Propeller Reverser

[Simtech209]

I'm running FSX-A boxed stable for several years. With the likes of MJ's L1049, C-97 and a DC-6, the reverse prop thrust work as advertised. No issues.
I'm trying to "install" a reverse thrust in an aircraft that didn't come with it, (but in RL it did). I chose to go the Martin bar route and installed the two
gauges (Martin bar and the indicator). The gauges appear to activate as the Prop RPMs decrease, as the props seem to feather but instead of the airplane decreasing speed, it accelerates. I can't confirm that the prop is going into negative pitch.

I've copied entire panels into this trial airplane and same results. I also copied the "propeller section: from the DC-6 and the L1049, and no change.

I even opened up the .air file to confirm the aircraft.config data and they match, or very close. I would just like to have the ability to slow
this beast down with prop reverse. The last few times I tried it, when the propellers went into reverse, the engines died... not sure why that is. Any ideas as to where my problem lies?
Thank you for any ideas.......Terry

The Prop section is included...

[propeller]
thrust_scalar=1.9
propeller_type=0
propeller_diameter=19.000000
propeller_blades=3
propeller_moi=160.000000
beta_max=60.000000
beta_min=15.000000
min_gov_rpm=700.000000
prop_tc=0.004000
gear_reduction_ratio=2.666000
//fixed_pitch_beta= 20.000
low_speed_theory_limit=80.000000
prop_sync_available=0
prop_deice_available=0
prop_feathering_available= 1
prop_auto_feathering_available=1
min_rpm_for_feather= 1100.000 //0.0
beta_feather=80.000 // per Beech Baron
power_absorbed_cf= 0.1000
defeathering_accumulators_available= 1
minimum_on_ground_beta= 22.00 // -14.00 test
prop_reverse_available=4.0 //0.000
minimum_reverse_beta= -12.00 //per DC-6..negative??
feathering_switches=0
fixed_pitch_beta=18.000000

 

[Deleted member 1281]

So which aircraft are you tweaking?

The instructions I was following for the C-97 and the B-50 were as follows (author unknown, sorry):

Step 1
Find an aircraft that needs reverse pitch props and go to its aircraft.cfg file. This should work for all constant speed prop aircraft. Go to the prop section and find this:
prop_reverse_available = 1
minimum_on_ground_beta = 1
minimum_reverse_beta = -14
If the section is already like this, leave it, if not change to the above values or add them.

Step 2
Next go to beta_max =
Now take the value there and subtract 1 and make it a negative # and put it in the beta_feather = Area. (If there is no feather value they will need to be added)

Step 3
You must make sure that the power_absorbed_cf = has a value of 0.1 if not props will go out of control. Also make sure that the min_rpm_for_feather = is 0

Step 4 test!
Use the steps below to test while aircraft is at a standstill. If it moves backwards you did it! (Note: make aircraft is not overloaded before testing.
Use in the sim To make the props reverse do these following steps:
1. Once on ground hit Ctrl + F1. (Or move prop pitch lever all the way back
2. Then hold Ctrl + F2 You will see on the rpm gauge that the rpm drops below its usual minimum. As soon as you see that, then advance the throttle.
3. To return props to normal hit Ctrl + F4. (Or move prop pitch lever all the way forward
4. That’s it!

As you can see, your prop section deviates from this in several possibly crucial respects (compare the prop section from the B-50/C-97 if necessary). Also, the testing is probably better handled via a gauge and/or levers (there is a previous thread on this here at FSDevelopers).

Cheers, Manfred

 

[Simtech209]

Manfred, thank you for your prompt reply and detailed explanation. After I expanded your post and performed said instructions...WOW... works great. The first time I didn't expand and didn't see the beta_feather comment. So it didn't work. After expanding it and annotating the Beta_feather values....works great...... Thank you.... You are spot on about using a gauge to activate. Using Ctrl-F2 is iffy. I found a spot on the panel to install a Martin bar from a DC-6 and an indicator lamp. Works consistently. BTW the aircraft is Gary Shetter's B-36A. I just love BIG, ROUND engines and this airplane is the epitome of b i g. Thank you again for pulling me out of the swamp. I'd spent two weeks and was getting no where fast. I fly your C-97 and DC-3 religiously. Both masterpieces... Thank you, sir for your many, many contributions... Blue skies..fair winds...terry

 

[Deleted member 1281]

Well done! That B-36 is a most impressive beast and I'm sure she needs all the reverse she can get! I actually managed to get that type of reverse also going for cars like Follow-Me's and crewbuses, so they can reverse out of and into parking spots.

 

[Simtech209]

That sounds like a novel approach...Super...again, I appreciate the guidance and this beast is very tame now..thanks to you...