Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft
The entire crew noticed a musty/moldy/melted crayon smell. It was present in the entire cabin; and flight deck. The smell was present on climb out; and descent. The odor seemed to become apparent in the flight deck before the cabin. On descent; I deselected the number 1 pack; and the odor seemed to weaken substantially. I feel confident in saying that the odor was emanating from the environmental system. I wrote it up as a persistent level 1 occurrence.
Air carrier flight crew reported a 'musty/moldy/melted crayon' fume event during flight. Flight crew deselected number 1 pack which weakened the odor.