Helicopter Steel Erection & Infrastructure Placement
Helicopter steel erection places structural members where a crane cannot reach them from a workable position, where the ground cannot carry one, or where the street cannot close for its setup. Erickson publishes maximum external cargo of 25,000 pounds for the S-64F Air Crane. The work runs under 14 CFR Part 133, and the allowable load for any pick depends on the specific aircraft and the conditions on lift day.
The boundary
When Does Helicopter Steel Erection Beat a Crane?
A crane's capacity chart falls as the radius grows. A helicopter's capacity does not shrink with horizontal reach in the same way, although it still depends on the aircraft, the rigging and the conditions on lift day. That difference explains most of the steel work that moves to a helicopter: the member is often within a crane's capacity but far from any place a crane can stand.
The picks that end up on a longline share a pattern:
- Bridge and pedestrian-crossing sections over water, rail corridors or ravines, where neither abutment offers a crane pad.
- Penthouse steel, dunnage frames, and screen-wall steel on occupied towers, where the street below is hard to close and a tower crane is hard to justify for a two-day erection scope.
- Spires, masts, and architectural steel at heights and setbacks beyond a mobile crane's chart, or where the crane setup would need a lane closure permit.
- Cell-carrier steel and antenna mounts on existing towers and rooftops, where the alternative is hand-rigging each piece into place. For full structure erection, see Tower Construction.
- Long-reach picks over occupied structures, where the area a crane boom would sweep is the area the owner cannot vacate. The helicopter's route over that area still needs its own protection under the congested-area plan.
For the estimator, the comparison usually turns on mobilization rather than the hourly rate. A large crawler or tower crane carries transport, assembly, mats and ground-bearing engineering before its first pick, plus lane-use fees and police details when the street is involved. Put those charges beside the helicopter's own setup costs: the pickup area, the protected flight route, ground protection and ferry charges. Some jobs still come out in the crane's favor; the full crane-versus-helicopter comparison is on the Aerial Construction hub.
The discipline
What Is a Non-Impact Protocol?
A non-impact protocol is a load-control method operators apply to high-value fabrications. The flight profile and the final approach are planned to limit the forces on the suspended member from liftoff through release.
A welded truss, a machined bearing assembly or an architectural spire with a six-month fabrication lead time cannot simply be replaced if it is damaged on the hook, so a lifting mistake can cost the schedule far more than the lift itself. The protocol handles the member as a precision component rather than as freight.
In practice that means three controls:
- Engineered flight profile. Acceleration, translation and descent rates are planned against the member's mass and rigging geometry before the aircraft launches, so they are not worked out over the connection point.
- Stabilized final approach. The aircraft establishes a hover above the connection and closes vertically at a slow, controlled rate while ironworkers control alignment from the structure.
- No side-loading at release. The member is plumb over its seat before it takes bearing. The hook releases only after the connection crew confirms the member is landed and pinned.
On the S-64F, an aft-facing pilot station gives the pilot a direct view down the longline to the connection point. When a proposal names an aircraft for precision sets, ask how the pilot sees the connection and how the connection crew communicates with the aircraft through the final set.
The airframes
Which Aircraft Do Operators Fly for Structural Steel?
Airframe selection starts with the member's weight, including rigging, then the placement tolerance and whether the aircraft's certification permits the proposed operation. The capacities below are published figures with different bases, so they cannot be read as lift-day allowances. Capacity depends on the specific aircraft and the conditions on lift day, including density altitude; the FAA Helicopter Flying Handbook, chapter 7, explains how those conditions affect performance.
| Aircraft | Max external load | Steel erection role | Certification category | Typical picks/hr |
|---|---|---|---|---|
| Boeing CH-47D Chinook | Not published here | Heaviest members: bridge sections, plate girders | Not published here | Not published here |
| Erickson S-64F Air Crane | 25,000 lb (Erickson: maximum external cargo) | Precision sets; aft-facing pilot station | Not published here | Not published here |
| Columbia BV-234 Chinook | 28,000 lb (Vertical: Model 234 UT/LR, on the hook) | Heavy steel members | Not published here | Not published here |
| Bell 214B Big Lifter | About 8,000 lb (McDermott Aviation: 3,636 kg maximum hook load) | Lighter members, infill steel, carrier mounts | Not published here | Not published here |
| Kaman K-MAX K-1200 | 6,000 lb (Kaman: published lifting capacity) | Repetitive lighter picks, lattice steel | Not published here | Not published here |
Certification category and cycle rate are not published here. Category belongs to the individual aircraft's certification record rather than to the model name, and cycle rate belongs to the operator's estimate against the actual pick list. Where a capacity cell reads not published here, this page has no source for that figure; take it from the aircraft's flight manual or the operator.
Certification needs its own check. §133.45(d) prohibits external-load operations with rotorcraft type certificated in the restricted category under §21.25 over densely populated areas, in congested airways or near busy airports with passenger transport operations. The congested-area section below covers the plan and approval an urban set also requires.
The hardware
How Is the Rigging Engineered and Inspected?
Steel is unforgiving of casual rigging. The lift plan should name the standard that applies to each component, along with the inspection criteria that follow from it, and confirm that the named standard actually covers that part. ASME B30.20 addresses below-the-hook lifting devices and ASME B30.26 addresses rigging hardware. Within that design:
- Slings are rated for the load at its planned sling angles and inspected to the criteria of the standard that covers them.
- Longlines are selected with the rest of the rigging design and within the aircraft's approved limitations.
- Spreader and lifting beams are engineered to the member's pick points and documented weights rather than to a generic capacity.
Two hardware concerns apply specifically to steel:
Anti-rotation control. A long plate girder or open truss behaves like an airfoil. Without control, it can weathervane and spin under the aircraft. Riggers place a swivel at the hook to decouple line torque from the load, and tag lines let the ground crew control heading through the final set. For members with a large surface area, the lift plan sets a lower wind limit than the aircraft itself requires.
Load geometry. Sling angles, center-of-gravity offsets and attachment eccentricity are calculated from the fabricator's drawings during technical vetting. A member hanging off plumb will not seat cleanly in its connection, so the geometry has to be settled before the member flies.
The pilot in command has final authority over the operation of the aircraft under 14 CFR §91.3 and can decline any pick. The lift plan should set when the rigging is inspected, both before the first cycle and during the operation, and who performs each inspection. The regulatory framework, including load classes and the physics behind them, is covered on the External Load Operations reference page.
The airspace
Can a Helicopter Set Steel Over an Occupied Building?
It can, within Part 133's congested-area requirements. Section 133.33(d) requires an operation-specific plan coordinated with the responsible FAA Flight Standards office, and FAA approval for the operation. The flight operator develops the plan. For a steel set, it addresses:
- Flight routes and altitudes that allow the load to be released, and the aircraft landed, in an emergency without hazard to people or property on the surface.
- Fall-zone security, including the agreement with local officials to exclude unauthorized people and any arrangements with the property owner and neighbors.
- An emergency jettison plan identifying where a load goes if it must come off the hook.
Put the FAA review into the erection schedule. Establish review timing with the responsible office, and carry approval as a milestone alongside notice to proceed and permit dates.
Certification also affects which aircraft can fly the urban set. Section 133.45(d) prohibits external-load operations with restricted-category rotorcraft over densely populated areas. Section 91.313(f) does not remove that restriction, and an approved congested-area plan does not remove it either. Certification belongs to the individual aircraft rather than the model name, so check the specific aircraft's certification and operating limitations before assessing it for a pick over an occupied block.
Noise is a local question. Check the ordinances that apply to the property and municipality, including any that reference a measurement standard such as ANSI S12.9, and agree the work window with whoever handles permits and tenant notices. A short flight estimate does not by itself establish an allowable noise window. The same regulatory requirements apply to Modular Building Placement and HVAC and rooftop unit work over occupied properties.
The manifest
What Do the Fabricator and Erector Provide?
Clear roles keep the lift day predictable. A planned division of responsibility on a helicopter steel operation can look like this:
| Deliverable | Responsible party |
|---|---|
| Certified load weight per member (scaled or calculated and stamped, including all attached hardware) | Fabricator / client |
| Engineered pick points on the member, with drawings | Fabricator / erector's engineer |
| Rigging design, hardware, and inspection to ASME B30 | Helicopter operator |
| Lift plan, load calculations, flight profile | Helicopter operator |
| FAA Part 133 compliance, CAP filing, FSDO coordination | Helicopter operator |
| Connection crew, tag line handlers, landing zone control | Erector, briefed by the operator's ground coordinator |
| Final go/no-go on every pick | Operator's pilot in command |
The certified weight drives the rest of the plan. Aircraft performance, the rigging design and the check against the aircraft's external load limit all start from that number, so an estimated weight is not a usable lift plan input. A member without certified weight documentation does not fly.
The erector's ironworkers stay on the steel and make the connections. OSHA 1926.551 requires daily briefings for helicopter construction work and addresses loose objects and static electricity. Before the first cycle, the operator's ground coordinator briefs the crew on protective equipment for work under rotor downwash, the planned static-discharge procedure for the suspended load, tag line handling, and hand signals with radio backup. Connections are designed for rapid landing and pinning: the aircraft holds position while the member is seated and pinned, then releases and returns for the next member while the connection crew completes the bolt-up.
The cadence
Why Does Cycle Rate Decide the Bid?
Cycle rate, the pace from one pick to the next, sets how long the aircraft works the job, and flight time is one basis of the helicopter's price. No default rate applies to every erection sequence, and this page publishes none. The rate depends on sequencing worked out in advance from the erection drawings: members staged in flight order at the laydown yard, shake-out matched to pick order, and connection crews positioned one set ahead of the aircraft. Use the operator's estimate for the actual pick list, and identify the assumptions behind it.
For a contractor's bid, that estimate feeds several lines:
- Labor. The raising gang's hours follow the flight window, plus the connection work that continues after the aircraft leaves.
- Mobilization on both sides. The helicopter avoids crane assembly and teardown, but its pickup area, route protection, ground protection and ferry charges belong in the estimate.
- Schedule exposure. A shorter flight window can reduce weather exposure only if the steel, the connection crew and the approvals are ready when the aircraft arrives. Include weather standby and rescheduling terms.
A helicopter proposal may arrive as a logistics package covering the aircraft, the estimated cycle rate, insurance documentation and the approval timeline. Before carrying it into a master bid as a single line item, check what it includes and excludes: ferry charges, standby and cancellation terms, and the insurance provisions measured against the project's actual requirements.
The honest boundary
When Does the Ground Crane Win?
A ground crane is the better choice when:
- The erection sequence requires long static holds. A crane can hold a member through an extended fit-up and welding. A helicopter sets and releases, so if the connections cannot be designed for rapid pinning, the member should not fly.
- A single pick exceeds the published capacity of the available aircraft. Vertical reports 28,000 pounds on the hook for Columbia's Model 234 UT/LR Chinook, the highest figure in the table above. A heavier member points to a crane, or to a change in how the steel is divided into picks.
- The site has clear access and a long-duration steel scope. A tower crane erecting a high-rise frame over months is the practical tool, and flight-hour arithmetic does not change that.
- Placement tolerance demands sustained mechanical guidance. Some slip-critical or machined-seat connections need a load that can be inched into place under full crane control.
Projects near that boundary are settled the same way each time: with the erection drawings, a cost for both methods and an engineering comparison. For structural steel, start with the total-cost framework on the Aerial Construction hub, then read the regulatory detail in External Load Operations. Related pages in this series cover Modular Building Placement and HVAC and rooftop units. New analyses are announced through the mailing list.
Frequently asked questions
What Erectors and Estimators Ask First
From the technical library
