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Long Legs


Mike Koerner

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I set a personal record yesterday with an 802 nm flight from Torrance, California (TOA) to Fort Stockton, Texas (FST).

I am referring here to a single leg, un-refueled, non-stop flight as measured from the airport of departure to the airport of landing.

The great circle distance is 802 nautical miles, which is 923 statute miles.

The flight was 6.9 hours from engine start to shutdown and burned 28 gallons. That works out to an average of 116 knots at 4.1 gallons per hour and 33 statute miles per gallon.

I had a significant tailwind for most of the flight.

I suspect that may be the longest distance for an un-refueled leg in a CT without fuel system modifications such as ferry tanks, but I don’t know. We’ve talked about long trips and long days before but not long legs.

Mike Koerner

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I set a personal record yesterday with an 802 nm flight from Torrance, California (TOA) to Fort Stockton, Texas (FST).

I am referring here to a single leg, un-refueled, non-stop flight as measured from the airport of departure to the airport of landing.

The great circle distance is 802 nautical miles, which is 923 statute miles.

 

That is remarkable.

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Jim, Jacques,

As I recall their wing tanks were modified to hold a lot more fuel.

Mike

http://flightdesign.com/wordpress/?p=2422

 

clic on the planes pictures to enlarge it  twice..looks like the auxiliary tank was in the back

 

anyway,,yes  they had   MUCH more fuel than usual  but ..they were solo light pilots

 

some guys ARE ABLE to do long flights like that .... not me

 

these guys   http://www.airplanefactory.com/expeditions/sling-around-the-world/  made VERY long legs...they had some 20 hrs of fuel flying their Rotax over water for very long

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http://flightdesign.com/wordpress/?p=2422

 

clic on the planes pictures to enlarge it  twice..looks like the auxiliary tank was in the back

One can see from the two vent tubes on each wing that most of the tanks were in the wing. They also had 31 gallons in specially designed tank on the passenger seat attachment points.

 

I was wondering how they plumbed the additional wing tanks. Given the wing dihedral, one wonders if there were shut-offs lest the fuel from the outboard tanks would over-flow out the inboard tank vents.

 

I wonder how they got fuel from the seat aux to the engine - is it enough above the engine fuel pump intake that it would gravity flow or did they need an aux pump, and if the latter, did they pump into the wing tanks or just into the fuel line ot the engine.

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we can see 3 vents [ SW style ] ...2 for the wings and 1 for the aux tank.  As for the plumbing...''maybe'' ...the aux is used first,then the mains goes in the aux tank.[2 valves on the mains ].....

  From the aux tank...   '' PROBABLY'' straight to the engine fuel pump   just like a low wing aircraft  but my 'guess' is that hey also had an electric pump.

 

just a guess   

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Al,

I’m not sure I can provide a usefully accurate estimate of average tailwind over the whole flight. One problem being that I was a bit slow to realize that I needed to be high to get into significant winds and the other being that I don’t believe my airspeed indication is accurate except at the low end of the scale (I should calibrate it).

During the later portion of the flight, maybe half the time, I was between 11,500’ and 12,500’ with the airspeed indicating about 95 knots and the GPS ground speed varying between 124 and a maximum of 140 knots. That would suggest a true airspeed of about 118 knots and a tailwind component between 6 and 22 knots. However, we can probably add another 5 knots to that based on past experience which suggests my airspeed indicator is a bit optimistic at cruise speeds.

So, over the second half of the flight I would estimate an average tailwind component of 19 knots. During the first half, at lower altitudes, it would have varied from zero to 19 knots with no guess at an average.

 

Tip,

I started out at about 4700 rpm during the first portion of the flight and around 5100 at altitude.

4.1 gallons per hour doesn’t seem surprising to me. During the last half of the flight I was trying to use the minimum throttle to maintain altitude without falling below the optimum speed band for the negative flaps, which I think is probably around 90 knots.

On a trip to Alaska in 2007 I averaged 4.15 gallons per hour. On a trip to the Bahamas I averaged 3.7. A round-about Oshkosh trip also averaged 3.7.

I fly a bit slower than most, I think. I only go wide open if I’m trying to get somewhere in a hurry or trying to get high. Also the CT2k has a slightly longer wing than the SW or LS which I suspect provides optimum performance at a lower speed.

 

Andy,

I was alone and I don’t have an autopilot. Altitudes varied continuously from 2,500’ under an overcast in the LA basin to 12,500’ later in the flight.

I don’t think fatigue was a problem. Not having the autopilot or the rudder and aileron trim that came with later models means I’m actively flying the plane (hence the continuously varying altitudes, airspeeds and engine settings). Also, for the second half of the flight the cockpit was too cold to fall asleep. And by then things were starting to get exciting anyway. ATIS at Deming and Las Cruces, New Mexico were reporting more surface wind than I’d like to land in. When I got a similar report from El Paso I contacted Flight Watch and asked them about Fort Stockton. I was relieved to hear that winds there were calm but by then it was getting dark so I still had plenty of stuff to keep me occupied.

And it’s exciting to see the ground speeds as high as 140 knots anyway!

 

Mike

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Thanks - I appreciate the informative replies.

Sounds like a great trip - and seems like you've enjoyed a few more besides this one!

I'd appreciate any comments you might have to make on the low speed handling of the plane in crosswinds, especially with the smaller vertical stab and maybe the longer wings?

Also, have you ever flown a SW with the larger fin or a CTLS by which you could make a comparison?

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Al,

I’m not sure I can provide a usefully accurate estimate of average tailwind over the whole flight. One problem being that I was a bit slow to realize that I needed to be high to get into significant winds and the other being that I don’t believe my airspeed indication is accurate except at the low end of the scale (I should calibrate it).

During the later portion of the flight, maybe half the time, I was between 11,500’ and 12,500’ with the airspeed indicating about 95 knots and the GPS ground speed varying between 124 and a maximum of 140 knots. That would suggest a true airspeed of about 118 knots and a tailwind component between 6 and 22 knots. However, we can probably add another 5 knots to that based on past experience which suggests my airspeed indicator is a bit optimistic at cruise speeds.

So, over the second half of the flight I would estimate an average tailwind component of 19 knots. During the first half, at lower altitudes, it would have varied from zero to 19 knots with no guess at an average.

 

Tip,

I started out at about 4700 rpm during the first portion of the flight and around 5100 at altitude.

4.1 gallons per hour doesn’t seem surprising to me. During the last half of the flight I was trying to use the minimum throttle to maintain altitude without falling below the optimum speed band for the negative flaps, which I think is probably around 90 knots.

On a trip to Alaska in 2007 I averaged 4.15 gallons per hour. On a trip to the Bahamas I averaged 3.7. A round-about Oshkosh trip also averaged 3.7.

I fly a bit slower than most, I think. I only go wide open if I’m trying to get somewhere in a hurry or trying to get high. Also the CT2k has a slightly longer wing than the SW or LS which I suspect provides optimum performance at a lower speed.

 

Andy,

I was alone and I don’t have an autopilot. Altitudes varied continuously from 2,500’ under an overcast in the LA basin to 12,500’ later in the flight.

I don’t think fatigue was a problem. Not having the autopilot or the rudder and aileron trim that came with later models means I’m actively flying the plane (hence the continuously varying altitudes, airspeeds and engine settings). Also, for the second half of the flight the cockpit was too cold to fall asleep. And by then things were starting to get exciting anyway. ATIS at Deming and Las Cruces, New Mexico were reporting more surface wind than I’d like to land in. When I got a similar report from El Paso I contacted Flight Watch and asked them about Fort Stockton. I was relieved to hear that winds there were calm but by then it was getting dark so I still had plenty of stuff to keep me occupied.

And it’s exciting to see the ground speeds as high as 140 knots anyway!

 

Mike

 

Thanks for the info Mike!  

 

4700rpm and 4.1gph seems believable.  I sometimes have to cruise at low rpm to stay with my buddy in his Avid Flyer, and usually cruise then around 4400-4700...I think I calculate 3.8-4.2gph in that regime.

 

No cockpit heater in the CT2K?  Glad you found a good place to land, strong winds make me nervous in my CT as well, especially if they are not lined up with a runway.  I bet that is even more a concern with your longer wings.

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we can see 3 vents [ SW style ] ...2 for the wings and 1 for the aux tank.  As for the plumbing...''maybe'' ...the aux is used first,then the mains goes in the aux tank.[2 valves on the mains ].....

  From the aux tank...   '' PROBABLY'' straight to the engine fuel pump   just like a low wing aircraft  but my 'guess' is that hey also had an electric pump.

 

just a guess

Look closer. There are 4 vent tubes, two in each wing, equally spaced. I have the book and they show up much clearer in the pictures in the book. How the seat aux tank is vented I do not know.

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