|
Hello Craig, Thank you very much for your picture. I got a lot of information out of it and spent quite some time looking at it – you can feed me a lot more of these before I will get tired of it… I kept a log of my power settings on different flights for the last year and I found one setting that is very similar to yours – unfortunately I didn’t get that good of a tailwind My fuel flow shows a little less – may be this is a calibration problem? My TAS shows higher – but mine comes from the bezel and is influenced by friction heating and air compression – it would make me very happy if someone on the list could give me a correction factor for my speeds/conditions. When I put my scribbled notes in a spread sheet and sorted it to altitude and OAT I found something in my opinion very interesting: on the lower altitudes the OAT has very little influence on the speed. At the higher altitudes (>=FL180) you can clearly see how the airspeed decreases with increasing OAT because I need to run the engine at lower power settings to get similar TIT and CHT. On low altitudes (<FL120) it seems I can feed my engine a lot more fuel without significant influence on the CHT (may be because of my plenum) - The high power setting at FL110 was more than 1.5 years ago – I kept it in there for reference and I won’t do this again On some warm/humid days I just have the feeling my engine doesn’t like it at altitudes higher than FL190. I don’t like higher than FL230 because I don’t have winglets and it doesn’t feel that firm anymore Info for the chart: TIT is my TIT2 - it is usually 40F warmer, TIT max is around 1720, warmest CHT is always #2 and CHT#1 comes close after it, the TAS comes from the bezel and would need to be corrected, all settings were in cruise for at least 45 min or so – sometimes up to 2 to 3 hours. Ralf Alt. | OAT | MAP | RPM | Fuel flow | TIT | CHT | IAS | TAS | % HP | ft | F | inHG | 1/min | GPH | F | F | kts | kts | | 10 | 40 | 29.9 | 2,500 | 17.0 | 1,570 | 310 | 212 | 240 | 69% | 10 | 45 | 32.2 | 2,500 | 18.1 | 1,600 | 322 | 208 | 248 | 73% | 10 | 54 | 32.4 | 2,500 | 17.9 | 1,620 | 344 | 205 | 246 | 73% | 11 | 35 | 33.8 | 2,500 | 20.8 | 1,690 | 356 | 220 | 260 | 84% | 11 | 53 | 34.0 | 2,500 | 18.6 | 1,610 | 351 | 204 | 249 | 75% | 12 | 34 | 32.3 | 2,500 | 17.9 | 1,590 | 318 | 205 | 251 | 73% | 12 | 36 | 32.6 | 2,500 | 18.6 | 1,620 | 330 | 209 | 255 | 75% | 12 | 47 | 32.3 | 2,500 | 17.9 | 1,610 | 344 | 203 | 251 | 73% | 12 | 49 | 32.4 | 2,500 | 18.1 | 1,610 | 340 | 204 | 252 | 73% | 16 | 40 | 32.4 | 2,500 | 17.8 | 1,620 | 366 | 199 | 264 | 72% | 18 | 13 | 34.0 | 2,500 | 19.1 | 1,630 | 346 | 205 | 278 | 77% | 18 | 28 | 32.3 | 2,500 | 18.0 | 1,620 | 362 | 194 | 265 | 73% | 19 | 21 | 33.1 | 2,500 | 18.2 | 1,625 | 360 | 195 | 275 | 74% | 19 | 26 | 32.4 | 2,500 | 17.9 | 1,620 | 366 | 196 | 276 | 73% | 20 | 20 | 32.4 | 2,500 | 17.8 | 1,625 | 366 | 194 | 278 | 72% | 20 | 20 | 32.4 | 2,500 | 18.1 | 1,625 | 362 | 194 | 278 | 73% | 20 | 21 | 32.4 | 2,500 | 17.9 | 1,620 | 368 | 190 | 274 | 73% | 20 | 32 | 32.3 | 2,500 | 17.3 | 1,620 | 377 | 186 | 270 | 70% | 21 | 10 | 32.4 | 2,500 | 17.9 | 1,625 | 360 | 192 | 278 | 72% | 21 | 18 | 32.4 | 2,500 | 17.7 | 1,620 | 370 | 191 | 280 | 72% | 22 | 22 | 31.9 | 2,500 | 16.9 | 1,620 | 380 | 182 | 272 | 69% | 23 | 0 | 32.4 | 2,500 | 17.7 | 1,620 | 368 | 190 | 284 | 72% | 23 | 0 | 32.4 | 2,500 | 17.8 | 1,620 | 373 | 188 | 282 | 72% | 23 | 13 | 32.3 | 2,500 | 17.1 | 1,630 | 379 | 185 | 280 | 69% | 23 | 20 | 31.9 | 2,500 | 16.3 | 1,600 | 380 | 179 | 274 | 66% |
From: marv@lancair.net [mailto:marv@lancair.net] Sent: Wednesday, October 16, 2013 3:47 PM To: lml Subject: Re: IV-P Recent Trip
Posted for Craig Berland <cberland@systems3.net>:
> I took this picture last Friday just to record the great tailwind. > With the recent LOP talk, Oil Temp, etc….I thought some might find this >interesting. > I am LOP and from previous tests, about 8 kts slow of ROP. > Craig Berland > N7VG > > >
|
|