Post by Bill Von Sennet on Aug 22, 2008 21:59:12 GMT -5
Tom Goodrick
FLYING TURBOPROPS
« on: Oct 14th, 2007, 12:47pm »
FLYING THE BEECH KING AIR 350
REFERENCES:
1. Article in Aviation Week and Space Technology: "Large, quiet cabin increases flexibility of Beech Model 350" by Edward H Phillips, September 30, 1991.
2. Article in FLYING Magazine: "LOAD IT UP AND GO", by J Mac McClellan, March 2007.
Of all the aircraft in my FS hangar, the Beech King Air 350 is my favorite. That may be why I have 130 hours in it, the most time in any aircraft. It has a very good reputation in the aviation business community where it continues to be very popular. It is great for any business that must frequently take up to 8 employees on day-trips ranging out to 500 nm. They depart at the beginning of a work day and return before the end of it having spent at least four hours at the destination. There are not many other ways to do that unless you spend a lot more money on a big jet. having done that many times using a Beech KA B200, I can vouch for that method of business travel as far better than anything commercial airlines can provide. Since it is private, the passengers can spend much of the four travelling hours in constructive conversation about business matters. Since all eight seats are equally large and comfortable, the "big wigs" do not have to sit in one section but can spread out through the staff people for better communication. You can fill all the seats with real people and fill the tanks and cargo bay. There is a private toilet on board so people can feel free to drink coffee in the morning and a cocktail at night.
I have my 350 loaded with a typical full load of 2x200 pilots, 8x170 passengers, 400 lbs of baggage (40lb per person) and full fuel and still have 142 lbs left over for the over-size employees or extra equipment going to a test site, etc. My total load is 14857 lbs of 15000 max with the CG at 33%. If the two pilots have to fly a leg with no payload, they see 13096 lbs and a CG at 12.1%. That is a significant change but is not overly difficult for pilots to handle. It does not require loading ballast.
We'll make a few flights to show the utility of the aircraft. First let's talk about the controls and how they can be used in various flight situations. Many people are confused when they see three sets of engine levers just like in piston aircraft. One set is the throttles that work very similar to the throttles in a piston aircraft except there is no manifold pressure. The throttle controls power rather directly. I use the percent of throttle position as the guide to setting the throttles though there are several instruments to consider. The percent of position is a handy index for all phases of flight: 100% on takeoff, 80% in climb, 60 to 70% in cruise and 0 to 40% during descent. (Yes, flight idle is a valid power setting in turboprops that does no harm to the engines.) The second set of levers control the prop RPM just as with a piston engine. But they normally have only two settings - max and reduced. Max is used for takeoff, climb and descent. Reduced RPM is used in cruise to reduce the cabin noise level. It has a slight effect on power. The third set of levers are not mixture levers but are called "condition levers." They have three positions: High Idle, Low Idle and Fuel Cutoff. At the start they are set at Low idle. On many flights, they are not changed from that until it is time to pull the levers to fuel cutoff to stop them after parking. Sometimes, high idle is used during descent for increased engine drag. Many modern turboprops only have a set of power levers (throttles). The engines are set to use one RPM throughout all flight and the condition is set to low idle at all times. There is a small lever to shutoff the fuel to each engine.
The throttle levers on turboprops can be moved from idle back into a negative pitch range. This can be done whether the aircraft is in flight or on the ground. This is often used to stay slow when taxiing as many turboprops tend to go too fast on idle speed. Just a touch into the beta range is useful to keep the aircraft slow enough so that brakes are used infrequently. After landing the throttles are pulled fully back into negative pitch to begin the braking process. This continues until the airspeed is below 50 knots when wheel brakes are used. Care must be taken not to injest debris from beside the runway or taxiway which can happen at low speed. There are times when a slight negative thrust can be used on final permitting a very steep approach down over an obstruction into a short field. I have done that with this aircraft many times, particularly going into small ski airfields in the Swiss Alps. I have taken this aircraft into and out of Chourcheval in the French Alps several times. That is a bit of a challenge as the field is short and hangs on the side of a mountain. Then there are several airports down in the valleys between the ski mountains in Europe. This aircraft can do things few aircraft can do. It is more responsive and forgiving than the turboprop airliners.
I recommend that when starting to fly any turboprop, if it isn't already sitting with the engines off, you shut them down (move the condition lever to the cutoff position). Then start them with the ctrl-e sequence. The reason for this is that it is the only way you can be sure the condition lever is set properly in the low idle position. the next thing you need to do after starting the engines is find the generator switches and turn them to the "gen" position. Failure to do this will create excitement in about two or three minutes when the panel goes black. On my panel for the 350 you'll find a small pop-up panel with these swtiches at shift+3. For your knowledge, you'll find a small pop-up panel of four old fashioned air-driven instruments at shift+2 in case you have to fly without power to the fancy glass panel. Incidentally, a recent feature story in FLYING (March 07) showed a very similar panel with a PFD and an MFD. They also have three or four standard instruments hidden at the bottom center of the panel.
The engine instruments we have on my panel are the torque as a % of maximum, the interstage turbine temperature, ITT, the fuel flow in pph, the N1 fan speed in % max, the oil temp in C and the oil pressure in psi. below those values is the total fuel in gallons and the hours of flight time remaining at the current power setting and flight condition. The toruqe is used as the main parameters determining power settings:
90% for takeoff
78% for climb
48% for cruise.
ITT is monitored to make sure it stays below 800C at all times. One pilot operates the throttles on takeoff while the other flies the airplane. The throttles will often need adjustment to keep ITT below 800 during takeoff. Once power is set and the aircraft is in steady climb, the pilot takes full control. in some aircraft such as the Beech 300 which the 350 replaces, the engines tend to surge when power is applied for takeoff. This can cause undesirable yaw as you roll.
On my panel, shift+5 activates the Landing Gauge. The law says I must do three takeoffs and landings before I carry any passengers. I'll do them with just the company of an instructor pilot. This aircraft is too heavy to qualify for single-pilot operation, even with no passengers. I'll use KHSV and practice ILS approaches. Each landing will be made to a full stop on the runway. Then a new weather condition will be selected. We start with Clear Skies.
As I taxied out, 10% throttle was needed to get started but then I went quickly to zero and tapped the brakes. Then I found that, once rolling, 1% was too much and 0% was too little. I rolled along using 1%, 0 and about -1% to control speed.
I have generally used one notch of flap for takeoff to shorten the roll. Mc Clellan says you have to go to zero flaps if you lose an engine so you might as well make all takeoffs at zero flaps. That makes sense so we'll try it. I dialed in 8 degrees of up trim. I rotated at 110 KIAS and began climbing. The torque went to 95% as the throttle was set first at 90% and then 80%. I backed off to 70% for the brief climb to 2500 ft onto a downwind leg. Things go pretty fst in this plane when you just want to fly a pattern. I generally go to 2500 ft and go out about 7 nm on downwind. The trim came down quickly to 1.5 degrees as we levelled off to fly the downwind leg. I had to bring the throttles back quickly to 20% to get the speed back down. At 170 KIAS I noticed the GASP was green and knew that first flaps could come out. It was time to turn back to final. With all that stuff hanging out, I needed 13 degrees trim and 40$ throttle to stay level in the 30 degrees bank. On final with 20 degrees flap we were on the glideslope and descending at 125 kias. I brought the trim to a full 15 degrees. We still decelerated a bit as we began descending in earnest. Half a mile out we set full flaps. We were on the glideslope at 112 kias.
We landed at 96.23 kias and -221 fpm. I did not like having to hold so much back stick on final. I think the cause was the forward CG with only two of us on board. I will change the trim limit (in the aircraft.cfg aircraft geometry section) from 15 to 22. So much trim will not be needed when flying with normal weights.
On the second takeoff I verified that 80% throttle is good for the takeoff when you don't have someone to continuously adjust the throttles. I lifted at about 112 kias. I thought I brought the nose too far up and then pushed it down. That caused a big unwanted dip. A smooth nose-up rotation is required. (I made the change to max trim and was careful to reset the weight for the flight so the CG is once again at 12%.. This time on the long downwind I noticed that 50% thottle gave 48 to 51% torque for a nice short cruise at about 180 knots. Soon I cut to 40% throttle and noticed the GASP was green. I dropped the gear before turning to base leg. I dropped 20 degrees of flaps (1st notch) on base and turned slowly to final. We were on the glideslope after the turn. The throttle went to 20%, 40% and settled on 30% for a while as we held about 114 knots. Then I got a little too slow with full flaps (85 kias) and needed lots of power to keep from getting slower. This set me up for a go around which would have been a good idea. But I decided to use beta thrust to get down and land midway down the 10,000 ft runway. The landing was survivable but not pretty at 82.08 kias and -428 fpm.
Once you start playing with the throttle too much on final, the lag in thrust messes you up and you should simply go around and try again. It is best to move the throttle very little on final. Good thing this was only the second try at landing.
Tom Goodrick
RE: FLYING TURBOPROPS
« Reply #1 on: Oct 14th, 2007, 12:48pm »
PART TWO
We had to taxi back for the next takeoff. We decided to make things a little more interesting. For the third landing we usually do a circuit around the entire metro area at 5,000 ft so our aproach is a little more like it would be from cruise. This time we decided to turn on "Building Storms" weather. That gives us a variety of wind but it is light at the surface and mainly from the south so we use 18L as usual. We may have to pay more attention to the ILS.
Takeoff went as usual. We encountered light turbulence during climb and after levelling at 5,000 ft with 50% throttle (51.4% torque). There was a lot of rocking going on during the flight. There was little yawing. Well, I checked the value of Cn_r. It was -0.5. I changed it to -0.4. I also decided to stiffen it a little in pitch so I increased Cm_adot from 10 to 15. In summary, it was too stiff in yaw and not stiff enough in pitch. Now it should be moderately loose in both axes. With both the autopilot on and the yaw damper (Y/D) it gives a fair ride but there is some movement in turbulence - there will always be. I decided to climb to 10,000 ft for the flight back to KHSV. We had gone over the line into Georgia while making and checking these adjustments. I decided to make one more slight adjustment. I would tighten the pitch a little more by increasing Cm_q a little bit. The value was -35.16. I decided to make it -42. When I went to another aircraft and switched back after making this change, there was a big swing in yaw as the 350 adjusted its flight. Then I noticed the yaw damper had been turned off (probably because the aircraft I switched to had no yaw damper).
The flight back at 10,000 ft looks good. The turbulence moved us around a little but not badly after these changes with A/P on and Y/D on. 50% throttle gave 49.5 % torque. Fuel flow was 293 pph per side. True airspeed was 213 - 219 KTAS in the turbulence.
At 30 nm out we start down to 4000 ft. We made 4000 ft just near the edge of the mountains northeast of the city. We set 40% throttle to come in level toward the west aiming at a point 10 nm north of the airport. Half way there we turned in to get the localizer 5 nm out. We came down to 2500 feet for that intercept. The turbulence was light. We turned off the A/P but not the Y/D to make the ILS intercept.
We were able to make a visual approach but we flew the ILS pretty closely. There was continuous motion and it was challenging to fight the drift of the crosswind. As we passed over the fence we dropped rapidly as we lost a headwind gust but I caught it in time to make a nice touchdown at 85.0 kias and -137 fpm.
The checkout was accomplished with some slight modifications to the aircraft that should make it more realistic. The yaw damper will come in handy at times.
CLIMB/CRUISE/DESCENT
We'll take a brief look at three cruise missions to give you some flight planning info. We'll look at cruising at 10,000 ft, 20,000 ft and 30,000 ft. We'll get the time, distance and fuel used to climb and to descend from those altitudes as well as the cruising data at those altitudes. We'll use the "full house" load: 2x200 lb pilots, 8x170 lb passengers (average), and 10x40 lb baggage. We'll start with full tanks. We'll use the torques recommended by Beech to take off (90 ft-lb), to climb (78 ft-lb) and to cruise (48-50 ft-lb). A More careful look at these torques shows we need throttle positions of 80%, 67% and 49%. We climbed using 1800 fpm direct to 20,000 ft. In cruise at 20,000 ft and 30,000 ft, we set 1500 RPM for a quieter cabin. Descent is made at -1800 fpm with the throttle cut to 0 in three stages.
10,000 ft
CLIMB___________________________CRUISE_______________________DESCENT
T1___5.01min_____________________KTAS__212.3__________________T3__4.23mi n
F1____14gal______________________GPH___88.06__________________F3__2gal
R1___10nm_______________________NMPG__2.41__________________R3__14nm
20,000 ft
CLIMB___________________________CRUISE_______________________DESCENT
T1___10.75min____________________KTAS__215.3__________________T3__10.00m in
F1____27gal______________________GPH___77.91__________________F3__3gal
R1___28nm_______________________NMPG__2.76__________________R3__35nm
30,000 ft
CLIMB___________________________CRUISE_______________________DESCENT
T1___16.67min____________________KTAS__226.9__________________T3__15.67m in
F1____40gal______________________GPH___78.81__________________F3__5gal
R1___47nm_______________________NMPG__2.88__________________R3_58nm
To plan a flight over distance R (from airport A to airport B)
1) Calculate T2=60*(R-R1-R2)/KTAS minutes
2) Calculate F2=(R-R1-R2)/NMPG gallons
Then Time = T1+T2+T3 and Fuel = F1+F2+F3
If R<74 nm fly below 10,000 ft.
If R<113 nm fly below 20,000 ft
If R<155 nm fly below 30,000 ft. Of course, headwinds at high altitude mean flying at a lower altitude.
Beech has done a lot of work with the King Air series to reduce the noise level. Props beating aganst the side of the fuselage create considerable noise. But I remember being able to carry on conversations in the King Air B200 raising my voice only a little. For a few years back in the '90's, Beech experiemented with active noise cancellation in the King Air. I microphone in the cabin records the ambient noise and controls a set of speakers built into the walls to send out a counter sound, 180 degrees out of phase. This is used today in many headsets. But it lead to a lot of maintenance problems. So they have gone to a passive method by installing small tuning forks attached to the inner frame. They are tuned to take out the frequency of the props. These absorb energy from the frame. They are covered as all the walls are in thick accoustic insulation that also helps to cut the noise level. The King Airs remain a comfortable place to spend half a day.
« Last Edit: Oct 14th, 2007, 3:30pm by Tom Goodrick »
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #2 on: Oct 15th, 2007, 10:43am »
In the recent FLYING article, the following cruise speeds were listed for the 350:
Long range cruise at FL330: 237 KTAS
IFR range at Long range cruise at FL350: 1715 nm
High speed cruise at FL240: 312 KTAS
IFR range at high speed cruise FL 330: 1500 nm
There are several problems with this set of specs.
1) The altitudes do not agree. Range or fuel flow should always be given for the same altitude as a speed spec.
2) There should be some indication of the power settings used for these speeds. Either fuel flow or torque would suffice and they must be at the same altitude as the corresponding speed specs.
3) Was RPM reduced as it normally is on Beech turboprops? This reduces total power output through the prop and thus reduces speed.
4) I cannot match the high speed spec with any reasonable power setting. At FL240 with throttle at 80%, torque at 74.4%, I get 265 KTAS, 2x 438 pph.
My FD is just slightly adjusted from the original default FD for FS2002 (used in FS2004 with little change).
There remains some question about the accuracy of our power for turboprop engines. We have no way of judging the accuracy of our setup in the FD.
The long range cruise specs are in line with what I have seen in my FS trials. I avoid anything over 30,000 ft and should avoid 30,000 ft itself because I doubt if this aircraft can ever be flown at those altitudes within US airspace. The reason is it would be run over by all the airliners at those altitudes that travel 100 to 150 knots faster.
« Last Edit: Oct 15th, 2007, 10:51am by Tom Goodrick »
Chris_Ross
Re: FLYING TURBOPROPS
« Reply #3 on: Oct 16th, 2007, 7:22pm »
From the Raytheon Beech Website
Performance
The tables below depict the Beechcraft King Air 350 climb performance. These charts show the time, the amount of fuel consumed, and the distance flown at various takeoff weights and from sea level to altitudes up to 35,000 feet Climb data assumes ISA conditions and no wind.
CLIMB PERFORMANCE
TAKEOFF PERFORMANCE
CRUISE PERFORMANCE
LANDING PERFORMANCE
CLIMB PERFORMANCE Pressure Altitude (ft) Takeoff Weight (lb)
15,000 14,000 13,000 12,000
20,000 Time min 10 9 8 8 Fuel lb 168 153 139 127
Dist nm 32 29 26 24
24,000 Time min 13 12 11 10
Fuel lb 207 187 169 153
Dist nm 42 38 34 31
26,000 Time min 15 14 12 11
Fuel lb 229 207 186 167
Dist nm 49 44 39 35
29,000 Time min 19 17 15 13
Fuel lb 266 238 213 190
Dist nm 61 55 48 43
31,000 Time min 22 20 17 15
Fuel lb 296 262 238 207
Dist nm 73 64 56 49
33,000 Time min 26 23 20 17
Fuel lb 330 290 255 226
Dist nm 86 74 65 57
35,000 Time min 32 27 23 20
Fuel lb 378 324 282 247
Dist nm 107 90 76 66
TAKEOFF PERFORMANCE
TAKEOFF DISTANCE (FT) FLAPS APPROACH — SEA LEVEL
Takeoff Weight (lb) Outside Air Temperature 15°C / 59°F
15,000 3,300
14,000 2,939
13,000 2,737
12,000 2,540
CRUISE PERFORMANCE
Maximum Cruise Power 1500 RPM
Cruise Altitude (ft) Aircraft Weight (lb)
14,000 13,000 12,000 11,000
20,000 KTAS 309 311 312 314
Fuel Flow (lb/hr) 870 872 872 874
24,000 KTAS 309 311 313 315
Fuel Flow (lb/hr) 770 772 774 776
26,000 KTAS 307 310 312 314
Fuel Flow (lb/hr) 720 722 726 728
29,000 KTAS 303 306 310 312
Fuel Flow (lb/hr) 644 648 650 654
31,000 KTAS 298 302 306 310
Fuel Flow (lb/hr) 594 598 602 604
33,000 KTAS 292 297 302 306
Fuel Flow (lb/hr) 548 550 552 556
35,000 KTAS 283 290 295 300
Fuel Flow (lb/hr) 498 502 504 506
Maximum Range Power 1500 RPM
Cruise Altitude (ft) Aircraft Weight (lb)
14,000 13,000 12,500 12,000 11,000
20,000 KTAS 219 214 209 206
Fuel Flow (lb/hr) 458 434 412 394
24,000 KTAS 226 222 220 217 212
Fuel Flow (lb/hr) 432 410 398 386 364
216 205 0 0 199 193 182
26,000 KTAS 228 226 221 215
Fuel Flow (lb/hr) 418 398 376 352
29,000 KTAS 236 230 228 221
Fuel Flow (lb/hr) 408 380 362 336
31,000 KTAS 243 234 230 226
Fuel Flow (lb/hr) 410 374 350 330
33,000 KTAS 241 242 232 230
Fuel Flow (lb/hr) 398 380 344 322
35,000 KTAS 229 240 241 231
Fuel Flow (lb/hr) 380 368 348 314
LANDING PERFORMANCE
Approach Speeds Normal Landing Distance — Flaps Down
Weight (lb) VREF (KIAS) Field Landing Temperature
15,000 109 Elevation Weight 15°C / 59°F
14,000 105 (ft) (lb)
13,000 102 S.L. 15,000 2,692
12,000 100 13,000 2,490
11,000 100 11,000 2,390
10,000 100
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« Last Edit: Oct 23rd, 2007, 8:50pm by Chris_Ross »
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #4 on: Oct 16th, 2007, 8:24pm »
The climb data is pretty close on time and fuel. But the cruise data is way off on speed - like 50 knots worth. That seems to indicate they slipped in a big improvement in the past 16 years that I didn't catch.
My cruise data is fairly close to their "long range cruise" data. I sure don't have any idea what they are doing for "high cruise".
We don't have any idea of what their power settings were.
Today I put together a pair of gauges that show estimates of the power output for each engine. There is no power value made available in the sim as there is for piston engine aircraft. So I estimated it. I made both a single panel gauge and a Popwer_Panel type of gauge that you can pull down for testing. But I am not ready to release them yet. We need to study them a while. Allen Peterson has an engineering background. I've asked him to look at them too. Eventually, we may have a better way of setting up power on Turboprops.
See the discussion in the FS2004 section.
« Last Edit: Oct 16th, 2007, 8:36pm by Tom Goodrick »
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #5 on: Oct 23rd, 2007, 8:47pm »
Here is my best effort for the KA 350 trying to match the data published recently by Beechcraft. I think there is something funny about the way they did their test. It is not at a constant power setting. For some reason they changed the set up at different altitudes.
PERFORMANCE OF KA350 AT HIGH CRUISE
Note: Entire sequence recorded with full data.
Throttle was at 90% all the time.
Prop RPM was at 1500 all the time.
ALTITUDE__KTAS___KIAS___TORQUE%__POWER%__FUEL FLOW pph__ELEV TRIM deg
20,000FT___308.2___231.8_____80.4________75.1________538_____________-8. 03
22,000FT___312.3___227.2_____77.1________72.5________542_____________-7. 77
24,000FT___317.3___223.5_____75.2________71.2________545_____________-7. 55
26,000FT___324.4___221.1_____74.4________71.0________549_____________-7. 41
28,000FT___332.4___219.1_____73.9________70.9________554_____________-7. 30
Before takeoff (630 ft msl) weight was 15,000 lbs with 2300 lb payload and 3610 lb fuel.
CG was at 34.75%
After cruise test (56 minutes, from Huntsville, AL, to 60 nm west of Little Rock, AR,
est 330 nm), weight was 14,014 lbs and CG was at 34.79%. There were 3.28 hours remaining
at that cruise condition.
You could find more economical cruise conditions by using lower throttle settings down to as low as 50%. But if you are in a rush, these will get you there quickly.
I have seen KA 350 data for 16 years and never saw data this high. I think what has happened is that Beechcraft is trying very hard to compete with the new Very Light jets or VLJ designs. indeed, most of them will not beat this. Whether Pratt&Whitney beefed up the engines to last long hours at this pace is unknown.
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #6 on: Oct 24th, 2007, 12:16pm »
KA 350 TURBOPROP CLIMB DATA - SUMMARY (Turboprop_Climb_TestA1)
CLIMB CONDITIONS: 90% THROTTLE AND 1500 RPM. AUTOPILOT LIMITED BY CLIMB RATE
TIME ALT KIAS KTAS CLIMB N1 N2 PPH SHP% TQ% BETA ETRIM
1.01 2166 143.8 146.0 2105 95.57 100.26 556.7 96.84 95.82 26.5 3.64
2.02 4172 181.4 190.2 1847 94.37 88.82 546.1 85.45 95.43 32.6 -3.16
3.03 6076 191.4 206.2 1813 94.07 89.26 543.6 85.33 94.83 33.6 -4.39
4.04 7935 191.4 212.1 1796 94.10 89.79 543.9 84.50 93.36 34.1 -4.42
5.22 10116 186.7 214.0 1792 94.33 90.47 546.0 84.19 92.31 34.4 -3.90
6.24 11969 182.1 215.0 1791 94.58 91.06 548.2 83.95 91.45 34.7 -3.37
7.41 14108 176.9 216.0 1791 94.90 91.78 551.1 83.87 90.65 34.9 -2.71
8.43 15974 172.4 217.0 1789 95.21 92.42 553.9 83.70 89.84 35.4 -2.10
9.61 18149 166.9 217.7 1789 95.64 93.17 557.7 83.45 88.85 35.9 -1.29
10.62 20045 162.3 218.6 1786 96.04 93.83 561.4 83.31 88.07 36.5 -0.76
11.96 22158 162.6 227.0 1495 96.35 94.52 564.1 80.01 83.97 37.3 -0.70
13.14 23972 158.7 228.5 1491 96.82 95.20 568.3 79.06 82.38 37.8 -0.03
14.49 26063 155.4 232.0 1495 97.39 95.96 573.4 79.10 81.78 38.6 0.57
15.67 27875 154.5 238.1 1500 97.86 96.58 577.6 79.09 81.24 39.6 0.75
This was a nicely-formatted table. The first row of data was taken while the RPM was still 1700 from takeoff. After that it was left at 1501. Data was taken every 10 seconds during the climb. The climb was made "hands-off" on autopilot starting with a takeoff at full gross weight. The loading is thesame as for the cruise data above.
« Last Edit: Oct 24th, 2007, 12:20pm by Tom Goodrick »
Chris_Ross
Re: FLYING TURBOPROPS
« Reply #7 on: Oct 25th, 2007, 10:06pm »
I compared the CFG of the kba350 in FS9 AND FSX and found these differences
empty_weight_CG_position = 0.5, 0, 0 // (feet) longitudinal, lateral, vertical distance from specified datum
parasite_drag_scalar = 0.677
fuel_flow_scalar = 0.936
turboprop_engine]
power_scalar = 1.0 //Scalar on Turboprop power
maximum_torque = 3270 //Maximum torque available (ft-lbs)
PowerSpecificFuelConsumption = 0.55 //Brake power specific fuel consumption (turboprop only)
[contact_points]
point.0=1, 13.00, 0.00,-4.70, 1181,0,0.596, 39.9, 0.296, 2.5, 0.9516, 4.8, 4.8, 0, 184.0, 184.0
point.1=1, -1.67, -8.58,-5.03, 1574,1,0.596, 0.0, 0.642, 2.5, 0.8152, 4.5, 5.2, 2, 184.0, 184.0
point.2=1, -1.67, 8.58,-5.03, 1574,2,0.596, 0.0, 0.642, 2.5, 0.8152, 4.8, 4.9, 3, 184.0, 184.0
point.3=2, -3.33,-23.92,-3.00, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 5, 0.0, 0.0
point.4=2, -3.33, 23.92,-3.00, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 6, 0.0, 0.0
point.5=2,-22.67, 0.00, 0.00, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 9, 0.0, 0.0
point.6=2, 23.08, 0.00,-1.50, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 4, 0.0, 0.0
static_pitch = 0.2
static_cg_height = 4.3
[Views]
eyepoint = 4.3, -1.20, 3.35
[deice_system]
structural_deice_type=2 //0 = None, 1 = Heated Leading Edge, 2 = Bleed Air Boots, 3 = Eng Pump Boots
my airfile in FS9 is 15kb and in FSX it is 13kb? Fiddling with air files is so far, beyond me
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #8 on: Oct 25th, 2007, 10:47pm »
As I've said before, I do not support FSX. I do not know why there may be differences in the files. I do not care to know. I would think that a set of FD for FS9 would work in FSX. There might be more things you can adjust or turn on in FSX. But I think the stuff that works in FS9 witll work in FSX. If it does not I don't care. I won't be trying to make anything work in FSX.
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #9 on: Nov 13th, 2007, 12:16pm »
I have updated the FD and panel for the Beech 350 on my web site.
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #10 on: Dec 6th, 2007, 12:10pm »
I think most of the issues about flying turboprops have been covered. If you have any specific questions, ask them here and I will try to answer or investigate or find an example that sheds light on an issue.
There is one thing that has become clear as a shortcoming of the FS model for turboprops. Now that we have a gauge that shows the percent power set at any time in a turboprop, it is clear that the behaviour of certain aircraft cannot be matched exactly. The problem is the currently popular practice of "flat rating" turboprop engines. With sophisticated controls, an engine is flat rated to operate at a constant power below its max rating while operating from sea level up to common cruise altitudes. In FS whatever power you assign to an engine (through choice of RPM and max torque), the engine produces max power at sea level and declining power with altitude. Thus if I set the power properly and then climb to altitude and set the drag to get the specified cruise speed, the cruise speed at lower altitudes can be a little too fast. I cannot set either drag or power to different settings at different altitudes. The sim has a feature that adjusts power with altitude as it normally would given the density variations affecting simple engines.
I think this problem is relatively minor though it makes some aircraft look faster and more efficient at low altitude than they really are.
FLYING TURBOPROPS
« on: Oct 14th, 2007, 12:47pm »
FLYING THE BEECH KING AIR 350
REFERENCES:
1. Article in Aviation Week and Space Technology: "Large, quiet cabin increases flexibility of Beech Model 350" by Edward H Phillips, September 30, 1991.
2. Article in FLYING Magazine: "LOAD IT UP AND GO", by J Mac McClellan, March 2007.
Of all the aircraft in my FS hangar, the Beech King Air 350 is my favorite. That may be why I have 130 hours in it, the most time in any aircraft. It has a very good reputation in the aviation business community where it continues to be very popular. It is great for any business that must frequently take up to 8 employees on day-trips ranging out to 500 nm. They depart at the beginning of a work day and return before the end of it having spent at least four hours at the destination. There are not many other ways to do that unless you spend a lot more money on a big jet. having done that many times using a Beech KA B200, I can vouch for that method of business travel as far better than anything commercial airlines can provide. Since it is private, the passengers can spend much of the four travelling hours in constructive conversation about business matters. Since all eight seats are equally large and comfortable, the "big wigs" do not have to sit in one section but can spread out through the staff people for better communication. You can fill all the seats with real people and fill the tanks and cargo bay. There is a private toilet on board so people can feel free to drink coffee in the morning and a cocktail at night.
I have my 350 loaded with a typical full load of 2x200 pilots, 8x170 passengers, 400 lbs of baggage (40lb per person) and full fuel and still have 142 lbs left over for the over-size employees or extra equipment going to a test site, etc. My total load is 14857 lbs of 15000 max with the CG at 33%. If the two pilots have to fly a leg with no payload, they see 13096 lbs and a CG at 12.1%. That is a significant change but is not overly difficult for pilots to handle. It does not require loading ballast.
We'll make a few flights to show the utility of the aircraft. First let's talk about the controls and how they can be used in various flight situations. Many people are confused when they see three sets of engine levers just like in piston aircraft. One set is the throttles that work very similar to the throttles in a piston aircraft except there is no manifold pressure. The throttle controls power rather directly. I use the percent of throttle position as the guide to setting the throttles though there are several instruments to consider. The percent of position is a handy index for all phases of flight: 100% on takeoff, 80% in climb, 60 to 70% in cruise and 0 to 40% during descent. (Yes, flight idle is a valid power setting in turboprops that does no harm to the engines.) The second set of levers control the prop RPM just as with a piston engine. But they normally have only two settings - max and reduced. Max is used for takeoff, climb and descent. Reduced RPM is used in cruise to reduce the cabin noise level. It has a slight effect on power. The third set of levers are not mixture levers but are called "condition levers." They have three positions: High Idle, Low Idle and Fuel Cutoff. At the start they are set at Low idle. On many flights, they are not changed from that until it is time to pull the levers to fuel cutoff to stop them after parking. Sometimes, high idle is used during descent for increased engine drag. Many modern turboprops only have a set of power levers (throttles). The engines are set to use one RPM throughout all flight and the condition is set to low idle at all times. There is a small lever to shutoff the fuel to each engine.
The throttle levers on turboprops can be moved from idle back into a negative pitch range. This can be done whether the aircraft is in flight or on the ground. This is often used to stay slow when taxiing as many turboprops tend to go too fast on idle speed. Just a touch into the beta range is useful to keep the aircraft slow enough so that brakes are used infrequently. After landing the throttles are pulled fully back into negative pitch to begin the braking process. This continues until the airspeed is below 50 knots when wheel brakes are used. Care must be taken not to injest debris from beside the runway or taxiway which can happen at low speed. There are times when a slight negative thrust can be used on final permitting a very steep approach down over an obstruction into a short field. I have done that with this aircraft many times, particularly going into small ski airfields in the Swiss Alps. I have taken this aircraft into and out of Chourcheval in the French Alps several times. That is a bit of a challenge as the field is short and hangs on the side of a mountain. Then there are several airports down in the valleys between the ski mountains in Europe. This aircraft can do things few aircraft can do. It is more responsive and forgiving than the turboprop airliners.
I recommend that when starting to fly any turboprop, if it isn't already sitting with the engines off, you shut them down (move the condition lever to the cutoff position). Then start them with the ctrl-e sequence. The reason for this is that it is the only way you can be sure the condition lever is set properly in the low idle position. the next thing you need to do after starting the engines is find the generator switches and turn them to the "gen" position. Failure to do this will create excitement in about two or three minutes when the panel goes black. On my panel for the 350 you'll find a small pop-up panel with these swtiches at shift+3. For your knowledge, you'll find a small pop-up panel of four old fashioned air-driven instruments at shift+2 in case you have to fly without power to the fancy glass panel. Incidentally, a recent feature story in FLYING (March 07) showed a very similar panel with a PFD and an MFD. They also have three or four standard instruments hidden at the bottom center of the panel.
The engine instruments we have on my panel are the torque as a % of maximum, the interstage turbine temperature, ITT, the fuel flow in pph, the N1 fan speed in % max, the oil temp in C and the oil pressure in psi. below those values is the total fuel in gallons and the hours of flight time remaining at the current power setting and flight condition. The toruqe is used as the main parameters determining power settings:
90% for takeoff
78% for climb
48% for cruise.
ITT is monitored to make sure it stays below 800C at all times. One pilot operates the throttles on takeoff while the other flies the airplane. The throttles will often need adjustment to keep ITT below 800 during takeoff. Once power is set and the aircraft is in steady climb, the pilot takes full control. in some aircraft such as the Beech 300 which the 350 replaces, the engines tend to surge when power is applied for takeoff. This can cause undesirable yaw as you roll.
On my panel, shift+5 activates the Landing Gauge. The law says I must do three takeoffs and landings before I carry any passengers. I'll do them with just the company of an instructor pilot. This aircraft is too heavy to qualify for single-pilot operation, even with no passengers. I'll use KHSV and practice ILS approaches. Each landing will be made to a full stop on the runway. Then a new weather condition will be selected. We start with Clear Skies.
As I taxied out, 10% throttle was needed to get started but then I went quickly to zero and tapped the brakes. Then I found that, once rolling, 1% was too much and 0% was too little. I rolled along using 1%, 0 and about -1% to control speed.
I have generally used one notch of flap for takeoff to shorten the roll. Mc Clellan says you have to go to zero flaps if you lose an engine so you might as well make all takeoffs at zero flaps. That makes sense so we'll try it. I dialed in 8 degrees of up trim. I rotated at 110 KIAS and began climbing. The torque went to 95% as the throttle was set first at 90% and then 80%. I backed off to 70% for the brief climb to 2500 ft onto a downwind leg. Things go pretty fst in this plane when you just want to fly a pattern. I generally go to 2500 ft and go out about 7 nm on downwind. The trim came down quickly to 1.5 degrees as we levelled off to fly the downwind leg. I had to bring the throttles back quickly to 20% to get the speed back down. At 170 KIAS I noticed the GASP was green and knew that first flaps could come out. It was time to turn back to final. With all that stuff hanging out, I needed 13 degrees trim and 40$ throttle to stay level in the 30 degrees bank. On final with 20 degrees flap we were on the glideslope and descending at 125 kias. I brought the trim to a full 15 degrees. We still decelerated a bit as we began descending in earnest. Half a mile out we set full flaps. We were on the glideslope at 112 kias.
We landed at 96.23 kias and -221 fpm. I did not like having to hold so much back stick on final. I think the cause was the forward CG with only two of us on board. I will change the trim limit (in the aircraft.cfg aircraft geometry section) from 15 to 22. So much trim will not be needed when flying with normal weights.
On the second takeoff I verified that 80% throttle is good for the takeoff when you don't have someone to continuously adjust the throttles. I lifted at about 112 kias. I thought I brought the nose too far up and then pushed it down. That caused a big unwanted dip. A smooth nose-up rotation is required. (I made the change to max trim and was careful to reset the weight for the flight so the CG is once again at 12%.. This time on the long downwind I noticed that 50% thottle gave 48 to 51% torque for a nice short cruise at about 180 knots. Soon I cut to 40% throttle and noticed the GASP was green. I dropped the gear before turning to base leg. I dropped 20 degrees of flaps (1st notch) on base and turned slowly to final. We were on the glideslope after the turn. The throttle went to 20%, 40% and settled on 30% for a while as we held about 114 knots. Then I got a little too slow with full flaps (85 kias) and needed lots of power to keep from getting slower. This set me up for a go around which would have been a good idea. But I decided to use beta thrust to get down and land midway down the 10,000 ft runway. The landing was survivable but not pretty at 82.08 kias and -428 fpm.
Once you start playing with the throttle too much on final, the lag in thrust messes you up and you should simply go around and try again. It is best to move the throttle very little on final. Good thing this was only the second try at landing.
Tom Goodrick
RE: FLYING TURBOPROPS
« Reply #1 on: Oct 14th, 2007, 12:48pm »
PART TWO
We had to taxi back for the next takeoff. We decided to make things a little more interesting. For the third landing we usually do a circuit around the entire metro area at 5,000 ft so our aproach is a little more like it would be from cruise. This time we decided to turn on "Building Storms" weather. That gives us a variety of wind but it is light at the surface and mainly from the south so we use 18L as usual. We may have to pay more attention to the ILS.
Takeoff went as usual. We encountered light turbulence during climb and after levelling at 5,000 ft with 50% throttle (51.4% torque). There was a lot of rocking going on during the flight. There was little yawing. Well, I checked the value of Cn_r. It was -0.5. I changed it to -0.4. I also decided to stiffen it a little in pitch so I increased Cm_adot from 10 to 15. In summary, it was too stiff in yaw and not stiff enough in pitch. Now it should be moderately loose in both axes. With both the autopilot on and the yaw damper (Y/D) it gives a fair ride but there is some movement in turbulence - there will always be. I decided to climb to 10,000 ft for the flight back to KHSV. We had gone over the line into Georgia while making and checking these adjustments. I decided to make one more slight adjustment. I would tighten the pitch a little more by increasing Cm_q a little bit. The value was -35.16. I decided to make it -42. When I went to another aircraft and switched back after making this change, there was a big swing in yaw as the 350 adjusted its flight. Then I noticed the yaw damper had been turned off (probably because the aircraft I switched to had no yaw damper).
The flight back at 10,000 ft looks good. The turbulence moved us around a little but not badly after these changes with A/P on and Y/D on. 50% throttle gave 49.5 % torque. Fuel flow was 293 pph per side. True airspeed was 213 - 219 KTAS in the turbulence.
At 30 nm out we start down to 4000 ft. We made 4000 ft just near the edge of the mountains northeast of the city. We set 40% throttle to come in level toward the west aiming at a point 10 nm north of the airport. Half way there we turned in to get the localizer 5 nm out. We came down to 2500 feet for that intercept. The turbulence was light. We turned off the A/P but not the Y/D to make the ILS intercept.
We were able to make a visual approach but we flew the ILS pretty closely. There was continuous motion and it was challenging to fight the drift of the crosswind. As we passed over the fence we dropped rapidly as we lost a headwind gust but I caught it in time to make a nice touchdown at 85.0 kias and -137 fpm.
The checkout was accomplished with some slight modifications to the aircraft that should make it more realistic. The yaw damper will come in handy at times.
CLIMB/CRUISE/DESCENT
We'll take a brief look at three cruise missions to give you some flight planning info. We'll look at cruising at 10,000 ft, 20,000 ft and 30,000 ft. We'll get the time, distance and fuel used to climb and to descend from those altitudes as well as the cruising data at those altitudes. We'll use the "full house" load: 2x200 lb pilots, 8x170 lb passengers (average), and 10x40 lb baggage. We'll start with full tanks. We'll use the torques recommended by Beech to take off (90 ft-lb), to climb (78 ft-lb) and to cruise (48-50 ft-lb). A More careful look at these torques shows we need throttle positions of 80%, 67% and 49%. We climbed using 1800 fpm direct to 20,000 ft. In cruise at 20,000 ft and 30,000 ft, we set 1500 RPM for a quieter cabin. Descent is made at -1800 fpm with the throttle cut to 0 in three stages.
10,000 ft
CLIMB___________________________CRUISE_______________________DESCENT
T1___5.01min_____________________KTAS__212.3__________________T3__4.23mi n
F1____14gal______________________GPH___88.06__________________F3__2gal
R1___10nm_______________________NMPG__2.41__________________R3__14nm
20,000 ft
CLIMB___________________________CRUISE_______________________DESCENT
T1___10.75min____________________KTAS__215.3__________________T3__10.00m in
F1____27gal______________________GPH___77.91__________________F3__3gal
R1___28nm_______________________NMPG__2.76__________________R3__35nm
30,000 ft
CLIMB___________________________CRUISE_______________________DESCENT
T1___16.67min____________________KTAS__226.9__________________T3__15.67m in
F1____40gal______________________GPH___78.81__________________F3__5gal
R1___47nm_______________________NMPG__2.88__________________R3_58nm
To plan a flight over distance R (from airport A to airport B)
1) Calculate T2=60*(R-R1-R2)/KTAS minutes
2) Calculate F2=(R-R1-R2)/NMPG gallons
Then Time = T1+T2+T3 and Fuel = F1+F2+F3
If R<74 nm fly below 10,000 ft.
If R<113 nm fly below 20,000 ft
If R<155 nm fly below 30,000 ft. Of course, headwinds at high altitude mean flying at a lower altitude.
Beech has done a lot of work with the King Air series to reduce the noise level. Props beating aganst the side of the fuselage create considerable noise. But I remember being able to carry on conversations in the King Air B200 raising my voice only a little. For a few years back in the '90's, Beech experiemented with active noise cancellation in the King Air. I microphone in the cabin records the ambient noise and controls a set of speakers built into the walls to send out a counter sound, 180 degrees out of phase. This is used today in many headsets. But it lead to a lot of maintenance problems. So they have gone to a passive method by installing small tuning forks attached to the inner frame. They are tuned to take out the frequency of the props. These absorb energy from the frame. They are covered as all the walls are in thick accoustic insulation that also helps to cut the noise level. The King Airs remain a comfortable place to spend half a day.
« Last Edit: Oct 14th, 2007, 3:30pm by Tom Goodrick »
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #2 on: Oct 15th, 2007, 10:43am »
In the recent FLYING article, the following cruise speeds were listed for the 350:
Long range cruise at FL330: 237 KTAS
IFR range at Long range cruise at FL350: 1715 nm
High speed cruise at FL240: 312 KTAS
IFR range at high speed cruise FL 330: 1500 nm
There are several problems with this set of specs.
1) The altitudes do not agree. Range or fuel flow should always be given for the same altitude as a speed spec.
2) There should be some indication of the power settings used for these speeds. Either fuel flow or torque would suffice and they must be at the same altitude as the corresponding speed specs.
3) Was RPM reduced as it normally is on Beech turboprops? This reduces total power output through the prop and thus reduces speed.
4) I cannot match the high speed spec with any reasonable power setting. At FL240 with throttle at 80%, torque at 74.4%, I get 265 KTAS, 2x 438 pph.
My FD is just slightly adjusted from the original default FD for FS2002 (used in FS2004 with little change).
There remains some question about the accuracy of our power for turboprop engines. We have no way of judging the accuracy of our setup in the FD.
The long range cruise specs are in line with what I have seen in my FS trials. I avoid anything over 30,000 ft and should avoid 30,000 ft itself because I doubt if this aircraft can ever be flown at those altitudes within US airspace. The reason is it would be run over by all the airliners at those altitudes that travel 100 to 150 knots faster.
« Last Edit: Oct 15th, 2007, 10:51am by Tom Goodrick »
Chris_Ross
Re: FLYING TURBOPROPS
« Reply #3 on: Oct 16th, 2007, 7:22pm »
From the Raytheon Beech Website
Performance
The tables below depict the Beechcraft King Air 350 climb performance. These charts show the time, the amount of fuel consumed, and the distance flown at various takeoff weights and from sea level to altitudes up to 35,000 feet Climb data assumes ISA conditions and no wind.
CLIMB PERFORMANCE
TAKEOFF PERFORMANCE
CRUISE PERFORMANCE
LANDING PERFORMANCE
CLIMB PERFORMANCE Pressure Altitude (ft) Takeoff Weight (lb)
15,000 14,000 13,000 12,000
20,000 Time min 10 9 8 8 Fuel lb 168 153 139 127
Dist nm 32 29 26 24
24,000 Time min 13 12 11 10
Fuel lb 207 187 169 153
Dist nm 42 38 34 31
26,000 Time min 15 14 12 11
Fuel lb 229 207 186 167
Dist nm 49 44 39 35
29,000 Time min 19 17 15 13
Fuel lb 266 238 213 190
Dist nm 61 55 48 43
31,000 Time min 22 20 17 15
Fuel lb 296 262 238 207
Dist nm 73 64 56 49
33,000 Time min 26 23 20 17
Fuel lb 330 290 255 226
Dist nm 86 74 65 57
35,000 Time min 32 27 23 20
Fuel lb 378 324 282 247
Dist nm 107 90 76 66
TAKEOFF PERFORMANCE
TAKEOFF DISTANCE (FT) FLAPS APPROACH — SEA LEVEL
Takeoff Weight (lb) Outside Air Temperature 15°C / 59°F
15,000 3,300
14,000 2,939
13,000 2,737
12,000 2,540
CRUISE PERFORMANCE
Maximum Cruise Power 1500 RPM
Cruise Altitude (ft) Aircraft Weight (lb)
14,000 13,000 12,000 11,000
20,000 KTAS 309 311 312 314
Fuel Flow (lb/hr) 870 872 872 874
24,000 KTAS 309 311 313 315
Fuel Flow (lb/hr) 770 772 774 776
26,000 KTAS 307 310 312 314
Fuel Flow (lb/hr) 720 722 726 728
29,000 KTAS 303 306 310 312
Fuel Flow (lb/hr) 644 648 650 654
31,000 KTAS 298 302 306 310
Fuel Flow (lb/hr) 594 598 602 604
33,000 KTAS 292 297 302 306
Fuel Flow (lb/hr) 548 550 552 556
35,000 KTAS 283 290 295 300
Fuel Flow (lb/hr) 498 502 504 506
Maximum Range Power 1500 RPM
Cruise Altitude (ft) Aircraft Weight (lb)
14,000 13,000 12,500 12,000 11,000
20,000 KTAS 219 214 209 206
Fuel Flow (lb/hr) 458 434 412 394
24,000 KTAS 226 222 220 217 212
Fuel Flow (lb/hr) 432 410 398 386 364
216 205 0 0 199 193 182
26,000 KTAS 228 226 221 215
Fuel Flow (lb/hr) 418 398 376 352
29,000 KTAS 236 230 228 221
Fuel Flow (lb/hr) 408 380 362 336
31,000 KTAS 243 234 230 226
Fuel Flow (lb/hr) 410 374 350 330
33,000 KTAS 241 242 232 230
Fuel Flow (lb/hr) 398 380 344 322
35,000 KTAS 229 240 241 231
Fuel Flow (lb/hr) 380 368 348 314
LANDING PERFORMANCE
Approach Speeds Normal Landing Distance — Flaps Down
Weight (lb) VREF (KIAS) Field Landing Temperature
15,000 109 Elevation Weight 15°C / 59°F
14,000 105 (ft) (lb)
13,000 102 S.L. 15,000 2,692
12,000 100 13,000 2,490
11,000 100 11,000 2,390
10,000 100
Copyright © 2007 Hawker Beechcraft Corporation. All rights reserved | Terms & Conditions | Contact Us
« Last Edit: Oct 23rd, 2007, 8:50pm by Chris_Ross »
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #4 on: Oct 16th, 2007, 8:24pm »
The climb data is pretty close on time and fuel. But the cruise data is way off on speed - like 50 knots worth. That seems to indicate they slipped in a big improvement in the past 16 years that I didn't catch.
My cruise data is fairly close to their "long range cruise" data. I sure don't have any idea what they are doing for "high cruise".
We don't have any idea of what their power settings were.
Today I put together a pair of gauges that show estimates of the power output for each engine. There is no power value made available in the sim as there is for piston engine aircraft. So I estimated it. I made both a single panel gauge and a Popwer_Panel type of gauge that you can pull down for testing. But I am not ready to release them yet. We need to study them a while. Allen Peterson has an engineering background. I've asked him to look at them too. Eventually, we may have a better way of setting up power on Turboprops.
See the discussion in the FS2004 section.
« Last Edit: Oct 16th, 2007, 8:36pm by Tom Goodrick »
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #5 on: Oct 23rd, 2007, 8:47pm »
Here is my best effort for the KA 350 trying to match the data published recently by Beechcraft. I think there is something funny about the way they did their test. It is not at a constant power setting. For some reason they changed the set up at different altitudes.
PERFORMANCE OF KA350 AT HIGH CRUISE
Note: Entire sequence recorded with full data.
Throttle was at 90% all the time.
Prop RPM was at 1500 all the time.
ALTITUDE__KTAS___KIAS___TORQUE%__POWER%__FUEL FLOW pph__ELEV TRIM deg
20,000FT___308.2___231.8_____80.4________75.1________538_____________-8. 03
22,000FT___312.3___227.2_____77.1________72.5________542_____________-7. 77
24,000FT___317.3___223.5_____75.2________71.2________545_____________-7. 55
26,000FT___324.4___221.1_____74.4________71.0________549_____________-7. 41
28,000FT___332.4___219.1_____73.9________70.9________554_____________-7. 30
Before takeoff (630 ft msl) weight was 15,000 lbs with 2300 lb payload and 3610 lb fuel.
CG was at 34.75%
After cruise test (56 minutes, from Huntsville, AL, to 60 nm west of Little Rock, AR,
est 330 nm), weight was 14,014 lbs and CG was at 34.79%. There were 3.28 hours remaining
at that cruise condition.
You could find more economical cruise conditions by using lower throttle settings down to as low as 50%. But if you are in a rush, these will get you there quickly.
I have seen KA 350 data for 16 years and never saw data this high. I think what has happened is that Beechcraft is trying very hard to compete with the new Very Light jets or VLJ designs. indeed, most of them will not beat this. Whether Pratt&Whitney beefed up the engines to last long hours at this pace is unknown.
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #6 on: Oct 24th, 2007, 12:16pm »
KA 350 TURBOPROP CLIMB DATA - SUMMARY (Turboprop_Climb_TestA1)
CLIMB CONDITIONS: 90% THROTTLE AND 1500 RPM. AUTOPILOT LIMITED BY CLIMB RATE
TIME ALT KIAS KTAS CLIMB N1 N2 PPH SHP% TQ% BETA ETRIM
1.01 2166 143.8 146.0 2105 95.57 100.26 556.7 96.84 95.82 26.5 3.64
2.02 4172 181.4 190.2 1847 94.37 88.82 546.1 85.45 95.43 32.6 -3.16
3.03 6076 191.4 206.2 1813 94.07 89.26 543.6 85.33 94.83 33.6 -4.39
4.04 7935 191.4 212.1 1796 94.10 89.79 543.9 84.50 93.36 34.1 -4.42
5.22 10116 186.7 214.0 1792 94.33 90.47 546.0 84.19 92.31 34.4 -3.90
6.24 11969 182.1 215.0 1791 94.58 91.06 548.2 83.95 91.45 34.7 -3.37
7.41 14108 176.9 216.0 1791 94.90 91.78 551.1 83.87 90.65 34.9 -2.71
8.43 15974 172.4 217.0 1789 95.21 92.42 553.9 83.70 89.84 35.4 -2.10
9.61 18149 166.9 217.7 1789 95.64 93.17 557.7 83.45 88.85 35.9 -1.29
10.62 20045 162.3 218.6 1786 96.04 93.83 561.4 83.31 88.07 36.5 -0.76
11.96 22158 162.6 227.0 1495 96.35 94.52 564.1 80.01 83.97 37.3 -0.70
13.14 23972 158.7 228.5 1491 96.82 95.20 568.3 79.06 82.38 37.8 -0.03
14.49 26063 155.4 232.0 1495 97.39 95.96 573.4 79.10 81.78 38.6 0.57
15.67 27875 154.5 238.1 1500 97.86 96.58 577.6 79.09 81.24 39.6 0.75
This was a nicely-formatted table. The first row of data was taken while the RPM was still 1700 from takeoff. After that it was left at 1501. Data was taken every 10 seconds during the climb. The climb was made "hands-off" on autopilot starting with a takeoff at full gross weight. The loading is thesame as for the cruise data above.
« Last Edit: Oct 24th, 2007, 12:20pm by Tom Goodrick »
Chris_Ross
Re: FLYING TURBOPROPS
« Reply #7 on: Oct 25th, 2007, 10:06pm »
I compared the CFG of the kba350 in FS9 AND FSX and found these differences
empty_weight_CG_position = 0.5, 0, 0 // (feet) longitudinal, lateral, vertical distance from specified datum
parasite_drag_scalar = 0.677
fuel_flow_scalar = 0.936
turboprop_engine]
power_scalar = 1.0 //Scalar on Turboprop power
maximum_torque = 3270 //Maximum torque available (ft-lbs)
PowerSpecificFuelConsumption = 0.55 //Brake power specific fuel consumption (turboprop only)
[contact_points]
point.0=1, 13.00, 0.00,-4.70, 1181,0,0.596, 39.9, 0.296, 2.5, 0.9516, 4.8, 4.8, 0, 184.0, 184.0
point.1=1, -1.67, -8.58,-5.03, 1574,1,0.596, 0.0, 0.642, 2.5, 0.8152, 4.5, 5.2, 2, 184.0, 184.0
point.2=1, -1.67, 8.58,-5.03, 1574,2,0.596, 0.0, 0.642, 2.5, 0.8152, 4.8, 4.9, 3, 184.0, 184.0
point.3=2, -3.33,-23.92,-3.00, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 5, 0.0, 0.0
point.4=2, -3.33, 23.92,-3.00, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 6, 0.0, 0.0
point.5=2,-22.67, 0.00, 0.00, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 9, 0.0, 0.0
point.6=2, 23.08, 0.00,-1.50, 787,0,0.000, 0.0, 0.000, 0.0, 0.0000, 0.0, 0.0, 4, 0.0, 0.0
static_pitch = 0.2
static_cg_height = 4.3
[Views]
eyepoint = 4.3, -1.20, 3.35
[deice_system]
structural_deice_type=2 //0 = None, 1 = Heated Leading Edge, 2 = Bleed Air Boots, 3 = Eng Pump Boots
my airfile in FS9 is 15kb and in FSX it is 13kb? Fiddling with air files is so far, beyond me
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #8 on: Oct 25th, 2007, 10:47pm »
As I've said before, I do not support FSX. I do not know why there may be differences in the files. I do not care to know. I would think that a set of FD for FS9 would work in FSX. There might be more things you can adjust or turn on in FSX. But I think the stuff that works in FS9 witll work in FSX. If it does not I don't care. I won't be trying to make anything work in FSX.
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #9 on: Nov 13th, 2007, 12:16pm »
I have updated the FD and panel for the Beech 350 on my web site.
Tom Goodrick
Re: FLYING TURBOPROPS
« Reply #10 on: Dec 6th, 2007, 12:10pm »
I think most of the issues about flying turboprops have been covered. If you have any specific questions, ask them here and I will try to answer or investigate or find an example that sheds light on an issue.
There is one thing that has become clear as a shortcoming of the FS model for turboprops. Now that we have a gauge that shows the percent power set at any time in a turboprop, it is clear that the behaviour of certain aircraft cannot be matched exactly. The problem is the currently popular practice of "flat rating" turboprop engines. With sophisticated controls, an engine is flat rated to operate at a constant power below its max rating while operating from sea level up to common cruise altitudes. In FS whatever power you assign to an engine (through choice of RPM and max torque), the engine produces max power at sea level and declining power with altitude. Thus if I set the power properly and then climb to altitude and set the drag to get the specified cruise speed, the cruise speed at lower altitudes can be a little too fast. I cannot set either drag or power to different settings at different altitudes. The sim has a feature that adjusts power with altitude as it normally would given the density variations affecting simple engines.
I think this problem is relatively minor though it makes some aircraft look faster and more efficient at low altitude than they really are.
