peevee Posted September 30, 2016 Report Posted September 30, 2016 10 minutes ago, aaronk25 said: Ya 105kts IAS works out to 145kts true when corrected for temp and altitude. Burning 6.7gph almost 25mpg (statute). Sent from my iPhone using Tapatalk Not 200, but 180. Hard to see, tried out 185 to 190ish, let's be honest the tas on the ai isn't that accurate. Hard to see, dirty glass and glare. Quote
N9201A Posted September 30, 2016 Report Posted September 30, 2016 Climb rate at 12k is 350-40015k 27519k 150Or look at the link it has climb rate Thanks for the reply on icing, Aaron. Curious what climb speed you used for those numbers, assuming very close to/at your Vy? Quote
aaronk25 Posted September 30, 2016 Author Report Posted September 30, 2016 Thanks for the reply on icing, Aaron. Curious what climb speed you used for those numbers, assuming very close to/at your Vy? 110kts-120kts to about 10k then 100kts to 15k92-95kts to top of climb. Really depends on gross weight of aircraft. These numbers are for about 2600lbs. Everything has to be perfect though, mixture about 40ROP, optimal rudder (ball centered). If anything is off, even a little these numbers cut in half. I suppose every plane is different but peak power on mine is at 40 ROP, not 80rop but also have powerflow exhaust and that may have some influence too, hard to tell. Sent from my iPhone using Tapatalk Quote
ArtVandelay Posted September 30, 2016 Report Posted September 30, 2016 The service ceiling of a J is over a DA of 23000 feet if at 2300lbs, I'd imagine that engine cooling would be my major concern at the slower climb rates in the thin air. Quote
aaronk25 Posted September 30, 2016 Author Report Posted September 30, 2016 The service ceiling of a J is over a DA of 23000 feet if at 2300lbs, I'd imagine that engine cooling would be my major concern at the slower climb rates in the thin air. Engine temps at fl200 were same as 12k. MP is so low (14.2) there just isn't much heat to deal with. Had cowl flaps closed from 15k to 20k. Now this also was near the Canadian border and it was -20c at altitude so I'm sure it would be warmer at FL200 over Yuma AZ. So that might be a concern, but given IAS was so low I don't think there would be any measurable penalty to leaving the cowl flaps open in trail, if needed. Given it takes so long to get up that high it's great when ATC will approve a pilots discretion decent allowing for a 200fpm decent which converts the most amount of stored energy (altitude) back to speed on the downhill. Sent from my iPhone using Tapatalk Quote
peevee Posted September 30, 2016 Report Posted September 30, 2016 (edited) 36 minutes ago, aaronk25 said: Given it takes so long to get up that high it's great when ATC will approve a pilots discretion decent allowing for a 200fpm decent which converts the most amount of stored energy (altitude) back to speed on the downhill. Sent from my iPhone using Tapatalk You don't necessarily need a pd descent for that. Descent rate is somewhat pd, but you should advise atc per the aim when it'll be a slow climb or descent. (less than 500 fpm aim 4-4-10) Just ask for lower when it works out for your planned rate. Since pd gives you the authority to level off at any altitude the controller might be hesitant to give you what amounts to a 15k plus block of altitude, but you can ask for lower and advise a slow descent. They will appreciate the heads up on rate, both up and down Edited September 30, 2016 by peevee 1 Quote
Piloto Posted September 30, 2016 Report Posted September 30, 2016 9 hours ago, aaronk25 said: Ya 105kts IAS works out to 145kts true when corrected for temp and altitude. Burning 6.7gph almost 25mpg (statute). Sent from my iPhone using Tapatalk Try that mpg on a car. My Ford Explorer the most will do is 19mpg on the highway at 60mph. One advantage of flying at altitude on a M20J is the noise reduction, due to low power and low air density. My wife and her sister take off their headsets and gossip the whole flight about everyone. Quote
aaronk25 Posted September 30, 2016 Author Report Posted September 30, 2016 Try that mpg on a car. My Ford Explorer the most will do is 19mpg on the highway at 60mph. One advantage of flying at altitude on a M20J is the noise reduction, due to low power and low air density. My wife and her sister take off their headsets and gossip the whole flight about everyone. Yep, with full throttle and lower MP the engine is so quiet and just purrs. If and when I move up to a turbo the main reason will to be higher rates of climb to get out of high cloud tops when at gross. Dragging along in the tops, where ice is common isn't much fun.Sent from my iPhone using Tapatalk Quote
cnoe Posted September 30, 2016 Report Posted September 30, 2016 19 hours ago, OR75 said: curious to know .... what kind of rate of climb do you get above 12000 ? How much oxygen did you use for 2 hours ? Just another data point here... Late last year there was a thread "Time to Climb" in which some numbers were posted. My J was admittedly light at ~2,100# but I ran it right up to 18K with no problem. IAS was from 97-102 mias. Here's an excerpt from my results. Alt. Time Leg FPM 10000 10:20 1:18 769 11000 11:52 1:32 652 12000 13:34 1:42 588 13000 15:29 1:55 522 14000 17:27 1:58 509 15000 19:39 2:12 455 16000 22:22 2:43 368 17000 25:23 3:01 332 18000 28:40 3:17 305 Started off at 25 msl and 23C. on the Texas coast. I kept it rich (200 ROP) throughout the climb and could likely have gotten more performance up high by leaning more. Cowl flaps were opened to trail position between 9K and 18K to keep oil temps down. MP at 17.9K was 14.6 on my JPI830. On this particular day my DA at 18K was 19,768' and she was still climbing. Yes, I love my J! 3 Quote
Piloto Posted September 30, 2016 Report Posted September 30, 2016 As in any plane weight and air temperature are big factors on climb performance. When fully gross with 100 gallons I do step climbing to save on fuel and time. Initial climb to 10,000ft, if the winds are good proceed higher after burning at least one hour of fuel. José Quote
peevee Posted September 30, 2016 Report Posted September 30, 2016 2 minutes ago, Piloto said: As in any plane weight and air temperature are big factors on climb performance. When fully gross with 100 gallons I do step climbing to save on fuel and time. Initial climb to 10,000ft, if the winds are good proceed higher after burning at least one hour of fuel. José pee breaks or what? Quote
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