MD-11 speed restriction on the climb

[fushi 0]

I have been able to set the speed restriction once, as below:However, it has been unable to save the 250/10000, rather it comes back to VCL/10000 afterward.Although FMS Operating Manual describes "The limit may be found on any climb waypoint VERT REV page and may be cleared by use of the CLR key or altered by pilot entry into data field 5R." on FMS.30.7 page, it cannnot be cleared, either.Aren't these caused by a bug?Sincerely,Kan-ichiro Fushihara

[NathanX 2]

Hi FushiI see 250/10000 restriction. What do you mean by it is unable to save 250/10000? Maybe provide some pictures of VERT REV page also a pic of TO/APP page (while on ground) so i can follow what you are trying to do.Nathan

[fushi 0]

Hi Nathan,The 250K/10000 restriction is a general setting.Isn't it very inconvenient to have to set it each time?Sincerely,Kan-ichiro Fushihara

[downscc 1,327]

I don't have anything to add, but I am curious. Where is there not a speed restriction below 10,000? Just curious.

[NathanX 2]

Hi Nathan,The 250K/10000 restriction is a general setting.Isn't it very inconvenient to have to set it each time?Sincerely,Kan-ichiro Fushihara

Okay, now i understand. Yes 250/10000 is normal, and yes VERT REV page will show VCL/10000 as default. But considering you are pretty heavy i would go with VCL speed as that would give you the best climb for your weight even though you will bust through the 250/10000 restriction.Real world, i don't know if pilots must maintain 250/10000 or can actually request higher speeds.Nathan

[fushi 0]

Okay, now i understand. Yes 250/10000 is normal, and yes VERT REV page will show VCL/10000 as default. But considering you are pretty heavy i would go with VCL speed as that would give you the best climb for your weight even though you will bust through the 250/10000 restriction.Real world, i don't know if pilots must maintain 250/10000 or can actually request higher speeds.Nathan

I understood well. Yes, I'm pretty heavy in this case:ZFW = 178,115kgFuel = 85 metric tonnesVCL = 274KTI will request higher speeds from now on.Sincerely,Kan-ichiro Fushihara

[2009 0]

Okay, now i understand. Yes 250/10000 is normal, and yes VERT REV page will show VCL/10000 as default. But considering you are pretty heavy i would go with VCL speed as that would give you the best climb for your weight even though you will bust through the 250/10000 restriction.Real world, i don't know if pilots must maintain 250/10000 or can actually request higher speeds.Nathan

That is the breakthrough in this thread, I hope Usually it is not a problem to fly faster than 250 below 10000ft, if you have a higher Vcl. In some countries you have to advice/ request that higher speed, in most countries the regulation for the max speed below 10000ft is: 250kts or minimum clean speed (VCL in that case).So: dont worry about that 250/10000ft restriction, in the real world, there is no problem with that.Have a nice Landing,TOM

[aentwis 61]

I find this all a little bizarre, as I have never had to set the 250 below FL100 restriction manually... It is always in there...Even when I switch to managed speed, the aircraft increases pitch to hold climb speed at 250 below FL100, and then pitches down to accelerate to FMS managed speed of around 340/M082 or so...OK, so I only have 70 hours in the MD11, but as I fly nothing further than 4 hours, with most trips under 2 hours currently, I have had quite a few takeoffs already for those 70 hours in the seat...May I assume this only becomes an issue at the much higher takeoff weights, that I have not experienced so far? (IE a Vcl greater than 250kts IAS)Andrew

[2009 0]

May I assume this only becomes an issue at the much higher takeoff weights, that I have not experienced so far? (IE a Vcl greater than 250kts IAS)Andrew

That is correct Andrew. As far as I know (I checked my documents to confirm that), at weights >204 tons the VCL starts to get bigger than 250kts. I have just tried this in the sim, where it seems to change at weights > than max LDGW (222,9 for freighters). The VCL is 1,5g times the stickshaker speed. Can somebody confirm that from the real one quickly:-)?TOM

[KCA9304 0]

That is correct Andrew. As far as I know (I checked my documents to confirm that), at weights >204 tons the VCL starts to get bigger than 250kts. I have just tried this in the sim, where it seems to change at weights > than max LDGW (222,9 for freighters). The VCL is 1,5g times the stickshaker speed. Can somebody confirm that from the real one quickly:-)?TOM

For a GW of 220 tons, Vcl equals 250 IAS.Regards,Harry

[downscc 1,327]

The Queen will usually require something higher than 250.. in fact, KIAH Houston TX has a NOTAM for as long as I can remember that 280 is in effect.

[2009 0]

For a GW of 220 tons, Vcl equals 250 IAS.Regards,Harry

Harry, the definition of Vcl is (acording to our documentation, might be wrong though...):VCL is the larger of 250 KCAS or 1.5 g stick shaker speed. Typically, 1.5 g speed becomeseffective at a weight of 204 t or higher. The VCL is used as the climb speed above accelerationaltitude and below 10 000 ft.Is your statement by memory or did u try it out, recently? Or can u confirm that definition of Vcl?RGDSTOM

[KCA9304 0]

Harry, the definition of Vcl is (acording to our documentation, might be wrong though...):VCL is the larger of 250 KCAS or 1.5 g stick shaker speed. Typically, 1.5 g speed becomeseffective at a weight of 204 t or higher. The VCL is used as the climb speed above accelerationaltitude and below 10 000 ft.Is your statement by memory or did u try it out, recently? Or can u confirm that definition of Vcl?RGDSTOM

Tom,Quikly? 220T / 250IAS is from a RW speed table.I know how to use Vcl.Standby for confirmation on Vcl's definition.Regards,Harry

[2009 0]

Tom,Quikly? 220T / 250IAS is from a RW speed table.I know how to use Vcl.Regards,Harry

Hi Harry, what is "RW"? The FMS will just calculate this value, are u using a table to confirm that speed during flt ops? To recheck the computation of the FMS?If I may ask you another question: what is the Vmin for 220T according to your knowledge?Thanks!

[trisager 2]

I find this all a little bizarre, as I have never had to set the 250 below FL100 restriction manually... It is always in there...

I'm in cruise now so I cannot check, but I'm pretty sure it is on the PERF CLB page. If my Vcl is > 250 kts, I just override the FMS until above 10,000Tom