Back from Vienna just before Corona Virus closed all borders! With the transducer installed before I went away I rechecked the installation and carried out pressure testing to ensure there’s no leaks and all seems to be secure.
Wiring up the transducer into the EMS220 is straightforward using 3 wires, a 12v supply, signal and ground. The SkyView panels need to be configured with the ‘K’ factor of the FT60 unit. This is the number of rotations per US Gallon. Entering the config screen I found that the SkyView had already detected the unit and configured itself which was handy.
Once configured a check needs to be carried out between measured and actual fuel flow. I removed one of the banjos from the carb and captured the flow in a measuring jug to carry this out. With no restriction the electric fuel pump delivered 66 litres per minute and when restricted to give 3 psi within the fuel system the flow rate was 44 litres per minute. This is significantly more than the 27 rpm that the engine needs at full throttle.
Testing throughout the RPM range was carried out switching between left and right tanks and using the engine pump and engine and electric pumps options to ensure there were no issues with fuel supply. After the engine runs a thorough check of the installation was made to ensure there were no leaks or issues.All’s fine so now for the paperwork for the LAA. Worksheets covering the work carried out and a fuel flow check form needs to be completed. A suitable entry needs to be entered in the Airframe logbook signed by myself and a permit maintenance release needs to be signed off by and LAA inspector with the appropriate authority, in this case Ian Daniels.
It’s been a month since we carried out the first part of the flight test. A couple of holidays and continued bad weather has prevented further testing but Monday and Tuesday both looked good so Rob made the trip down on Monday morning so we could finish it off.
After a cuppa we planned what we were going to do. Avionics testing on the first flight, the Airmaster and feathering on the second flight and during the third flight which would be for 2 hours we would test the autopilot and complete any outstanding general flight tests.
To ensure that we achieved the 15 landings required by the LAA to validate the flight test Rob suggested that we carry out some Touch and Go’s at Lydd EGMD. A quick call to them and we were set up for that on Tuesday.
All the flights were completed at the end of Tuesday at 16:03. We logged 15 landings with a total flight time of 7:31. During the flights all aspects of the the aircraft worked faultlessly.
The Airmaster was a dream to use and produced some very impressive results with maximum rpm for very sprightly acceleration and a very short take off run. Once Climb is selected we noticed a very good climb rate even at MTOW. The transition between different settings on the prop was very smooth and predicable. With the engine off and the prop feathered it reduced the drag to negligible rates which was reflected in the reduced descent rate achieved.
The engine ran faultlessly and never missed a beat. It was very responsive to throttle changes throughout the range.
The autopilot performed faultlessly too. It did everything that was asked of it. Tracking a flight plan, climbing or descending at a specific VS or to intercept an altitude. It even protected the aircraft by ensuring it didn’t fly outside the flight envelope.
The Dynon screens are clear and easy to read. They take a bit to get used to as they are not quite as intuitive as an iPad, but they worked very well with good aural warning annunciations coupled with the display of appropriate alerts.
The Bristell was lovely to fly. It was stable and had a good solid feel but very responsive when you need it. It settled on the ground during landings very nicely even in moderate turbulence. The cabin is very spacious and the seating is very comfortable. It felt that you could fly for hours and not get fatigued.
Overall I’m very happy with my decision to buy a Bristell. The options I’ve included have enhanced the end result and my decision to fit the Airmaster have resulted in an aircraft that’s a delight to fly.
So the flight tests are done and the paperwork is with the LAA. Now it’s a waiting game before I receive the permit to fly but hopefully it won’t be too long before I’ll be able to take G-MLSY for a flight myself and then take Karen for a few flights including a little tour around the Kent coast.
G-MLSY is a joy to fly and it was great to get back in the air.One of the tests to carry out if you have a feathering prop is to switch the engine off, feather the prop and restart with a dive and then repeat with a starter restart. Both work faultlessly. Once feathered and trimmed for best glide we achieved and impressive descent rate as can be seen in the photo.. It never ceases to amaze me what you see from the air. Here a staggered river or drain reveals itself at height.Dungeness Power station off the right wing tip. The landscape around here is quite barren. Set up for a very turbulent final to ’03’ The Bristell handled very well and was very responsive even in these conditions. Touch & Go’s were really very easy. Land, dial up 10 degrees of flap, full throttle and away you go. On climb out with positive rate of climb, flaps away and switch the Airmaster to ‘Climb’. The rpm reduces to 5500 with no stress or fuss.One of the things that we had noticed is the EGTs tended to be a little on the high side. During construction I made a decision to add exhaust wrap to the exhaust downpipes. This was to protect surrounding pipes and lines from excessive heat. However it seems to have an adverse effect and produce higher than expected EGT. This shows the EGTs with the exhaust wrap fitted.I decided to remove the exhaust wrap and run the engine again. The EGTs are running up to 80 degrees cooler now so I’ve decided to leave them off now.G-MLSY looking good after a thorough clean and ready for the next flight…
It was a long weekend which ended with a complicated Monday.
On Saturday I flew into Palmers Farm for a Bristell Fly In organised by Tony Palmer one of the owners of Bristell UK. It wasn’t planned but luckily Chris Knight who owns G-CILL had some free time so asked if I’d like to go with him.
Sunday was a tugging duty in tricky ESE winds which was quite demanding and takes a lot of concentration.
And on Monday I was supposed to fly some family in my other Aircraft which is a Grob 109b, Unfortunately it went ‘Tech’ and despite speaking to the aircraft maintainer to try fo fix it it was quite obvious by 1300 that it needed major surgery. I managed to fly everyone but had to use one of London Gliding Clubs DR400s instead. This proved a better option in the end as there were 12 people to fly.
Tuesday was a ‘rest day’ but I decided to use it to complete some of the paperwork that needs to be done including the Weight & Balance calculations which I’m pleased to say worked out ok. All of these forms need a sign-off so will have to be done when Ian returns.
Following the build of my Bristell NG5 Kit No. 382 Registration G-MLSY
G-MLSY 