B737-800 first officer reported that departing out of bwi; the aircraft is unable to make the 17000f...

Attributes
ACN	1560763
Time
Date	201807
Local Time Of Day	0601-1200
Place
Locale Reference	BWI.Airport
State Reference	MD
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	SID TERPZ 6
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 230 Flight Crew Type 1600
Events
Anomaly	Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Published Material / Policy

Narrative:

I have flown out of bwi on the terpz 6 to either ottto or ramay the last three weeks. Each time I have flown a 737-800 or MAX8. The first two times in the 737-800 we had to adjust our climb out speed below the econ schedule (which was around 300) to make the 17;000ft.; or above restriction at foxhl (FMC warnings were received 'unable next altitude'). In the 737 MAX8; it was less. So by starting early to adjust our profile we were able to meet the restriction. It appears like a trend that heavy 737-800 aircraft in summertime will have a hard time meeting the climb restriction; and if you do not catch it soon enough you may not make the foxhl restriction.[suggestion].in the departure section of the SID add a note. If departing the terpz 6 to ottto or ramay be aware that high gross weights and hot temperatures may not allow you to climb via the FMC econ speed and meet the 17;000ft.; or above restriction at foxhl.

Original NASA ASRS Text

Title: B737-800 First Officer reported that departing out of BWI; the aircraft is unable to make the 17000ft. restriction at FOXHL on TERPZ 6 departure.

Narrative: I have flown out of BWI on the TERPZ 6 to either OTTTO or RAMAY the last three weeks. Each time I have flown a 737-800 or MAX8. The first two times in the 737-800 we had to adjust our climb out speed below the ECON Schedule (which was around 300) to make the 17;000ft.; or above restriction at FOXHL (FMC warnings were received 'unable next altitude'). In the 737 MAX8; it was less. So by starting early to adjust our profile we were able to meet the restriction. It appears like a trend that heavy 737-800 aircraft in summertime will have a hard time meeting the climb restriction; and if you do not catch it soon enough you may not make the FOXHL restriction.[Suggestion].In the Departure Section of the SID add a note. If departing the TERPZ 6 to OTTTO or RAMAY be aware that high gross weights and hot temperatures may not allow you to climb via the FMC ECON Speed and meet the 17;000ft.; or above restriction at FOXHL.

Data retrieved from NASA's ASRS site 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.

B737-800 first officer reported that departing out of bwi; the aircraft is unable to make the 17000ft. Restriction at foxhl on terpz 6 departure.