In addition to the flight crews, the work of ensuring commercial aircraft take off and land safely falls to a support cast of professionals. These staff, including crews on the tarmac and those in the airport terminal, participate in operations-critical pre-flight workflows, such as dispatch control, weight and balance, and more.

Standards and procedures for these processes were formerly captured in thick, paper-based manuals, some as long as 3,000+ pages. Now in the digital age, aviation companies turn to intelligent cloud-based solutions to speed up their operations. And driving digital transformation is Uniscope Cloud Services, a one-stop, all-in-one aviation document information management system, provided by Uniscope Global Sales & Marketing and developed by its sister company, Uniscope R&D.

Uniscope CEO Robin Masson stated,

“We have a system that goes from end to end -- from creating a new document or updating an existing document right through to the delivery to the line crew.”

In December 2019, Uniscope set out to expand its end-to-end system with a web-based PDF viewer that would digitize internal review and approvals on aviation manuals destined for publication.

Uniscope first went with a low-cost commercial PDF SDK that seemed to cover off its basic requirements to let users view their PDFs on the web, and collaborate with their annotations, bookmarks, and comments.

Two-and-a-half months later, bookmarks and annotations still would not render as expected, while lengthy manuals would take up to seven minutes to display for users. Uniscope ultimately had to abandon its first proof of concept and eat the sunk costs, including nearly a month worth of person-hours spent working with insufficient documentation and seeking workarounds to broken API functionality. The resulting delays meant that Uniscope lost a major opportunity to convince one of its existing customers to use the new capability.

“It was a pretty dreadful experience, to be honest,” says Masson. “The library just did not work as advertised.”

Today, Uniscope has migrated to the PDFTron SDK. It built a working WebViewer prototype within a matter of days; annotations, bookmarks, and user comments now all render as expected, while long PDF manuals that once took several minutes to display for users now take only seconds.

linkBusiness Challenge

  • Uniscope wanted to fast-track development of a PDF web viewer with real-time collaboration capabilities with user annotations, bookmarks, and comments
  • Poor vendor documentation and APIs with broken functionality led to unexpected delays and cost overruns
  • Uniscope sunk 1 month worth of work into patching broken functionality and customizing the UI
  • But with long manuals still taking up to seven minutes to display, Uniscope could not develop an acceptable prototype in time, losing a major opportunity to convince an existing customer to go digital.

linkBusiness Solution

  • Uniscope evaluated and selected the PDFTron SDK and WebViewer, which provided all of its feature requirements out of the box and was up and running in a matter of days


  • Development time reduced from 1 month to 1 week
  • All annotation, bookmark, and comment capabilities work as advertised
  • Long aviation manuals now open in a fraction of the time -- in seconds as opposed to several minutes


In the conservative world of aviation, where safety is priority #1, aviation companies have been slow to move off paper-based workflows.

“They were still stuck with downloading aviation manual drafts, printing them, and pushing them around for review,” says Masson.

In December 2019, Uniscope hoped to advance digital transformation by encompassing workflows used to create and maintain aviation manuals within Uniscope’s end-to-end cloud solution.

As part of these approval workflows, multiple stakeholders would need to provide input using their markups and comments. All operator collaborations would also need to be stored and tracked separately, to be later shared with the regulator, if needed, for final sign off and oversight.

“The regulator may want to know why 20 was changed to 30, for example, and who was responsible, such as in the case of an accident,” stated Masson.

Uniscope initially looked to PDF as a single file format on which to consolidate its document workflows. One of its existing customers was also moving to Uniscope Cloud Service, and the company wanted to fast-track its new web viewer development to offer it as an add-on to the client’s cloud-based system as it went into production.

“We had a small window of opportunity to ‘stick it to them digitally’; that is, provide the client with something completely new and have them say to their internal users, no more paper, sorry!”

Uniscope, therefore, sought out a PDF SDK that would allow them to fast-track development of PDF and document collaboration features and get a working proof of concept to market as soon as possible

Initially, Uniscope considered two possibilities to help it accelerate development -- PDFTron and another commercial PDF SDK. With both options seeming to offer similar capabilities on a surface inspection of the documentation, Uniscope went with the commercial PDF SDK with a cheaper initial price point, as the company felt this would let it cut straight to development.

linkFirst Experience

Not long after starting development, however, Uniscope ran into issues with its other PDF SDK.

The Uniscope team started to second-guess themselves as annotations and bookmarks disappeared unexpectedly.

“We had developed quite a serious prototype for the back-end,” stated Masson. However: “big documents could take like six-to-seven minutes to load for users, and their comments and bookmarks didn’t appear in the viewer. We got to the point where we were saying, ‘but they did appear last time, didn’t they?”.

Lead Uniscope Developer Carlos Villegas, in charge of building out the back-end to handle the collaboration layer, describes his experience as follows:

“We had a problem with the SDK API; it was incomplete and not functioning. I had to go back and develop workarounds many times,” he said.

Likewise, customization of the UI proved challenging and time-intensive:

“I had to reverse-engineer the CSS to know what to overwrite because the documentation was not good.”

linkThe Hidden Costs of the Wrong PDF SDK

Due to the extra costs and delays, Uniscope eventually ran out of time, and it had to demonstrate an incomplete proof of concept to the customer in hopes it would be enough. But the slow load times Uniscope encountered before were even worse within the customer’s environment.

“For us, the performance was slow. But for them, it was molasses,” Masson stated. “The client asked us, ‘do you really want to give us this?’”

The customer ultimately decided not to use the additional functionality as it was, but instead, and fortunately, asked Uniscope to come back later with a better solution.

linkSwitching to PDFTron SDK

Three months later, after its previous solution had fallen flat, Uniscope decided to build its proof of concept with the PDFTron SDK.

Setting up its PDFTron SDK proof of concept turned out to be simple and straightforward, taking Uniscope just a matter of days. Everything worked as expected. Comments, bookmarks, and markups rendered on top of documents flawlessly, and lengthy manuals that once took up to seven minutes to display for users took only seconds to pop up on screen.

“We just connected WebViewer to our backend, and when we saw the difference in performance, that was a big decision point,”

Lastly, PDFTron proved open to negotiating a flexible licensing agreement that would fit the small scale of UniScope’s implementation, including at most a couple of hundred users.

“PDFTron understood our limited requirements and progression. We were able to come to an arrangement that was very useful and attractive to us, and let us move forward,” stated Masson.

linkLessons Learned

Having worked with two different PDF SDKs and being burned by the first, Uniscope has advice for other developers and integrators attempting a similar build.

Masson stated: “We had an opportunity in terms of delivery, and we tried to fast-track it, putting interface customization in front, which was a lot of work, without knowing whether all the actual PDF SDK functions -- the collaboration part, the annotation storing, or the viewer -- were actually working.”

“In hindsight, you’d make sure the core features you want to use actually work.”

“We just assumed it did, and we received assurances that it would. The other vendor came back with a reasonable price very quickly, making it very attractive to us. But the solution turned out to be a false economy” he added.

“It’s not cheaper in the end if you can’t build the product.”

linkAbout Uniscope Cloud Solutions

Remote collaboration for aviation operational documentation

Uniscope has been delivering on-premises document management software systems to aviation customers for almost 30 years, making remote collaboration and crucial consultations made simpler and faster. Learn more at