I wish I'd spoken to you before doing the flight, because I'd have been more diligent about collecting data.hilltop170 wrote:That is AWESOME!
Lots of questions come to mind like, do you think 20,000' is the limit?, was there any wave lift?, was it all due to the engine or maybe the MT prop?, was the engine really quiet?, were the controls mushy?, what were the engine temps doing?, what version cabin heater do you have?, did it keep the cabin warm?, etc?, etc?.
I know there is more to the story and it would make a great read in the 170 News, hint, hint.
To answer your questions, I think 20000 wasn't the absolute limit, but we hung there for a long time. We might still have had 20 fpm, and I might have been able to squeeze a bit more altitude with smoother flying or leaning to best power. But we were basically down to zero climb. Interesting that 20k was our goal, and there may have been some unconscious bias. Objective test flying is difficult, and I don't claim to have the skill.
The winds were probably 60 knots, much stronger than forecast, and we were right where mountain wave would occur, but I don't think that's what got us the altitude. I've flown in mountain wave and orographic lift, but we didn't feel any. It was just a straight climb from Longmont northeast, with steadily decreasing ROC as we went. Never felt like we were getting a free ride, nor did we feel anything external in the descent. Also, we've had the airplane as high as 17500 several times before and always thought 20000 was in reach, particularly in the winter. But I could be wrong about that. There were a few lenticulars off to the south.
The engine didn't seem quiet, I think because I had the RPM at full and because my door seals don't seal very well.
The airplane has the stock 1954 heat setup, and it worked; we weren't cold. I was wearing a long sleeve shirt and hoodie sweatshirt. No gloves.
Engine temps were high considering the low power output. Oil temp was 180, where it always is, but CHTs were high. I richened the mixture to keep CHTs below 380. They'd have gone over 400 if I'd leaned to best power.
Controls were definitely mushy. We were just hanging there, and anything that changed airspeed caused us to descend.
While we were up high I took off my O2 for about 15 minutes to see how I felt. Mainly just unpleasant. I felt slightly headachy, annoyed, and had feelings of anxiety. Definitely not euphoric. I bungled a call to Center, so I knew I was impaired. Back on O2, I noticed my peripheral vision improved and I just felt better. I did feel more tired than usual for the rest of the day, though. For the record, my son is commercial/instrument and was PIC for the flight.
Bruce, I thought about you a lot while we were way up there, knowing how much you dislike flying high!
We did shoot a GoPro video. Here are a couple of screenshots and a Foreflight screenshot from about 18500.