Questions about Agusta A109

[EatMyShorts!]

Hello everyone,

I do have two questions about the Agusta A109 that I could not get an answer from the manuals that we have available. I looked them up on the net, but no luck. Should you have a link to such a manual, please share it. I am involved in a fixed base simulator of the A109 and we would like to gather some details to improve the system behaviour. This is not a toy, but a real discarded A109! I can share more details, if you like to know more about it.


Question 1: when activating ENG A/I, by how many degrees will the TOT rise, approximately?

Question 2: why is there a time-limit of 7 seconds that has to be respected when switching the STATIC INVERTERS to ON after selecting the GENs ON?

We'd be thrilled if we could get some expert answers from current or former A109 pilots and we may come up with some more :p

[Mustapha Cuppa]

Which variant are you talking about?

[EatMyShorts!]

That's a good question, I thought "A109" would be good enough to get the answer(s). The helicopter is pretty old and was taken out of service some years ago.

Will these photos help?
http://www.flugsimulator-karlsruhe.de/img/gallery/6/01.jpg

http://www.flugsimulator-karlsruhe.de/img/gallery/6/04.jpg

http://www.flugsimulator-karlsruhe.de/img/gallery/6/13.jpg

[noooby]

If you have a Serial Number on the data plate, that will help. There are differences between the A, AII and C, and I'm not good enough to know the differences externally!

That is a mighty impressive set up!

[MOSTAFA]

I'm pretty sure it's a A109A Mk2 and I've about 1200 hours on the A model but sadly from 20 years ago the best answer I can give you about the inverter was that prior to starting the first engine (either one, usually the No1 on odd dates and the No2 on even) the inverter switch was put to Main position, it had 3 positions? and the AC INVERTER caption cleared, I don't remember a limit. As for the De-Ice checks with both engines running, you would put the De-ice Eng 1 ON and check the No1 TOT rises and No1 Q falls then turn it off unless +4ish, De-ice Eng 2 ON and check No2 TOT rises and No2 Q falls, then off (same +4 - sorry it's all from memory and many different types have gone subsequently and they all merge into the ether. I don't think there was a 'how much' just that you could see it. It was never more than about 10-20. I might have a manual or the FRCs somewhere but it would be and old book - Hope that helps.

Can I ask are you trying to get the instruments to actually work? I have seen a A109A similar to this at either Cardiff heliport (the old G-USTA) or possibly Shobden but they used several big monitors behind the inst panel holes and it worked superbly.

[EatMyShorts!]

Hi!

Thanks a lot for the replies so far!

I shall try to get more details about the exact model.

The model here has 3 separate inverter switches, does that make sense?

http://flugsimulator-karlsruhe.de/img/gallery/6/09.jpg

You can have a look at a few more photos here: Flugsimulator Karlsruhe von AST (http://flugsimulator-karlsruhe.de/gallery/set6)

It really is a great setup that the owners of the SIM centre have achieved to create and it is getting better by the day, literally. Flying the Agusta is a lot of fun, but hard work. I am NOT a helicopter pilot, but a fixed wing pilot, so these helicopters are stressing me out :bored::eek: Already made a non-crash landing on a fregate off San Francisco :\

We do have checklists for the Agusta and we do all the first flight of day checks, including the inverters, generators, anti-ice etc.. 10 degrees TOT-rise is a very good piece of information! Thanks! Also the bit about "starting ENG1 first on odd days and ENG2 on even days" is a great piece of information. If you ever come by here in Germany, we will surely give you a ride :ok:

And yes, the nearly all instruments work, just a few are still work in progress.

[Ascend Charlie]

The generators had input quill shafts that were a bit weak. After the gen is switched on, it takes a while to get up to its load-bearing speed, and if you bung on electrical load too soon, the quill shafts can shear. Expensive.

Nice-looking sim, by the way! Yours looks like a Widebody variant, which is probably a 109A Mk 2 plus, with the C variant Allisons.

[MOSTAFA]

The A models I flew definitely only had a single 3 position switch marked INV with MAIN OFF SPARE from top to bottom, when in the OFF position the AC system was de-energised and in either of the other 2, the selected inverter supplied power to the 115V and 26V bus bars. Both static inverters were capable of the same loads but normally power was supplied by the main while the other carried the loads in case the MAIN inverter failed. The system was 115/26V-400 Hz mono phase type. I think Charlie is spot on about the quill drives and it is the wide body version which incorporated different doors which I think was initially modified to accom the medevac fit so they may well have changed the electrics a bit to accommodate the AC extra loads. It also gave the corporate ones a slightly bigger cabin.

It's looking good, the veritair/Tiger one I was talking about was (I think) certified as a FNPT Flight and Navigation Procedures Trainer and without actually moving was good for learning procs prior IR.

Good luck.

[EatMyShorts!]

Brilliant! Thanks so much for these answers, they do make sense and we appreciate your time very much! Would these quill shafts break quickly or would it be a question of higher wear&tear, causing the quill shafts to shear off after a few times of engaging them under too much load only? The owner of the SIM might be able to incorporate this into the model.

We might come up with some more questions :cool:

[MOSTAFA]

It's a long time ago but I can't remember in 6 years of operating 4 Aircraft flying @ 1000 hrs (250 ish apiece) a year there ever being an inverter problem. But you have got my mind working overtime. Before you started the 2nd engine, if the battery power (DC) was a bit low we used to advance the power Lever to 70% N1 and switch the respective generator on until the load fell below 115A (1min) we would switch the gen back off and then start the second engine. Once both engines stabilised, N1 60-64? Advance both power levers to 70%N1, then turn on both generators. So you can see that the ALTs were working really hard and the tiny quill drives I guess did take a hammering. What I can tell you was the quill drives were tiny in fact everything was - the compressor section of each engine was the size of a can of baked beans turned on its side and it had quite a few stages (4/5) of compressor but the Allisons were really good, powerful little engines.

I seem to remember if you got an AC INVERTER caption you reset the CBs first (if popped) if that didn't clear it you moved the Alt switch to SPARE if that didn't work you lost loads of stuff including the ASE.

Now I need to lie down.

[John Eacott]

Some dim and distant recollections from the A109AII:

The inverters were an issue inasmuch as if you left them off until after engine start and gens online, it took a while for the AC systems to get up and running so IFR checks couldn't be done until they were
BUT if you had a soft battery, running the inverters before first start could leave the start at risk of going hot.

Delaying turning the gen on after start (optimum one minute) is common across C20 applications, be it SE or multi. The starter gen is just that, both a starter and a generator; so it pays to let the poor thing settle down before switching from one mode to another. Shearing the quill is usually the result, to the chagrin of many a hotshot getting airborne too quickly in a Bell 206!

The engine oil temp would suffer from poor cooling airflow in protracted hovers, even worse in the A109C with the coolers buried into the airframe. They need forward airflow to keep cool.

ISTR that after start, 70%N1 would be selected for idle having checked that ground idle was 61 +/- 2%. We didn't idle for any protracted period at ground idle.

I believe that MOSTAFA is referring to the A109A, which had only two inverters and a significantly different electrical system. The AII was totally redesigned and a third inverter was part of that, as was the hydraulic system.

I'm riding home (leaving tomorrow) and will check my memory against the flight manual in the study when I get there!

edit: I see in your photos that the triple tach is down one engine, and the Nr is set too high?

[Ascend Charlie]

Aren't you also missing the second exhaust for each engine?

[A109_Daniel]

Hi together,

my name is Daniel and I am the owner and also the developer of this A109-Simulator.

Thank you to everybody for all the information and indeed it is A109A Mk2 in a Widebody-configuration.

@John: You are right, the needles are not correctly aligned on the picture.

The triple tach and the radar altimeter are the only two REAL instruments which we modified to make them functional in the simulator.

All the other instruments are also "hardware" gauges which are self made to replicate the original ones. I didn't want to use a monitor to show those instruments.

Thank you so much for all the compliments on the simulator.

Daniel