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PostPosted: Sun Jun 03, 2012 11:17 am 
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pjc747 wrote:
After 12 practice attempts at Qamdo Bamda Airport in China (Altitude: 14,219ft Runway Length: 18,045ft), I have deemed it impossible to takeoff at max gross weight in the Stratocruiser, when using all 18,045ft of the runway. I tried numerous flap configurations, such as flaps up until 100kts, then put them down, I tried more flaps, less flaps, even fuel dump on takeoff, to no avail. The engines only produce about 40-in at this altitude, and with no wind allowed, there is no runwa wind advantage. Another must be found.


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PostPosted: Sun Jun 03, 2012 3:34 pm 
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Location: Texas, USA
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Well started out leaving KSFO- San Francisco heading out into the Pacific towards Pago Pago. Take-off went as planned 46" at 2500 RPM. Climb also went well leveled off at 8,000 ft. and started a step climb to 12,000 ft. There we leveled off,and put the airplane in a nice step cruise 2,300 RPM at 130-135psi burning around 700pph on fuel and airspeed at 175-180 kts. at Auto-Lean,tried too lean more but the temps. were just too high for my taste,so back too Auto-Lean. Stayed there for approx. 4 hours or so to let the weights reduce some then started a Auto-Lean step climb too 20,000ft.
At 20,000ft. got back into a step-cruise 2,200RPM 125-130psi airspeed 155-160 kts. at first and just let the airplane excelerate over time.
After about 10hrs. of this I was feeling pretty darn good about making the whole way,we were around 600nm. S.W. of Honolulu,than the sh** hit the fan. Lost #3 engine too random failure,no biggie I thought shut down & feather descended to 15,000ft got on a nice step cruise again,all looked well and good(These words came back to haunt me). Around couple of hours later Engineer "Larry" stated "We have a problem on Engine #1",lost turbo.(no shut-down) I did use a few loud colourful medaphors when this happened,woke my wife up out of a nice deep slumber and got this look :twisted: :evil: my reply look was :shock:.
Started down,hastley looking at my map,and noting that I was 700-800nm. from Honolulu,double back was not an option looking at my fuel gauges,so too find a nice sutiable runway,of course where I was located either too far of too short. As I started descending found Palmyra Atoll(PLPA) 6,000ft. runway about 250nm. from my location. Made it there and touched down with no runway lights,I cannot recall my weight now.
Got the passengers out,and soon discovered there a few Japanees Marines on the Island,that thought the War was still going on :mrgreen: :mrgreen:
Sorry so long
Mark S.

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PostPosted: Wed Jun 06, 2012 4:52 pm 
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Well after putting around 20 hours In the mustang I came back to here. Departed kden today enroute to gvac. 4386 nm in total. Starting the cruise at 31k. Time to cruise was 47minutes. Starting out ias 188kt 162psi mp 44.5 rpm 2190 mixture .56 pph 850ish. Projected range 3800 but with more leaning I can reach my destination I hope. I have alternates along the way of needed. But I will push to the end.


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PostPosted: Wed Jun 06, 2012 5:03 pm 
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Nice write up 84t. Quick question for you. Why stop the climb so many times? This aircraft will climb nonstop with no temp issues to 24-25000. Then the turbos come in and start to get in the yellow. But only till 150 when they are hot must you manually take them over. I just no stepped climb to 31k. With the full load. The leaner you get the collet the engine runs. Temps go up at peak then lean of peak engines cooler drastically. Yes you can't truely determine lean of peak since there's no multiprobe egt. But watch your psi. Once it starts going down its a good indicator. I find to truely reach into the range potential you must manual lean. Just my 2c. Thanks for participating.

Release the beast.


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PostPosted: Wed Jun 06, 2012 5:08 pm 
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Bigjuicy I have yet to try and get off this airport. I was able to get off of Los alto. I trick I could think off. Take the turbos out off takeoff. Manually increase them not to exceed the 60". That's why( I believe) they are essentially disabled on takeoff. The supercharger creates enough at sealevel to over post the engines. But at high altitudes try things. Also when I first started flying this I started a thread about using a slightly reduced rpm to increase thrust at higher altitudes. There was some debate that it actually does and or doesn't. Make the aircraft work for you. Try your systems. THINK OUTSIDE THE BOX. Throw the manual aside.


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PostPosted: Wed Jun 06, 2012 5:50 pm 
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I apologize Bigjuicy. I meant pjp


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PostPosted: Wed Jun 06, 2012 8:12 pm 
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Progress report....4h 11m into the flight out of Denver I'm coming up on dc still at 31k where I will remain as there no real benefit of climbing 2000 more feet to fl330. Mixture is back now and has effected my ias. Mix setting .53 730pph. Cruising attitude is a nice level 176kt cruise. Distance traveled 1252nm. Current ground speed 290kt avg 296. Est range 10h36min 3068nm. I believe I have the range to complete the flight. I will check it before I go to bed and set away from keyboard for emergencies. I have been taking photos along the way.

Happy landings.


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PostPosted: Thu Jun 07, 2012 3:13 pm 
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Lyonsdan, good luck on your flight. If you come up short, what is Plan B?

Just now I finished the Honolulu to Washington, DC (KADW) trip. Weight was as specified (71 passengers, 3046 Lbs cargo). I climbed in one step to FL300 at IAS 150 (took me a lot longer than 47 minutes). Then I cruised the whole way at 170-173. Mixture was adjusted to keep from gaining speed. MP 38.3" was monitored by the FE. RPM was set for 2090.

Distance was 4210 nm; time in flight was 15:40. Got a nice round of applause from the passengers and a "Beautiful Landing" from somebody in the cockpit.

Now for the scary part. Landing was made with 88 lbs of fuel left. (By the time I shut down at the terminal I had 8 lbs.) Sure, the passengers are "only" electronic blips, but they have blip families. And there is Heidi to think about. More realistically, I was putting my career on the line which is up to 2.7M passenger miles. I would hate to loose all that. I doubt if I will try another one of these any time soon.

Thanks for setting up the "contest."

Wayne


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PostPosted: Thu Jun 07, 2012 4:33 pm 
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Wayne thanks for the write up. The beauty is though yes you pushed the fuel. Bit you could have and did divert if needed. Right now I'm about 300nm short of destination and have 8% fuel left.
Travels 4136nm so far. 13h33m in the air. My backups are past me now and the back up backups for simply island airports with 4500 foot strips. They can be done at lite weights like this but it's challenging. Here's my plan. Get to within best glide distance. From 31k assuming around 700fpm-1000 I'm going to lean to .40 and start descent. Alot of people think the same power is needed for descent. Quite wrong. If you lean way back the engines are very healthy. But you simply don't have the power to stay level. Hence when I get to best glide distance. So here's how I figured it. My planned descent is 700fpm. Cruising at 290 from 31k I need 44 minutes to descend. Multiply 290 by 3/4(I rounded 44 to 45, quick math) you get 217nm. I said my descent at 217nm out from destination. So the leaning will allow me to descend on virtually no fuel. Typically my math allows for the natural slowing due to the atmosphere. I'll see how this turns out.


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PostPosted: Thu Jun 07, 2012 8:03 pm 
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Right before takeoff from KDEN rwy 8
Image

settled in cruise notice total time in flight. Departing from den saved me between 30-40 minutes in climb.
Image

Just coming up on DC. cruising nicely but not settled back in eco cruise.
Image

just started my descent as planned.
Image

the next few pictures show my mixture, fuel flow, etc in descent.
Image
Image

my completed stats
Image
Image

career in nut shell. 5 flights. 1 trip around the world on this career and a contest run of 4392nm. not a bad start. in 5 flights i'm over a 1mil miles. But still not good enough for myself in the notes. i must be really hard on myself. But then again i'm only a average pilot.


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PostPosted: Fri Jun 08, 2012 10:01 am 
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Lyonsdan,

Congratulations on a winner of a flight. I am intrigued by your climb to altitude in only 47 minutes. What was your vertical air speed? How did you manage the higher altitude drop offs in psi?

I am also intrigued by your initial cruise settings (higher rpm and mp than in the 'book'). At some point I will set up my aircraft in a similar fashion to see the range reading. At the beginning of a flight, 3800 nm is quite remarkable.

Lastly, I wish I had thought through the low mixture setting on descent. I did not think it would make a difference, but evidently it does. It is also something I want to try.

Wayne


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PostPosted: Sat Jun 09, 2012 8:16 pm 
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I'm not done yet. And please keep going and beat me. I like challenges. I want to break 4600nm. My next challenge will be max endurance and that will come some. Since my findings were correct in planning my takeoff at an airport with higher altitude next I need to find an airport above 14000. Which I know of many but that I can climb at my own pace without the risk of mountains.

My climb initially started at 8-1000fpm. I have been criticized how I climb. I climb based on angle not speed. They do almost match until around 24k. My initial climb is set 6.8degrees on the autpilot. This matched with a mp of 51ish and rpm mid yellow range will yield a nice steady climb through 15-16k. I do use mp hold. It lightens my load. Around 15k I increase throttle to Mac and with the mp hold the turbos back off. I also use my optimum climb angle of 5.7-5.8 at that point I use all the way to my cruise. Near 26-27k your turbos will be getting hot. I allow then to get around 148. Then I take control of turbos and disable mp hold. That isthe point were you just watch the turbo temps and increase till they are Maxed out. Then you simply adjust angle of climb not to go below 140 ias. With this technique it will allow you to reach to 33k. Based on weight 33k may not be optimum. Just remember with weight needs speed at altitude. Above 29k it does take longer to climb. It you can at least keep 2-300fpm.

My low psi compared to my higher mp is a result of my leaning. At 31k I was around 43" and set rpm to 2200. Leaning will result in lowered psi which equals longer range. The lower psi the longer range. Say this for example. 40"mp 2200rpm 168psi at .68mix equals 1000pph. My 43" at 2200rpm .58mix at 145psi equals 700pph. Leaning here is the key. The more you lean the less power is made. Hence lower psi.

Leaning while in descent. It all depends on how much power you need. Now here is a key to leaning on descent. There is a HUGE power difference between .40 and .38mix. This is why I get to best glide distance. If I can basically glide then I use .38. If not use .40 or more. Descent just like any other phase of flight has to be planned. I can descend at 1000fpm at .38 or lower and slow down at the same time. Try that in auto lean. I can descend from 33k at 1000fpm lowered to 5-700 down low for comfort and use less then 2% fuel. I have seen pph as low as 30per engine if planned right. That equals 120pph. I use mixture to control speed in descent. Kind of bizarre but works great.

My initial range of 3800 is good. That if I remember correctly was at .62mix or less. Have to read my write up. I use a high mp to keep speed but lean for range. Rpm is also a key. Use between 21-2200. Any more or less will not allow for good cruise. I can certainly make a video of me actually flying this and showing you my setup if interested. Remember I didn't just do this off the bat. I fine tuned it over several hundred hours. I didn't listen to others here about needing step climbs because they really are not required. Just use your systems to your advantage.

Happy landing.


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PostPosted: Sun Jun 10, 2012 4:44 am 
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As a complete amatuer I can't comment on step climbs or much of anything else.

La Paz has an airport at 13K. I've gotten out of it a couple of times with full fuel but a medium load. A high altitude takeoff does seem to tax the engines for a longer time before cutting back, so I wonder about the strain on the engines. If they are healthy it won't matter for that particular flight, but it will cut into the total hours before an overhaul.

Anyway, La Paz to Spokane is just about 4660nm. It has the advantage of being over a lot of airports for diversion if needed.

Thanks for sharing your settings.

Wayne


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PostPosted: Wed Jun 13, 2012 5:44 pm 
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I have just landed at Spokane having taken off at La Paz. Distance: 4676nm; Take Off at 3:14 am, Landing at 7:27 pm (both, aircraft time); Fuel Remaining: 547 lbs; Oil Remaining: 52 lbs; Cost per Mile: $ 0.85.

After gaining cruise altitude (FL300), I eventually settled in at IAS 184-5, RPM 2067, MP 44.0". Speed was maintained by adjusting the mixture. I descended at .40 as you suggested.

Just before turning to final, number 4 went out from fuel starvation. I should have taken over the FE work as I knew the tank was low and could have anticipated the problem by putting number 4 on manifold prior to quitting. Even worse, on final number 3 went out from wear and tear. Both engines were feathered and I landed on the two port engines. However, I could not taxi in a straight line as a result so I emptied the plane on the runway.

All in all, the observations about a higher MP was helpful. I used a lower RPM, though, and kept a higher speed (.50 Mach). The two starboard engines took something of a beating as 3 went caput and 4 went from "Good" to "Fair." The port engines made the flight in "Good" condition the whole way.

Wayne


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PostPosted: Thu Jun 21, 2012 7:17 pm 
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Posts: 143
Lyonsdan - WOW thanks for the info !

I am just starting to learn this lovely beast.


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