WestWind Airlines

So, I figured on an easy flight for my first one as a qualified Cat1 pilot...a KIAD to KCAK milk run.

Generated my flight plan in FSX, chose 12,000 feet as my IFR altitude, and it said my estimated fuel required was ~2500lbs.  So I loaded twice that amount just to be "safe" and took off from DC in beautiful weather (I set to real world updated every 15mins, including winds aloft).

The flight was going smoothly until I got over West Virginia and realized that I had burned through most of my fuel already.  Changed my IFR flight plan in-flight (via FSX flight planner) and diverted to Wheeling, WV (KHLG).  I pulled up my Jepp chart (ILS runway 3), set my frequencies on the VORs, and as a backup loaded the approach into my GPS.

Figured I was good to go, but a pair of unfortunate circumstances intervened.  First, the ever so helpful FSX ATC denied my request to descend and started vectoring me all over creation...I don't know if it was my mistake or not, but I was burning dinos and needed to get DOWN.  So, I squawked 7700, turned around and headed for the IAF!  It was pretty cool that the real-world weather was pretty low ceilings and vis, and the area around KHLG is hilly with obstructions...so following the approach was not an academic exercise by any stretch.

The approach was going well enough until I realized that the glide slope wasn't 'coming alive' when I thought it should have. I missed the window to descend and ended up waving to the runway as I flew by it. I started the missed approach procedure, but ran out of fuel.  Turns out that I had neglected to switch my system from "GPS" to "NAV", ouch!

Wish I could figure out what caused me to burn so much more fuel than FSX estimated.  Even so, despite snotty ATC and my self-generated SNAFU it was a great time that really challenged my brain!

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Matt Smith - WWA2218
Washington DC (KIAD) Hub

HI Matt,

What was your winds at your cruise altitude?  That may have caused the extra fuel to burn.  My rough estimate of the fue burn for the CRJ 700 is ~7000 lbs an hour but it will be a bit more at lower altitudes (lower than say 25K ft)  I also add in about 60% of the fuel burn for the take off which in this case would be about another 4200 lbs. and an extra hour of fuel for in case you are divereted to another airfield.

 

So if your flight time was 1 hr long your fuel required would be 1 Hr X 7000 lbs = 7000 lbs + 1 hr extra fuel (7000 lbs) plus 60% for takeoff (4200 lbs) which would equal 18200 lbs.  

 

Also keep in mind that FSX figures your flight time  as if you were already at altitude so in my example above if the flight time said 1 hour I would add at least another 30 mins for the climb out.  So the total flight time would be 1.5 hours and use that for your fuel calculations.

 When you are on a flight with a unfamiliar aircraft keep an eye on your fuel flow so you can have your own data to calculate your fuel requirements.

 

Hope this helps,

Ed

 

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WWA 843
Toronto Hub

Luck is when preparation meets an oppotunity

If you were flying a regional jet, they burn a lot of fuel at 12,000 ft. They need to be up around FL300 (30,000 ft msl and altimeter set to 29.92) to be happy and burn less fuel, iirc. Havn't flown a regional jet in a while. That is true for all the jets. The higher you are the less fuel you burn. Way down low, they guzzle it like there is no tomorrow. Hope that helps. Right now I am flying the Gulfstream G550 and am at FL510 (51,000).

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WWA1702 Senior Command Captain +3
RWP SEL Instrument Rating (almost)
WW Test Pilot
Monster Driver

Thanks, guys...my thinking on the 12K feet was to cut down on fuel spent climbing for such a short flight. Clearly that was the wrong answer!

Thanks for the info on the fuel consumption Ed.  "Fuel Flow" is something I don't understand at all yet (units of measure and their implications).  Plus I think Mike said that the fuel flow gauge on the CRJ was off?

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Matt Smith - WWA2218
Washington DC (KIAD) Hub

VirtualMatt:

Thanks, guys...my thinking on the 12K feet was to cut down on fuel spent climbing for such a short flight. Clearly that was the wrong answer!

Thanks for the info on the fuel consumption Ed.  "Fuel Flow" is something I don't understand at all yet (units of measure and their implications).  Plus I think Mike said that the fuel flow gauge on the CRJ was off?

If it is the fuel gauge I am thinking of, it is off by a decimal point so it uses 10 times what it reads. We used it in the G550 and during flight testing, I took off, climbed to FL510, looked at the fuel guage and it was almost all gone. I ran out of fuel at about FL400 and had to find an airstrip to put it down on dead stick.

Also, I didn't try to see how far apart your airports were. We have RW regional jets that fly from XNA to DFW (about an hour flight) that climb to FL330 on the trip. Usually ATC wants you down to about 10,000 when about 40 miles out.

Hope this helps.

Cheers.

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WWA1702 Senior Command Captain +3
RWP SEL Instrument Rating (almost)
WW Test Pilot
Monster Driver

Thanks, Mike.  I think I've figured out the Jet fuel flow gauges...CRJ and Airbus give PPH, while I think the Boeings give "Thousands of PPH".  On the 738 it seems to be an aggregate total like 5.8 (x1000), while on the 744 it is per engine.  If that is true, boy the big 4 engine jets use a lot of fuel!

The route that I was flying probably did lend itself to a lower altitude (it was something like 250 miles), but I just missed on my fuel estimate (with the help of FSX).  Now that I'm aware of the FF gauges I think I can make better estimates.

The biggest thing though was how cool it was to divert to an unknown airport in fog and have to fly an instrument approach under pressure!

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Matt Smith - WWA2218
Washington DC (KIAD) Hub

VirtualMatt:

The route that I was flying probably did lend itself to a lower altitude (it was something like 250 miles)

True, but when flying a jet a lower altitude is something like FL220 to FL260.........that's about as high as any of the flights between the DFW area and Austin, San Antonio and Houston fly.......The other day I flew from BGR to EWR and we flew at FL400 (I fly a Challenger 300).

It's a definite tradeoff between the fuel you use to get to altitude vs. how long you'll be in cruise flight vs. what ATC will let you do on that route.  In order to stay in the 10,000 to 12,000 foot range you probably need to be doing a flight of about 100nm or less if you're in a jet.....

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EHAM-YSSY B772LR

Thanks, Kim - I am interested to learn more about fuel consumption over my next few flights...that's where you can really make money compared to just filling the tanks and hauling it around!

Hope you guys had a great weekend!

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Matt Smith - WWA2218
Washington DC (KIAD) Hub

I was on a flight from LAX to Santa Barbara not too long ago (RW) in a regional jet and it only climbed to 10,000 I think. I was a little surprised by that and just assumed it was because of the heavy traffic around the LAX area.

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WWA1702 Senior Command Captain +3
RWP SEL Instrument Rating (almost)
WW Test Pilot
Monster Driver