Re: Gph
Hi all.
On my last flight from visiting Mike in Savannah, I was playing with 65% power settings given the tremendous tailwind.
Typically, I will keep my TIT between 1500-1550.
I was flying at 7500 so using 24"/2400.
In the range of 1500-1550 TIT, I was seeing fuel flow at 8.5-9 GPH. Is that remotely accurate? If it is...that is great. I just did not think it could lean to that type of GPH.
Just curious...
Thanks all.
Well, it's not a 112 Hot Shot, but my 114 Hot Shot would easily cruise LOP at 9.5 GPH... It wasn't fast, but it was a really cheap way to fly. I used it on those $100 hamburger runs, or when I really wanted to stretch the fuel.
FYI, whenever you have a question pertaining to a power setting and fuel flow, it is important that you also include whether you're operating rich or lean of peak EGT (or TIT), and by approximately how much (100º rich of peak TIT, for instance).
The max TIT limit can be a limiting factor in certain situations, but leaning should still be done relative to peak EGT temps, and then you cross-check to ensure you're not exceeding the TIT limits. If you don't have all-cylinder EGT, then TIT can be used as a proxy, but it is important to know whether you're operating rich of peak or lean of peak...
Why? Because of the actions you need to take (and very quickly) if you begin to see CHTs rise into the danger zone. If you're running on the rich side of peak, you want to enrichen the mixture further - in fact on a turbo-normalized airplane, you would normally go to full rich, wait for CHTs to return to normal, and then re-start the leaning process, but this time staying a bit further on the rich side of peak to avoid re-creating the same issue.
But if you're already running on the lean side of peak EGT (or TIT if you don't have all-cylinder EGT gauges), then your proper action would be to lean the mixture even more to get those CHTs down. (EGT, TIT, and CHTs all go DOWN on BOTH sides of peak EGT mixtures - they just go down a lot faster on the LEAN side of peak EGT.)
