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When I calibrated my fuel gage my Legacy
held 33 gal each tank. If I fill it to the top, I will lose some fuel out
of the vents. Shouldn’t the backflow valves prevent this???
Bill B
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Jay Phillips
Sent: Sunday, May 15, 2011 8:05 AM
To: lml@lancaironline.net
Subject: [LML] Re: N23PH Flight
time
Lancair lists the
Legacy’s (RG) fuel capacity at either 64 or 65 gallons depending on where
you look. My Legacy is marked as 66 gallons. I recently emptied the fuel tanks
to weight the aircraft. I emptied them by discconecting the output line from
the gascolator and running a temp line into fuel cans. Then I used the boost
pump until it sucked air. That should have left only unusable fuel in the
system. After weighing the aircraft I had the fuel truck come out and fill me
up. I took 33 gallons in each tank. Of course, since every Lancair is custom
built and therefore serial number 1, the capacity can very by aircraft.
Jay Phillips
L2K-254 N92SX
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Colyn Case
Sent: Friday, May 13, 2011 3:14 PM
To: lml@lancaironline.net
Subject: [LML] Re: N23PH Flight
time
Thanks Paul. Are those cruise numbers WOT?
Also - I'm confused about standard capacity of Legacy tanks. Is
it 60 or 66 and how much is normally usable?
On May 13, 2011, at 3:43 PM, Paul Bricker wrote:
I had an IO-550 in my Lancair ES, which I
ran per APS guideline. During takeoff at sea level fuel flow was ~ 30gph, and
above ~3000' I would start leaning to match takeoff EGTs during
climb. This improved performance but still maintained detonation
margin.This engine sucks fuel at high rpms and rich. I used 26 gph average
(reducing to 2500 rpms at 500 AGL), even when leaning during climb.
I would go LOP when in cruise. At 8000'DA
and ~ 70 deg LOP I'd see around 13.5 gph, going to ~11.5 gph at 11000'.
I generated a duration spread sheet to
verify fuel for long trips. Tested against actual flights I had about 3 gal more
at the end of a long trip then it would estimate. I'm pretty comfortable with
the assumptions that when into my calculations.
I ran my range calculations for a 60 gal
usable AC, leaning during the climb to 8000' LOP after that. I assumed a
leisurely cruise climb to 8000' averaging 700 fpm. This gives a time to
exhaustion of 4 hrs, 16 mins.
There are several factors which will
radically shorten this. First, was his 60 gal usable? I found I had 4 gals
unusable in my ES, but I ran each tank dry (one at a time over an airport at
altitude) to determine that. Had he verified usable fuel? This alone shortens
TTE to 3 hr 58 mins
Also, if he ran ROP the fuel flow would
probably be about 18 gph. TTE is now 3 hs 15 mins w/ 60 usable. At 56 usable
his TTE is 3 hrs, 2 mins.
The bottom line is his time to exhaustion
is greatly influenced by how he ran his engine, and he could have easily run it
dry.
I don't have definitive information.
As far as I know, never took HPAT or
equivalent.
As far as I know, total time in last 6
months was the 5 hours engine breakin time.
There were conflicting reports about
whether the "pressure" problem was oil pressure or fuel pressure.
I believe he was intending to operate LOP
on this trip.
Anyone
have LOP numbers for an IO-550 at 8000?
Again the log records 3:17 of flight but
does not include the climb (7 minutes?)
nor the descent ( 12 minutes? but was
that power on or power off? one thing very peculiar about the track log is that
there is no descent.)
If you add 3 gallons for climb and take
off, the total burns come out like this:
If he were really at 17 and knew it I
think he would have done something about it.
I suspect there were other contributing
factors. ...like faulty fuel flow reporting, faulty fuel level gauging,
max usable fuel less than thought, or maybe it really was oil pressure.
I looked at the google earth view for the
general area. I'm not sure which field he landed in but they all looked
smallish and maybe intimidating at speed.
It's hard to know what happened in the
final moments but the wreckage doesn't look consistent with forward progress
once on the ground.
Do we know this was fuel exhaustion? I
know I ran my IO-550 150+ degrees ROP throughout the break-in
process. I also flew low to keep 75% power. That's at or
above 15 GPH.
I thought I read something about oil
pressure. I guess we'll find out more in time. Only 5 hours on a newly
rebuilt engine seems minimal before a long cross country. A rebuilt
engine doesn't constitute a major modification, so there's really no need to
re-enter Phase 1 flight testing for a minimum of 5 hours, unless there was more
work done that just an R&R.
Losing an engine shouldn't be
fatal. What do we know about the pilot and his training, time in type,
etc.? Maybe Colyn can give us a bit more about the pilot's experience.
Just sorting through the scenario like I
do with every Lancair accident.
In a message dated 5/11/2011 1:17:19 P.M.
Mountain Daylight Time, edmartintx@aol.com writes:
At high
altitude, a stock Legacy with IO-550 should burn approximately 10.5
gallons/hour using "lean-of-peak" technique. In
this example, actual flight time was over four hours with 21 gallons remaining
(66-gallon capacity). Please see: http://flightaware.com/live/flight/N767EM
-----Original
Message-----
From: Karen Farnsworth <farnsworth@charter.net>
To: lml <lml@lancaironline.net>
Sent: Tue, May 10, 2011 11:22 am
Subject: [LML] Re: N23PH Crash
Flight Aware shows 3 hours 50 min,
not 3 hours 15 min. That is a long way on 60 gallons..
If, as has been reported, the engine was
new, I would think that it was still being broken in. This would lead me to
thing that fuel flow would be on the high side; thus reducing range.
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