Can't Get Started - Again!

[Tom Goodrick]

I seem to run into this every few months. The last time was on the Boeing 314 after making some changes. I solved that problem but don't remember all the details. It happens every so often. We take for granted that holding ctrl and tapping E will start the engines on any plane. Then it doesn't work.

I have been working on the Queen Air by Stone. The original plane did not have turbocharging so I have been setting that up. A week or so I had this trouble and I just boosted the starter torque in this line:
normalized_starter_torque= 0.600

I have managed to get all power-related parameters to look good in flight. Then after many tests and many adjustments of power-related parameters, I have run into the no-start problem again. This time "reasonable increases" in the starter torqu have not worked. I have looked at comparable aircraft - the Beech 18, the Duke, the Baron, The DC-3, other "light" piston twins, etc. They all use starer torques no greater than .6 and most are down around .3. With .6 I can get the Queen Air's engine tocrank 95 rpm for a while and then it just shuts down. But when I watch the rpm on other aircraft as they start, most fire before the rpm even gets to 90. Some do crank at 700 for a while before they fire. I think that may be closer to reality.

I thought the problem may be a fuel shut-off switch that was not being turned on. But that is not the case because I have the Baron throttle quadrant with its fuel selectors. You can set them to OFF and Ctrl-E sets them to ON as it moves the mixtures to full rixh.

Any other ideas?

[Bill Von Sennet]

Are you sure there is fuel in the tanks being selected?

If you start with another plane that is running, then switch to the Queen Air does it stop?

[Bill Von Sennet]

Is there fuel in the tanks that are selected?


If you start with another aircraft that is running and swith to the Queen Air does it keep running.

----------------
I recall you asked if the Queen Air is pressurised.


Only the Model 88 beginning in 1965 was pressurised.

[Tom Goodrick]

You've got the answser. Thanks!

The left and right tanks were zeroed and all the fuel was in the center tank as an easy way to get weight below the limit. But the fuel tank selector only has left and right tanks.

So there was no fuel in either tank selected!!

Yes, if I start another aircraft and then switch to the Queen, it runs fine.

I am going to split the center tank.

[Tom Goodrick]

Well, that was not the fix. And I should have know based on the development history. While working on the gear drag (which started all this), I noticed it would not start. I boosted the starting torque a little and it started okay. This time I split the center tank into two halves so my selector could select them as left and right mains and that did not solve the problem! I decided I would try a starter torque of 5.0 (far larger by a factor of 10 than most starting torques). It worked fine. It kicks the engine up to 700 rpm where it fires. one of the things I also verified tonight was that a large prop is needed to enable the prop levers to control rpm in normal phases of flight. This was what I had done earlier that had caused starting to stop working. I'd like to have the props at 6.17 ft diameter which agrees with the real aircraft. But it needs 7 ft props to give real engine numbers in flight while enabling prop control. 65% power happens at 34 inches and 3000 rpm as with the real aircraft (at 8500 ft where you also get 35 gph and 175 KTAS (153 KIAS). So now the Queen Air works. works.

[n7rg]

well with the above information, and if this was a real life problem, I would start with the mag starting system like impulse or Energize.
It sounds like your must bring RPM up to the mag kick in speed.
I have no idea if the sim model this, but some plans will not start
without the Energize switch on ( DC-3-C )