Flight1 Mustang SID/STAR Capability

[spesimen 135]

I take it you have the most recent patched version. What happens if you initiate a climb through say, 8000 at 200kts in FLC mode? Does it porpoise? I'd love to know.

as far as i can tell the porpoising is a bug introduced by using external views or pause. if i stay in the cockpit i get very stable FLC climbs, but when i use external camera or pause the sim, the FD resets instantly to 0 pitch before it gradually moves back to where it was before, leading to the plane trying to chase the FD down and up a few times. it's a little annoying, one of the only things that bugs me about the plane which otherwise flies beautifully.i'm not so sure about the OAT problems either. every issue i had with that seemed related to an earlier build of ASA and went away after switching to 394. haven't really flown it with default weather much.cheers,-andy crosby

[Yoda967 23]

Spaceman,As I write this, I'm "bracing for impact". My original post in this thread was intended as a courtesy to the community at large, and not meant to spark a debate on the merits of the Flight1 offering. Please accept my responses below in the spirit in which they're offered: a genuine interest in being helpful.

From my experience with the Flight1 Mustang, if you set it to FPA mode, everything is solid.

I've never heard of FPA mode. Are you referring to VS mode? If so, you're correct, it's solid as a rock.

Well I have looked at the mustang forums in the past. The reason I'm asking these questions is because I returned the airplane due to missing SID's/STAR's and the faulty autopilot for the most part. I'd love to repurchase it if these things have been corrected, but it sounds like the autopilot is still FUBAR. In the real world, a Mustang cruise climbs at around 200kts. The autopilot should be able to handle such a configuration smoothly. If not, then something still sounds broken.

You're right, there's a YouTube video out there that includes an astonished remark to the effect that the Mustang is climbing at 200 knots, made by a first-time Mustang flyer accustomed to his piston twin , but I don't believe they mention the rate of climb at the time.The Flight1 Mustang will absolutely climb at 200 KIAS, but as with almost any aircraft, indicated airspeed will tail off as you climb. Starting at MTOW and climbing from sea level, you can expect to maintain at least 200 KIAS and a 2,000 fpm climb up to about 12 or 13 thousand feet, depending on air temperature. (Hotter air plus same rate of climb plus roughly constant thrust equals less airspeed.) When folks say that you should be climbing at 170 knots, they're referring to the best rate-of-climb airspeed, which is initially 170 KIAS, and somewhat less at higher altitudes. Now, as I said, you can climb at 200 knots, though as someone else pointed out, you can't expect to maintain that speed above FL250 and climb very quickly. To respond directly to your comment about the autopilot -- you're correct, the Flight1 Mustang's autopilot should be able to handle this kind of demand. It does.

I take it you have the most recent patched version. What happens if you initiate a climb through say, 8000 at 200kts in FLC mode? Does it porpoise? I'd love to know.

What happens is very much dependent on the aircraft's state when you initiate the climb. Let's say that you're at 8,000 feet and you've got the throttles in the CRU detent, so you're cruising at around 245 KIAS. You select a higher altitude (doesn't matter what it is), and choose FLC. The Flight1 G1000 does what the real one does: it sets the FLC airspeed to 245 knots. You'll maintain level flight. If you rapidly dial the speed down to 200 knots, the AFCS will pitch the nose up in order to reduce airspeed, and you'll climb until you reach the selected altitude. But there's a catch -- that rapid decelleration will drive you past the target speed, which causes the AFCS to pitch down so that speed increases. I've seen that happen in many, many MSFS aircaft, enough that I suspect that's how it actually is in the real world. The Mustang has no autothrottle as there is with a Boeing-style autopilot, so the airplane will (as conditions change in the climb) seek to meet the commanded airspeed purely by varying pitch. That's what sets up your porpoising. That is not how FLC mode is intended to be used.

Can you give me the quick and dirty. What is the suggested fix? Not to climb faster than 170kts? I own many advanced payware add-ons, I've never seen one have this sort of problem with the FSX weather system. If my memory serves me, I never had any trouble getting the airplane up to alititude, I just couldn't use FLC mode to do it or it was Mr. Toad's Wild Ride.

Even in the real Mustang, the proper technique is to select the altitude, establish the climb, wait for the airspeed to bleed off to the desired climb airspeed, and THEN select FLC to maintain the climb. This works very well in the Flight1 Mustang. Hope this helps.

[Spaceman3 1]

Kurt,Thanks for your detailed response. Good stuff. Just to clarify. You said:"Even in the real Mustang, the proper technique is to select the altitude, establish the climb, wait for the airspeed to bleed off to the desired climb airspeed, and THEN select FLC to maintain the climb. This works very well in the Flight1 Mustang."I'm fairly sure that was the technique I was using, but it was 3 months ago. So given your example, I'm at holding at an intermediate altitude, say, 8000 and 240kts, in the cruise detent. Then I dial in FL280, advance the throttles to climb power and roll 200kts into the AP, as the plane slows to 200, I hit FLC and it takes it smoothly up to altitude? I understand that the climb rate approaching 280 at 200kts would be low (900fpm or less I'm guessing), but would it handle this scenario ok at that speed? As to your comment about autothrottles, I'm not sure that it should matter in this situation. The throttles will be commanded to climb thrust and the elevator will be used to maintain a constant speed. Just like the EMB's "speed on elevator" mode. The rate of climb is what it is. My only concern is that the airplane does not hunt for the proper air speed.Anyway, I'd be a happy camper if the Flight1 Stang could do this without making me feel like I was at Six Flags.

as far as i can tell the porpoising is a bug introduced by using external views or pause. if i stay in the cockpit i get very stable FLC climbs, but when i use external camera or pause the sim, the FD resets instantly to 0 pitch before it gradually moves back to where it was before, leading to the plane trying to chase the FD down and up a few times. it's a little annoying, one of the only things that bugs me about the plane which otherwise flies beautifully.i'm not so sure about the OAT problems either. every issue i had with that seemed related to an earlier build of ASA and went away after switching to 394. haven't really flown it with default weather much.cheers,-andy crosby

Interesting info. I rarely switch view modes, but since the airplane was new, I may have. That's an odd bug, but one that I could work around.Thanks for the info.

[SAS263 1]

"Even in the real Mustang, the proper technique is to select the altitude, establish the climb, wait for the airspeed to bleed off to the desired climb airspeed, and THEN select FLC to maintain the climb. This works very well in the Flight1 Mustang."I'm fairly sure that was the technique I was using, but it was 3 months ago. So given your example, I'm at holding at an intermediate altitude, say, 8000 and 240kts, in the cruise detent. Then I dial in FL280, advance the throttles to climb power and roll 200kts into the AP, as the plane slows to 200, I hit FLC and it takes it smoothly up to altitude? I understand that the climb rate approaching 280 at 200kts would be low (900fpm or less I'm guessing), but would it handle this scenario ok at that speed? As to your comment about autothrottles, I'm not sure that it should matter in this situation. The throttles will be commanded to climb thrust and the elevator will be used to maintain a constant speed. Just like the EMB's "speed on elevator" mode. The rate of climb is what it is. My only concern is that the airplane does not hunt for the proper air speed.

Close, but allow me to suggest a few changes to your style :)Ok, we

[Spaceman3 1]

Yeah, sorry I wasn't clear. I know you manually control thrust in cruise, but I thought the annunciator showed crz or something like that. It's been awhile, so I could be wrong.I'll trust you that it works ok using the method described. I guess my only other question is if this is the real world procedure? One would think that you should be able to go from cruise into flc mode directly as vs mode serves an entirely different (obviously) purpose than flc. If the method you just described is more of a work around, I can be ok with that (to get it to work smoothly), but it just seems a bit awkward.Thanks again.

[SAS263 1]

Yeah, sorry I wasn't clear. I know you manually control thrust in cruise, but I thought the annunciator showed crz or something like that. It's been awhile, so I could be wrong.I'll trust you that it works ok using the method described. I guess my only other question is if this is the real world procedure? One would think that you should be able to go from cruise into flc mode directly as vs mode serves an entirely different (obviously) purpose than flc. If the method you just described is more of a work around, I can be ok with that (to get it to work smoothly), but it just seems a bit awkward.Thanks again.

I

[FalconAF 213]

And keep in mind...comparing the Mustang to any other business class jet can be very misleading. It isn't a Lear 45. It's a VLT...Very Light Jet. Those two engines hanging on the side are nowhere near as powerfull as other business class jets. Once you get above FL 250 in the Mustang, it just isn't going to continue to climb like a Lear 45. Especially if you have a full fuel load and/or took off at close to maximum operating weight limits. The service ceiling of it may be FL410, but you ain't gonna get there with your hair on fire, or anything close to max weight loads from an initial takeoff. Those engines just aren't powerfull enough to do that.The Mustang forums have several posts in them from real-world Mustang pilots who explain how to fly this thing. The biggest "complaints" about the Mustang when it was first released were from users who expected it to fly like a B737 or the Lear 45. You just CAN'T expect that type of climb performance out of it as a VLJ. And yes...one of the real-world Mustang pilots in those forums said in one of his tutorials that the RECOMMENDED and STANDARD climb speed for the Mustang is initially 170 knots...as stated in the Operating Manual that comes with the Flight1 Mustang. So if you ARE flying it with climb speeds of 200 knots, you are NOT doing it as the real world pilots normally do it.The other main problem people experience is they DON'T understand how to correctly use the autopilot system in the Mustang. There is a proper and improper way to initiate climbs and descents with it, and it is not intuitevly the same as using most other autopilot systems, due to lack of an autothrottle system. All the "proper" ways ARE discussed by these real-world Mustang pilots in the Mustang forum tutorials they posted. When you use THOSE ways to do it, which do coincide with the included Operating Manual that comes with the Mustang, the Mustang works perfectly. But the PERFORMANCE of the Mustang may still suffer from using the default FSX OAT temperatures at altitude, if that is what you are using in FSX. One "fix" for this is to use the FSX Advanced Weather Settings screen to change the upper altitude temperatures to something more realistic if you are using default FSX weather. Most third-party weather generation programs that use real-world weather downloads will have much more accurate upper altitude temperatures if you use those programs.FalconAF

[SAS263 1]

Just to add to our statements regarding climb speeds. Look at this short video of a flight test...ish of a Mustang. Pay attention to what speeds the pilot is talking about, it

[martin-w 3,239]

To be honest chaps, I don't know if i'm missing something, but i'm not sure what all the fuss is about. :( FLC in the Mustang is not akin to flight level change in an airliner. It's more akin to indicated airspeed hold. Pitch is automatically adjusted to maintain the target airspeed. Therefore, of course there will be variations in pitch [call it porpoising if you like] because that

[Yoda967 23]

Thanks, Martin.I took the time last evening to do a little flight testing, first to see how the Mustang performs in a 200 KIAS climb to FL280 with FLC selected, and second, to compare this performance with the Cessna-recommended 160-170 KIAS climb. I started at KMYF runway 28R, weather clear, default takeoff speeds, flaps set to TO/APR. Started the timer for each run when I advanced the throttles to TO. On liftoff, I held ten degrees nose up pitch until the aircraft was cleaned up (gear up, flaps up, throttles in the CLB detent), then went on the AP in VS mode at 2,000 fpm climb until the Mustang had accelerated to the desired climb speed. In both cases, the Mustang was still accelerating fairly rapidly, so to minimize the inevitable zoom, I increased the VS to maintain the desired climb airspeed before selecting FLC.In both cases, climb in FLC mode was stable, with airspeed maintained within plus or minus 1 knot. At 200 KIAS, the variations in climb RATE were significant, though the speed was maintained. At 200 KIAS, I had about 850 fpm of climb going at FL270. The airplane did not overshoot the selected altitude.At 200 KIAS, time to climb was 18:15, distance traveled 75 miles, fuel used 364 pounds.At 170 KIAS, time to climb was 12:30, distance traveled 47 NM, fuel used 224 pounds.What I found interesting about the 170 KIAS climb was that after leveling off and accelerating to cruise airspeed (220 KIAS or so), the Mustang was just about 75 miles from the field at the 18:15 mark, but had used less fuel (287 pounds). Basically, there was no time savings by climbing at a faster airspeed, but the slower airspeed climb offered a significant advantage in fuel consumption. Them Cessna boys are WICKED smart!

[Spaceman3 1]

To be honest chaps, I don't know if i'm missing something, but i'm not sure what all the fuss is about. :( FLC in the Mustang is not akin to flight level change in an airliner. It's more akin to indicated airspeed hold. Pitch is automatically adjusted to maintain the target airspeed. Therefore, of course there will be variations in pitch [call it porpoising if you like] because that

[Spaceman3 1]

Thanks, Martin.I took the time last evening to do a little flight testing, first to see how the Mustang performs in a 200 KIAS climb to FL280 with FLC selected, and second, to compare this performance with the Cessna-recommended 160-170 KIAS climb. I started at KMYF runway 28R, weather clear, default takeoff speeds, flaps set to TO/APR. Started the timer for each run when I advanced the throttles to TO. On liftoff, I held ten degrees nose up pitch until the aircraft was cleaned up (gear up, flaps up, throttles in the CLB detent), then went on the AP in VS mode at 2,000 fpm climb until the Mustang had accelerated to the desired climb speed. In both cases, the Mustang was still accelerating fairly rapidly, so to minimize the inevitable zoom, I increased the VS to maintain the desired climb airspeed before selecting FLC.In both cases, climb in FLC mode was stable, with airspeed maintained within plus or minus 1 knot. At 200 KIAS, the variations in climb RATE were significant, though the speed was maintained.

Big time thanks for performing this test. Did variations you mentioned at any time include a loss of altitude? So per your test, I'm hearing that FLC is still not that stable at speeds over 170. Just so long as it doesn't command a descent to recover airspeed.

What I found interesting about the 170 KIAS climb was that after leveling off and accelerating to cruise airspeed (220 KIAS or so), the Mustang was just about 75 miles from the field at the 18:15 mark, but had used less fuel (287 pounds). Basically, there was no time savings by climbing at a faster airspeed, but the slower airspeed climb offered a significant advantage in fuel consumption. Them Cessna boys are WICKED smart!

Well no time savings getting to altitude, but on a short flight you'd cover more ground. The idea is that you would trade fuel efficiency for speed (over the ground) and better visibility.Thanks again.

[FalconAF 213]

Hate to disagree with you, but the way you describe it, FLC mode would be useless. It's used specifically for accomplishing climbs OR descents at a selected speed.

Not sure exactly what you mean by the second sentence, but if you are saying the Mustang FLC mode CAN or SHOULD ONLY be used to control SPEED, or should control BOTH rate AND speed BY ITSELF in climbs and descents, then I have to disagree with your conclusion. That belief is what caused many Mustang purchasers to think the autopilot is broke and doesn't work correctly.Your second sentence should say, "The FLC mode is used for accomplishing climbs or descnts at a selected speed OR rate, but can not do BOTH at the same time by itself in all flight configurations. Pilot intervention in manually managing the throttle settings MAY BE required, as the FADAC system does not perform the same way as a fully-functional auto-throttle system in all flight regimes."You can use the FLC mode to select a desired speed, OR a desired Feet Per Minute Rate (of climb or descent). You have a CHOICE of which one you want to use. But you can't select BOTH a speed AND rate at the same time, like you can with an auto-throttle equiped aircraft. The FADAC system is NOT an auto-throttle. It REQUIRES the pilot to still MANUALLY position the throttle in one of the DETENT positions...Climb, Cruise, T\O, etc, OR manage the throttles OUTSIDE one of those detent positions manually. Note there is NO "Descent" detent position. This is what is confusing a lot of sim pilots who are used to using an auto-throttle equiped airplane prior to using the Mustang.If I want to descend, I can use the FLC to set EITHER a desired SPEED, OR a desired RATE of descent...but not BOTH at the same time. In either case, I as the pilot MAY HAVE to manually adjust the throttles to a PERCENTAGE of engine power BELOW "Cruise Detent" position to establish a flight configuration that won't rip the aircraft apart.In a climb, even if I have the throttle positioned in the FADAC's "Climb Detent" position, IF I set any parameters of the FLC (speed or rate) "out of range" of the Mustang's performance envelope (for instance, asking it to maintain a 2000 FPM rate of climb at FL350), the aircraft may not be able to DO that and maintain an acceptable airspeed that would prevent a stall. Airspeed could bleed off to the point of stalling the Mustang. PORPOISING will occur when the pilot has used the FLC in an incorrect manner or "sequence", or made settings (speed or rate of climb/descent) that result in the aircraft being incapable of continuing to fly within safe operating limitations. The Mustang will then osscilate back and forth pitch-wise to TRY and do what the pilot has requested. But it is a "pilot error" induced osscilation by improper use of the FLC, or improper rate or speed request settings for the current flight regime, which result in the FADAC system not being able to DO what the pilot wants, even if it is in the "correct" throttle detent position. As a pilot, I can induce the same "porpoising" in the Mustang using the throttles manually if I insist on doing it by constantly changing the throttle setting during a climb or descent. The FADAC system will do the same thing if you use the FLC mode to set an improper speed or rate request for the current aircraft's flight regime...like asking it to maintain an unrealistic speed or rate during a climb when the OAT just won't support those speed and rate performance capabilities of the aircraft at the same time.FalconAF

[Spaceman3 1]

Not sure exactly what you mean by the second sentence, but if you are saying the Mustang FLC mode CAN or SHOULD ONLY be used to control SPEED, or should control BOTH rate AND speed BY ITSELF in climbs and descents, then I have to disagree with your conclusion. That belief is what caused many Mustang purchasers to think the autopilot is broke and doesn't work correctly.

I know what FLC should do. As I explained earlier in the thread, it should use the elevator to hold a constant speed. What I was seeing was it trying to do that, but over controlling, resulting in a climb then a dive then a climb. That's what I'm talking about.

Your second sentence should say, "The FLC mode is used for accomplishing climbs or descnts at a selected speed OR rate, but can not do BOTH at the same time by itself in all flight configurations. Pilot intervention in manually managing the throttle settings MAY BE required, as the FADAC system does not perform the same way as a fully-functional auto-throttle system in all flight regimes."

Where did you read that I expected the AP to manage the throttles in any way? I never said that.

You can use the FLC mode to select a desired speed, OR a desired Feet Per Minute Rate (of climb or descent). You have a CHOICE of which one you want to use. But you can't select BOTH a speed AND rate at the same time, like you can with an auto-throttle equiped aircraft. The FADAC system is NOT an auto-throttle. It REQUIRES the pilot to still MANUALLY position the throttle in one of the DETENT positions...Climb, Cruise, T\O, etc, OR manage the throttles OUTSIDE one of those detent positions manually. Note there is NO "Descent" detent position. This is what is confusing a lot of sim pilots who are used to using an auto-throttle equiped airplane prior to using the Mustang.

I think you're confusing FLC mode and VS mode. FLC should be used to maintain a constant speed. VS to maintain constant rate.

If I want to descend, I can use the FLC to set EITHER a desired SPEED, OR a desired RATE of descent...but not BOTH at the same time. In either case, I as the pilot MAY HAVE to manually adjust the throttles to a PERCENTAGE of engine power BELOW "Cruise Detent" position to establish a flight configuration that won't rip the aircraft apart.In a climb, even if I have the throttle positioned in the FADAC's "Climb Detent" position, IF I set any parameters of the FLC (speed or rate) "out of range" of the Mustang's performance envelope (for instance, asking it to maintain a 2000 FPM rate of climb at FL350), the aircraft may not be able to DO that and maintain an acceptable airspeed that would prevent a stall. Airspeed could bleed off to the point of stalling the Mustang. PORPOISING will occur when the pilot has used the FLC in an incorrect manner or "sequence", or made settings (speed or rate of climb/descent) that result in the aircraft being incapable of continuing to fly within safe operating limitations. The Mustang will then osscilate back and forth pitch-wise to TRY and do what the pilot has requested. But it is a "pilot error" induced osscilation by improper use of the FLC, or improper rate or speed request settings for the current flight regime, which result in the FADAC system not being able to DO what the pilot wants, even if it is in the "correct" throttle detent position. As a pilot, I can induce the same "porpoising" in the Mustang using the throttles manually if I insist on doing it by constantly changing the throttle setting during a climb or descent. The FADAC system will do the same thing if you use the FLC mode to set an improper speed or rate request for the current aircraft's flight regime...like asking it to maintain an unrealistic speed or rate during a climb when the OAT just won't support those speed and rate performance capabilities of the aircraft at the same time.FalconAF

Asking the Mustang to climb at 200kts is well within the established flight envelope and is realistic per real world operations. As I've said, real world Mustang pilots have reported using this as a cruise climb speed. Not every pilot always uses the best rate of climb (for various reasons), as a result I'm certain the AP in the real Mustang handles speeds higher than best rate smoothly.Again, you're shadow boxing. I'm was not expecting the airplane to do anything out of the ordinary.Anyway, it sounds like the work around should make the airplane flyable. That, and the addition of SID's and STAR's is probably enough for me to pick it up.

[SAS263 1]

Anyway, it sounds like the work around should make the airplane flyable. That, and the addition of SID's and STAR's is probably enough for me to pick it up.

Not trying to be a smartalec here, but you keep refering "the work around". What precisely in our explanations on how to properly manage the airplane is it you consider to be a work around? I