IBob

That'll be this one:

I thought this was a pretty good watch:

It's not unusual for pilots of jump planes to wear a parachute......I would say because there are very occasional incidents where a departing jumper damages the aircraft. Perhaps he was wearing a parachute and attempting to exit.

Hi Marty......all sounds like progress! FWIW: My front CHT always read lower than the other one: probably inevitable given the position of the sensors. I think Rotax now recommend initial warmup at 2200RPM, dropping back to 2000 after a few minutes. And my 912 always felt better at 2200 when cold. And I'm not sure about 1800 as the min setting. Mine went lower than that, which was kinder to the engine/gearbox when finally stopping (no big clunk). I set my idle jet and throttle stop as per the Rotax manual, it's quick and easy and one of them was out on a new engine, so worth checking.

I didn't, Skippy. I know MEK is just about instantaneous compared with thinners. Is isopropanol similar?

Other things keep coming back to me: The manufacturer's printing on the 6061 needs to come off, or it will bleed through. Thinners will do this, but MEK does it far quicker and cleaner. However, MEK is nasty stuff, so needs handling with care.

Also this: the polycarbonate in my doors still had it's protective peel-off coating. I then added a thick layer of paper, fastened round the edge with masking tape. This turned out to be totally inadequate, as when I removed those, the surface of the poly was lightly fogged. Presumably paint solvents had made their way through. I believe what the professionals do is mask this stuff with some sort of metal foil and tape. No doubt someone here can tell us? It gave me a bit of a scare: the door is basically two poly panels with a huge number of rivets round the edges and across the middle. But I was lucky (that time): the fogging was 'only' surface and I was able to remove it using a Meguires smooth surface clay kit and a great deal of elbow grease.

Some other bits and pieces for those coming at it for the first time, as I did: My assembly priming was done with a cheap gun, but when it came to the final job, I bought a good quality gun. They just do work better. The wing side I had to wash back and repaint went on too dry, and the reason was too much air. I bought an air pressure gauge that goes on the gun, as the pressure at the compressor is not the same as at the gun once you start spraying. This allowed me to set the pressure at the gun correctly. I had a mixing table in the booth, with a DIY stand for the gun. For mixing I used straight sided pots and a measuring stick to get precise mixing ratios. The measuring sticks are available at spray shops. I then used fine mesh disposable filters (also from spray shop) to filter the mix. I wore a (disposable) lightweight suit, with hood, and neoprene (?) gloves. My mask was 3M full face with Organic Vapour cartridges. This has a neat setup whereby incoming air comes via the face, but outgoing air does not, so there is no misting up. I also bought disposable particulate filters: these go on the outside of the cartridges and catch the overspray, which will otherwise quickly block the (expensive) cartridges. Also from the the spray shop: Tack cloths. Masking sheets (for masking off big areas). These come in a dispenser with adhesive tape attached to one edge and are far quicker and neater to use than DIY solutions.

Hi Marty, I have very limited spray painting experience and set about it with real trepidation. I managed to get a good finish, though I did have to wash off one wing side that went on too dry. My setup was as follows: A Supercheap car parking tent set up inside my workshop, with the bottom edges duct taped to the floor. At the far end, two 150mm domestic extractors (as used in kitchens and bathrooms). These had no ducting, went straight out through the tent and (ply) workshop wall. The pilot who donated these had used them with a long length of ducting and said they were useless like that. I had no trouble, so I think it's worth noting that spiral ducting may greatly reduce airflow over any distance. I painted in winter, so at the near end I had a hole in the tent where I placed an oil filled radiator. I would turn on the fans, which provided a very gentle airflow, turn on the radiator and watch the temp rise in the tent where I had a cheap thermometer. When the temp rose to about 23' I would suit up, turn off the radiator, go in and mix the paint and spray. The temp would continue to rise a bit due to the residual heat in the radiator. For lights I had fluoro strip lights all down one side , with DIY foil reflectors behind them. I thought this would be more than enough in a white tent, but it wasn't. The only way you can see how you are doing is from the reflection of bright light in the surface, and to get that without having to walk round the job and view it at various angles, you need lights on all sides. Simply put, you can't have too much light. I made simple tilting mounts for the wings so that the surface was angled towards me at about 45'. This is a big area to spray, and I found it far easier to work the gun with the job tilted towards me that way. I did not have the confidence to spray both sides , so the wings were each done in two sessions, one side then the other. I partly rotated the fuselage for the same reason, and that was painted in 4 sessions. I found with the colour on the fuse it was really easy to see the finish, compared to the white on the wings etc, where I had to paint then walk round the job squinting at odd angles to get a good reflection. You haven't got much time to be doing this, and the less you move around the less dust you disturb. For all the smaller parts, empennage etc, I also went to some trouble to set them up so I wasn't trying to use the gun at odd angles.

At a BBQ in town some 40yrs ago, we got a lovely low fast banked pass from a Spitfire. We were all amazed and delighted, most of us had never even seen one. About an hour later we heard he was down in a paddock. Apparently he ran out of fuel....or ran out of accessible fuel: had more in wing tank/s (?) but the engine has to be running to pump it across. So once the music stopped, that was it.....

I would say quite likely in skydive operations, where the emphasis is on minimum flight time. Certainly there are pics out there of freefall jumpers with Porters in the background in pointing straight down....that would a descent rate of 10,000fpm. However, that's certainly not to say this accident aircraft was flown in that way.

Could be, Nev. Jumped a Porter at Peterborough in the UK, late '70s. We later heard that when in when the pilot selected Beta shortly after takeoff. I have no idea if that is likely or correct, but certainly the aircraft was written off. Oh, hold on, that's all wrong: aileron/s separated during descent, here is the report: https://www.baaa-acro.com/crash/crash-pilatus-pc-6b2-h2-turbo-porter-near-peterborough

I'd say it was the perfect loo with a view???

There was some guy in the US, during the barnstorming days, used to exhibition jump with a little set of moth-shaped wings strapped on. I believe he came to grief after striking the aircraft somehow on exit, presumably damaging the wings which would have had no quick release. If I jumped a wingsuit, I'd want to be very sure that none of the stitching or fabric could fail...........but I guess they will be very strongly constructed with modern materials. As for conventional skydiving: I was recently told that there are now more accidents and fatalities due to poor landing of high speed canopies than there are to gear malfunctions.

Nev, there are....or were.........various types of malfunction: bag-lock, line over, inversion, streamer etc. What was called a roman candle, or more usually a streamer, was where the lines and canopy came out okay, but the whole lot then streamed instead of opening. I don't think that happens with the ramair canopies now used.

I just searched that. It sounds like wingsuit fliers can have both main and reserve canopy, but with wingsuits for base jumping (off solid objects) there is just the main canopy. The reason being that there would generally be insufficient time/altitude to operate a reserve? That suggests canopies must be a great deal more reliable nowadays, and it does say they are optimised for reliability.

I'm with you on that, sfGnome. And while there seem to have been a fair few fatalities (it would be interesting to know what the actual figures are on that) I'm pretty sure it could be done quite safely: not all of us need to fly as close to the rocks as possible.

It seems they get a glide ratio of about 3, which is pretty good. 'Old school' skydiving has an arms back legs out 'tracking' position, typically used to gain horizontal separation from other jumpers just prior to opening. I believe a sustained track can generate something like 60mph horizontally, but with the rate of descent increasing to about 180mph. So a glide ratio of approx 0.3

That or hypoxia: 'It's all cool, man.................'

Marty, re the 912 oil pressure: Originally Rotax fitted a VDO (or VDO type) sensor. These put out a voltage, but were prone to failure. They then moved to a sensor that puts out 4-20mA, which is far more reliable. However, you need the right gauge to go with whichever sensor you have: they are not interchangeable.

Apologies if I've misunderstood: You should have coolant already in the overflow, with the overflow pipe going down to the bottom of that. I ran with my overflow about 50%full when cold. As for this first run: you quite possibly had air in the system, so I would not expect to see coolant passing immediately into the overflow.

Excellent, Marty! And Blueadventures is right. I think Rotax now reccomend initial warmup at 2200RPM, easing back to 2000RPM after some minutes. And mine always felt good at those cold to warm settings. As for getting the oil temp up with a ground run, you may well have to blank off part of the radiator. The 912 is very slow to warm the oil regardless...

Looking great, Marty! I fired mine up with the cowls off, allows an observer to check for leaks during the initial run, I had a fuel leak at the splitter. Also for any pipework or wiring etc that is vibrating and requires further securing.

My test pilot grabbed the cowl through the front airholes and checked it for movement. That was added to my own walkround......

It seems to me he's grasping at straws.........but I can agree with his larger point: that it's all speculation unless we get a good look at the detail of the data. And until then, it is wrong to be suggesting where the error/s may lie.