operation.

Latches should exhibit no free play and should be tight against the gate. If the latches are loose in any way, return the hook to LSC for spring replacement.

If soiled, clean with mild soap and fresh water. Thoroughly rinse and allow the hook to completely dry. Lubricate latches and gate with light oil such as WD-40. Remove excess lubricant.


Repairs should normally be limited to cleaning, removal of surface corrosion and lubricating. Minor blending of nicks (up to 0.025 inches in depth) on the hook may be performed by qualified personnel. The D-LOK hook assembly should be replaced if beyond these limits or returned to LSC for serviceability determination.

LSC can rebuild hoist hooks to a like new condition including replacement of all springs, re-conditioning, passivation, and proof loading.


 Header 2

Service Life

CONDITIONAL: On Inspection: Recommended NDI every ten years or after significant shock-load event (broken strands in hoist cable)

Service Life Conditions

Documented positive in-service and monthly inspections.

Load Limit

600 lbs (272 kg)

Breaking Limit7,000 lbs (3,175 kg)
Factory Proof Load3,000 lbs (1,360 kg)


(missing or bad snippet)



PHONE: 813-645-2748

[email protected] -

(missing or bad snippet)