Alright cool, thanks for the reference. I knew that they used metric altitudes, but I didn't know that they used metric distances and speeds as well.

 

I should add though that since Russia's+majority of CIS implemented RVSM, altitudes above FL290 are given in feet now. China and Mongolia are two jurisdictions that operate on a hybrid Metric/Imperial system at RVSM altitudes.

Never ever cross controls in a jet. It's extremely dangerous.

To get down quickly all that is necessary is to pull the speed brakes out. A good daily example of this is coming over the Alps into Torino Casselle. The descent is from FL230 to 4,500ft in about 15dme. Throttle back to 210 kts and apply full spoilers. Your descent rate will be above 2000fpm and fully under control. And, safe!

You are confusing airspeed with groundspeed!! This procedure is done on almost every flight from NW Europe. Only the ones that ATC request to turn at TOP descend normally!

I am not confusing anything, you need to know what the ground speed is to determine what the average decent rate will be over a given distance. In fact, I intentionally error-ed in your favor by assuming the ground speed was 210kts. The reality is that at 210kts indicated at 23000' would be roughly 295kts true airspeed on a std temp/pressure day. As of this posting, winds aloft at that location at 24000 are 252@28. You mentioned flights from the NW, so the upper winds will more then likely increase the ground speed.

 

23000 down to 4500 = 18500 we need to descend

15DME @ 210kts = 4 minutes (actually is 4:17)

18500 feet/ 4 minutes = 4625 feet per minute (should have been 18500/4.25=4352fpm)

 

Figure the ground speed into all of that and the decent rate would be more then 5500fpm

 

Willy

Or, instead of calculating, wondering, etc, use the power of the FMS.

On the route page make sure you have the full STAR and landing runway entered, without route discontinuities. To select the correct ones, having the airport charts helps.. A lot! Then you need to enter the "hard" speed and altitude restriction at the FAF (final approach fix) in the right fields. This is not mandatory because usually the STAR will have the correct speeds predetermined. You set speed and altitudes only if you want to be slower or lower at certain point which will help the VNAV if your plane is heavy for example. With the hard altitudes and speeds set by you, the TOD point will be calculated earlier and the VNAV will initiate the descent further from the destination airport thus allowing your heavy plane to slow down in time. Pressing VNAV and the only thing you'll have to do is set the next lower altitudes and enjoy the ride. If you have not entered the winds enroute you might need to pop the speedbrakes here and there for a moment. With this regards - respect to PMDG for having such a beautiful VNAV programmed...

I am not confusing anything, you need to know what the ground speed is to determine what the average decent rate will be over a given distance. In fact, I intentionally error-ed in your favor by assuming the ground speed was 210kts. The reality is that at 210kts indicated at 23000' would be roughly 295kts true airspeed on a std temp/pressure day. As of this posting, winds aloft at that location at 24000 are 252@28. You mentioned flights from the NW, so the upper winds will more then likely increase the ground speed.

 

23000 down to 4500 = 18500 we need to descend

15DME @ 210kts = 4 minutes (actually is 4:17)

18500 feet/ 4 minutes = 4625 feet per minute (should have been 18500/4.25=4352fpm)

 

Figure the ground speed into all of that and the decent rate would be more then 5500fpm

 

Willy

 

Take a flight from Uk to NW Italy and you will see for yourself. Or ask any pilot who does that route! AND, it is perfectly replicated in the sim!

Take a flight from Uk to NW Italy and you will see for yourself. Or ask any pilot who does that route! AND, it is perfectly replicated in the sim!

 

I don't have to ask anyone, based on the numbers YOU provided, you are flat out wrong. Even if the pilots had there hands hanging out the windows, there is now way the NG could hold that speed with the decent rate required to descend 18,500' in 15 nautical miles.

 

Willy

I don't have to ask anyone, based on the numbers YOU provided, you are flat out wrong. Even if the pilots had there hands hanging out the windows, there is now way the NG could hold that speed with the decent rate required to descend 18,500' in 15 nautical miles.

 

Willy

I can't find any approach or STAR at Turino that has those requirements. Maybe it's not a public approach. Dunno. I wouldn't expect to see that in a normal STAR.

 

Gear down, speedbrakes and 250kts will get you down pretty quickly. At least 4000fpm. I don't use that option every day. I did use it at Fairbanks a few weeks ago when we were expecting 20R and the offered us 2L which was a much shorter route.

I can't find any approach or STAR at Turino that has those requirements. Maybe it's not a public approach. Dunno. I wouldn't expect to see that in a normal STAR.

 

Gear down, speedbrakes and 250kts will get you down pretty quickly. At least 4000fpm. I don't use that option every day. I did use it at Fairbanks a few weeks ago when we were expecting 20R and the offered us 2L which was a much shorter route.

But can you hold 210kts with a decent rate of 5285fpm? This is what would be required after averaging the true airspeed between 23,000 and 4,500. Add in the wind in and it only increases the decent rate. I never said that the NG can't descend at a higher rate then standard approach profiles. Based on the numbers provided by the person I questioned, I believe it would be fair to say that they are stretching the truth a bit. Off the top of my head, the Avro RJ would be the only commercial passenger jet that would have a shot at that, not EVERY aircraft arriving from the NW and they certainly don't do it at "a little more then 2000fpm." The math doesn't lie. If my numbers are wrong, then please do correct me.

 

Willy

 

But can you hold 210kts with a decent rate of 5285fpm? This is what would be required after averaging the true airspeed between 23,000 and 4,500. Add in the wind in and it only increases the decent rate. I never said that the NG can't descend at a higher rate then standard approach profiles. Based on the numbers provided by the person I questioned, I believe it would be fair to say that they are stretching the truth a bit. Off the top of my head, the Avro RJ would be the only commercial passenger jet that would have a shot at that, not EVERY aircraft arriving from the NW and they certainly don't do it at "a little more then 2000fpm." The math doesn't lie. If my numbers are wrong, then please do correct me.

 

Willy

I agree with everything you said.