B757-200
Flight Crew Air Transport Pilot (ATP)
Physiological - Other; Troubleshooting
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Physical Injury / Incapacitation
Aircraft
On the descent; the Captain and I both noticed a smell similar to formaldehyde. We began to notice it at approximately 15;000 FT and continued to smell it through the descent; landing; and taxiing in. We had noticed the same smell on the descent on the previous leg. The cabin crew did not notice any smell. The Captain did not think we needed to write this up since neither of us was experiencing respiratory stress or watery eyes. I am submitting this report because I have had a headache since this flight and it is now almost 48 hours later. I rarely get headaches and this one has not gone away after using Excedrin. I am concerned that the smell we experienced may be the same as the 'sweaty gym sock' smell caused by TCP in the synthetic oil. I suspect the cause of the smell may be from the bleed air from the engine. The APU was off at the time. Since the cabin crew did not notice the smell that leads me to believe the problem may be coming from the left pack. We tried turning the left pack off when below 10;000 FT and the smell decreased somewhat. This plane needs to be monitored to see if there is a problem.
A B757 First Officer had a headache two days after a flight on which a formaldehyde odor was detected during descent on two consecutive flights. The smell may be the gym socks TCP odor.