An insider close to the planned water cannon salute informs Flight that the chief pilot had informed the fire department at Washington DC's Dulles airport of the retirement of the 777's pilot, who was completing his last scheduled flight. The fire department logged it as a routine training exercise. However, fire crews onboard the truck decided to swap the water for foam, to give the impression of snow, ahead of the Christmas vaction period.
Onboard the flightdeck of N772UA, the crew were not concerned, our source informs us, until both exhaust gas temperature gauges spiked to maximum after the foam shower.
Folloiwng an engineering inspection, the aircraft has been taken out of service for repairs to the Pratt & Whitney PW4077 engines. for extensive anti-corrosion treatment.
United is understood to have permanently ended the tradition of foam salutes as a result.
This tradition is now likely to end at Dulles, if not everywhere else. Spontaneity will have to be planned in future..