SOH P-61 project

**fliger747** · August 17th, 2010, 11:01

Driving it around in the new Solomons Scenery, quite nice. However still working on the ground handling. The coral and PSP surfaces are particularly challenging due to their simulated lack of friction. None of the WWII aircraft had nose wheel steering, so as with the A26, we should be steering with differential brakes and thrust. This worked a bit better in FS9. The palnes were not equipped with antiskid, but hitting the "B" key to activate this helps get around the overdone wheel skid "feature".

I did notice that the prop blade angle animation is backwards, Moving the prop lever to low RPM makes the pitch finer and to high RPM flattens the blades, which may be why they are not going to feather.

Cheers: T

***warchild*** · August 17th, 2010, 15:48

Actually, if i remember correctly, the P-61 had NWS as well as reversing props, but i cant be positive which models had them and which didnt..
Differential braking only really works if the differential brakes are in the main gear and in front of the tail wheel.. On a nose wheel plane like the 61 hitting differential brakes only would cause the plane to drag the nose wheel sideways in an arc, until the caster realigned itself with its arc of movement..

**fliger747** · August 17th, 2010, 17:17

P-38 had no nose dragger steering, nor did even the B-29! That came along with the B-50. The A26 did not have it till the Vietnam era rebuild. The ground handling notes in Hundred Thousand indicate the necessity to castor the nose wheel and use of power and brakes for turning, with cautions about too tight turns. Examination of nose gear reveals no steering cylinder nor does the hydraulic system show such a device.

Check Pilot Operating Handbook Page 28, item 9. Taxi instructions.

No mention I can find of the Curtiss electric 714-7C2-12 indicated reversing capability. I'll keep looking on that one.

**fliger747** · August 17th, 2010, 17:20

Item from P-61 POH

**fliger747** · August 17th, 2010, 17:38

Props:

Unable so far to find any information which would confirm reversable propellers, either in the control illustrations or operating notes in the POH of the P61-A&B models. Usually reversable props, especially with large radials, have obvious controlls and copious operating notes and cautions. An excellent way to quickly destroy an engine through improper operation.

Great if someone can find confirming data. I do know the CB16-17 as used on the DC6 does have reversble props, as did the Vietnam Era conversion of the A26.

Cheers: T

***warchild*** · August 17th, 2010, 19:15

Thanks for finding that info on the castoring nose wheel.. its bizaar, especially in light of the fact that from the P-36 onward most tail draggers had steerable tail wheels..

**fliger747** · August 17th, 2010, 20:24

Steerable tailwheels? Lockable but not steerable as far as I know. The P51, F4U4, F4F, A6M2 and FW 190 certainly do not have steerable tail wheels, as evidenced by the lack of control cables or any sort of control horn on the TW assembly to attach them to.

Many GA Taildraggers I have flown, such as my Supercub, 180's 185's etc do have steerable/castoring tail wheels which break free beyond a certain side force (determined by the number of springs on the friction plate and the torque of the spindle nut). Larger aircraft such as the Beech 18 and DC2/DC3 only have lockable tailwheels. I suspect that the force of trying to steer the tailwheel would act in addition to the already sizeable rudder forces of apowerful aircraft.

Perhaps some aircraft of the era had steerable tailwheels, but I have not as yet seen any erection drawings indicating so. I do not have drawings of every aircraft, nor detailed knowledge of everything, so anything is possible!

Cheers: T

***warchild*** · August 17th, 2010, 22:10

Oh yeah.. definitely steerable, but it was a weird kind of steerable.. In the Pasped, P-36, p-40 and so on, the tail wheel was steerable to 30 degrees and then went into free rotation beyond that ( like the GA's you've flown ).. Blew me away too..

Your speculation on size however has a valid merit to it.. That makes me wish i had a way to test that theory in real life.. ::cchuckles:: it would be fun to find out.. if maybe only a little destructive to some poor fence ( or, with my driving a building or something more expensive). On second thought maybe it would be safer to simply research it online..

.

Oh yeah.. heh.. i dont have a detailed knowledge of everything either..

***warchild*** · August 17th, 2010, 23:21

i guess the main question from me at this point then, is; Do we want to make it steerable or do we want to make it real?? I'm good either way..
Team?? Need your feedback on this.. I know some of you think this is a no brainer, but in truth it needs to be decided upon.. Lets discuss it and do it by majority consensus.. Fliger and I and Paul can make this flight model terrifyingly realistic if you let us.. But it's your call..

by the way, terrifyingly real isnt that terrifying.. this thing had ( from what i can see ) the stall characteristics of a feather.

***jankees*** · August 17th, 2010, 23:56

I'm all for real..

***warchild*** · August 18th, 2010, 00:36

I think were gonna need a little smoke..
http://www.youtube.com/watch?v=KabB1TNW8fY

***warchild*** · August 18th, 2010, 00:43

just an addendum for animators:::

taken from the wiki..

The XP-61's weight rose during construction of the prototype, to 22,392 lb (10,157 kg) empty and 29,673 lb (13,459 kg) at takeoff. Engines were R-2800-25S Double Wasp radials; turning 12 ft 2 in diameter Curtiss C5425-A10 four-blade propellers, both rotating counterclockwise when viewed from the front.

I dont know.. i'm getting conflicting information from other sites that say both props rotated clockwise when seen from the front.. Has anyone got the definitive on this??

**deathfromafar** · August 18th, 2010, 02:01

The props turn right! I've seen Moonlight Serenade at the Air Force Museum and the prop pitch and shape clearly shows both engines turn right from the pilots perspective(looking forward).

As far as the R2800 smoking? I serviced the CAF's C-46 several times many years back and the engines did smoke at startup due to the oil accumulation in the bottom cylinders but the smoke dissipated fairly quickly during the low rpm warmup. I imagine that during cold weather the effect would be considerable worse than warm/hot weather warmups. They did tell me that as the engines developed wear, they would smoke longer after startup/warmup and at idle after long flights but by that time the engines were nearing partial or full overhaul. I remember the smell of burning Aeroshell mineral oil we put in radial engines. You never forget it!