I descend when Simbrief tells me to but I fell like I go to steep because it started me way too late. Any suggestions on how to fix this?
The way I descend is at 1800, each 50nm = 12,000ft. Until 12,000ft, where I slow and descend at 1200-1400.
Also, this is a great tutorial to finding your T o D. Then you can work your VS from there.
You haven’t linked it 😉
@CaptainHugh 😂😂😂, thank you!
Topic is linked bow @Trey_Weger 😉
Unless you are picking a real route SimBrief will often generate the VS based on estimates which may be unrealistic.
Hi @Trey_Weger I use simbrief quite frequently when flying but I’ve never noticed a high VS descent needed to reach the altitudes simbrief gives.
How high of a vs do you need to set your autopilot at? What’s your mach speed on descent? What aircraft type are you flying?
@Snow_Cone Today when I was flying into Macau Intl, I started my descent right when Simbrief told me to and I had to set my VS close to 3000 because of not, I would overshoot the airport. I was going 310 knots when above 10000 feet so I may have been going a little fast. When Simbrief gives me a descent profile of 84/310/250, I thought I was supposed to hold 310 when above 10000 but I read the link that the other person posted and it said no greater than 280
M.84 until FL280, 310 until 10,000 then 250K
Edit: I still think those speeds are a kinda fast
3xFL. That’s all it is:
Say your crusing at FL330 (33,000ft). All you need to do is multiply 330 by 3. That gives you 99. Then descend as best as you can at a vertical speed where you have 0% thrust set, and still maintaining airspeed/mach. This will require you to adjust your vertical speed a bit during descent, but it works like a charm.
Do you happen to know the decent waypoints you used into Macau as well as the altitudes that were provided?
Also @FlyerCharm is right about that profile. However keep in mind that you need to reach 250 knots at 10,000 ft. So you do need to keep in mind that there is a point at which you need to slow down to 250 knots from 310 knots to reach the airspeed restriction. It is possible that by keeping 310 knts until maybe lets say 10,500 ft that you’ll need to increase your vertical speed to maintain that descent profile.
Though just to be sure of what I said, it’d be good if you could show the STAR simbrief gave you for you arrival as well as the altitudes given.
@Snow_Cone Starting at TOD…
TOD - Altitude: S1250 (that’s 41,000 feet)
GYA - Altitude: S0885
POU - Altitude: S0545
SAREX - Altitude: S0385
NLG - Altitude: S0200
VMMC - Altitude: 20 feet
@Snow_Cone Also, I know that you have to slow down before 10,000 😂
there are numerous equations for this approach mathematics , but i think game oriented - this is the best finger formula that @Luke_King-kong has posted.
I usually use the following formula to determine when to begin my descent:
At time [in minutes] = (Cruise Altitude)-10
I usually start at around -1000 to -1200 ft./min and gradually increase or decrease the VS depending on the flight parameters. I rarely ever exceed -1500 ft/min though.
My typical final cruising altitude is anywhere between FL380 and FL430, so using the above formula, I usually begin my descent around the 28-33 minutes to destination (ETE to Dest) mark. This is typically how a long a realistic descent lasts in real life commercial services. Including the slowing down and pattern, my total time from initial descent to touchdown lasts around 45 minutes.
Although this is sometimes a crude way of doing it, I find that it gets the job done while allowing for flexibility in my approach. However, if you want to go very mathematical about it, I recommend some of the links given above. Hopes this helps!
Wow, that’s crazy I actually tried that right now and that’s so weird you’d get less than 1 min to be able to descend 12,000ft, guess it is what Chris mentioned.
Weird, I never experienced that before.
@Snow_Cone Ya that’s what I was concerned about
Same for me,way too steep! Climbing works fine do…
Actually it is not that unusual to descend with -3000 VS or more. Sometimes after initiating descent they hit -5000 VS but with descending altitudes your aircraft gets slower. If you leave your speed at 280-300 knots until 10000 ft, that’s okay. Every descend and approach are different due to different wind combinations and aircraft weights, etc… But no worries, these speeds and VS are actually quite normal as you want to descend the longest time possible in idle to save fuel. And that is rather difficult, if you descend with -1500 to -2000 VS.
NOTE: These estimates are for jet airliners and as said may vary a little bit.