Bell 360 Invictus readies for flight but still no engine

[NutLoose]

Larger Article with pretty pictures of it.

https://www.thedrive.com/the-war-zone/bells-360-invictus-readies-for-flight-but-still-has-no-engine

Bell’s 360 Invictus prototype (https://www.thedrive.com/the-war-zone/nearly-complete-invictus-armed-scout-helicopter-looks-wicked-in-new-photos) has been disassembled, trucked from Amarillo to Fort Worth, Texas, and is being put back together in preparation for ground runs and a first flight this year, if all goes to plan.

The company’s pitch for the U.S. Army’s Future Attack Recon Aircraft, or FARA (https://www.thedrive.com/the-war-zone/32748/bell-and-sikorsky-to-compete-head-to-head-to-make-the-armys-future-armed-recon-helicopter), is 95 percent complete and awaiting the GE T901 Improved Turbine Engine so it can begin ground runs ahead of a planned takeoff sometime in 2023. The engine is being developed by another Army office within the Future Vertical Lift effort.

When The War Zone was given a glimpse of Invictus on Jan. 27 it didn’t look 95 percent complete, because it was being reassembled in the company’s hangar in Fort Worth. Many side panels were removed, revealing wiring and other internal components. Very apparent were bright orange wiring and boxes used for instrumentation only during testing and will not be included in the final production aircraft if it gets chosen by the Army.

[Lonewolf_50]

Thanks for the update.
I was interested to see that there is a plan to retrofit the GE T901 into the Blackhawk and Apache to replace T700's.
What are the odds GE meets its milestones and can get the engine delivered sometime in the spring so that Invictus can begin some 'power on' testing?
Betting lines are now open ... :}

[SplineDrive]

Thanks for the update.
I was interested to see that there is a plan to retrofit the GE T901 into the Blackhawk and Apache to replace T700's.
What are the odds GE meets its milestones and can get the engine delivered sometime in the spring so that Invictus can begin some 'power on' testing?
Betting lines are now open ... :}

Retrofits to the H-60 and AH-64 were the original point of the ITE program that the T901 won. The ITE program started long before FARA was a program.

[Lonewolf_50]

Retrofits to the H-60 and AH-64 were the original point of the ITE program that the T901 won. The ITE program started long before FARA was a program.
Good to know. I suppose that HP increase / fuel flow decrease target has been a bugger to achieve.
With 3000 HP, on a Blackhawk, the single engine hover chart becomes a lot more forgiving. :ok:

[JohnDixson]

It will be interesting to see how the OEM’s design teams react to the 901, bringing a 100% increase in SHP from their original power plants. Beyond the hot/high envelope obvious gains, I’d look for the OEM’s to upgrade the drive trains and rotors to take full advantage of the new engines. Actually, it would be surprising if they both don’t have preliminary designs for these areas already in place, and have had them for awhile!

[SplineDrive]

It will be interesting to see how the OEM’s design teams react to the 901, bringing a 100% increase in SHP from their original power plants. Beyond the hot/high envelope obvious gains, I’d look for the OEM’s to upgrade the drive trains and rotors to take full advantage of the new engines. Actually, it would be surprising if they both don’t have preliminary designs for these areas already in place, and have had them for awhile!

Indeed, I’m sure they do. I expect that a fair bit of the new capability will be used to install and haul mission equipment packages that simply didn’t exist in the 1970’s and have been eating into payload and performance margins for years. The improved fuel burn will be as welcome as anything else… “free” range and time on station.

[60FltMech]

It will be interesting to see how the OEM’s design teams react to the 901, bringing a 100% increase in SHP from their original power plants. Beyond the hot/high envelope obvious gains, I’d look for the OEM’s to upgrade the drive trains and rotors to take full advantage of the new engines. Actually, it would be surprising if they both don’t have preliminary designs for these areas already in place, and have had them for awhile!

John,
I’ve been meaning to ask you: do you know how much power throughput the current UH-60M transmission can take? Ever since talk began about the power of the ITEP/T901 I’ve wondered if all of that power would be available without limitations or if it would be like the case if the UH-60A+ with 701C/D engines and torque limitations would apply due to the transmission?


FltMech
p.s. Hope the weather improved down your way and you were able to get some golf in today!

[retoocs]

The MH-60M with the CT7-8B5 is in the 2600 shp range.

[Lonewolf_50]

With the straight T-700 401C or 701C providing about 2000 HP
(as I read the GE brochure, that's 1900+ at contingency power, 1800+ for 30 minutes)
a boost to 2600 HP would potentially work the transmission harder.
With a boost to 3000 HP in the 901 - yes, I think you'd want a beefier transmission.
(And maybe you'd need to refigure the loads on the hub)

[casper64]

It looks great but Single Engine armed aerial scout in 2025-2030…. Must be a joke. One single AK round and the thing is on the ground! 🤔

[The Sultan]

Well, another year slip in the engine announced. Puts the whole program on the chopping block.

https://www.defensenews.com/industry/techwatch/2023/03/15/us-armys-new-helicopter-engine-hit-with-another-delay/

[megan]

One single AK round and the thing is on the groundJust like the Spitfire, Hurricane, or any other single engine airborne conveyance, it's a possibility depending on where that single round hits, engine oil cooler or the gunners backside while seated on the floor, experienced both.

[60FltMech]

Point taken on vulnerability, although the OH-58D took more of a beating than you would imagine. One MTP I flew with had picture of one from Iraq that had two Main rotor pitch links shot through with 7.62mm (among many other things!), and the crew made a safe, normal landing at their base field.

Of course that was a much simpler machine. As airframes got battle damaged the Army even started refurbishing stripped fuselages at the Army Depot and classifying them as spare parts, just swap in the good parts and data plate and good to go!🤣

FltMech

[JohnDixson]

60FM, LW, Megan, Caspar, it seems to me I recall some conversations from the distant past re putting the 92 box and drive on the Hawk. 2 degrees different shaft tilt, but that can be managed. Makes the bigger GE engines candidate power plants. Conversation mentioned the 92 tail rotor as well. All good to go and flight qualified. All it needs is a decision to go. A couple of other no-brainer mods would attend these few, and it would/should leave some folks in the higher echelons wondering if all that money for the speed will be worth it. Just thinking about what-ifs.

[SplineDrive]

60FM, LW, Megan, Caspar, it seems to me I recall some conversations from the distant past re putting the 92 box and drive on the Hawk. 2 degrees different shaft tilt, but that can be managed. Makes the bigger GE engines candidate power plants. Conversation mentioned the 92 tail rotor as well. All good to go and flight qualified. All it needs is a decision to go. A couple of other no-brainer mods would attend these few, and it would/should leave some folks in the higher echelons wondering if all that money for the speed will be worth it. Just thinking about what-ifs.

A drop in update to the Hawk is no longer as simple as originally envisioned and I suspect an update to the H-60 with T901 engines would involve a new design transmission for the H-60, modded MR blades and modded tail rotor blades rather than use modified S-92 parts. In any case, if the Army is basing it's future strategy on fewer bases much further apart, I'm not sure the increased range of a H-60 "Block II" with these mods suits their needs. Without an increase in speed, longer range is just slower response time. It's a fair question, then, how FARA fits into this as the range/speed of either competitor isn't a good match for FLRAA.

[JohnDixson]

SD-good question re the transmission, but remember, the S92 transmission layout is the same as the UH-60. As I may have mentioned, backfitting drive components was part of the 92 strategy ( as in, thats why the 92 has 4 instead of 5 main blades for instance-a number of us did not prevail in that discussion ), thus the 92 box, other than the shaft tilt, is backfittable and has the advantage of standing the primary servos up vertically ( or almost ) thus getting rid of all the heavy iron carrying control loads from the swashplate to the horizontal primary servos on the UH-60. The 92 main box cannot handle all the sea level power of the 901, but flat rating it for hot/high was in the plan for the 901 for Apache and Hawk anyway, or at last I think it was (?). However this all works out, the AH-64 and UH-60 pilots are going to be smiling.
SD-your point re the FARA/FLRAA speed/range differences to these two machines, not to mention the CH-47 as well, presents a thorny question in senior Army Aviation circles, one might expect.

[SplineDrive]

John, after a raft of S-92 gearboxes cracked at the joint to the airframe, I'm not sure they're easily retrofittable to the H-60 any more once fixes were implemented. In any case, reacting the S-92's head moment on the same bolt pattern as an H-60 hasn't been without problems. I suspect the same would be true for the TGB. Physically pinning up is just one part of compatibility with a new airframe.

[JohnDixson]

SD: Was not aware of that history and your observation seems sound. Appreciate the information. Another aspect of your news is that of course, the usage, that is to say, the maneuver spectrum of the S-70 Army version is different than the usage/maneuver spectrum of the S-92 ( at least I’d certainly assume so ) and this would add to the decisioning re application of the 92 rotor/gearbox to an upgraded Army S-70. I’d not be surprised if those conversations might have already occurred-the interesting part will be about what action results. Good discussion.

[JohnDixson]

60FltMech-re the 60M model main box ratings: I don’t think they have changed from the 3400 shp box in the L, that is, dual engine continuous 100% above 80 KIAS, 120% below 80 KIAS. 100% is 2800 shp/120% is 3400. Sent a note to the M project pilot, who s retired like me and will get back when I can.
Apologize for being tardy with a response.

[retoocs]

60FltMech-re the 60M model main box ratings: I don’t think they have changed from the 3400 shp box in the L, that is, dual engine continuous 100% above 80 KIAS, 120% below 80 KIAS. 100% is 2800 shp/120% is 3400. Sent a note to the M project pilot, who s retired like me and will get back when I can.
Apologize for being tardy with a response.

Do the MH-60M with the CT7-8B5 use the same gearbox as the L's?

[NutLoose]

Now with pop out seating for carrying external troops.

https://twitter.com/Aviation_Intel/status/1707546793691824148

https://twitter.com/Aviation_Intel/status/1707546793691824148


https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/900x506/khw44mi5_928f4d4954db607f1291016019588bd81f574ee1.jpg

[Lonewolf_50]

Do the MH-60M with the CT7-8B5 use the same gearbox as the L's?
From a technical respect, the MH-60M uses the same gearbox as the UH-60M, but to be fair that is mostly the L Model Main Transmission with the Navy Tail Takeoff assembly to allow the Rotor Brake installation. The USAF HH-60G Nighthawks did something similar, and also have the rotor brake.
There is capacity to add an additional take off pinion/assembly (like the Navy did for the MH-60R's dipping sonar pump/motor) onto the Main Module, but I don't know if the MH-60M options include something like that. (This perspective is a few years old, so something new may have come up that I am not aware of).
I translated (in my head) CT7-8B5 as being the descendant of the YT-706, a 2600 hp engine of the T-700 / CT-7 family. My apologies if that's in error.
Rated in the 2,600-shaft-horsepower (shp) class, the CT7-8B5 was certified by the U.S. Federal Aviation Administration (FAA) in 2004. The CT7-8B5 features an advanced, higher-flow compressor designed with new three-dimensional aerodynamic (3D Aero) technology, a modern full authority digital electronic control (FADEC) system, plus hot-section and turbine components proven in millions of flight-hours on GE's family of commercial engines.
It strikes me as improving single engine performance, but I wonder at how they had to re-rig the governors / fuel control to avoid overtorque on the main transmission.
That's a substantial power available increase from the standard T-700 to the 2600 hp engine.

Adding the 901 (when it arrives) ... looks like more of the same. The suggestions above about putting a beefed-up transmission onto any Blackhawk with the new engine seems prudent. (But I wonder if that's affordable, across a fleet of over a thousand H-60M helicopters?)
Many thanks to SplineDrive for the insights on the S-92 transmisions limitations. I had always understood that the backward compatibility idea was intended to pay off downstream (and informed not using a 5 bladed main on the 92) but I guess that hasn't panned out.

Back on the Invictus topic:
As to the pop out seating mod: sure, sign me up to travel strapped-in to the outside of a helicopter doing over 100 knots.
Wait a sec, no, I'll not buy that ticket to ride. :p

[Robbo Jock]

Just sit 'em on the wings, save all that expensive pop-out seating rubbish. :}

[albatross]

John, after a raft of S-92 gearboxes cracked at the joint to the airframe, I'm not sure they're easily retrofittable to the H-60 any more once fixes were implemented. In any case, reacting the S-92's head moment on the same bolt pattern as an H-60 hasn't been without problems. I suspect the same would be true for the TGB. Physically pinning up is just one part of compatibility with a new airframe.


As I recall the problem that caused the “cracked feet” was that the fuselage mounting points were misaligned during manufacture.
The mounting points were repaired in the field and the problem did not reoccur.

[60FltMech]

“I wonder at how they had to re-rig the governors / fuel control to avoid overtorque on the main transmission.
That's a substantial power available increase from the standard T-700 to the 2600 hp engine.“

The UH-60M engine management has protections against over speed and over temp conditions, I haven’t heard anything about MH-60M, they may have something that limits max engine torque, I don’t know how they would ingrate that into the system though.

The current main module if I’m not mistaken can handle up 120% dual engine torque(with 701D engines). It takes off like a rocket at 120% dual engine torque, in case you are wondering. 🤣

I have to assume since I don’t have access to the MH-60M -10, with YT706 engines they would only have a placard on the instrument panel similar to what the UH-60A+ had, which used the “old” Main Module, not the “Improved Durability” (aka UH-60L Main Module), with 701C/D engines that showed max dual engine torque the transmission could handle under certain conditions.

Excess power is therefore always available for conditions where the 701D would TGT or NG limit(therefore causing NR droop) before reaching the transmission torque limit, but it has to be managed to not get in trouble.

Also consider certain MH-60M components that are common to the standard UH-60M such as drivetrain or structural components also have different retirement lives, which could also suggest that the MH-60M has significant operational limitations differences, and transmission torque may be one of them.

FltMech

[Lonewolf_50]

The UH-60M engine management has protections against over speed and over temp conditions, I haven’t heard anything about MH-60M, they may have something that limits max engine torque, I don’t know how they would ingrate that into the system though. I'd be wary about implementing something like that, though, since you want all of the power and torque that you can get out of single engine performance if one of the two quits. I guess the placards are as good of a control measure as any.

For Robbo Jock:
Just sit 'em on the wings, save all that expensive pop-out seating rubbish.
But they'd go through a fortune in air sickness bags, wouldn't they? :}​​​​​​​

[NutLoose]

Question is, will they come with pop out, pop out cupholders?

[60FltMech]

Question is, will they come with pop out, pop out cupholders?


Initially they won’t have cup holders, but a freshly retired Colonel will form a company that produces such an item and it will be installed with a Modification Work Order(MWO) at a future date.

FltMech

[JohnDixson]

Spline Drive and Albatross: Good and very relevant comments. You can imagine that mounting a main box with not only higher head moment capability, but also a 5 degree forward main shaft tilt as opposed to the Hawks 3 degrees, generated some serious redesign effort. I do not recall the specifics of their solutions, but your comments hit the high points. Added to those considerations, don’t forget that the solutions had to meet all of the Army’s now standard crashworthy and ballistic survivability design requirements.