REALLY, REALLY long flight

[fredmoss]

It's been a long time since I've posted (or even read the forum) because I've been stuck here in Singapore for two years and my building is put on hold.

However, the bug is still there and I do flight planning every single day (and studying for my IFR). I really want to take my RV (if it's ever finished) around the world to show her off.

One thing has been bothering me. And I'd like some input.

Many RV's have made the really, really long hop from Hilo, HI to Santa Barbara, CA (+2000NM) which equates to roughly 15 hours of flying time at 55% power. Now.. here comes the sticky part.

The useful weight of an RV-7 or RV-9 is under 600 lbs (even less kitted out for a global flight). If a pilot weighs in a 165 lbs and he has 30 lbs of kit (clothes, survival gear, a sandwich) that leaves only 435 lbs for fuel and oil before approaching Gross Weight.

Now, that equates to just over 60 gallons of fuel (45 in the wings and a ferry tank in the PAX seat) and with a burn rate of 6.5 GPH at 55% that give you just under 10 hours of flying (no reserve) -- a rough cruise speed of 150 knots at that speed give you a range of 1420NM OR about 600NM of swimming.

Jon Johansson did this in the RV4 by taking on a LOT of extra fuel with a ferry tank in his rear seat and wing tip tanks. But even a cursory look at the RV4 specs gives me approximately the same mathmatical problem.

So --- here it comes -- how do they do this? Are my performance figures 30% off -- OR -- are these long flights done significantly over Gross Weight.

I still have my lessons in my head about flying within the operating envelope and I'm still new enough to do a W&B everytime I take up a rental (even if I'm solo). I read about pilots going over GW all the time (as long as it's balanced) without problems.

Can anyone give me insight to this thorny issue?

Thanks!

[dan]

Originally Posted by fredmoss

The useful weight of an RV-7 or RV-9 is under 600 lbs (even less kitted out for a global flight).

Typical empty weight of an RV-7 is around 1100 lbs. An RV-7 with Van's stock 1800 lb max gross = 700 lb useful load.

I don't know about this 45 gal in the wings thing. The RV-7 holds 42 gal (252 lbs) in the stock wing tanks.

Regardless, I think anybody serious about long distance ferry flights would need to make exceptions gross weight wise.

[Kevin Horton]

Originally Posted by fredmoss

Jon Johansson did this in the RV4 by taking on a LOT of extra fuel with a ferry tank in his rear seat and wing tip tanks. But even a cursory look at the RV4 specs gives me approximately the same mathmatical problem.

So --- here it comes -- how do they do this? Are my performance figures 30% off -- OR -- are these long flights done significantly over Gross Weight.

Jon Johansson did his takeoffs at several hundred pounds over the normally recommended gross weight.

[pierre smith]

[quote=fredmoss;156931

I still have my lessons in my head about flying within the operating envelope and I'm still new enough to do a W&B everytime I take up a rental (even if I'm solo). I read about pilots going over GW all the time (as long as it's balanced) without problems.

Can anyone give me insight to this thorny issue?

Thanks![/QUOTE]

Mornin',
Short answer is that it can't be done within published weights. Did you notice how long Steve Fossett took to get airborne and the huge bow in the wings from all the load for his round-the-world flight? It can get really dicey since you're essentially on your own. Jon Johannson added weight in the rear incrementally and took off and landed with that weight aboard, exploring the handling and capabilities of his airplane heavily loaded.

Recently an across-the Atlantic trip ended in disaster shortly after takeoff in A modified Wheeler Express that was nearly double the manufacturers suggested max weight recommendation.

Not only would you need enough fuel for the trip but a safe reserve is a must. Jon's book detailing his trips is a good read and helpful resource if you're serious about doing this.

Regards,

[weeav8ter]

One, you will have to figure out where you could store some additional fuel in your plane, i.e. fuel bladder in the baggage area, wing tip tanks, etc and then apply to the FAA for a permit to fly your plane over gross, which is a temporary permit.

I flew my B55 Baron to Europe and back and had an aux fuel tank in the back seat area. When I would take off with full fuel I would be at 750 lbs over gross weight. Most planes will fly over gross, you just don't want to get into a situation in that configuration if possible. On the Baron, I had IO550's, I really couldn't even tell the difference in handling.

You would need to check with Van's and see what would be the max special gross weight that they believe you could have. I would think you could add an additional 60 gallons of gas, 360lbs, and still be ok, however I don't know your plane. I have an RV10.

Wayne Edgerton

RV10 N602WT
in the paint shop hoping to make LOE

[justinmg]

I have an RV9. Can a 7 really do 150Kt at 55% power at MAUW?

[matt]

Don't know if you noticed but there is a comment on Van's webpage about the MTOW of Jon's RV-4:

After reviewing Jon?s modifications and qualifications, Van felt comfortable issuing a one time approval for a take-off weight equaling 136% of the recommended gross.

Taken from this page: https://www.vansaircraft.com/public/jj-plane.htm

[frankh]

As her is planning on flying his 7 from Euegene Oregon to Australia...

I believe his outboard wing section will be made to carry fuel...I.e the whole leading edge of the wing will be fuel.

This would be the most sensible place to put fuel as it would not add to the bending moment at the wing roots as it would if you put all the extra fuel in the fuselage.

I don't know the specifics but I could hook you up with Steve if he doesn't reply

Frank

[n5lp]

Originally Posted by frankh

As her is planning on flying his 7 from Euegene Oregon to Australia...

I believe his outboard wing section will be made to carry fuel...I.e the whole leading edge of the wing will be fuel.

This would be the most sensible place to put fuel as it would not add to the bending moment at the wing roots as it would if you put all the extra fuel in the fuselage...

I took this picture at LOE 2002. The owners name is Jeff Nielsen. The tanks hold 120 gallons.

[dan]

Originally Posted by justinmg

I have an RV9. Can a 7 really do 150Kt at 55% power at MAUW?

Yep, easily. My fuel burn at 150 KTAS is around 5.5 gph. FWIW, my normal travel (full throttle, 2280 RPM, 50 LOP) fuel burn is 7.0 gph at 165 KTAS.