[Altomar718]

I am really struggling to find out what the Static RPM should be for the Eurostar EV-97 with a 3 blade composite prop.
I have looked in the Operating and Maintenance manuals and there is nothing as I think originally, they were supplied with a 2 blade wooden prop so only this is mention in the publications.

I emailed BMAA who suggested I phone Light Sports Aviation (dealers) who told me to download the manual for the SL Eurostar. I did that, and it does say, for the ROTAX 912UL and a 3 blade composite prop, it should be 4,600 rpm.

As this is not the actual model of aeroplane, but the same engine and prop, would you think it is the same Static RPM please.

I have spent ages trying to find this information, so any help would certainly be appreciated - Thanks in advance

Chris

[patowalker]

If it is an SL, 4600 rpm for the Kiev and Woodcomp composite props.
https://www.bmaa.org/files/tads_bm82_ev ... tar_sl.pdf

If it is a 'classic' Team Eurostar. The pitch on a Kiev prop must be 28 degrees, which will poduce the correct static RPM, i.e. 4600.
https://www.bmaa.org/files/tads_bm67_ev97_eurostar.pdf

Why the BMAA did not refer you to their own documentation is a mystery. LSA has not been the Eurostar dealer for some time now. .

[Altomar718]

Hi Bypatwalker - It is the 'classic' EV-97 and that is exactly the answer I was looking for, so thank you so much for taking the time to answer and give me the information - Cheers mate - appreciate it very much

[TheFarmer]

I find it amazing that a static of 4600 is recommended, when the engine gives max hp at around 5600 rpm.

The max permissible rpm is 5800.
Max for 5 mins is 5600.

I have always gone for 5300 rpm static on a 912 and 912 S, and this unloads on the roll to around 5400. This setting also means that WOT is pretty much bang on the 5800 max, so you’re getting the most from the engine.

A static of 4600 is seriously coarse, and will hamper take off performance. Yes, it might give a better cruise, but the Eurostar is hardly the slipperiest airframe, and I’d be amazed if any more than 5300 is achievable at WOT with such a coarse set-up, therefore a complete waste of top end HP, as well as putting some serious strain on the reduction gear.

The 912 is often pampered and people seem afraid to run it hard.

Just my thoughts.

[patowalker]

Glad to help. When you've built and fly a Eurostar, it is difficult not to answer questions about them.

[patowalker]

Farmer,

You are quite right, but rules are rules.

The static rpm was set at 4600, so that the aircraft complied with the UK two seat microlight regulations at the time, which required the maximum empty weight to be 450kg, less 2 x 86kg occupants and one hour of fuel at MCP. A finer pitch would produce higher fuel consumption, hence more load, requiring a lower empty weight. Choices had to made.

I have a a 480kg LAA Eurostar SL with a two blade Woodcomp prop. It is not a microlight and the static rpm is set at 5200.

[Altomar718]

The Farmer ...... I asked the question becasue I heard if it is set incorrectly, it can cause wear in the gearbox and with Rotax, that is bound to be expensive !! - As patowalker said above, it does state 4,600 rpm in the 'book' and an angle of 28 degrees on the prop and I should think Evektor and Rotax have given these figures for a reason.

[TheFarmer]

No worries.

As you say, you need to go by the book, but it just seems madness to only be using about 70% of your available horsepower on take off, and to also put strain on the gearbox.

If that’s all for M/light weight restriction purposes, then the tail is wagging the dog, and it’s a silly requirement IMO. Especially when an identical Group A version can have a set up to perform much better.

[patowalker]

I am surprised that microlight factory built Eurostar owners and/or the Eurostar dealer have not asked the BMAA to review the prop pitch limitation in view of this.

[Altomar718]

I emailed the BMAA tech office and asked the same question as above and they told me to contact the UK dealers !! Light Sport Aviation told me to read the manual for the Eurostar SL (latest version) - all the dimensions, weights etc. are different, but now you have told me the information (above) as it happens, they are correct - 28 degrees at 350mm radius

[patowalker]

I don't understand how the BMA can tell you to contact Light Sport Aviation, when V1 Flight has been the Evektor dealer for quite a while.
https://www.v1flight.com/aircraft-sales/eurostar-sl-sl/

[bvq]

I'd be interested to know the rationale behind the 4800 static RPM on an EV97A Classic (912UL) with a Woodcomp Klassic 3 bladed prop registered with the LAA. I have to say that there is no lack of take-off performance and it cruises at 90mph at 4800rpm. That said, I agree with the comments above, it is certainly not using the full power of the engine.

[patowalker]

The mandatory pitch setting is designed to work out the maximum empty weight. At 4800 rpm the 912 UL in a Eurostar EV97 burns 14 litres per hour, i.e. 10kgs of fuel, while the 912 ULS burns 13 kgs. Presumably, no effort was made to get a different approval for the 97A and SL.

2.10 Maximum permitted empty weight
Model Engine Max empty weight
EV-97 Rotax 912-UL 268 kg
EV-97A/SL Rotax 912-UL 298 kg
EV-97 Rotax 912-ULS 265 kg
EV-97A Rotax 912-ULS 295 kg-

I applied for approval of my Woodcomp 2 blade and this was granted with static rpm at 5200.