What was found
DURING TAKEOFF, THE AIRCRAFT PUTS OUT A BAD ODOR INTO JUST THE COCKPIT. THE FLIGHT ATTENDANT IN THE BACK SAYS THERE'S NO SMELL TO THEM. IT STARTS GIVING THE SMELL AGAIN DURING THE DESCENT AROUND 18000 FEET BUT NOT NEAR AS SEVERE DURING THE TAKEOFF. DURING TAKEOFF IT TAKES ABOUT 10 MINUTES FOR THE SMELL TO FULLY DISSIPATE OUT OF THE COCKTAIL. THE SMELL IS BAD ENOUGH THAT YOU NEARLY NEED TO PUT ON THE OXYGEN MASK. ACCOMPLISHED DUAL HEAT EXCHANGER CLEANING IAW EJ-2100-006. NO FURTHER DAMAGES NOTED. MEL RESTORED.