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Post by joscyriacv2 on Mar 1, 2024 14:02:32 GMT
One of the most common problems I faced while planning my historic jet flights were the lack of adequate flight planning data. Sure there was B707, DC-8, DC-9 performance documents regarding takeoff, cruise and approach available but these were not available for every variant and every engine option. Also, it took a lot of time to find and browse through these performance charts and plan a flight. So while updating my FSX NavDB i came across this software named AJPC which reads the .air file and assists you in planning your flight. The AJPC website description reads: "Advanced Jet Performance Calculator (AJPC) is an utility designed for accurately calculating all performance tables and trip data (climb, cruise, descent or mission) of any jet aircraft (FS9/FSX/P3D) from model data (without any assumption). All calculations are based on exact equations and may greatly help model designers as well as pilots. No need to launch FS for using it !".I tried this for a couple of flights and observed that the calculations were correct. I suggest you all to try this once and see how it goes. CLICK HERE FOR THE WEBSITECyriac
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Post by alex94 on Mar 2, 2024 9:48:35 GMT
Good tool, will have a go. Cheers mate
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Post by Nathan Ford - HJG on Mar 4, 2024 4:29:30 GMT
Sounds interesting
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Post by joscyriacv2 on Mar 4, 2024 7:20:31 GMT
Also this website has FSX NAVDB update which will update all your FSX Navaids to the latest AIRAC cycle.
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Post by walterleo on Mar 4, 2024 16:47:26 GMT
Hi friends: GOOD FIND! I am doing a calculation for a flight KJFK-MMMX 3390 km around 2000 NM: By a ball point calculation, I got: Doing the same with AJPC: For the Take Off in heavy snowfall one gets: According to the real handbook: Looks GOOD! Will try it "flying". Have to add, that for exactly that flight exists an accident report which gives quite similar datas for the failed Take Off on 19 of January 1961 with XA-XAX: aviation-safety.net/database/record.php?id=19610119-0Kind regards Walter
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Post by joscyriacv2 on Mar 5, 2024 2:29:44 GMT
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Post by walterleo on Mar 5, 2024 8:58:42 GMT
Hi Cyriac: As "we" will not have a check-captain with us, the take-off should go as planned. The report is interesting as it shows the real data of the take-off. BUT: As the runway at the time of the accident was snow covered near the maximum permitted by Douglas, I used the maximum friction (0.1) permitted by AJPC and V-liftoff should be reached at 6916 ft of the 10.000 feet runway after 1,02 minutes. Kind regards Walter
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Post by joscyriacv2 on Mar 6, 2024 4:24:36 GMT
Hey Walter. I did some calculations on my own and noticed there were some errors in the way you did your calculation. The runway pressure altitude would be 274 feet. Headwind would be 18 knots. ISA deviation would be -22C. N1 % would be 96 (From the accident report) Although the calculated Vspeeds were slightly different, the runway required calculation was 4356 feet which is within 500ft of what the investigators calculated. So I think that's pretty decent.
Cyriac
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Post by walterleo on Mar 6, 2024 11:40:55 GMT
Hi:
ISA should be F and not C, and the rwy calculation in FS9 can not include the snow covered rwy, so I put friction 0,1. And I did not reduce N1 for my flight. But thanks for your interest and comment.
Walter
P.S.: I would not have selected flap 15 but 25 instead and would have firewalled the throttles.
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Post by ozflyer on Mar 9, 2024 18:50:45 GMT
Hi: FS9 can not include the snow covered rwy, so I put friction 0,1. And I did not reduce N1 for my flight. Walter Just wondering what that means?
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Post by ozflyer on Mar 10, 2024 0:46:14 GMT
By the way, interesting program (no idea if accurate or not) with approximately zero info provided and what anything does or how to use it.
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Post by walterleo on Mar 11, 2024 9:26:30 GMT
Hi:
As I use FS9 there is no direct way to include runway conditions like snow-covered. If you like to add the effect of 10 cm snow you have to increase the friction coefficient to simulate its braking effect, therefore take off distance increases, as it happened in real on the Jan. 19 accident. As N1 was reduced, the take-off run was still longer as it was reported by various people. In my "flight" I will firewall the throttles as I have not the intention to repeat the accident. the 200 ft of altitude difference makes no noticeable effect. The programe AJPC can be used with some practice, some input of knowledge about aircraft operation and trial and error.
Kind regards
Walter
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Post by ozflyer on Mar 11, 2024 16:37:47 GMT
Hi: you have to increase the friction coefficient to simulate its braking effect, Kind regards Walter I think that's the part I'm interested in. How to do that? Is that something similar to the sim1.dll mod?
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Post by walterleo on Mar 12, 2024 12:18:26 GMT
Hi:
Its much easier: Look at the last line of the take-off calculator the value FCoef. By default its set 0,05 the maximum permitted is 0,1. Assuming one has some 10 cm of snow at least on part of the runway the take-off run and its time will be quite longer. So, the runway condition is the same as dry but the effect of the snow is CALCULATED. The DC8-21 will fly away in FS9 same as in dry conditions. My calculation relates to the accident on January 19th. Many persones among them an aeronautical engineer and some DC-8 pilots testified an unusual long take-off run lasting around 1 minute. If one wants the effect "built into the runway conditions" one has to use FSX. OR: Fly the PT Tu-154M of Project Tupolev. This bird accelerates and brakes according to the meteorological conditions selected. One will eat up the runway of LOWI (2000m) in winter while snow-covered landing a PT-Tu-154M at max landing weight.
Kind regards
Walter
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Post by ozflyer on Mar 12, 2024 19:33:32 GMT
Ok that makes sense. I thought you may have had a little trick to doing the same in FS9 as in FSX etc. I haven't tried it with some of the HJG jet era, but with the 737NG/747-400, I would use topcat if it was raining and use the dry setting in topcat giving a derate until it had the same takeoff distance as if I choose the rain option with a higher takeoff setting. Best one could manage with Fs9's limitations.
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