APLA - Vref gusting winds calculation
Thread Starter
Join Date: May 2024
Location: Australia
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
APLA
Hi everyone, I'm just self-studying APLA and wanted to ask a question about the load and trim sheet and fuel loading. My question is below. I just wanted to ask if the fuel in the aux tank is also included in the fuel loading curve, or do I only plot the 18,000kg? cheers.Q: Your B727 has a total fuel of 19,000kg with 18,000kg in tanks 1, 2 and 3 and 1000kg in the aft auxiliary tank. If your ZFW is 61,500kg (MAC: 29%), what is your TOW and % MAC respectively?
Thread Starter
Join Date: May 2024
Location: Australia
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
APLA - Vref gusting winds calculation
Hi everyone,
Just a question about APLA and calculating Vref speeds. Am I correct in saying that you would calculate the approach speed by adding half the wind speed + half the gust + Vref = approach speed? I found it didn't work for the question below as I'm getting an answer of 150kts and the answers are showing 152kts
Just a question about APLA and calculating Vref speeds. Am I correct in saying that you would calculate the approach speed by adding half the wind speed + half the gust + Vref = approach speed? I found it didn't work for the question below as I'm getting an answer of 150kts and the answers are showing 152kts
- You are flying a B727 and decide to calculate your VREF speed given the followinginformation: Approach Speed (1.3Vs): 139kts
Wind Speed: 18kts/ gusting 22kts.
Any help would be appreciated!
No idea what APLA is, but where I am on Boeing we use Vref plus half the steady wind plus ALL of the gust, with a minimum of 5 and a maximum of 15. So 18G22 would be 9+4= Vref+13 = 152
Hi everyone, I'm just self-studying APLA and wanted to ask a question about the load and trim sheet and fuel loading. My question is below. I just wanted to ask if the fuel in the aux tank is also included in the fuel loading curve, or do I only plot the 18,000kg? cheers.Q: Your B727 has a total fuel of 19,000kg with 18,000kg in tanks 1, 2 and 3 and 1000kg in the aft auxiliary tank. If your ZFW is 61,500kg (MAC: 29%), what is your TOW and % MAC respectively?
This question is checking if you know the fuel distribution requirements and how to account for abnormal loads. The trap here is if you don't apply the change because of the fuel in the AUX tank vs normal loading it will throw off your %MAC at TOW. On the fuel curve you need to calculate the MAC change for the 18t loaded normally, and 1t in the Aux tank.
Last edited by NaFenn; 2nd May 2024 at 01:11.
I’m confused. How does all of 22 = 4?
The following users liked this post:
Gender Faculty Specialist
Do you mean half the steady head wind compinent plus all of the gust or do you actually use half the steady wind plus the gust?
Thanks for the explanation, eckhard and rudestuff. I knew I was missing something.
Please also note the difference between a gust and maximum recorded wind speed in the last 10 minutes.
There is no such thing as a 4 knot wind gust.
There is no such thing as a 4 knot wind gust.
Last edited by Xeptu; 2nd May 2024 at 00:38.
Thread Starter
Join Date: May 2024
Location: Australia
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
You need to account for the fuel in the AUX tank.
This question is checking if you know the fuel distribution requirements and how to account for abnormal loads. The trap here is if you don't apply the change because of the fuel in the AUX tank vs normal loading it will throw off your %MAC at TOW. On the fuel curve you need to calculate the MAC change for the 18t loaded normally, and 1t in the Aux tank.
This question is checking if you know the fuel distribution requirements and how to account for abnormal loads. The trap here is if you don't apply the change because of the fuel in the AUX tank vs normal loading it will throw off your %MAC at TOW. On the fuel curve you need to calculate the MAC change for the 18t loaded normally, and 1t in the Aux tank.
What makes this interesting is that the word "gusting" appears to no longer be used on ATIS transmissions. "Minimum 10, Maximum 20" is current verbage- I GUESS that means the same as 10 gustnng 20??
The term gusting has been used out of context for decades, It came about as a consequence of met observer training when wind speed measuring equipment came into use at regional airports and it stuck.
The equipent measures prevailing wind and notes the maximum recorded wind speed in the last 10 minutes, This is not a gust. Primary airports have gust measuring equipment and threshold wind sensors. Pilots are advised when the threshold wind is significantly different. I'll leave you guys to look up what a gust is defined as. Use that new learning to find the hidden trap in the Op's question.
The equipent measures prevailing wind and notes the maximum recorded wind speed in the last 10 minutes, This is not a gust. Primary airports have gust measuring equipment and threshold wind sensors. Pilots are advised when the threshold wind is significantly different. I'll leave you guys to look up what a gust is defined as. Use that new learning to find the hidden trap in the Op's question.
The BOM says this about METAR/SPECI:
What is the source of the wind information used in the OP's question?
The wind speed, given in knots (KT), is the mean value over the sampling period. The maximum gust during the sampling period is reported when it exceeds the mean speed by 10 KT or more. It is indicated by the letter G which is followed by the gust value. In Australia, mean wind is sampled over 10 minutes and a 2 minute period is used for maximum gust.
