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<< Lancair Builders' Mail List >>
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For all those interested, here is the progress report requested by Bill Hogerty.
Recall that John Forker of Palo Alto is preparing to ferry Chris Toms's
unpressurized LIV from New Zealand. After considering various alternatives, the
leading candidate is a bladder tank shaped like a parallelogram to match the slope
of the front and back seat backs (20 degree back slope) about 25 inches high. It
would be constrained by a 5 sided box (four sides and bottom) about 20 inches high
made of prepreg panels and reinforced against bending loads with uni-carbon strips
added to the panels near the top edges. It would probably be assembled with a mix
of piano hinges and screws to permit assembly in the fuselage as it will not fit
through the door.
The bladder supplier made a rough estimate of $1500 and initially said there were
no economies for multiple buys, but we have not started the negotiation. The
prepreg panel and other hardware would add another $500 or so. The filler cap
would be offset to the front left to it would be easily accessible when the door is
open.
The problem is that for Chris' airplane the CG goes way aft of the limit when the
tank is filled past about 90 gallons, so John is evaluating options including
moving the battery and oxygen tank forward as these are currently installed aft for
reasons unknown to us.
Checking with others suggests that a hard flight limit is 1 inch aft of the rear CG
limit as the airplane gets squirrely above 10-15,000 feet, and night and IFR flying
are not recommended until burning off about 2 hours of fuel to get the CG where it
belongs. Slowing to 250 knots makes 90 gallons adequate for the Pago Pago to
Hawaii leg, the longest of the trip, when combined with 104 gallons in the wings.
Today we reviewed drawings and did measurements in my fuselage to verify fit and
location. We are trying for simplicity, and want to avoid a "tank well" in the
passenger foot well area. This area could hold about 10 more gallons and permit
the tank CG to move a bit forward.
For those of you with CG data, one can do the evaluation by assuming that the rear
tank CG is at about the same position as the rear passenger CG location. Remove
the weight for the bottom and back cushions, add back 25 pounds (estimated) for the
tank, then add as much fuel as you would like. The maximum (tallest tank) that
allows a life raft to be folded and stored above the tank is about 123 gallons.
John also found he could buy and modify a ham HF radio and get an antenna coupler
that permits operation with automatic tuning regardless of the antenna length. Both
packages total a bit less than $2K, and information is available on the Internet
showing how to modify the radio to permit transmitter operation in the aircraft
bands. The radio is compact, about 4" H by 10" W by about 12" deep. I have not
seen the coupler assembly.
John is currently thinking about using the KISS principle for the antenna which
would exit the belly aft of the landing gear doors. Coil it up and tape it on to
the belly. Taxi out to the runway. Get out and untape the antenna letting it
trail, and then take off. Reverse procedure after taxiing off the runway. Avoids
reels and such which represent single failure points.
For much of the world, a Globalstar Telecommunications Inc. satellite phone
(www.globalstar.com) would be the preferred option, and apparently works within
1800 miles of the mainland for North American, Europe, Asia, and Australia (in
spite of the fact that their literature shows a 200 mile limit for international
treaty reasons) and also covers the entire North Atlantic. But the air regulations
mandate an HF radio. The satellite phone would be a nice back up, though. Gary
Burns used an expensive earlier generation satellite phone when the HF radio took a
holiday. In talking with a friend with United Air Lines who flew regularly to
Hong Kong I learned that the expensive air liner HF radios are not that good,
either, and they use sat phones to talk to their dispatchers.
More reports will be forthcoming as we continue.
Fred Moreno
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LML website: http://www.olsusa.com/Users/Mkaye/maillist.html
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Please send your photos and drawings to marvkaye@olsusa.com.
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