Colin wrote:
One interesting thing that the engine analyser showed, that you would never pick up on the old factory fitted analogue gauge, is that the Prop was overspeeding by 5 to 10 RPM on take off.
I wouldn’t be trying to adjust anything for that tiny discrepancy, it’s surely such a small difference it makes no difference to anything
It was the fuel flow gauge giving inaccurate readings mainly, which in turn meant it was difficult to lean the engine properly, according to the POH power tables. Using the factory fitted fuel flow system meant you over leaned the engine.
When the new CGR-30P engine analyser was fitted it made a big difference, as you can now lean the engine using Manifold Pressure, RPM, but also EGT’s and Fuel Flow far more accurately. The end result was that the aircraft flew at the correct speeds according to the POH, which is what I had been trying to achieve. The new Fuel Flow Transducer was fitted forward of the firewall and not where the factory fitted (below Fuel Cock in the belly) can be found.
One interesting thing that the engine analyser showed, that you would never pick up on the old factory fitted analogue gauge, is that the Prop was overspeeding by 5 to 10 RPM on take off.
Very strange to start adjusting surfaces and then looking at the tacho… You’re sure you hired pros?
Hi there,
An update for you.
The Rigging has been checked and some minor adjustments made to the Stab and 1 aileron. The aircraft was rigged according to the MM (with the aircraft levelled) and also visually checked against older and newer aircraft of the same type.
On the subsequent test flight there was almost no difference other than it now likes to turn right all the time when hand flying (trim tabs will sort that, but create more drag).
Next item to go through will be Tacho, to check that the Prop is rotating at the same RPM, as the Gauge in the cockpit is reading. The Tacho gauge shows the aircraft to have flown 31000 hours, which it clearly has not done. The readings of the Tacho appear to be correct as it shows 2575 rpm on take off and 650 on idle.
Are there any known issues with the standard fit Tacho?
Colin wrote:
The rigging is being checked today to make sure everything is aligned and/or retracted fully.
That’s a god start Colin, but a good rigging session also includes test flying to be sure that the plane flies straight, ball perfectly centered and with no tendency to drop a wing with both hands & feet off the controls.
He would have to be very rich of peak to get such a speed loss, IMHO.
I suspect a clue may be the incorrectly installed fuel totaliser. What Socata did was a Grade A joke. The reading was something like 25% too high, so if you set say 12.5 USG/hr you were getting only 10 USG/hr. In some cases the dealer who supplied the plane tried to make the best of a bad job and tweaked the K-factor (the number of pulses per USG, configured in the instrument) to take out this 25%, but there is about a 10 percentage point variation in that 25% (it’s not a nice constant error) so the best you can get is an error which varies between 0 an 10% according to the day of the week. Actually running the electric pump would shift it by about 10% so much depended on what % of a flight’s time had the pump running 
The analog gauge cannot be read to better than 10-20% so that’s no help.
Colin wrote:
There is a fuel computer (original from factory) and I am running rich of peak when checking my speed, to avoid over leaning, as there is no Engine Analyser yet. I am fitting the EI CGR-30P this winter. The Fuel Flow reading against the POH data settings is definitely worth a look.
Have you tried optimising speed with respect to the mixture? It may be that you are well rich of best power.
Michael wrote:
ALL airplanes are very susceptible to rigging issues and 2 or 3 seemingly small issues like a gear door that’s not tight or flaps not fully retracted plus a bit of “skew”, can add up to 10 – 12 knots off the top end in no time .. .
The rigging is being checked today to make sure everything is aligned and/or retracted fully.
