Helicopter FlightSims

[ptwaugh]

Sure, great idea.

Well, here is where it all began.... the early rotors baldes... before the addition of 5 degrees geometric twist, and 2.25 degrees of pre-coning. Still haven't figured out where to align the cord angle at zero collective, neutral cyclic.



And here is an early panel design which includes working annunciators and failures. It is being redesigned nearly from scratch, thanks to a nice trojan.



And finally, the state of the model itself. This is only one of several variations that will eventually be offered, including low and high skids (maybe floats), WSPSs, etc.



It will part of a package for FS that will contain adventures Fams, complete FMs and procedures.

Ah, just as I thought, if the pitch horns lead by 90 degs, then delta must be zero.

Anybody know how I should line up the rotor cord?

Thanks,

Patrick

[BlenderPilot]

Rotor Chord position is variable, we get helicopters in from all parts of the country for service and the auto RPM's are adjusted for the elevation at which the aircraft is to be routinely flown.

For example during maintenance I ask the mechanics to adjust full down collective pitch angle to maintain proper RPM here in Mexico City which is at 7500FT, and then the customer takes the helicopter the helicopter to sea level, an tests his auto RPM, the helicopter is going to have trouble maintaining proper auto RPM's with anything but full down collective, and if he tries it when he's at low weight he might not even get above 90% NR, so he's going to have to adjust his full down collective pitch even lower.

So you see its a variable thing depending on different factors, but looking at it from the ground it looks like 2or3 degrees negative at the tips when collective is full down.

Thanks for posting your models, that looks pretty impressive!

[ptwaugh]

Wow, hadn't even considered that, but it makes total sense aerodynamically. Funny that you say 2-3 degrees, as I choose +2 at the root, and -3 at the tip, haha. I guess well I guess.

And thanks for the encouraging comments!

I'll post some more pics as I get the thing closer to completion. Pprune members have been a big help.

Thanks,

Patrick

[ptwaugh]

Normal/Recover Switch

Hey guys,

From the FAM1 flight gouge:

12. Normal/Recover Switch. The normal/recover switch in the TH-57C should be in the "recover" position between official sunset and sunrise.

Anyone tell me what this does?

Thanks, Patrick

[[email protected]]

Yes, I've got one of these...in my owners manual it says I have to be put in the recovery position between sunset and sunrise...is it the same thing d'ya think?

[ptwaugh]

Hmmm.... if you have one, then my question was what is it for?

Also, looking to determine what the abreviation DECCA on a fuse is refering too.

thanks for the help.

Stick

[Camp Freddie]

in the context I know it DECCA was a navigation system which operated on the principle of hyperbolics (hyperbollocks even) which was used in the north sea, uk area, the last DECCA chains went offline there on 1/4/2000.

dont know where else it was used, or have I completely missd the point (I dont know)

[ptwaugh]

That makes sense, as the pic I have was from an aussie machine and suggests it is still used down under.

Thanks, Patrick

[heedm]

Just a wild guess, but since a generator fail results in loss of power to the fuel pump when in NORMAL, I'm guessing that RECOVER connects the fuel pump to an essential bus or battery bus (not sure of the electric system). This makes a bit of sense wrt the use of the Normal/Recover switch since this means an engine failure at night will require fewer switches to recover the engine.

Again, just a guess. I've never flown the TH-57C.

[ptwaugh]

Thanks. As you know, the TH-57 is a military B206, so if you know one, you'll probably be on course with the other.

Stick

[Ascend Charlie]

Decca down under?? No, that is a North Atlantic thing.

In Oz, it used to be a record label, but that's about it. We had VLF Omega for a while, but even that is gone with the arrival of GPS.

Try asking this question on a military forum?

[ptwaugh]

Good idea... and I would, if I knew of one. =)

But, I know who I can ask that is military.

Thanks all,

Stick

[NickLappos]

ptwaugh,

I did some net cruising and found the explanation. That switch is the essential bus control switch, albeit poorly labeled. The TH-57 only has a generator and a battery, so electric power is minimal, and the battery will only last a short while after generator failure. The system dumps most loads automatically if the gen fails, including the fuel boost pumps and some lighting (I think). For safety, the pilot selects the "recover" position while flying in darkness to override the load sheding. See:


http://www.bryanweatherup.com/gouge/...CPT/cpt3.shtml

[ptwaugh]

You're awesome. Funny thing is that was the guy I was going to email! I had seen the gouge site months ago, but must have missed that.

Thanks for all your help.

Patrick

[John Bicker]

Similar arrangement on the 205A/A-1 as it was derived from the UH-1H etc. UH-1 (I Think) has two generators which supply two busses. One is the Starter Generator and one is driven by the Main GB generator. On the 205 you have a Non Essential and Essential Bus. When the engine sops the Non Essential is shed. There was a selector switch for Non Essential AUTO or MANUAL. Where we used to operate it was kept in MANUAL as the HF wireless is on the Non Essential bus and most of the time was the only way to squeal for help.

Apologies for the spelling etc. Airline Lounge and crappy busted A Billy Box!

[ptwaugh]

Preconing measurement question

When a semi-rigid rotor is said to have 2.25 degrees of preconing, does this mean each blade above the level? Or does this mean total between the two blades?

Thanks

[Dave_Jackson]

Each blade.

Like the pre-cone angle, the coning angle and the flapping angle are for each blade also.

The top of the page shows the pre-cone angle of some small helicopters, if you are interested.

[SEL]

Hi

Like Dave said, it is for each blade. Imagine a horizontal line, through the rotor hub, through it's centre. The pre-cone angle is measured from this plane. In most types it is a few degrees above it, like the examples on Dave's page.

[ptwaugh]

B206 Model Update

Hi all.

Many of you have helped me in the past on this project, and while I've been gone for awhile, I'm back, and as I near completion I wanted to share a picture of the Flight Sim 2004 helicopter I am completing.



In the coming weeks as I finish the interior and begin modeling the aircraft systems in earnest I may have a question or two for you.

[misunderstood]

Is this just a repaint or a whole new design with reworked flight model, etc?