Can anyone explain this ?

[Christopher Low 5,353]

I have just attempted a short flight in the Beechjet between Tacoma Narrows and Gray Air Force Base. In fact, I have attempted it THREE times, and I have experienced both engines shutting down on final approach.....every time. I am flying in heavy rain.Is there an explanation for this ?Chris Low.

[Guest Seadog]

In the Peter James article about the Beechjet, he advises in "Secret #2, "Run your ignition during areas of moderate or heavier rain, expected turbulence, and any crosswinds you're going to hit on landing or takeoff," and "Run your boost pumps during actual turbulence." All this appears under the heading "Flameouts."Of course, I haven't actually tried any of this as I'm still monkeying around with my computer trying to get the CH USB controllers to work properly.x( HTH, Seadog

[Christopher Low 5,353]

How do I "run the ignition", or "run the boost pumps" ? :-eekChris Low.

[Christopher Low 5,353]

Well, I can't touch the ignition switches in flight, so that's a waste of time. As for the boost pumps, am I supposed to flick them on and off, rather than just keep them on ? I tried keeping them on for the duration of the flight, but the engines failed YET AGAIN during final approach :-fumeChris Low.

[Christopher Low 5,353]

Flicking the boost pump switches on and off does NOT solve the problem.Chris Low.

[Christopher Low 5,353]

I must be missing something here. Perhaps I should send the weather file to one of you lot, and then you could attempt the same flight ?Damn these people who go out on a Saturday night :-fumeChris Low.

[Guest Seadog]

Call me clairvoyant, but I sense a degree of frustration. Chris, I have virtually no experience with this program - yet - and am only qualified to pass along the wisdom I've received from others. That said, I just took the Beechjet up for the very first time, and was able to operate the ignition while flying. I was in the F3 view, and clicked open the overhead instrument panel and mouse clicked the on-off toggle for ignition in the lower left section of that panel, adjacent to the boost switches. I did it multiple times, and they properly toggled on and off each time. For me, they are operable during flight. Whether that would solve your flameout problem is a different question. That's really all I can say, and we'll have to wait for someone with much more knowledge and experience to help you further. Which I fervently pray comes soon.-Seadog

[Christopher Low 5,353]

You can operate flick the ignition switches on and off without the engines shutting down ? :-eek I wonder if you need to have ENGINE FAILURE switched to ON in the AIRCRAFT options menu ?Chris Low.EDIT: Nope, that doesn't make any difference. If I flick the ignition switch to OFF when the engines are running, they shut down.

[Guest Seadog]

We really must be talking about two different things. What I am describing is how the original, stock, FU3 Beechjet, US version, patched, operates on my computer. I have found one, and only one, way to shut down the engines on purpose, using Ctl + E. Toggling the igniter switches on the overhead panel above the magnetic compass will not affect anything other than turbine speed. If you're using a non-original, non-stock, modified Beechjet, all bets are off.Here's what the printed FU3 manual says on page 83:"The IGNITION is for "backup" for the most part. It is a steady state firing of sparks into the fuel flow instead of the once only firing during startup on the ground. If you turn this on, you are running the igniters "in the background" so to speak. Pilots use this during takeoff or landing as a precaution for actual engine failure, just like small airplane pilots run fuel pumps. This ignition should be used also during heavy precipitation and icing conditions where engine "flameouts" can occur."BOOST PUMPS should be left in AUTO all the time. The lights illuminate showing you're in auto mode. Shutting them off will not hurt much, but if for some reason fuel flows are weak or sporadic in nature, you could have engine failure. Note that engine startups can be done with this switch off."And the checklist on page 105 shows turning on both the boost pumps and the igniters prior to takeoff and turning off the igniters during climbout, and turning igniters on again just prior to landing. So they are meant to be turned on and off without shutting down the engines.Nothing I do with the Engine Control Panel in the lower left of the main instrument panel affects engine operation once they are running.I hope this helps you isolate the problem you're experiencing. And, please, would someone who knows far more than I help this good man?-Seadog

[Christopher Low 5,353]

I have just tested the igniters with the Beechjet parked in sunny weather. I switched the igniters off when the engines were at idle (20.8 per cent power). The power reduced to 19.8 per cent. In other words, the engines remained ON.So why do the engines totally shut down when I use my bad weather file ? They do so even when I am sat on the parking spot at Tacoma Narrows with the engines at IDLE power. Turn the igniters off, and the power is gone.Weird :-eekChris Low.

[Guest Ansgar]

Hi Chris,I just tested the standard Beechjet at Takoma and found the same than you regarding the little rpm drop to 19.8 after switching the ignition OFF.So this seems OK. The problem with flameout at bad weather I have not - also at bad weather with 39mph wind.Is it possible that you have an extremely crosswind which causes an flameout or so? We all know that the sensitive flameout is a small problem at FU3 jet fans. I experimented a lot with that at the B747-400 and definitely found no solution to make it more realistic = unsensitive.The only reason for your effect seems an strange crosswind which cause then an flameout at low rpms. Which wind did you have from what direction?Try to change these a bit with an new or other bad weather definition should solve then the problem.Ansgar A

[Guest Seadog]

Gratified to see the igniters work properly under normal conditions, but your Bad Weather File might be from an alternate universe. Knowing absolutely nothing about that universe, I can only speculate that operation of the igniter switches in that alternate universe triggers a command which shuts down the engines.I've now found a second way to kill the engines, through the mixture control. In joykeys syntax, the regular way is "key_ctrl_e" and the new one is "key_ctrl_kp_-" to decrease the mixture. (The leading "key_" is optional.)All I could suggest at this point is to search your bad weather file for one or the other of those combinations, either standing alone, or as a temporary command console binding instruction. If this is irrational or futile, it only shows how little I know, but those are the only ways I can see to kill the engines. I'd feel more confident about this approach if I could find a joykey command which toggles the igniters (which might thus be inadvertantly remapped), but I can't.Just to show no effort is wasted, all this research led me to an interesting discovery. I've been unable to make the mixture lever work on my CH USB yoke, you may recall. Closely reading the printed Keyboard Reference card shows some joysticks allow you to press Button 4 and move the yoke in and out to control that lever, et, Voila! Works on mine. Now all I have to do is figure out how to remap that button to the proper axis and give that a try. So, thanks for inspiring the effort.-Seadog

[Christopher Low 5,353]

You're welcome, Seadog :-)By the way, Hans Petter Roverud has confirmed the problem of the Beechjet engines shutting down. I sent him my weather file, and he experienced the same problems.Chris Low.

[Christopher Low 5,353]

Ansgar,I generated a bad weather file (a warm front with heavy rain), and then reduced the front speed and before and after wind speeds to 1, 2 and 3 mph respectively. These winds aren't very strong, although I am not ruling out the possibility that FU3 is still considering them to be so. There is very little buffeting (as you would expect), but there could be a bug that makes the software still "think" that the winds are 50+ mph ! :-eekChris Low.

[Hans_Petter 1]

I just tried this weather file for another flight. Rather than heading towards Gray I went for Seatac. The same thing happened -- after flying for a couple of minutes the engines died. However, by pressing "E" they came back to life. I barely avoided the terrain as I started climbing again. I gave up on Seatac and focused on climbing. All seemed well until the engines died again. I recovered once more by pressing "E". A couple of minutes later the engines died again. This time they were in the process of revving up as my belly touched terra firma.It may seem this weather file programs for engine failure every two minutes or so.Still, pressing "E" does restart the engines.Another test might be to use this weather file with a piston engine aircraft. It might very well be that the buffeting of sudden gusts of wind blows out the jet engines. As we know, the FU III jet engine model is overly sensitive to engine stall. In any event, the engines do restart but rarely in time for a recovery, And, it's got nothing to do with Gray.Hans Petter