inflight emergency

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Cliff Wimberly
Airman
Posts: 42
Joined: 10 Jul 2015, 16:56

inflight emergency

Post by Cliff Wimberly »

Is there a way to get rid if the inflight emergency that pops when approaching a low fuel state 20% +/-?
The Pilot comes on line and apologizes to the passengers for a non existent inflight issue. No problems are to be found in the aircraft except that the fuel might be a bit low but absolutely not critical.

flapman
Staff Sergeant
Posts: 457
Joined: 10 Oct 2013, 21:35

Re: inflight emergency

Post by flapman »

Long standing issue, at this point I just ignore it.. expect it on almost every flight.

Cliff Wimberly
Airman
Posts: 42
Joined: 10 Jul 2015, 16:56

Re: inflight emergency

Post by Cliff Wimberly »

Roger that Flapman. I will continue to ignore.
I was hoping that some super savvy pilot had discovered a fix.
Thanx for the reply

ROB - A2A
A2A Colonel
Posts: 3647
Joined: 02 Mar 2004, 02:56

Re: inflight emergency

Post by ROB - A2A »

Current low fuel vocal warning is set to something like below 10%. And there is another one, more alarming, set at almost empty state. How about we make that first warning to trigger at 5%?

regards
ROB
A2A Simulations Inc.

TreeTops
Master Sergeant
Posts: 1086
Joined: 07 Apr 2010, 06:13

Re: inflight emergency

Post by TreeTops »

5% or less would be reasonable Scott. 5% equates to about 30 minutes fuel?
Cheers
Trev

flapman
Staff Sergeant
Posts: 457
Joined: 10 Oct 2013, 21:35

Re: inflight emergency

Post by flapman »

Rob,

Please see the case I made for new trigger values below, TLDR:

5.57% First warning,
3.71% Emergency threshold.
based on total fuel quantity for all tanks.
flapman wrote: 21 Sep 2017, 23:03I disagree that these numbers are appropriate for the L-49. I don't think you're considering how large these fuel tanks are. The fuel and payload manager (and the aircraft.cfg) show tanks 1 & 4 have 1550 gals, and tanks 2 & 3 have 820 gals. For a power setting, lets use FL220 off the chart (2160 RPM, 120 BMEP) and 353 total gal/hr.

Current U.S. airline regulations use the standard "fly to most distant alternate, then 45 minutes" IFR reserve requirements for all domestic operations. Including propliners. Of course we live in a different regulatory environment than the late 1940's when our Connie entered service, but it's a good standard to work with.. and probably close to the margins they used anyways.

If I use the :45 standard, here are the fuel tank percentages which would equal standard domestic IFR fuel regulations in the Constellation.

4.27% fuel in tanks 1 & 4, which would be 8.07% in tanks 2 & 3. This leaves a little over 66 gal in each tank.

And really, 66 gallons isn't an emergency situation. If you're over the alternate with this little amount of gas on board, you still have the full IFR reserve. In the airline world, we generally don't declare an emergency until we reach :30 fuel endurance. Expecting to land with less than :45 justifies a "minimum fuel" advisory at most.

If we go off the :30 standard.

2.85% fuel in tanks 1 & 4, which would be 5.38% in tanks 2 & 3. This leaves a little over 44 gal in each tank.
And this is using 353 total gallons burned per hour, almost the highest charted fuel burn.

ROB - A2A
A2A Colonel
Posts: 3647
Joined: 02 Mar 2004, 02:56

Re: inflight emergency

Post by ROB - A2A »

Sure, I can make it 5.57% and 3.71%.

regards
ROB
A2A Simulations Inc.

TreeTops
Master Sergeant
Posts: 1086
Joined: 07 Apr 2010, 06:13

Re: inflight emergency

Post by TreeTops »

These warnings would be triggered by total fuel remaining and not minimum for any tank?
Fuel tanks should be balanced at the landing phase we know, but the lowest tank shouldn't be the trigger.
Cheers
Trev

ROB - A2A
A2A Colonel
Posts: 3647
Joined: 02 Mar 2004, 02:56

Re: inflight emergency

Post by ROB - A2A »

By % of total fuel.

regards
ROB
A2A Simulations Inc.

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