<< >> NASA ASRS Report 592623, September 2003

MD88 flight crew attempts to climb to a higher altitude for WX avoidance and exceeds the aircraft's performance envelope.

Attributes
ACN	592623
Time
Date	200309
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : spa.vortac
State Reference	NC
Altitude	msl single value : 35000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 72 flight time total : 8000 flight time type : 4923
ASRS Report	592623
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	inflight encounter : weather inflight encounter : turbulence other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : airspeed mach indicator other flight crewa other flight crewb
Resolutory Action	flight crew : exited adverse environment flight crew : declared emergency other
Supplementary
Problem Areas	Aircraft Environmental Factor Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

During climb out of richmond, requested climb from planned cruising altitude of FL310 to FL350 to avoid WX. ZDC approved the climb with a stated restr to level at FL350 for conflicting traffic. The climb was started at mach .76, slowing to approximately mach .64 at FL350. FMS generated maximum altitude was FL364. At FL350, the aircraft would not accelerate to cruise mach of .76. The flight entered light turbulence which resulted in additional airspeed decay. I requested immediate descent clearance twice and it was denied due to traffic. I declared an emergency and the captain descended the aircraft to FL310. Contributing factors: 1) highly qualified captain whose judgement and flying skills were exemplary which made me less likely to question his zoom maneuver. 2) last leg of a long 4 day trip which may have resulted in decreased situational awareness. 3) what must have been a warmer than standard day because typically the aircraft, at that gross weight, accelerates just fine. 4) perhaps lack of experience with the answer to the question: 'how slow is too slow?' 5) desire to please both passenger and ATC by getting to FL350 quickly.

Related reports:

• During turbulence and WX avoidance in a very light aircraft ...

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Original NASA ASRS Text

Title: MD88 FLT CREW ATTEMPTS TO CLB TO A HIGHER ALT FOR WX AVOIDANCE AND EXCEEDS THE ACFT'S PERFORMANCE ENVELOPE.

Narrative: DURING CLBOUT OF RICHMOND, REQUESTED CLB FROM PLANNED CRUISING ALT OF FL310 TO FL350 TO AVOID WX. ZDC APPROVED THE CLB WITH A STATED RESTR TO LEVEL AT FL350 FOR CONFLICTING TFC. THE CLB WAS STARTED AT MACH .76, SLOWING TO APPROX MACH .64 AT FL350. FMS GENERATED MAX ALT WAS FL364. AT FL350, THE ACFT WOULD NOT ACCELERATE TO CRUISE MACH OF .76. THE FLT ENTERED LIGHT TURB WHICH RESULTED IN ADDITIONAL AIRSPD DECAY. I REQUESTED IMMEDIATE DSCNT CLRNC TWICE AND IT WAS DENIED DUE TO TFC. I DECLARED AN EMER AND THE CAPT DSNDED THE ACFT TO FL310. CONTRIBUTING FACTORS: 1) HIGHLY QUALIFIED CAPT WHOSE JUDGEMENT AND FLYING SKILLS WERE EXEMPLARY WHICH MADE ME LESS LIKELY TO QUESTION HIS ZOOM MANEUVER. 2) LAST LEG OF A LONG 4 DAY TRIP WHICH MAY HAVE RESULTED IN DECREASED SITUATIONAL AWARENESS. 3) WHAT MUST HAVE BEEN A WARMER THAN STANDARD DAY BECAUSE TYPICALLY THE ACFT, AT THAT GROSS WT, ACCELERATES JUST FINE. 4) PERHAPS LACK OF EXPERIENCE WITH THE ANSWER TO THE QUESTION: 'HOW SLOW IS TOO SLOW?' 5) DESIRE TO PLEASE BOTH PAX AND ATC BY GETTING TO FL350 QUICKLY.

Data retrieved from NASA's ASRS site as of July 2007 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.