Scan Eagle Cutaway and feature

ScanEagle cutaway.gif

It was 11 years ago when Insitu co-founder Tad McGeer received thetelephone call that launched the unmanned air system that eventuallybecame known as the ScanEagle.

Insitu had already demonstrated in 1998 that a low-altitude UAScould cross the Atlantic Ocean on a single flight. That one successfuldemonstration quickly attracted interest far beyond remote Bingen,Washington, the base for the then-small company of eight employees.

Insitu had traversed an ocean with an aircraft equipped to monitorweather data. But the flight raised what today may already seem aquaintly obvious question: instead of weather sensors, what if Insituinstalled a camera in the nose of the air vehicle?

The idea did not spring from the military community. A few years -and the terrorist attacks on 11 September 2001 – would pass before theUS armed services embraced the ability to persistently observe an areaor even a precise spot for several hours. Rather, Insitu’s foundersfortuitously timed their idea immediately ahead of a decade-long,frenetic pursuit of unmanned aviation technology by military operatorsall over the world.

Within less than a decade, that sea-change in operational philosophyhas turned the ScanEagle UAS into a globally ubiquitous piece ofmilitary kit. It also has stamped Insitu as a universally recognisedbrand, which since September 2008 has been wholly owned by Boeing.


Along the way, the ScanEagle’s now-proven technology successfullynavigated the high barriers to entry into the US military acquisitionsystem for a small company with no defence pedigree offering adisruptive technology.

As an operational system, the ScanEagle is credited for rapidlyinventing and refining the now-standard operational role and profilefor what the US Navy calls a small tactical UAS (STUAS) and what the USMarine Corps labels a Tier II UAS.

As a leased service, the ScanEagle has accumulated 175,000h ofoperational flying since 2004 and is adding another 10,000 flight hoursevery month.

Its larger and more capable successor – the Insitu Integrator UAS -is now competing for the STUAS/Tier II contract, a role defined largelyby the experience and lessons accumulated over five years with theScanEagle.

But the call that came to Insitu co-founder Tad McGeer in 1998 -true to the ScanEagle’s inauspicious beginnings – came not from themilitary but instead from two consultants representing the tuna fishingfleets of the North Atlantic.

Their idea seemed logical. Insitu had already designed an unmannedaircraft to serve as an airborne weather observing station – or”aerosonde”. Perhaps it could also design a UAV to serve as an airbornecamera scanning just under the ocean surface for roving schools oftuna. This unmanned observing post would thus replace mannedhelicopters stationed on fishing boats for the same purpose.

“[The consultants] were able to convince Tad that [tuna boats]needed something like helicopters, but [the fisherman] absolutely hatedthem,” says Jeff Knapp, Insitu’s head of product development.

Moreover, highly competitive tuna fishing operators were alsodescribed as “early-adopters” of new technology, Knapp says, addingthat this was a key requirement for McGeer. Insitu had struggled tosell UAS technology to risk-averse government agencies charged withweather observation for five years.

So McGeer tapped aerodynamicist Pere Frank – both alumni of fellowUAS pioneer Aurora Flight Sciences – to solve the unique challenges ofoperating from a fishing trawler, Knapp says. Insitu’s design teamfaced more than the challenge of integrating a stabilised, off-axis,sensor turret to provide 360° surveillance coverage. Operating from thesea also involved the stressing task of launching and recovering theaircraft from a platform moving three-dimensionally in real time.

Insitu’s novel engineering solution to the recovery problem, whichincludes a redesigned man-crane purchased at a local hardware store, isthe patented SkyHook. The technology has been refined and improved overthe past decade. But the basic approach, which involves patentednavigation algorithms, nylon tether and wingtip hook, remains inservice today among several naval customers, including the USN andSingapore.

“To us it’s kind of a routine thing,” says Erik Edsall, Insitu’sbusiness development director. “But some of our customers have troublegetting their heads around that recovery system.”

The military would later prove that Insitu’s unique technicalsolutions to sea-based challenges worked. But the tuna fishing trawlersthat sparked Insitu’s inspiration have yet to embrace the ScanEagleconcept, which is branded for commercial customers as the SeaScan.

“That market didn’t materialise,” Knapp acknowledges. “For the tunafisherman, it was really kind of a risk question in the end.”

Fortunately perhaps for Insitu, the potential market for helicopterreplacements on tuna trawlers would soon be overtaken unexpectedly byan all-new military requirement for airborne persistent surveillance.

Indeed, the market for unmanned aircraft capable of themilitary-level intelligence, surveillance and reconnaissance (ISR)mission evolved faster than anyone could have expected in the late1990s.

By 2002, Boeing Integrated Defense Systems (IDS) was standing up anew organisation focused on unmanned systems, which was headed byCharlie Guthrie.

“It was post-9/11,” recalls Guthrie, now an executive at Insitu. “Sothere was kind of a big change going on across the military.”

As an aerospace company based in Washington state, members ofInsitu’s 10-person staff in 2002 were already known by engineers withinBoeing IDS, Guthrie says. Through those connections, he became awarethat Insitu’s offering for the fishing industry could be well-suited tothe US military’s still ill-defined need for unmanned surveillance.

“We thought, ‘here’s this little airplane that can go out and findtuna and we think this could go out and find targets for the USmilitary’,” says Guthrie, adding that Boeing executives considered it a”long shot. But it was a good long shot.”


After a two-year sales campaign, the US Marine Corps signed up asthe ScanEagle’s first customer in 2004, Edsall says. The capability wasurgently needed as a nascent insurgency continued to escalate in Iraq.There was no time to work through the Department of Defense’s lengthyacquisition process. Indeed, five years later, the USMC and USN areonly now close to signing the first standard acquisition contract for aScanEagle-like capability.

Instead, the marines in 2004 did not acquire a system but a service.Boeing and Insitu formed four-person teams to deploy with the marinesand operate the ScanEagle. Performance is measured not by sortiesflown, but by availability for collecting imagery over a defined period.

“We are actually responsible for anywhere from 10, 15 sometimes20-plus hours a day of guaranteed imagery support,” Edsall says.

The USMC’s service contract was followed a year later by a similardeal with the USN. The Australian Defence Force also deployed theScanEagle in 2007. Singapore purchased the ScanEagle as a ship-basedairborne imagery service in 2008. Canada signed a similar service deallast year, and followed by signing a full acquisition contract withBoeing/Insitu in April.

The 178mm (7in)-diameter ScanEagle design remains easilyrecognisable even as the market becomes crowded with similarly sizedaircraft. Its graceful lines and 23° wing sweep still compares wellvisually to aircraft entering the market even years later.

Those defining characteristics are hallmarks of its intendedpurpose. The founders’ goal was to design and configure the aircraft tocross the Pacific Ocean, Knapp says, having already conquered the NorthAtlantic.

Efficiency is the overriding principle of the design. Although theScanEagle’s commercial forebearer was intended to replace a ship-basedhelicopter, McGeer and Frank would never have even contemplated arotary-winged platform.

“This thing has a glide ratio of 18:1,” Knapp says. “A helicopter has a glide ratio of zero.”

The airframe structure bears the legacy most of all of Insitu’sunique location. Bingen, on the Columbia River Gorge, is famous as ahaven for windsurfers. The all-composite airframe was originallysupplied by local surf board makers. Traditional aerospace suppliers,such as Quattro, have joined Insitu’s composite structure supply chainin recent years, but local shops remain in the system.

The aircraft is powered by a German-made engine normally applied tolawnmowers, Edsall adds. The two-stroke engine generates 1.5hp (1.1kW),which is enough to keep the 20kg (9lb) airframe aloft for up to 22h ona standard day with standard temperature.

With an off-the-shelf Sony 1000 video camera – upgraded from theoriginal Sony 780 model – as the primary daytime sensor, the ScanEagle’s “sweet spot” for surveillance is at a 2,500ft slant range fromthe target, Edsall says. This is the distance where it is practicallyinvisible visually and acoustically from the ground, but stilleffective as an imagery collector.

“What we do to that Sony 1000 is we take it apart, put it in aspecially gimballed turret,” Edsall says. “We give it an off-axis,auto-track capability, add a lot of software stabilisation, platformstabilisation and come up with a capability that gives a near-seven,nears-eight-plus capability that comes with the [ground controlstation] and a geolocation accuracy that’s comparable to about anyoneelse out there.”

For nighttime and bad weather missions, the ScanEagle is now beingupgraded from a long-wave infrared sensor to mid-wave, cooled IRcamera, Edsall says, which corrects a recognised deficiency with thelong-wave system.

Both the engine and the daytime sensor are typical of ScanEagle’s component architecture.

“What we’ve done differently and part of the reason for our successis most of these pieces of kit in the ScanEagle system are commercialoff-the-shelf [COTS] equipment,” Edsall says. “They are things webought off the shelf, added a little bit of ‘secret sauce’ and patentedit. This makes the system affordable and easy to use and maintain.”

There is no better example of this approach than the SkyHook recovery system.

“This SkyHook in its original manifestation was a Genie Liftmechanism that you could buy from the local Home Depot,” Edsall says.”We hung a nylon rope from the boom off the top, put a GPS antenna onthe air vehicle on the top of the boom and then patented the algorithmthat we used for the GPS that allows guidance to a particular point onthe wing where the nylon rope engages the wing within a couple ofcentimetres.

“That GPS algorithm is patented,” Edsall adds. “When it engages therope, the aircraft yaws at the point of impact. The rope gives, therope flies to the end of the wing where a hook catches it. The hook ispatented. The GPS [algorithm] is patented. We’ve taken some COTS kit,added some secret sauce, but this is not a real expensive mechanism atthe end of the day and it’s pretty flexible.”

Concerns have been raised in the field about the size of thelauncher equipment, Edsall says. Insitu is now in the process ofdeveloping a more powerful, but smaller, Mk4 launcher. The system wasoriginally designed for the larger Integrator UAS. However, the samesystem can be used for ScanEagle. “It is smaller, but has more abilityto get a heavier aircraft off the launch stroke,” Edsall adds.


Subscribe to our e-mail newsletter to receive updates.

, , ,

17 Responses to Scan Eagle Cutaway and feature

  1. Matt 8 June, 2009 at 10:48 pm #

    Very cool, but I can’t read any of the descriptions. I suppose an even bigger version is reserved for subscribers to the magazine or whatever.

  2. chris 10 June, 2009 at 4:41 am #

    “This thing has a glide ratio of 18:1,” Knapp says. “A helicopter has a glide ratio of zero.”

    …not exactly. A helicopter might have L/De (weight*V/P) of 4-5. If you take the propulsive efficiency hit that is baked into the equation for the Scan Eagle, L/De might be 14-15. Still better than the chopper, but not infinitely so.

  3. Ryan Podlas 30 December, 2009 at 10:46 pm #

    I completely agree with the above comment, the internet is with a doubt growing into the most important medium of communication across the globe and its due to sites like this that ideas are spreading so quickly.

  4. 2010 roar 20 April, 2010 at 10:24 pm #

    My name is James I’m from the UK and I will start fly-fishing this year. I already bought some equipment but especially the range of fly fishing reels is confusing me…

  5. EyeHate FlyFishers 17 September, 2010 at 10:42 pm #

    James. Shut up with the fly fishing…How copy?

  6. netent casino free spins 2012 6 August, 2013 at 11:09 pm #

    Hi there this is kind of of off topic but I was wondering
    if blogs use WYSIWYG editors or if you have to manually code with HTML.
    I’m starting a blog soon but have no coding know-how so I wanted to get guidance from someone with experience. Any help would be enormously appreciated!

  7. used horseboxes for sale in scotland 22 August, 2013 at 12:22 pm #

    Fantastic beat ! I would like to apprentice while you amend
    your site, how can i subscribe for a blog website? The
    account aided me a acceptable deal. I had been tiny bit acquainted of this your broadcast
    offered bright clear idea

  8. Kareem 1 September, 2013 at 8:59 am #

    Greetings! I know this is somewhat off topic but I was wondering if you knew
    where I could get a captcha plugin for my comment form?
    I’m using the same blog platform as yours and
    I’m having trouble finding one? Thanks a lot!

  9. how to beat online casinos at their own game 5 September, 2013 at 5:45 pm #

    Does your website have a contact page? I’m having a tough time locating it but, I’d like to shoot you an e-mail.
    I’ve got some ideas for your blog you might be interested in hearing. Either way, great blog and I look forward to seeing it develop over time.

  10. Online Casino Bonus Codes Blog 7 September, 2013 at 6:40 pm #

    Hurrah! Finally I got a web site from where I can truly obtain valuable information regarding
    my study and knowledge.

  11. Santiago 12 September, 2013 at 7:05 am #

    I am curious to find out what blog platform you’re using?
    I’m having some small security issues with my latest site
    and I would like to find something more risk-free.
    Do you have any suggestions?

  12. playtech online casino no deposit bonus 24 September, 2013 at 5:41 am #

    Aw, this was an extremely good post. Taking the time and actual effort to produce a good article… but what can I
    say… I hesitate a whole lot and never manage to get anything done.

  13. free playtech slots no download or registration 30 September, 2013 at 5:51 am #

    This is very fascinating, You’re an excessively professional blogger.
    I’ve joined your rss feed and sit up for searching for extra of your fantastic post.
    Also, I’ve shared your web site in my social networks

  14. netent Com Games 10 October, 2013 at 12:15 am #

    Hey! Do you know if they make any plugins to safeguard
    against hackers? I’m kinda paranoid about losing everything I’ve worked hard on.
    Any suggestions?

  15. netent casino 13 October, 2013 at 8:27 pm #

    Hello to all, as I am actually keen of reading this blog’s post to be
    updated regularly. It contains pleasant material.

  16. Indira 15 October, 2013 at 3:33 am #

    Wow, superb blog format! How long have you been running a blog for?
    you make running a blog glance easy. The overall glance of your website is excellent, let
    alone the content!

  17. netent casinos list 19 October, 2013 at 8:53 am #

    Nice post. I learn something totally new and challenging on websites I stumbleupon everyday.
    It’s always interesting to read articles from other writers and practice something from other web sites.

Leave a Reply