Flying Issues...

[BoeingB17]

Hello:wavey:
I downloaded a USAF C-54 4 engine transport. But I'm having a very hard time flying it.:isadizzy: It won't take off quick enough, I am about 2 runway lengths past the base runway before the wheels leave the ground. And it is almost imposible to gain any signifigant ammount of altitude! How should I go about flying something this big? I've had similar problems with other large aircraft before. After a few minutes I usualy stall out and crash.:banghead:
Thanks in advance and happy holidays!:friday:

[Pratt&Whitney]

Hello:wavey:
I downloaded a USAF C-54 4 engine transport. But I'm having a very hard time flying it.:isadizzy: It won't take off quick enough, I am about 2 runway lengths past the base runway before the wheels leave the ground. And it is almost imposible to gain any signifigant ammount of altitude! How should I go about flying something this big? I've had similar problems with other large aircraft before. After a few minutes I usualy stall out and crash.:banghead:
Thanks in advance and happy holidays!:friday:

Oy... I once had a C-47 Dakota that was about that way... Slow to take off, even tough to maintain level flight. I think it is more a problem with the .air file, or maybe I am just a lousy pilot?

[winslow33]

I've had problems with huge planes too. That can be frustrating, looking back after 5 minutes of climbing and seeing your still barely off the ground, lol. :isadizzy:

[minuteman10]

~S~ Gents...try a touch of flaps to gain some lift....

[Ivan]

Hello Minuteman10,

Flaps might be a good idea in real life, but in CFS, often the planes can't even maintain altitude with flaps down. I know the flap drag on the planes I built is too high.

The problem I have run into most with multi engine CFS planes is that they tend to move too well and are too responsive.

- Ivan.

[hubbabubba]

I downloaded a USAF C-54 4 engine transport. But I'm having a very hard time flying it.If you have a link for that C-54, it would certainly help. Everything depends on the AIR file.

Ivan; go fly BRETOAL's Bréguet for a while and we will see if you still are of the same advice! As for me; I gave up!:redf:

[Ivan]

Hello Hubbabubba,

Do you mean that the Breguet is not as agile as it is supposed to be? Or that the flap drag is too low?

BTW, I tried about a half dozen other changes to the jeep. The critter is still unstable and I have no idea as to why.

- Ivan.

[Ivan]

Hello Hubbabubba,

I flew the Breguet this morning. Now keep in mind that I have no idea how a Breguet 693 (or whatever the number was) is sposta fly, but one can expect a certain kind of response based on the fact that it is a twin engine light bomber.

The flap drag was MUCH higher than it should have been. The rudders were pretty much ineffective except at low speed. The ailerons were about what one would expect. The elevator was overly sensitive. The aircraft also seemed to bleed off speed way too fast.

The model was the best I have seen anywhere.

- Ivan.

[BoeingB17]

The link to download the C-54 is HERE (http://www.flightsim.com/cgi/kdl/main/18/usaafc54.zip?jTlzD03b). Flaps don't really help much, to keep from crashing I have to constantly fly with almost full flaps. Anything less than 50% flaps and I'll lose altitude.:banghead:

[smilo]

The link to download the C-54 is HERE (http://www.flightsim.com/cgi/kdl/main/18/usaafc54.zip?jTlzD03b)...

I don't know about anyone else, but that link doesn't work for me.

[Ivan]

I believe the link that was supplied only has a partial parameter in it. It probably was only the first line of the URL that word wrapped in an editor. It would be better if he just email the zip file because it is not available via anonymous download.

I believe the same archive can be found here:
http://www.combatfs.com/cfc_archive/aircraft/cargo/

- Ivan.

[Johnny]

~S~ Boing17,

24% flaps and the whole runway, no problem. Not one of the best I have ever flown. You did run it through CFSCONV.exe. It said there were errors, but it flew. By the way, 25% gives lift, the more flaps you give a plane, the drag you add, slower it flies.

J:ernae:

[Ivan]

Hello Johnny,

I believe that just about all CFS aircraft have way too much flap drag to be realistic. The first hint I had of this was when I tried to tune the SBD Dauntless dive bomber I was working on. The plane would not accelerate in a vertical dive with full flaps. The effect of spoilers was tuned down to be almost neglible and yet the aircraft would hit a limit of around 300 mph. I had to tune down the flaps significantly to allow for drag from dive brakes and still be able to dive with engine idling past 350 mph.

Some Aeronautical Engineer out there is probably going to beat the heck outta me for making these generalizations, but here goes:

From what I could tell, Flap drag should never exceed airframe drag and be somewhere between 50% and 75% of the airframe drag. The coefficient of lift can be gathered from a couple graphs which aren't hard to find, but my ballpark estimate was that the Coefficient of lift which normally maxes out at about 1.35 or so should increase by around 0.25 to 0.5 with full flaps.

Even with full flaps down, on full throttle, you SHOULD be able to accelerate past the limiting airspeed for use of flaps which is usually (more generalizations) around 150 knots or 175 mph. The engine thrust is enough to greatly exceed this speed, but in real life, the flaps would blow closed (blow-up) or might be damaged by excess loads.

The general effect on most WW2 fighter aircraft is a fairly slight nose down moment with landing gear down and a fairly LARGE nose down moment with flaps down. There are exceptions, but these are the general effects gathered from reading a bunch of pilots notes / flight manuals.

Again, these are generalizations and I do welcome aero engineers out there to correct any misconceptions stated here.

- Ivan.

[hubbabubba]

OK, BoeingB17, got the a/c.

Will install and give it a spin, but I can already see that it is a FS98 file as it was fetch from this section of FlightSim. BTW- the link doesn't work because you have to be logged-in to search and download at their site.

Ivan, I do tend to concur with you on the flaps being "overdone" in the game, but I already see a "short fall" (pun intended:kilroy:) in getting all a/c a more realistic flap drag number. Finals procedures will certainly have to be revised... or runways elongated!:costumes:

[BoeingB17]

Ok... I thought that 100% flaps would give me the most lift.:redf: I'll go try it with 25% and see.
Thanks

[Ivan]

Hello BoeingB17,

You are correct, 100% flaps WILL give you the most lift, but it will also give you the most drag. With flap settings like most CFS aircraft, the increased drag may be enough for you to NOT reach T-O speed. I will try to check out the C-54 this evening. Can you confirm for me that this is the same aircraft as you are using?

Hello Hubbabubba,

I don't actually read much of the standard procedures for CFS. I DO read a fair number of flight manuals though. I figure if the procedures do not reflect reality, they should be revised so that they do. Along the same lines, if we have a flight model that is not representative of reality, it should also be modified. Let whoever owns the documents be the judge.

- Ivan.

[Pratt&Whitney]

How does that old carrier pilot saying go?

(To Air Force Pilots) "Flaring to land is like squatting to pee."

Flaps? We don't no stinkin' flaps (to land) :kilroy:

[Ivan]

Hello BoeingB17,

Here is what I found with the C-54 (Usaafc54.zip):

Aircraft is green, FS98 flight model

About 25% flaps seems to shorten the distance needed to take-off.
Take-Off is at about 105 kts with 25% flaps.

Aircraft has serious nose-down trim

Roll stability is very low.
Maximum G appears to be around 2.0-2.5.

Deceleration with engines at idle is VERY, VERY slow.

Flap Drag is VERY high.

- Ivan.

[hubbabubba]

OK BoeingB17:mixedsmi:...

I tried T/O under three different methods, and they all worked!

First of all, make sure all your engines are running. Keep throttle at zero for about thirty seconds before doing anything after having started your engines.

First method; clean configuration (no flaps):

Go full throttle and let it go straight until it goes over 120MPH TAS. You should be near ¾ of the runway. At that point, compress the nose gear oleo by pushing the stick, and then pull hard. Gear-up once airborne and let the speed get over 150MPH before doing any serious climbing.

Second method;

Same as above up to 120MPH TAS. Then ¼ flaps (F5 once), pulling stick. Gear-up once airborne. Flaps-up and horizontal flying until you get 150 MPH TAS.

Third-method;

Same as above with any flaps increments. The a/c literally jumps off the runway with 100% flaps! Simply remember to get the gears up and the flaps retracted as soon as you're airborne.

The trick here is to let the a/c build-up speed before using any flaps. First method is a bit tricky. Method number two is giving the best ratio speed/lift but number three would be indicated on short runways.

Initial climbing is around 1 000 FPM with an airspeed of ±150MPH TAS. Not a rocket, but decent enough for a big bird.

[Ivan]

Hello Hubbabubba,

I believe I am using a MUCH shorter runway than standard. It is Pooh field in the Hawaiian scenery. It is my normal test field and doesn't leave much margin for either a B-25 Mitchell OR a P-47D Thunderbolt.

Have you figured out how to land this beast (The C-54)?

It doesn't bleed off speed hardly at all unless you use flaps. But if maximum flap deployment speed is 150 mph, how do you get down to 150 mph to use flaps????

- Ivan.

[Pratt&Whitney]

"Well he got to the bottom safe and sound
Everybody asked Bandit how he made it down
He said folks when the truck picked up too much speed
I just run along beside it and drug my feet" --- The Legend, Jerry Reed

Ivan, maybe a long, low, and slow approach? At what airspeed can you lower the landing gear? Shouldn't they add some nice drag, and allow you to brake to a stop?

I try not to flap on landings, more fun to ride the brakes and try to my propeller out of the dirt :isadizzy: (A lot easier with the tricycle landing gear on some planes, like the A-20, A-26, B-25, etc...)

[hubbabubba]

Hello guys:wavey:
I did my test at AAC_Ripe on runway 180. It is as long and wide as any stock CFS1 runway.

I performed few landings, as it was not what BoeingB17 was asking, but I did mine using the tri-colors VASI of the two main runways at Ripe. It gives a glide path of 3°.

5 nautical miles from the threshold, I went to 0% throttle and nose up to get under 150MPH TAS. Gear down, full flaps, I went on the green ball 'till touch-down, maintaining a speed between 128-150MPH. Nose up for a three-points landing, full breaks until I got under 80-70 MPH.

Lateral control has a very wide amplitude. You can bleed speed going side slipping right and left, a bit like a downhill skier. Landing speed around 130MPH is quite fine, but 3° glide path is even more important.

Will go back and make a few more landings...

P.S.- Did a dozen or so landings at Ripe.

Saved a flight with the a/c pointing to runway 360 at 2 700ft, distance of 5nm, speed 180MPH TAS.

Ideally, it should be ± 1 500ft at 5 nm, so I had to find a way to descend and bleed speed to get under 150MPH.

So I went nose up, throttle 0%. Went up to about 3 200ft before I went under 150MPH, then went full flaps, gear down. Easing on the stick, I tried to keep a/c under 150 by side-slipping while going down to catch the green slope.

Aircraft would go up to 170MPH nevertheless, but this is still acceptable once flaps are fully deployed. Once "on the ball", I would go straight, maintaining the a/c within 130/140MPH with throttle.

I would try to get on the threshold at 130MPH, nosing-up a bit for a three point landing. Once on ground, full breaks. This way, I could come to a full stop within ½ of the runway lenght.

I tried other methods, but they all failed. Diving down and redressing as I was about to mow the landscape, I was still going over 250MPH on the treshold! Maintaining nose up with full flaps and gear down, I was still going to overshoot the runway. Stall horn start at 109MPH TAS in that configuration, but a/c doen't go lower than 107-108! Interesting fact; my stick was pulled to its maximum at that time, so I couldnt get it to go slower. Tried to get to the ground diving and redressing at the last moment... and went in a ball of fire.:banghead:

[Ivan]

Hello Hubbabubba,

3 degree glide path seems rather shallow. I did not try to go nose up to bleed off speed. The full power run had taken me to about 228 knots and I just throttled back to see how long it would take to bleed down to 150 knots (my self determined safe flaps speed). It took an awfully long time. With flaps down, it bled off speed quite fast, to the point where I needed to add power to maintain altitude. This was a "test" landing over water to get a feel for how far out to being the approach.

Hello Pratt&Whitney,

There is a limiting speed for landing gear as well. On the P-47, it is 250 mph, but on most aircraft, it is much lower. I believe on the Spitfire, it is only about 120 mph. I figure 150 knots is a pretty reasonable average. On the real aircraft, lowering the gear at a higher speed may damage the gear or airframe.

- Ivan.

[hubbabubba]

3° is the standard for any glide path instrument. I know because I did extensive research on the subject before building my tri-color VASI. That "golden number" was determined in the mid 30's and hasn't changed since. It is the same for any a/c, big or small, fast or slow.

It is the same standard everywhere, on land or on aircraft carriers. It would only depart from the 3° when natural obstacles are in the way.

HERE (http://en.wikipedia.org/wiki/Visual_Approach_Slope_Indicator) for "corroborating" evidence!:jump:

I always try to keep under 150MPH TAS before lowering flaps or gears, 250MPH for "navalized" version, when I want to play "by the book". In MP games, I will not hesitate to go full flaps, gear down, 300 feet from the treshold!:costumes:

[Ivan]

Hello Hubbabubba,

Didn't know about the glide path. I actually use 150 knots (172.5 mph) as my flap and gear limiting speed. I found that number to be pretty reasonable for bombers of that era and fairly representative or just a touch high for fighters of that era.

For fighters that allow combat flaps, I restrict this to around 25% below 250 mph IAS.

What do you mean by "Navalized version"?

- Ivan.

[hubbabubba]

Navalized version are a/c built for or modified for aircraft carrier operation. They tend to have strengthened gears, flaps, and overall airframe and can normally operate at higher speed. An old member of Joint Ops used to fly a Corsair in WWII and was telling us that one way they had found to get rid of a pursuing "Jap" was to dive and, as they were diving, to get the gear down, well in excess of official limits.

The pursuer who was foolish enough to dive behind would pass in front of the prey.:gameoff:
If he tried to get his gear down, they would be ripped-off. Any way, he was "cooked".

This is why I give them 250MPH instead of 150MPH for flap-gear operation limit. Of course, I don't fly much Japanese a/c...:kilroy:

[Ivan]

Hi Hubbabubba,

Yes, Navalized aircraft are stressed a bit higher in terms of typically stronger gear for the high descent rate landing, a stronger tail cone to reduce the chance of the tail pulling off with the arrestor hook.

The rest of the story is that their speed limitations for flap deployment were not any greater, at least not for the Corsair and Hellcat. The Corsair had a special setting for the landing gear that would NOT extend the tail wheel. The main gear would come down partially (not fully because the wind resistance would prevent it) but enough to act as an air brake. If the regular gear extension were used in a dive, it would rip the tail gear doors off!

The Seafire never did properly make the transition to naval aircraft because its airframe just could not take the beating. Some land planes were stressed much higher than expected. Maximum gear down speed for a P-47 was 250 mph....

I don't think that navalized really made all that much difference for the most part. Consider that the F8F Bearcat had very low stress limits on its wings even though it was the "ultimate" in naval fighters.

The typical Japanese fighter (The A6M Reisen) had very low dive speed limits (400-460 mph) because of an overly light structure. With that in mind, it would make more sense (unless you are flying a Wildcat) to let the dive speed build a bit and outrun the pursuer by 100 mph or so.

- Ivan.

[hubbabubba]

We both know that airspeed has no real effect on gears or flaps in CFS1. You can go full flaps while going 400MPH without any danger.

All a/c of the era had their little idiosyncrasies. My choices are as arbitrary as yours.

Now, if you want to second guess a WWII veteran and his tactics...:kilroy:

[Ivan]

Hello Hubbabubba,

I poked around at the AIR file for the C-54 yesterday. What I found was that the wing efficiency was set at about 1500. Lower is better. Typical settings are more like 4000-7000.

You are absolutely right about arbitrary limitations. Mine are no better than yours, but at least we are both trying to make the game a bit more realistic.

- Ivan.

[Ivan]

P-40D/E

175 mph Landing Gear
140 mph Flaps
175 mph Cowl Flaps

Just some additional information.
- Ivan.