The next time you scan a document and feel overwhelmed by the tedium of the process, consider the people in Kansas who have to scan in an entire Apache helicopter. A group at the National Institute for Aviation Research (NIAR), part of Wichita State University, is creating a three-dimensional digital rendering of an Apache attack helicopter, a process that involves scanning each part. The project will last three years and is the result of an army contract.
Melinda Laubach-Hock, who is leading the massive scanning effort, estimates that Apache may have as many as 5,000 to 6,000 parts. Her estimate is based on a similar project her team is completing that involves scanning about 5,000 parts of a Black Hawk helicopter.
“We’re taking an airframe, taking it apart, cleaning it, scanning it, [and] reverse engineering,” she says, describing the process for the Apache jet. “We build detailed, production-quality level models for each part, and then we basically digitally reassemble the airframe.”
A three-year venture like this, which one NIAR describes as “tedious,” begs the questions: Why do this? And how?
The goal is twofold, says Lauback-Hock. The first is to help with repairs, or “to improve the way we’re doing support for the legacy Apache fleet,” she says. The Apache variant they’re working on is an AH-64D, or delta, model, and she estimates the US military has 800 of them in service. Having a high-fidelity digital representation of a part can help the fabrication process when it comes to repairing or replacing a helicopter component. She also argues that a digitally designed repair solution for a part can be more sustainable than a single fix created by one person. It probably won’t be a digital version of a helicopter in a Dropbox folder, but you get the idea.
The second involves exploring, more generally, the role that having a detailed digital version of an aircraft – a concept commonly called a digital twin – could play in the future. Next-generation helicopters and tiltrotor planes are being born in the digital age (with Sikorsky and Bell competing in two separate Army programs), setting them apart in some ways compared to older machines.
[Related: Why Bell’s sleek new helicopter has detachable wings]
With Apache, beyond just scanning the parts, the goal is to digitally stitch them together to represent a virtual version of the real aircraft, which can be used to model how loads or stresses might affect the real thing. . She refers to the digital beast they will create as a “high-fidelity structural engineering model.”
“Basically, this is an engineering model that says, ‘If I push here on the structure, this is how the load spreads through the structure,'” she adds. And then to make sure that digital model is real, she says they’re going to buy a second Apache helicopter, which they’re going to physically stress. “We’ll push and pull and measure the response and use those measurements to calibrate our engineering model,” she notes.
[Related: Take a peek at Sikorsky’s scout helicopter prototype]
She also argues that overall, having a digital version of a helicopter can help perform maintenance in a more predictive and proactive manner.
So why not just get the plans from the company that made the helicopter in the first place, which for the Apache is Boeing? “I don’t know if they exist at Boeing or not,” Lauback-Hock says. (The version of the Apache Boeing is producing today is the AH-64E, while the version being scanned in Kansas is an AH-64D. A Boeing spokesman said via email: “Boeing maintains detailed data in a variety of D and E model formats – model Apaches.” They also noted, regarding the NIAR project, that “Boeing has provided assistance.”)
But in general, the ways aircraft manufacturers created designs for flying cars in the past were different from today’s standards. “My experience is that we’ve taken models on other legacy platforms that we’ve built [digital] twins for,” says Lauback-Hock, “and there is a lot of work to be done to improve them to today’s standards.”
How is a scan done in a helicopter?
The team is using an Apache helicopter they have on site in Kansas, although it is not a full-fledged aircraft. “There was an airframe involved in an incident and it couldn’t be repaired,” she says. “We started there, and then the Army is looking for ways to allow us to access parts that we don’t currently have.”
Any damaged parts are now gone, so what’s left is roughly 80 percent of the helicopter. But with a project as big as scanning an entire helicopter, it made sense to start with what they have, she says. To scan in parts, they use a device called a hex arm that can capture components in 3D. “You just laser the surface a few times and it creates a very dense geometrically accurate point cloud that can represent the outer shape of the item,” she says.
The Apache is not the first aircraft to undergo this type of digital acquisition. The Black Hawk project is about 95 percent complete, she says. They’re also scanning in a B-1 bomber and an F-16 fighter jet, the latter about 15 to 20 percent done. Laubach-Hock notes that other programs exist in this arena that have not been publicly disclosed.
Students will also help. Ultimately, Lauback-Hock says about 65 people will work on the Apache program, with 30 of them students. One student told ksn.com that the project “looks really great on my resume.”
This post has been updated to include comments from Boeing.