Sierra Technical completes 5GAT engine runs

Sierra Technical Services announced the successful completion of engine runs, including full power runs, of their 5th Generation Aerial Target drone. The aircraft is also a contender for Loyal Wingman. It's a high subsonic platform, powered by twin J85 engines, used on the T-38, capable of short periods of +7.5Gs and -2Gs. It will be capable of carrying an interchangeable sensor suite, capable of replicating multiple threats, electronic warfare systems, or even ISR.

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surprised it is limited in negative Gs. Do you think that has more to do with fuel feed than structural issues? I always thought the limit on negative Gs was more so for the sake of pilots.

a reply to: dubiousatworst

Pilot limits are part of it, but you're also looking at structural, airflow over the wing, fuel and oil flow... There are multiple factors.

a reply to: Zaphod58
Thanks for the reply. Guess I need to up my research on the subject, I had just figured that oil/fuel wasn't as much of a problem and had been "solved" due to the history lessons of the Battle of Britain. Time for me to look into it!

a reply to: dubiousatworst

It depends a lot on the aircraft. Aerobatic aircraft usually have pressurized fuel systems that keep fuel flowing as they maneuver. Something like this is designed more for hard turns and evasion maneuvers that will be more positive G maneuvers.

a reply to: Zaphod58

Nice Pics. What strategic advantage does this create?

a reply to: Sabrechucker

There are currently no aircraft that can replicate the threat a fifth generation aircraft represents. The Su-57 and J-20 are probably not actual 5th Gen, but they are Low Observable. This will be an LO target drone that will help to develop tactics and technology to fight against LO opponents.

a reply to: Zaphod58

Thanks. A-10 replacement?

a reply to: Sabrechucker

No, target drone. It may also become the unmanned Wingman controlled by the F-35 and F-22 as well.

originally posted by: Zaphod58
a reply to: Sabrechucker

No, target drone. It may also become the unmanned Wingman controlled by the F-35 and F-22 as well.

It absolutely boggles my mind how the pilot can fly his/her aircraft, all while remotely operating a drone. I have heard that they can pass off the drone to other personnel.

I’m surprised it can pull only 7.5 Gs. Many manned fighters can pull 9. One of the supposed advantages of combat UAVs is they aren’t limited by frail human aircrew, who can’t withstand 9 Gs for long before passing out.

a reply to: Scapegrace

They're trying to stimulate a manned aircraft.

originally posted by: dubiousatworst
surprised it is limited in negative Gs. Do you think that has more to do with fuel feed than structural issues? I always thought the limit on negative Gs was more so for the sake of pilots.

Think of it like this: your wings are designed to support the airframe, and a keel supports the fuselage across it's length (or an otherwise exceptionally strong fuselage construction) -- we need to make sure the wings are attached and sometimes braced in such a way that they don't separate from the fuselage under the weight. Wings are pushing up (lift), while fuselage is basically pushing down (gravity). Boeing made the news recently with pickle forks that do this. We need this as light as possibly can be done.

So to support 10 g's, I plan ahead and strengthen the airframe as much as needed to carry 10 times the vehicle weight. Relatively simple, right?

So let's say I build a balcony, and weight is a prime concern. You can comfortably fit five people on the balcony, but to be safe, I make sure it is capable of supporting the weight of ten people and heavy furniture (as well as it's own weight). My structure easily holds 3 tons. But if you start pushing on it from below (negative g), then my joins, braces, etc are not going to be as strong. Say a freak wind causes stress "up" under the balcony. It's going to fail well before three tons because forces are being transferred differently, and I didn't build it to withstand strong negative g's and that transfer.

You could build a structure to withstand higher stresses in that direction, but that's more weight. And since most negative g's in flight (and balconies) are short lived (sharp maneuvering and turbulence) and lower in magnitude, there is little call for an aircraft that survives exceptionally high negative g's. Most forces, and the strongest (deliberately) experienced are in the positive direction. Since adding structure means adding weight, strengthening the fuselage for negative g's can weaken it in the positive direction. Have to find a balance.

Pilots, as you note also are notoriously squishy, and fussy, and they hate nose bleeds and headaches, and have found red eyeballs are not a hit with the ladies afterhours.

a reply to: Bigburgh

You don't play Video Games?

So in essence, this is a dual purpose test? One of which simulates a true 5th Generation target AND a unmanned drone to act as a force multiplier and AI wingman.

Pretty ingenious.

Of all of Americas greatest technologies, is this our greatest edge?

a reply to: Arnie123

It's primary mission will be as a target, but yes, it's also going to be one of the potential AI Wingman aircraft. The Loyal Wingman program will also allow F-22s and F-35s to talk together.

a reply to: Arnie123

They've been hired to produce a target. They really want to sell it to someone as a UCAV, Loyal wingman, Skyborg.

It can probably do those things after a fashion, but it's hard to see where the money comes from. Once they get the kinks worked out and production rolling, they'll have a better chance of selling a buy for other missions. Size/cost and lack of an internal bay is going to kill it as an LCAAT-style competitor, imo. But there may be an EW or SEAD role for it eventually.

a reply to: RadioRobert

It currently is supposed to have an interchangeable electronics bay allowing for ISR, EW, and signature simulator installation.

a reply to: Zaphod58

Correct, that's their plan, but it isn't what they're being paid for -- and ordnance would have to hang out in the wind. Which along with cost makes it a lousy fit as a competitor to the Valkarie, imo. And the ISR/EW mission is being handled by things with much lower signatures across multiple bands. Once they get up and running, they'll probably find suitors on the intl market for other roles, but hard to imagine it carves out budget slices to find another niche in the US.
It's impressive as it stands from a small house. Just hard to see a justification for spending to give it other roles.

Twenty-four taxi tests were completed in six days preparing the 5GAT UAV for its first flight at Dugway Proving Grounds.

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