Simviation Forums

G'day all,

I'm currently preparing for my first true cross country flight departing at 08272000 (6 am local time). The flight is from Moorabbin Airport, which is to the south east of Melbourne, to Bankstown Airport west of Sydney. Total flight time is expected to be around 4 hours, covering a distance of about 400nm.

What I need help with is deciding whether I should land and refuel enroute or not. I've crunched the numbers out using a standard fuel flow of 36 litres per hour. Best case scenario (20 knot tail wind for every leg) will see me arrive with 48 litres margin fuel (excluding reserves). Assuming worst case (20 knots head wind for every leg) I will arrive over head the aerodrome and just enter into my reserves. Assuming most likely for this time of year, a quartering tail wind, I should arrive with about 10-20 litres of margin fuel.

As most would understand, 36 litres per hour is quite conservative and if the aircraft is leaned it will only use 30-32 litres per hour. I would prefer not to land and just go direct, but I also want to be on the safe side.

I ask those which have more experience than I, with these numbers in which cases would you plan a fuel stop?

I try to be my over-the-top, on the safety side of fuel planning. I've been in a plane where an unexpected headwind put me WELL into reserves.

IT AINT FUN

Now.. I've also got a buit-in safety device (my bladder is only good for 2.5 hours of flying at a time), so I'm rarely pushing the limit.

ANYWAY (using non-metric volumes)( 40 gals available.. 9GPH).. a C172 has a 4 hour duration with full tanks (that leaves just about 1/2 hour of VFR reserve)

If your bladder can take it.. I'd PLAN for for no fueling,, but MAKE SURE it's a viable option. I know that's obvious advice, but it's the only real answer to your question.

Thanks Brett. I understand what you're saying, I'll assess the forecast winds on the day and make my decision on that knowing that I'll most likely be able to do a non-stop. In the aircraft I'll keep on top of my ground speed, time intervals and fuel consumption. My planned refuelling point is an aerodrome I'll be overflying enroute, so if things aren't going as expected I can always drop in for a drop.

On the other note, my bladder doesn't pose a problem. It could easily outlast the endurance of a 172

Two general rules of thumb:
1) An hour reserve for VFR is wise.
2) If the trip is a RT with the return on the same day, forget any benefit from a tailwind on the way out.

1) An hour reserve for VFR is wise.

That's the truth, brother. Get into that hour and you'll get to see the minute-hand on your watch move like a sweep, second-hand..

2) If the trip is a RT with the return on the same day, forget any benefit from a tailwind on the way out

More infinite sage-dom..

Using today's winds (which should be similar to tomorrows) I'll be arriving with a 39 litre margin on top of my 45 minute reserve, so that should give me nearly 2 hours in the tank on landing.

It isn't going to be a round trip, just a one way with the return flight on Tuesday. I'm going to assume I'll have to land and refuel on the way down due to a likely headwind.

Using today's winds (which should be similar to tomorrows) I'll be arriving with a 39 litre margin on top of my 45 minute reserve, so that should give me nearly 2 hours in the tank on landing.

It isn't going to be a round trip, just a one way with the return flight on Tuesday. I'm going to assume I'll have to land and refuel on the way down due to a likely headwind.

That's not exactly conservative (be sure to check your groundspeed ASAP after leveling off; yesterday's winds may be of no use at that point), but it should work out well enough.

If I were you, though, I'd plan on a possible stop halfway or thereabouts... after 2 hrs you may need a break, or wind or weather may force your hand.

I flew a 4-hr leg in a Skyhawk once; it was plenty long enough. My fuel planning worked out just right, but it easily could have gone sour.

In any case, it's better to have that Plan B prepared rather than have to whip it up while in flight.
When you approach that field, decide then whether or not you want to stop there.
good luck, and have fun!!  :)

The flight went well and I didn't need to put plan B into use. Once levelled off and leaned I was burning about 24 litres per hour with a ground speed averaging 113 knots. I landed with about 80 litres left on board

When flying a cross country I always keep fuel my fuel above half tanks in case of a delay or I get send into a hold for a couple of hours gawd forbid if my aircraft burns 10.9 gallons per hour I will caculate it at 13 gallons in case I catch a really bad headwind my numbers give me room for reserve I would plan a stop when tanks get below half

When flying a cross country I always keep fuel my fuel above half tanks in case of a delay or I get send into a hold for a couple of hours gawd forbid if my aircraft burns 10.9 gallons per hour I will caculate it at 13 gallons in case I catch a really bad headwind my numbers give me room for reserve I would plan a stop when tanks get below half

You can never fault someone for erring on the safe side... or in other words.. it's impossible to be too safe..

Realistically of course, that's not the case. The numbers you use here denote a light, piston single. And I'll assume we're still takling about VFR flying. The chances of being asked to hold while flying VFR are very VERY remote.. and the only viable circumstance I can think of, is that you insisted on landing at a crowded airport and would CHOOSE to circle around for a couple of hours..

I was flying a Cessna 172RG I think over Arkansas I came into a airport there Fort Smith Regional the military took over the place airplane after airplane I was VFR and holded for 15-30 minutes while they sorted the military out never say never

I was flying a Cessna 172RG I think over Arkansas I came into a airport there Fort Smith Regional the military took over the place airplane after airplane I was VFR and holded for 15-30 minutes while they sorted the military out never say never

OK.. there's a learning experience here, for us all.

This was back in 2006 I was doing Traffic Pattern work I had done Three touch and go's I was gonna fly for about a hour or more but then the controller started taking alot I never heard military talk I guess because they were on TACAN channel all the sudden the Tower Controller told me Cessna 514 proceed downtown fort smith and hold which basically I got booted out of the pattern but I still did the Holding Pattern

There were no NOTAMS for the event or TFR's it just showes always take more than the VFR requirements which are 30 min day I always carry at least one hour of reserves