SW Pacific Event Aircraft Eligibility

[PRB]

Both Aircraft:
Sim: FS9
MP: 31”
RPM: 2000
ALT: 5000 FT
MIX: RICH

JBK
WT: 65,500 LBS
KIAS: 165

FSDB
WT: 61,400 LBS
KIAS: 220

The chart is from T.O. 1C-54D-1, which is the C-54 pilot manual.

On the chart, Blue = FSBD, and Red = JBK. The Xs are speeds from the sim, and the lines are what the chart says the speed should be for the conditions specified.

The chart shows what the speed should be at the specified weight, power settings, altitude, and mixture setting. According to the chart, the JBK ought to have been going 178 knots. In the sim, the plane went 165 knots (13 knots slow.) The FSDB plane should have been making 182 knots by the chart, but in fact was making 220 (38 knots fast.)

So, based on this, it would seem the FSDB model is a bit “hot” and the JBK one is authorized for the event. The JBK model is newer and has a VC too.

All the above assumes I was reading the charts correctly...

[salt_air]

Appreciate this effort Paul! ...


BTW: I've put my P-38 away ... just leave anything else in the can.

Besides it's a bunch easier to open a box-o-donuts.

[srgalahad]

Thanks Paul.
The above shows several things:
1. Even well-respected models with a good reputation are not necessarily accurate to the real-world data. This can be attributed to the FDE skills of the modeler, the amount of research and the availability of info as comprehensive as the C-54 manual. In the past there have likely been cases of "who really cares, it's close enough?" as well, but we'd like to assume good intentions.

2. As can be seen, speed is dependent on a number of criteria and unless the tests are done with the SAME parameters, significant disparity can result.

3. Reporting needs to use the same precision.. the chart shows CAS (Calibrated Air Speed) which Paul used, and which can be read using AFSD or FSDat but it's, in this case, about 1.5 Kts lower than the IAS shown by the ASI and reported using Shift+z. Additionally, the chart shows TAS which you can see produces a higher number so it's essential to know which is used for comparison. (in my test of the C-54 = 166.2 IAS/ 165.1 KCAS and 177.7 KTAS)

Who cares? I bet the pilot or team that loses because someone slips in a "hot" plane cares. In this event, where navigation and route selection come into play the impact may be less but...
This type of testing takes time and often a LOT of research which is why last minute requests for 'new' a/c are often met with less-than-enthusiastic response by race committees.

Rob

[PRB]

I would imagine it would be a huge undertaking to build a flight model that would match these types of charts perfectly, if it's even possible. I wonder how close the A2A guys got with the much acclaimed Accusim B-377, for example... In the case of this C-54, there is a chart like this for sea level, 5000. 10,000, 15,000, and 20,000 feet. Each chart has a huge range of configurations between weight and power settings.

One other interesting item in this manual under "airspeed limitations". There are two of them, one for level flight (217 knots) and one for diving (290 knots). I don't understand how you can have two "do not exceed" speeds. The max speed in the reference section of the JBK C-54 is the 217 knots figure.

[salt_air]

I would imagine it would be a huge undertaking to build a flight model that would match these types of charts perfectly, if it's even possible. I wonder how close the A2A guys got with the much acclaimed Accusim B-377, for example... In the case of this C-54, there is a chart like this for sea level, 5000. 10,000, 15,000, and 20,000 feet. Each chart has a huge range of configurations between weight and power settings.

One other interesting item in this manual under "airspeed limitations". There are two of them, one for level flight (217 knots) and one for diving (290 knots). I don't understand how you can have two "do not exceed" speeds. The max speed in the reference section of the JBK C-54 is the 217 knots figure.

Good question Paul ... all I can tell you and the rest is you're in trouble in the JBK C-54B after 218 kts no matter what the pitch.

I'm trying to work in an audible overspeed alarm [sort of like a Fire Bell] for those times when yo're "visiting" the back of the plane .... beans and K-rations ... shoulda stayed in school I tell ya.

Bet I could win the funniest video prize with one of me doing the bunny hop ... bound at the ankles by britches with the overspeed alarm going off loudly in the back ground.

Maybe a remote F1 key would be time better spent?

[Willy]

When Flight 19 was flying the JBK DC-4 around the western US online, we were using Gunter's Real Engine gauge which I've left installed. I think that kept us out of overspeed troubles from fear of blowing the engines. From personal experience trying to take off and land overloaded with ore on a gold mine's gravel strip in the Canadian Rockies with 3 blown engines, it's quite the handfull when Real Engine kicks in and the engines begin to pour smoke out of them.

[salt_air]

When Flight 19 was flying the JBK DC-4 around the western US online, we were using Gunter's Real Engine gauge which I've left installed. I think that kept us out of overspeed troubles from fear of blowing the engines. From personal experience trying to take off and land overloaded with ore on a gold mine's gravel strip in the Canadian Rockies with 3 blown engines, it's quite the handfull when Real Engine kicks in and the engines begin to pour smoke out of them.

Thanks Willy, that sounds like even more fun ... I had almost forgotten there's a new C-46 model (gac46v2) out that I looked at ... must have had that gauge or something like it.

After a flat out top speed run, I grabbed a pencil to write down some numbers and heard a loud pop from the simulator ... (there was almost a loud smell too!) ... and when I looked around to figure where it came from I realized the port side engine had blown.

We should get John to put a check for that gauge in the next Duenna update ...

Think I'll try that out for the next couple of days ... see how it works ... or not.

Now ... where's that gauge?

Attachment 35827

[Willy]

I think it's here under Teson. The fly in the ointment is that it has to be set up for each aircraft. We played the dickens getting a hold of a C-54 manual to set it up for that one. Moses did the actual setup. I've got most of the parameters for a few other aircraft, but am lacking just enough to keep me from installing the gauge into the D18, DC-3 and DC-4M. I haven't started looking for C-46 parameters yet. Hopefully, I can find a flight manual for it.

The update to the C-46 is great. We've got another event for this year in the works that I intend to fly it in. Hopefully I'll have Real Engine installed in it in time.

If you need the C-54 parameters that Moses set ours to, I can post them here or PM them to you.

[salt_air]

Yeah Willy ... that would be great!

Maybe post'um here in case somebody else might get curious or want them too.

Good of ya!

[Willy]

Here's the RE parameters for the C-54/DC-4

Nominal Engine Power 1450HP
MP/RPM Limitations MP RPM
Max Continuous Lean 33.0 2112
Max Continuous Rich 40.5 2550
Max Climb 20 min 38.5 2300
Max Take Off 5 min 50.0 2700

Gear Overspeed Vle Vlo
Extended/Operation Sp? 130 130
Flaps Overspeed Vfe Vfo
1st stage 176 176
Full Flaps 127 127
CHT Limits 28F 500F
Oil Temp Limits 28F 212F

[teson1]

Hi Willy,
good to hear that you're using RE

Austin,
make sure to use RE version 1.2.
It's only available at SOH
http://www.sim-outhouse.com/sohforum...l=1#post454217
Message 14
That version has a single xml file ("RE1_Parameters_v12.xml") in which all important parameters can be set for a plane, which should make it easier to adapt RE to a plane.

Gunter

[Willy]

Trying to find a free copy of a C-46 flight manual at the moment to set up RE for it.

[Moses03]

Try this one Willy. I think it's a free registration to download.

http://avialogs.com/index.php/BookLi...afts/C/Curtiss

(Have not checked it yet myself).


Here is another one. If you have a Facebook account (I don't) it's free.

http://www.scribd.com/doc/11327612/C46-Manual

[Willy]

Moses, I was looking at the second one last night, but dealing with that website locked my computor up twice so I'm not going there again. Not to mention that it wanted access to my whole facebook account.

I'll check out the first one.

Got it! It's the Pilot Flight Training Manual which should have all the data needed.