AIRBUS RACER / Clean Sky2 LifeRCraft Demonstrator

[H_K]

Another Racer update from Farnborough... just hit 227 knots with room to spare!

Racer sprints to target speed within just seven flights

Just seven flights and 9h into its test campaign, Airbus Helicopters Racer technology demonstrator has already beaten its 220kt (407km/h) target speed and opened up 80% of its flight envelope since its 24 April maiden sortie.

www.flightglobal.com

Racer sprints to target speed within just seven flights​

Just seven flights and 9h into its test campaign, Airbus Helicopters' Racer technology demonstrator has already beaten its 220kt (407km/h) target cruise speed and opened up 80% of its flight envelope since its 24 April maiden sortie.

(...) The Racer beat its target speed during a test flight on 21 June, hitting 227kt in level flight, says its test pilot Herve Jammayrac. That milestone was also achieved without fairings installed on its landing gear or a highly aerodynamic main rotor cowling, as such “we believe we have additional margin for faster flight,” he adds. (...) The Racer has also been tested on more dynamic maneuvers, for example flying at a bank angle of 45° at speeds above 200kt.

Test flights are paused for the summer and to allow routine maintenance but will resume in September as the company targets opening up the remainder of the flight envelope. A next step for the programme will be to test the ‘ecomode’ function on its twin Safran Helicopter Engines Aneto-1X powerplants. This will allow one of the engines to be shut down in cruise and then rapidly restarted – within 10s if needed – improving the efficiency of the remaining powerplant, cutting fuel burn.

 

[yasotay]

Great news for Airbus. Surprisingly aggressive schedule.

 

[MihoshiK]

Living up to it's name there. Dang.

 

[TomcatViP]

From Airbus:

The flight test crew consisted of Hervé Jammayrac, Chief Flight Test Pilot, Dominique Fournier, Flight Test Engineer, and Christophe Skorlic, Test Flight Engineer. The next phase of flight testing will focus on single engine operations and finalise the flight envelope.

Airbus Racer speeds past 400 km/h

Racer, Airbus' high-speed helicopter demonstrator, has reached its fast cruise speed target of 407 km/h (220 kts).

www.airbus.com

 

[Grey Havoc]

Airbus Racer demonstrator surpasses speed milestone of 420 km/h

London, UK (SPX) Jul 24, 2024 - Airbus's Racer high-speed helicopter demonstrator, part of the European Research Clean Sky 2 project, has successfully achieved its fast cruise speed target of 407 km/h (220 kts). On June 21, less t

www.spacedaily.com

Or just a shade under 261 miles per hour.

 

[TomcatViP]

So what are the news now?

 

[yasotay]

Probably figuring out how to deal with vibratory loads at high speed. Even with a dual speed transmission, all of the whirly bits, likely induce some undesired vibration frequency issues.

So guesses a crayon level aero engineer.

 

[Scott Kenny]

Probably figuring out how to deal with vibratory loads at high speed. Even with a dual speed transmission, all of the whirly bits, likely induce some undesired vibration frequency issues.

So guesses a crayon level aero engineer.

Active vibration controls, like the EH101.

 

[H_K]

The Racer teams were on vacation in August and there was also a scheduled maintenance period to install the remaining drag reduction features (low drag rotor hub fairing, aka project LATTE and landing gear doors aka project ANGELA) with flight testing projected to resume in September.

LATTE low drag rotor hub: https://www.clean-aviation.eu/media/news/smooth-latte-streamlines-racers-airflow

ANGELA landing gear doors: https://www.researchgate.net/public...osite_Door_for_High_Speed_Compound_Rotorcraft

Vibration should not be a problem since the main rotor is unloaded at speed. In fact the X3 had no vibration control equipment whatsoever (neither active controls or passive dampeners) yet all the pilots who flew it reported a very smooth ride. Same should go with Racer.

 

[H_K]

P.S. Racer should be able to fly almost 50 knots faster (vs. 227 knots achieved in June on the 7th test flight) according to what Airbus said at Farnborough… so 270-275 knots?

That would make it much faster than previously stated… potentially fast enough to compete directly with a tilt rotor.

 

[Scott Kenny]

The Racer teams were on vacation in August and there was also a scheduled maintenance period to install the remaining drag reduction features (low drag rotor hub fairing, aka project LATTE and landing gear doors aka project ANGELA) with fight testing projected to resume in September.

LATTE low drag rotor hub: https://www.clean-aviation.eu/media/news/smooth-latte-streamlines-racers-airflow

That's an odd looking fairing...

 

[yasotay]

While I have no doubt that Racer will make mid-200 knots, will it be as efficient as a turboprop airplane? With the same range?

 

[aim9xray]

While I have no doubt that Racer will make mid-200 knots, will it be as efficient as a turboprop airplane? With the same range?

Category error.
Flip the question: does that [reference] turboprop aircraft have VTOL capability?

 

[yasotay]

The ones I am referring to, do have VTOL capability.

 

[TomcatViP]

Whatever you think of the end-result for that rotor fairing, paying half a million euros for that is flabbergasting. What happens if the rotor config is slightly altered, you break the bank again?

 

[H_K]

The ones I am referring to, do have VTOL capability

I’m confused as to what you’re referring to… can you clarify? Unless by « turboprop airplane » you meant tilt rotor??

 

[yasotay]

Indeed, tilt rotor. A turboprop airplane that can take off, fly, and land like a helicopter.

 

[MihoshiK]

Whatever you think of the end-result for that rotor fairing, paying half a million euros for that is flabbergasting. What happens if the rotor config is slightly altered, you break the bank again?

A six year engineering program developing a completely new rotor hub fairing, with all the attendant aerodynamic and structural testing involved for less than half a million bucks.

Doesn't sound like that much money to me, especially now they know what not to do. But it's Airbus, so obviously it's a waste of money, amirite?

 

[yasotay]

Also, drag is exponential. Open rotor hub at.~250 knots is likely to be a significant part of the drag on the platform.

 

[TomcatViP]

They haven´t flown with the fairing yet!

Yes, 0,5M$ is a high price to pay for such study in that part of Europe for, basically, a CAD-CFD study with a bit of shop hours.

 

[Scott Kenny]

My point was that there were still parts of the rotor hub outside the fairing. Whatever that link between blades is should be inside the fairing, not exposed outside!

 

[WatcherZero]

The blades still have to be able to pivot up and down, if you partially enclosed that you would be creating small gaps that high speed air was being forced into by centrifugal rotation. The dampeners are exposed as they will be moving and are inside the stable air pocket.

 

[VTOLicious]

That's an odd looking fairing...

full articulated - low vibration

 

[H_K]

There was a public lecture this week by the Racer chief engineer which will hopefully be posted soon to the RAES Youtube channel: https://www.youtube.com/@Aerosociety

Some interesting tidbits:

- 240 knot speed objective for the next flight tests (with drag reduction features incl. faired rotor hub)
- No vibration issues - the Racer has been rock steady so far at 220+ knots
- Less parasitic drag than a 3-ton helicopter (!)
- ~7.3 ton takeoff weight (my estimate) according to the 1st graph which shows parasitic drag relative to other Airbus types

- Cabin sized for 8-9 passengers... "between an H145 and a Dauphin". Which is not much for a 7.3t aircraft... that means the cabin is a little smaller than the ~5 ton AW169, despite a 50% increase in take-off weight! The cabin also will be much smaller relative to a helicopter with a similar TO weight like the AW139 (6.8-7t, 12-15 passengers)... high speed obviously comes at a cost (no surprise)

- Fuel consumption per kilometer: -25% at 220 knots and -37% at 180 knots
But this is compared to a helicopter of the same weight flying at best range speed (typically ~130 knots). For an honest comparison we might want to compare to a helo weighing 1/3 less (like the AW169), and therefore using ~1/3 less fuel... so in real life it seems like the Racer should burn about as much fuel as an AW169, both at economical speed (180 vs. 140 knots) and at high speed cruise speed (220 vs. 150 knots). While fuel consumption won't improve (which is what was being sold for CleanSky funding), obviously there will be a huge speed gain.

 

[WatcherZero]

The Racer has 10 passenger seats at the moment. That is indeed between the AW169's 8-12 and the Dauphins 11-12. The AW169 in particular the capacity varies between 12 seat or 8 with 250kg of extra storage.

You said it has less drag than a 3 ton helicopter then compare its drag to being the same as a 5 ton helicopter based on 7.3 ton MTOW minus 1/3rd.

 

[H_K]

The Racer has 10 passenger seats at the moment. That is indeed between the AW169's 8-12 and the Dauphins 11-12. The AW169 in particular the capacity varies between 12 seat or 8 with 250kg of extra storage.

You said it has less drag than a 3 ton helicopter then compare its drag to being the same as a 5 ton helicopter based on 7.3 ton MTOW minus 1/3rd.

What’s your source for Racer’s 10 passenger seats? With the narrow fuselage likely limiting it to 3 abreast seating (instead of 4 abreast in most medium helos), the 9 seats quoted by the chief engineer makes sense (ie. 3x 3 rows). I don’t see 10 passengers as likely unless single pilot operations are allowed, freeing up the copilot’s seat.

To clarify my point, there were 2 comparisons made in the lecture. One was about parasitic drag being less than a 3 ton helo (1st graph).

The other, more interesting comparison (2nd graph) was not related to drag but to kilometric fuel consumption, which the graph showed to be ~25% lower @ 220 knots and ~37% lower @ 180 knots. Both relative to a typical helo of same T-O weight flying at best range speed.

Now my estimate is that a 7.3t helo could be expected to burn ~ 3.2 kg/nm at 130-140 knots (using a pretty typical fuel efficiency factor of 0.44kg/nm/ton, ISA 5,000 ft). Reducing that by 25%-37% for the Racer, I get:

Racer (7.3t estimate)
~ 2.0 kg/nm @ 180 knots
~ 2.4 kg/nm @ 220 knots

Both of which would compare favorably to the AW169:

AW169 (5t, 5,000 ft, ISA)
~ 2.2 kg/nm @ 130 knots
~ 2.28 kg/nm @ 150 knots

 

[yasotay]

@H_K - some nice analysis there. Of course, we need to be careful not to overly prescribe operational capabilities with that of a technology demonstrator. I do think that the significant improvements in efficiency, even if not at the highest speeds, would be the primary selling point for a compound rotorcraft like the RACER. If you can accomplish task(s) with a 1/3 saving on fuel, that is a significant cost burden avoidance. Even the 1/4 reduction is significant. I think the greatest challenge will be how well the aerodynamics size up to a platform that could meet the expectations of larger transit requirements (military and offshore oil).

I do however expect that a military version of the platform will naturally see a reduction in the efficiencies of the demonstrator as sensors and antenna get attached to the exterior of the aircraft. Drag is exponential (?). This is not something that most rotorcraft users have concerned themselves with up to this point.

 

[WatcherZero]

What’s your source for Racer’s 10 passenger seats? With the narrow fuselage likely limiting it to 3 abreast seating (instead of 4 abreast in most medium helos), the 9 seats quoted by the chief engineer makes sense (ie. 3x 3 rows). I don’t see 10 passengers as likely unless single pilot operations are allowed, freeing up the copilot’s seat.

Dont have to hand but some articles state its got 10. The cabin for the Racer is based on the EC145/H145 and offers 8 executive seats plus one next to the pilot but can also be configured for 10 seats.

H145 technical information

As the quietest helicopter in its class, the twin-engine H145 offers exceptional performance along with upgraded main and tail rotor systems.

www.airbus.com

 

[TomcatViP]

From earlier in this thread:

 

[H_K]

I do however expect that a military version of the platform will naturally see a reduction in the efficiencies of the demonstrator as sensors and antenna get attached to the exterior of the aircraft. Drag is exponential (?). This is not something that most rotorcraft users have concerned themselves with up to this point.

Interestingly, he specifically addressed this challenge and mentioned that Airbus have already done drag studies on the impact of external stores, and that it’s not a concern… to be continued.

 

[H_K]

Good write up from Aviation Week…

Airbus Eyes Higher Cruise Speeds For Compound Rotorcraft Demo | Aviation Week Network

The Racer is currently in maintenance after its first 8 hr. of flight testing, during which it achieved speeds of 227 kt. in June after just seven flights.

aviationweek.com

This quote pops out: Racer has « been built to specifications that would meet certification standards for a serial production aircraft »… this aligns with my impression that it is much closer to a production ready prototype than a mere technology demonstrator.

 

[TomcatViP]

So will Racer remain slower than SB-1 ?

Racer: 220kt
SB-1: 247kt

 

[Scott Kenny]

So will Racer remain slower than SB-1 ?

Racer: 220kt
SB-1: 247kt

I think Racer might be able to beat the SB1.

 

[H_K]

Racer's target speed for the 2nd round of testing, once drag reduction features are installed, is 240 knots.

These targets will be beat (they always are, e.g. Racer hit 227kts vs 220kt preliminary target, X3 hit 255kts vs 240kt target etc), so 247 knots or thereabouts sounds about right. Further optimizations should be possible in future rounds of testing to go even faster.

Anyway the comparison is meaningless... can't compare a 7-7.5 ton vs. 14.5 ton helicopter, ~5,000hp vs 8,000+hp engine power.

 

[TomcatViP]

Anyway the comparison is meaningless... can't compare a 7-7.5 ton vs. 14.5 ton helicopter, ~5,000hp vs 8,000+hp engine power.

Why? Don´t we do that all the time with planes? F-104 Vs F-4. Mirage Vs F-15, Ye-166 Vs YF-12?
It also didn´t refrain the hype around Racer do better than a 2000shp like an AW169...

 

[yasotay]

Good write up from Aviation Week…

This quote pops out: Racer has « been built to specifications that would meet certification standards for a serial production aircraft »… this aligns with my impression that it is much closer to a production ready prototype than a mere technology demonstrator.

Only because I put aviation program managers and business development types in the same category as used car and insurance salesmen, I have to ask; Are we sure that the statement « [RACER has] been built to specifications that would meet certification standards for a serial production aircraft » is explicitly speaking to a military rotorcraft?

Regardless the capability will provide a significant improvement over conventional helicopter. If the price point can be kept relatively consistent with current platforms it will certainly be considered by a number of nations.