A B737-300 captain believes the crossing restriction of 'at or above FL270/280KTS' at lynkn on the j...

Narrative:

On the jaggr one RNAV arrival into den; the chart shows the requirement to cross lynkn at 280 KTS at or above FL270. We were cruising at FL340 and our top of descent point was past lynkn. To cross lynkn at 280 KTS would require flying fairly close to the barber pole speed at FL340; well above our profile speed at FL340 of something close to .74 mach. The only other way to actually cross lynkn at 280 KTS would be to initiate a very early descent and even then I don't know how often a given combination of mach # and transition to 280 would have the aircraft still flying a mach # at lynkn at FL270 and slower than the stated 280 KTS.we ended up flying the arrival using the VNAV profile and a transition speed of 280 KTS; which we transitioned to during our descent (i.e. Well past lynkn). ATC said nothing; as we were on a normal speed profile. (We did not accelerate early to an extremely high mach number in order to be at 280 KIAS at lynkn nor did we descend early.)this looks to me like a design problem with the arrival. As long as later waypoints have the 280-KT mandatory speed then a properly programmed FMC will fly a constant speed profile; without the issue of forcing crews to either (a) descend early; (b) fly an extremely high mach number; or (c) fail to comply with the stated 'at 280-KT' restriction at lynkn.

Original NASA ASRS Text

Title: A B737-300 Captain believes the crossing restriction of 'At or Above FL270/280KTS' at LYNKN on the JAGGR RNAV STAR to DEN is unrealistic for his aircraft and would require a barber pole descent from their cruise altitude (FL340) or a very early TOD.

Narrative: On the JAGGR ONE RNAV Arrival into DEN; the chart shows the requirement to cross LYNKN at 280 KTS at or above FL270. We were cruising at FL340 and our top of descent point was past LYNKN. To cross LYNKN at 280 KTS would require flying fairly close to the barber pole speed at FL340; well above our profile speed at FL340 of something close to .74 Mach. The only other way to actually cross LYNKN at 280 KTS would be to initiate a very early descent and even then I don't know how often a given combination of Mach # and transition to 280 would have the aircraft still flying a Mach # at LYNKN at FL270 and slower than the stated 280 KTS.We ended up flying the arrival using the VNAV profile and a transition speed of 280 KTS; which we transitioned to during our descent (i.e. well past LYNKN). ATC said nothing; as we were on a normal speed profile. (We did not accelerate early to an extremely high Mach number in order to be at 280 KIAS at LYNKN nor did we descend early.)This looks to me like a design problem with the arrival. As long as later waypoints have the 280-KT mandatory speed then a properly programmed FMC will fly a constant speed profile; without the issue of forcing Crews to either (a) descend early; (b) fly an extremely high Mach number; or (c) fail to comply with the stated 'at 280-KT' restriction at LYNKN.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1062668
Time
Date	201301
Local Time Of Day	1201-1800
Place
Locale Reference	DEN.Airport
State Reference	CO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR JAGGR ONE
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 101 Flight Crew Type 8500
Events
Anomaly	No Specific Anomaly Occurred All Types

A B737-300 captain believes the crossing restriction of 'at or above FL270/280KTS' at lynkn on the jaggr RNAV STAR to den is unrealistic for his aircraft and would require a barber pole descent from their cruise altitude (FL340) or a very early TOD.