AF Form 4018: Computed Air Release Point (CARP) Guide & PDF

AF Form 4018: Computed Air Release Point (CARP) Guide & PDF – Accurate airdrop operations are critical for mission success in delivering personnel, equipment, supplies, and cargo precisely onto drop zones (DZs). The AF Form 4018, titled Computed Air Release Point Computations, serves as the standard tool for USAF navigators and aircrews to calculate the Computed Air Release Point (CARP). This ensures loads exit the aircraft at the exact point needed to land on the intended Point of Impact (PI).

U.S. Air Force aircrews involved in low-altitude airdrops (non-gliding canopies) for container delivery systems (CDS), heavy equipment, or personnel rely on this form or MAJCOM-approved software. It supports dead-reckoning principles combined with parachute ballistic data for reliable results.

What Is the Computed Air Release Point (CARP)?

The CARP is an imaginary point in the air where the first parachute-suspended load (or jumper) must exit the aircraft to reach the desired Point of Impact on the drop zone, accounting for forward throw, descent time, wind drift, and aircraft motion.

The navigator (or designated crewmember) computes it using average parachute ballistics and fundamental navigation techniques. The pilot maintains the proper track and drift offset, while the navigator controls timing for “Green Light” (release initiation) and “Red Light” (end of usable DZ time).

Key related terms:

  • Point of Impact (PI) — Desired landing spot on the DZ (e.g., Personnel PI or Heavy Equipment PI).
  • Drop Zone (DZ) — Surveyed area meeting minimum size requirements per drop type and aircraft formation.
  • HARP — High Altitude Release Point variant for certain high-altitude operations.

Primary references include AFMAN 11-231, Computed Air Release Point Procedures (current as of 2020) and DAFMAN 13-217, Drop Zone and Landing Zone Operations.

Purpose and Importance of AF Form 4018

AF Form 4018 standardizes CARP calculations and documentation. It records all inputs and outputs for preflight planning and in-flight adjustments. This minimizes errors in altitude, wind, drift, and timing—factors that directly affect airdrop accuracy and safety.

The form replaced the older AMC Form 512 and dates to the 1998 version (AF IMT 4018, 19980501, V2). While modern aircraft like the C-17 or C-130J may use mission computers for automatic CARP solutions, the AF Form 4018 remains a required or backup tool for many scenarios and documentation.

Accurate CARP computation supports:

  • Personnel parachute drops
  • Container Delivery System (CDS) bundles
  • Heavy equipment airdrops
  • Training and combat resupply missions

Proper use helps ensure loads land within surveyed DZ boundaries, reducing risks to ground personnel and maximizing mission effectiveness.

How to Download the Official AF Form 4018?

You can download the current official PDF directly from the Air Force e-Publishing site:

→ Download AF Form 4018 PDF: https://static.e-publishing.af.mil/production/1/af_a3/form/af4018/af4018.pdf

Always verify the latest version on www.e-publishing.af.mil before use, as forms and procedures can receive updates.

Key Sections and Fields on AF Form 4018

The two-page form includes header information and detailed computation areas:

Header / Administrative Data:

  • Navigator’s Name (Print) and Signature
  • Call Sign
  • Organization
  • Date
  • Preflight Altimeter Setting (standard 29.92 inHg)
  • Drop Zone details
  • Scheduled Drop Time(s)
  • Load description, weight, parachute type/number, flight station of load

Factors Section (Items 1–35+): The form guides sequential calculations:

  1. Drop Altitude (AGL)
  2. Terrain Elevation (highest point on surveyed DZ)
  3. True Altitude (MSL)
  4. Pressure Altitude Variation (PAV) 5–6. Pressure Altitude and Corrected Drop Altitude 7–8. Indicated Altitude adjustments
  5. Temperature 10–11. Indicated/Calibrated/Equivalent Airspeed to True Airspeed 12–13. Rate of Fall and Adjusted Rate of Fall (density-corrected) 14–16. Altitudes above PI, vertical distances, stabilization altitude 17–19. Time of Fall, constants, Total Time of Fall 20–26. Ballistic Wind, drift effect, course/heading, drift correction, ground speed 27–30. Exit time, deceleration quotient, forward travel time and distance 31–35. Stopwatch times, usable drop zone length and time, Red Light Time

CARP Timing Graph (Page 2) helps visualize timing versus groundspeed in knots and yards/meters for quick reference during run-in.

Additional areas cover results, raw/corrected circular error, formation position, and error tracking.

Basic Computation Steps (per AFMAN 11-231):

  • Start with drop altitude and terrain elevation to derive true altitude.
  • Apply pressure variations and temperature for density adjustments.
  • Calculate rate of fall and total time of fall using parachute ballistic data.
  • Factor in winds (ballistic and surface) for drift.
  • Compute forward throw and timing for green/red light signals.
  • Plot or record the release point relative to the PI.

Crews often use a Dead Reckoning (DR) computer or equivalent for intermediate steps.

  • Documentation: Complete AF Form 4018 for drops where manual computation applies. Certain aircraft may document differently when using mission computers.
  • DZ Coordination: The Drop Zone Safety Officer (DZSO/DZSTL) marks the PI and provides updates. Minimum DZ sizes vary by load type, altitude, and formation (refer to DAFMAN 13-217).
  • Wind and Environmental Factors: Accurate wind data at multiple altitudes is essential. Ballistic wind represents the effective average affecting the load.
  • Modern Enhancements: While AF Form 4018 remains foundational, systems like Joint Precision Airdrop System (JPADS) offer GPS-guided steerable parachutes for higher accuracy in challenging conditions.

Aircrews must maintain thorough understanding and teamwork between navigator, pilot, and loadmasters for successful CARP operations.

Why Accurate CARP Matters for USAF Missions?

Precision airdrops enable rapid resupply in contested or austere environments without landing. Errors in computation can lead to loads missing the DZ, increasing recovery time, risking damage, or compromising safety. The AF Form 4018 provides a proven, standardized method to mitigate these risks.

For the latest guidance, consult:

  • AFMAN 11-231 — Computed Air Release Point Procedures
  • DAFMAN 13-217 — Drop Zone and Landing Zone Operations
  • Your MAJCOM supplements and aircraft-specific manuals (e.g., C-130, C-17, HC-130 series)

Download the Form Here: AF Form 4018 PDF

Stay current with Air Force e-Publishing for revisions to forms and manuals. Proper training and adherence to these procedures ensure safe, effective aerial delivery operations supporting U.S. military objectives worldwide.

This article is for informational purposes and references official U.S. Air Force publications. Always use the most current versions from official sources and follow applicable directives, training, and safety protocols.