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keefpee

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About keefpee

  • Birthday 05/07/1938

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    Cheltenham
  • Occupation
    Retired aircraft design & development engineer

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    Aircraft Sim

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  1. A descent rate of more than 300 fpm (or is it 800 fpm?) can cause ear problems for passengers, so the dump valves control the pressurisation rate independent of the actual aircraft rate of descent. Keith
  2. Its a long time since I played with AI aircraft, but your posts did ring a feint bell when talking contact points. I think if one changes the contact height of each wheel by the compression value & adjust the static C of G then one is there, (pressing 'Y' in the controllable version is a check that the C of G height is correct). I noticed that AI aircraft do not show undercart deflection, so its dragging its wheels underground........ Keith
  3. The Tiger normally does not have any brakes, & has a skid on the tail, so is very sluggish on tarmac & in certain crosswinds impossible to go where you want it, which is why you see wingmen helping on the ground. One has to blip the throttle to get some air passing over the rudder, so if one must try to get it to turn then you would need to look into the .air file, or give it more authority to the rudder. Not sure about the Cub, could be similar rudder/ airflow problem when tail down. Keith
  4. Being different again, I modify the value in the air file table 1101, for Pitch - Cm_dt Pitch moment - Trim =x. The value of x pure guesswork, but in general less than the current value. One does though have to be careful & leave sufficient for the difference between flaps & U/Cart up or Down. Keith
  5. I was brought up on taildraggers, my father owned a Percival Proctor which he bought in 1949 for about £400, (I would have been 11 years old). He was a licenced ground engineer, so he was able to keep it for 18 years at a small cost, being able to use it for business travel occasionally. When I was apprenticed at Vickers Armstrongs I was lucky enough to be subsidised to learn to fly, paying only 10% of the real value per hour. The course was for 30 hours flying to achieve ones PPL & it had to be completed in 6 months, so off to Fairoaks & start in a Tiger Moth of course. Nothing new really I had flown with my Dad in 1946 in one when civil flying restarted after WW2. I had no chance of equalling my Dads record of going solo in 1 hour 30 mins, but after 5 hours 30 I went for the test, unfortunately the weather was too gusty so had to be delayed, but my log book says 6 hours 30. I converted to fly an Auster Alpha & then the Taylorcraft plus D that was in the fleet. I was worried about the Auster because in the Tiger one is Right Handed on the joystick but Left handed in the Auster & Taylorcraft, but really it was easy. Always taught to 3 point & the only wheeler I remember doing was in a landing competition where I forced the wheels onto the touchdown line - well almost! Unfortunately, as one does, girls marriage, house buying & kids put paid to flying, but I did most of my working life in aircraft design & development, & now enjoy making & flying FS 9/FSX models - available here. The main difference is one has lost the 3D & easy scan capability in real life, which makes quite a difference when landing, as well as the loss of sensation of air turbulence on oneself & the necessity of correcting the aircraft after being upset by turbulence. Maybe the commercial simulators reduce those problems. Keith
  6. Was replying but have lost it - so starting again. Sent you a PM with my e-mail, I can then send it to you when replying. Not sure how to attach it here. I wonder - have gone advanced, can attach I think.- no luck says invalid file. Revert to sending me. In the meantime I also have Jerry Beckwiths AirUpdate v 1.0.0.1 which I think does just that to the original AirEd v 1.0.5.2. Another useful one is by Herve Sors Aircraft Airfile Manager V2.2. This shows some tabular entries as a graph. Regards Keith P.S. The cub does not have table 517 & its elevator effectivity is set to 1 throughout its range, so the cub shows up as not realistic I would say in the sim. K
  7. Bounce fixed!!! Found that I could not 3 point her because of insufficient elevator authority at the stall, so she would touchdown on the main wheels & tend to try & nose over causing her to bounce. So for a first try I modified table 517 Cm_de(q) Elevator Deflection (moment) Factor vs q at X=9.460485, y=.7207, to y=1. This now gives plenty of elevator authority at the stall, so could easily be adjusted to tune it so that one does run out of elevator at the stall, try .85? I can now get a 3 pointer with ease. If one compares the Spartan with the J3 Cub, the cub has plenty of elevator at the stall so is easy to 3 point. Keith P.S. Just tried 0.85 & that is just right, elevator has just enough authority at the stall to need full up elevator. K
  8. Don't forget though that some tail dragger aircraft were prone to ground loop if three pointed, the DH Mosquito was one. Seems that the design position of the tailplane & of the fin & rudder had an effect & so it was normal to do a mainwheel touchdown. Looking at the video of a French made 7/8 scale Mosquito which came to grief a couple of years ago was because the pilot did a 3 pointer. Bounce effect could be result of too stiff a setting in the contacts data in the aircraft.cfg? Keith
  9. Elmer, yes a lot of the time reverting can be a marvellous cure, one has to do only 1 thing at a time, which can be very tedious, otherwise something else changes one did not consider. But surely a pilot must have some knowledge of aerodynamics? Anyway glad you got sorted. Just got me wondering - as I was brought up by my father who owned & maintained his aircraft back in the late '40's through the 50's & into the 60's, flying was in my blood, I then became a design draughtsman & for a short time had a pilots licence - got married & bought a house - that put paid to flying.....so am I a designer or a pilot - or a bit of both? Master of none! Keith
  10. Not having FS8, but the real way is to adjust the Cl vs AOA curve in the air file around the AoA of zero degrees. One should be able to calculate the value of AOA in cruise at sea level from the standard aero formula W= Lift= aircraft weight= rho/2 . (v x v) . Cl . Wing area. So rearrange the formula for Cl. Then look up the Cl vs AoA graph & then read the AoA at that value of Cl. After that move the value of Cl up or down changing the straight line slope....remember you are using angle in radians, value 'x' ; for Cl value 'y' in the graph. This also works for Cm vs AOA as an alternative to changing table 1101 Cmo Pitch moment Coeff at AOA (trim os) = 0 Sounds worse than it reads! Keith
  11. ChuckB, Thats the one I was thinking of & couldn't remember - its the click in the open space, not to click on the folder. Keith
  12. I would like to know if someone could help me with my problem, when I download the scenario the scenery and texture folders have files inside them. But when I'm in the simulator and I'm going to add them they are empty and it doesn't let me. Sorry Rick, used DeepL to translate, which seems to make the last sentence more logical. I think I've had that problem, but for the life of me cannot remember how to get out of it, but then I rarely install scenery add-ons Keith
  13. Could also be the C of G height, & I believe that AI aircraft undercarts do not animate so stay at extended length - could be wrong...Good luck Keith
  14. This sort of thing is usually due to a bad contact point or CofG value, does it do it on an addon airfield or a bog standard M$ airfield? If you hit 'Y' then F4, then 'Y' again (slew mode) to get it in the air does it fly & land OK? Thought - what level is your Crash susceptibility set?
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