Tuesday, February 28, 2012

VNKT - Kathmandu Airport EOSID Design

Step by steps of EOSID design for this airport with aircraft A320 is as follows:

1. Examine the required data for EOSID: airport/flight procedure data from AIP, terrain data, and aircraft data.


Kathmandu airport is located in the valley surronds by mountanious area. The normal takeoff flight path crossing a high terrain area which requires a very high minimum climb gradient. The terrain and obstacle profile during a takeoff on runway 20 is given in the picture below. 

 
2. MTOW comparison.
The resulted RTOW chart gives MTOW of 59.4 tons for take off with CONF 1+F at 24 deg C OAT as shown below. This MTOW is too low compared to normal MTOW of 77 tons. Thus a EOSID procedure is required to get a higher MTOW.


3. EOSID procedure design.
The EOSID design requires many aspects to be considered. The propossed procedure is climb on runway heading 022 deg to KTM, at D1 KTM RIGHT turn to intercept D4 KTM Arc, crossing R-015 KTM maintain 106 deg magnetic, at D5.7 KTM RIGHT turn to intercept R-106 KTM inbound to KTM, at KTM RIGHT turn to R-015 KTM to intercept D4 KTM Arc, crossing R-084 KTM LEFT turn to intercept R-106 to IGRIS. The pictorial of this procedure and it vertical profile are shown in picture below.

4. Overlay propossed procedure into topographical map.
The 3D view of contour map with the EOSID procedure is shown in picture below.


5. Update obstacles data.
The terrain and obstacles data along the procedure is used to generate a new RTOW chart based on EOSID. The obstacle used with its height correction is shown in table below.


6. New RTOW chart
The new RTOW chart shows a significant increase in MTOW for the same setting as discussed previously. Now it gives MTOW of 68 tons.


7. Re-design EOSID to get a better RTOW chart if your boss is not satisfied.

-o0o- 

1 comment:

  1. Sir

    Could you please elaborate on the topic 5 update obstacles data such as?
    • How the obstacles distance is calculated?
    • What is distance flown in last turn?
    • How is height increase calculated?
    Also could you mention whether or not loss in 2nd segment climb gradient due to bank is considered while computing RTOW chart.
    If not what happens to RTOW for EOSID from KTM RWY 20, which avoids all major obstacles by remaining within 2.5 DME. But makes 15 degree bank while avoiding obstacles. How do we take into consideration loss in 2nd segment climb gradient due to 15 Degree Bank?

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