Help with the Douglas F3D Skynight

[falcon409]

The one I'm referencing here is the Alphasim version modified to V2 and released by "LLS". It was dated 2017 if that is any help. The author left no email. If anyone has that airplane I'd be interested to know if you also felt the throttle response was "off/sluggish". At cruise and in a climb it's fine, but especially on final approach it's infuriating. The response is so slow that I find myself chasing the sweet spot and never finding it, lol. Any help would be appreciated.

[MrZippy]

In case someone wants to try it, this looks like the one you are referring to.......http://www.allflightmods.com/microsoft-flight-simulator-x/douglas-alphsim-f3d-skyknight-x-package/

[Mike71]

The one I'm referencing here is the Alphasim version modified to V2 and released by "LLS". It was dated 2017 if that is any help. The author left no email. If anyone has that airplane I'd be interested to know if you also felt the throttle response was "off/sluggish". At cruise and in a climb it's fine, but especially on final approach it's infuriating. The response is so slow that I find myself chasing the sweet spot and never finding it, lol. Any help would be appreciated.In the aircraft.cfg file there is a line
fuel_flow_gain=X.yyyyy . This has an influence on throttle response (spool up per inch of throttle movement). Increasing the value increases spool up.

I also would say that the J-46 engine, though an axial flow design likely had a very slow spool at low/mid rpm typical for the day. I would make sure you have flaps full down and speed brakes OUT on final - standard USN SOP even to this day. Helps keep rpm requirement in the upper range.

Also if it has a fuel flow gauge, try adjusting that rather than rpm - it resets faster and is more stable as the rpm curve follows it. I used fuel flow (along with subconscious sensory position of the throttle(s)) to set speed in all kinds of Navy jets and it worked well.

[mcanx]

This aircraft was recently updated in April of this year. It's available over at Simviation. Robert

[falcon409]

This aircraft was recently updated in April of this year. It's available over at Simviation. Robert
Yes, that's the one I have. The 2017 release I mentioned was based on the dates on some of the files contained in the aircraft folder.

[falcon409]

. . . . .I also would say that the J-46 engine, though an axial flow design likely had a very slow spool at low/mid rpm typical for the day.

According to the description in the aircraft config file and the specs for this particular engine it was a J-34-WE-36, which was what was used on this airplane and quite a few others (with some modifications). However the config file shows a max thrust of 4,600 lbs while the engine specs show 3,400lbs. Given that I would suspect that there are other numbers that are also off.

[Mike71]

According to the description in the aircraft config file and the specs for this particular engine it was a J-34-WE-36, which was what was used on this airplane and quite a few others (with some modifications). However the config file shows a max thrust of 4,600 lbs while the engine specs show 3,400lbs. Given that I would suspect that there are other numbers that are also off.

You are correct - the original plan was to use the J-46, an upgraded, larger J-34. However the J-46 had problems as installed so they switched to an uprated J-34.

I wen through basic jet training in the T-2A, which had a single J34-WE-46 rated at 3400 lbs thrust. It spooled up from idle to 80% in about 2 days - terrible - but much better in the 90 -100% range. They also smoked like hell.

I suspect the uprated J34-WE-38 in the standard F3D-2 in fleet use had more thrust, supposedly 4600 lbs is roughly correct.

As I recall, the various version numbers (WE-38, etc) were not necessarily indicators of greater thrust - there were tons of modifications to these engines to improve reliability, etc and they did not come on line in any particular order. Some version numbers only related to the particular airplane type they were intended to be used in.

[Mike71]

After considerable research regarding the actual features of the F3D-2 / EA-10B "Skyknight" and realistic data for use in the upgraded ALPHASIM model for FSX, I offer the following conclusions.


The F3D-2 was a miserable failure for use aboard carriers, and was only operated from a couple CVs during initial trials, two "workup periods" in the Atlantic (VF-101 and VF-111) and an aborted deployment during the Korean War. VC-4 Det 44N was embarked in USS LAKE CHAMPLAIN (CV-39) but quickly offloaded to join land based Marine squadron VMF(N)-513.


The plane had major problems with catapult launch compatibility and general Flight Deck handling. Carrier CO's informed the chain of command that the F3D-2 was an unacceptable detriment.


It was always underpowered, and always used the 3400 lb J-34, due to development issues with engine replacement programs.


However, the Marines had great success with it in Korea, and many F3D-2s found useful service as modified as EF-10Bs and miscellaneous training / development missions. None of these were manufactured, but modified by overhaul depots and field service changes.


As best I can tell, the modified EF-10B never was evaluated for carrier use. Arrested landing procedures and limits only applied to land based arresting gear installations.


With that, I offer the following data which I have deduced from several credible sources and my own insight after a 30 year career as a carrier aviator.


I am working on and testing an improved F3D-2 aircraft.cfg file as well as a photoshop paint kit that covers a clean, gloss sea blue scheme. More on those later
//----------------------------------------------------------------
First, They all used the J-34 with 3400 lbs thrust


Second, they burned AVGAS and only used JP-4 in an emergency with limitations on engine use


Third, they had 2 inboard wing stations that could carry up to 2000 lbs each, including bombs. However the most common configuration for the F3D-2 was a 150 gal /1000 lb drop tank on each, Alternatively they had 300 gal / 2000 lb drops available.


There were only two flap selections 1/2 (25 deg) and FULL (50 deg). The ALPHASIM model aircraft.cfg file shows some weird sections including an apparent LE section. However, the plane seems to fly OK so I leave it alone.


Field takeoffs used 1/2 flaps unless a short field is attempted - then FULL
Catapult launches used FULL flaps
Field and carrier landings used FULL flaps and speed brakes - OUT


Fourth - the ALPHASIM model aircraf.cfg file needs some fixes.


**************** The most serious being the fuel_flow_gain= 0.002 which gives insanely slow engine spool up in the higher N1 range. I recommend fuel_flow_gain=.008, which substantially improves engine acceleration in the landing pattern *********************




The plane had 3 fuselage fuel cells, all gravity fueled. The capacity values in the aircraft cfg are wrong, and in order to adjust quantities, cg position and use of AVGAS, I recommend the following [FUEL] section change:


[fuel]// from NAVAIR / NATOPS manuals
//Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
fuel_type =1 //normal fuel was AVGAS at 6 lbs/gal
number_of_tank_selectors = 1
electric_pump = 1


Center1 = 0.00, 0.00, 0.00, 650.00, 5.00
Center2 = 0.00, 0.00, 0.00, 290.00, 3.00
Center3 = 0.00, 0.00, 0.00, 410.00, 2.00
//std 150 gal drops
External1 = 0.00,-12.40,-2.25, 150.00, 0.00
External2 = 0.00, 12.40,-2.25, 150.00, 0.00


F3D-2 Weights:
Empty Op weight 15600 lbs
Max internal fuel 1350 gal / 8100 lbs AVGAS
Max field takeoff: 27500 lbs
Max catapult takeoff: 26750 lbs
Max field landing 24500 lbs
Max carrier landing 20000 lbs


airspeed limits (KIAS):
480 KIAS or buffet onset
LG ext/ret 150
Flaps 25/40 deg 170
wiper 200
Speed Brakes 345


field takeoff speed 27500 lbs: 110 KIAS rotation; decrease 2 kias per 1000 lbs GW
approach speed - carrier flaps FULL 20K max trap: 100 KIAS; decrease 2 kias per 1000 lbs GW
approach speed - field landing flaps FULL 24500 lbs: 110 KIAS; decrease 2 kias per 1000 lbs GW


The EF-10B had an increased field takeoff limit of 28800 lbs but the max field landing weight remained at 24500 lbs.

[tgycgijoes]

In case someone wants to try it, this looks like the one you are referring to.......http://www.allflightmods.com/microsoft-flight-simulator-x/douglas-alphsim-f3d-skyknight-x-package/

I saw this version but found I believe an even better one here:

https://flyawaysimulation.com/downloads/files/5102/fsx-douglas-f3d-skynight-upgrade/

[tgycgijoes]

I will be implementing all of the changes from Mike71 to the upgraded version by Bob Chilico I posted the link above in MrZippy's.

[tgycgijoes]

Joe Baugher has consistently provided a lot of good information. I have used him on countless occasions. Here is a link to the Skynight:

http://www.joebaugher.com/navy_fighters/f10_2.html :loyal:

[Mike71]

Joe Baugher has consistently provided a lot of good information. I have used him on countless occasions. Here is a link to the Skynight:

http://www.joebaugher.com/navy_fighters/f10_2.html :loyal:I agree with you regarding Baugher, but his weights are not in accord with actual NATOPS manual information and data curves I have.

Also, "participating in cruises" is a little misleading - they were hated and offloaded for shore operations as often as practicable. Remember - we are talking about straight deck ops here, before angle deck conversions or the FORRESTAL Class. A big plane to handle on deck, and for hydraulic cats.

[tgycgijoes]

I agree with you regarding Baugher, but his weights are not in accord with actual NATOPS manual information and data curves I have.

Also, "participating in cruises" is a little misleading - they were hated and offloaded for shore operations as often as practicable. Remember - we are talking about straight deck ops here, before angle deck conversions or the FORRESTAL Class. A big plane to handle on deck, and for hydraulic cats.

I always enjoy hearing comments from you. I know from my experience talking with veterans WWII and Korea years ago the inaccuracies between recorded history and what actually happened. I am sure you are right. Joe I believe is going by records not recollections. When I had my hobby shop years ago a group of us would get together and swap "war stories" every Saturday morning. Gus was in the Occupation in Germany after WWII; Art was an Army Korean War Vet; Paul was former NSA he would make a comment and then often stop before he said too much LOL; John, Dave and myself were Vietnam Vets. Dave was a "Tunnel Rat" and had a lot of issues he was still counseling about; Jack was a B-52 crew chief and Stan was a retired Air Force BrigGen who started as a ferry pilot at the end of WWII. He spent most of his time in the Pentagon under Adm Hyman Rickover. One by one the "Breakfast Club" went on to glory. I am the only one left now. We had a lot of good times eating breakfast together in "the shop" back in the day (1985-1995). My family always gets upset with me when I criticize Hollywood movies with their inaccuracies.