I just finished this video:
It motivated me to launch yet another subproject while waiting for engine parts: design and implement a really capable onboard video setup.
The goal is to produce top quality footage for publication.
I am thinking 3 synced cams, one in cockpit, one in radar pod pointing towards fuselage and one 360 degree cam on top of the cabin.
Input and advice most welcome. First obvious question: How do you keep em from freezing to death up there ??? thanks!
OT, but what happened on that takeoff from Lausanne? Looks scary. I hope you don‘t say that‘s normal for an MTOW takeoff from an 875 metre runway…
Honest answer is a combination of :
- Lausanne has a 2000 ft altitude and a sloping runway. We were departing in the climbing direction (rwy 36) but there was no headwind to help…
- My experience is that a 800m runway is adequate at SL.
- I normally rotate at 80 kias – higher than book, but it feels safer and nicer. So I could have done it a few seconds earlier in a pinch
- We found a dragging brake 2 months later
- The engine was making plentiful rpm and mp, so I cannot see a lack of power. This said, it failed 2 months later so maybe high internal friction? Any idea how an engine that is making full rpm and mp, with appropriate fuel flow could be putting out less than nominal power? All temperatures were fine…
Nice video. Looks like a lot of fun.
Flyingfish wrote:
Any idea how an engine that is making full rpm and mp, with appropriate fuel flow could be putting out less than nominal power?
YEs, normally airflow restrictions or incorrect ignition timing. As you know well as long as FF is well into ROp range, it is not indicative of power. MP and RPM are.
The impact of airflow restrictions upstream of the compressor (air filter?) or downstream of the turbine (your new exhaust outlet?) are amplified by your air-amplifier aka turbocharger.
In your case it is more likely airflow restrictions in the induction to some cylinders due to inlet valves not opening fully due to cam wear.
You can monitor evolution of airflow in each cylinder by the evolution of mixture distribution throughout different flights (deg LOP for the same power setting, altitude and ff). If a cyclinders evolves towards richer without another apparent cause then airflow restrictions could be the culprit.
You can also tell engine power by t/o roll vs a good reference, or climb performance, but there are so many variables that they are difficult to isolate.
I never take off in a marginal situation without using my TOPC:
I have found it to be surprisingly accurate, if not straightforward to use on TC’d aircraft.
I’ve written a simple program to compare the performance of each flight as recorded on the G500TxI vs book (actually creating the performance tables was what took the longest time), it can work with any aircraft type as long as you create the tables. It’s open source shared so if you have some knowledge of Python you can have a go. Happy to explain how to create the perf tables and help you install it a bit, in exchange for the perf tables for your plane.
Thank you very much Antonio, as always, very insightful and useful post.
FWIW – re exhaust: Galatea used to have a shorter exhaust pipe which the factory extended on later serial numbers, to keep the belly clean. At the occasion of a repair to the exhaust pipe, I have asked them to do this extension and then cut back to this shape after finding that it was eating 2 knots. So this extension really is the latest factory set up with a slightly less brutal tip.
Your TOP Computer looks very clever.
to loco; Yes it was a lot of fun, except for the bit in heavy rain and turbulence which my co-pilot did not exactly love . I have cut off a lot of it.
As usual, lots of lessons learnt. The most striking one is: if you have to avoid weather and your choices are land or water, pick water- the clouds havr nothing to hang on to…
Lesson number two is: from above, even pretty nasty weather that tops out at 8000 feet can look harmless.
Chapter 2 of this video will show the flight from Dubrovnik to Santorini,
This was my first experience of flying very fast eastbound at sunset with the resulting rapid decline in luminosity. On that moonless night this made for a spectacular and kind of spooky approach.
To denopa: thank you for the proposal, I am under a bit of work stress at the moment, but I will take a look into your program whenever possible.happy to share my data, but I do not get it from the G 500, rather from the EDM 930
denopa wrote:
I’ve written a simple program to compare the performance of each flight as recorded on the G500TxI vs book
That is great! Thank you for the development and the open source. I have not found anything online with the capabilities of my TOPCompusaurus . Does your program factor those same items?
denopa wrote:
It’s open source shared so if you have some knowledge of Python you can have a go.
That is indeed a great development and i would like to try it with data from my G5 and Electronics International engine monitors.
Unfortunately the Git Clone request failed due to “Permission denied (publickey)”
Up to now I am using Savvyanalysis and FlySto to review my flights.
Regards,
Carmine
