external-noticable-critical-operation-conditions-3 Jamming of the engine(engine seizure)Causes:secondary failure of- main bearing failures,- blade jam after blade fractures (e.g., 'hair cut'),- extreme unbalances.- During start up: rotorbow (volume 2, Ill. 7.1.2-9.2).Typical operation condition:probably only at the high pressure compressor at lowrotor speed during shut down (e.g., in-flight shutdown).Does not occur at fans ofbig engines (windmillingforces, centrifugal moment/inretia).After landing after shut down with no more windmilling.Features/symptom:- Vibrations,- fast speed drop,- sudden jamming of the rotors,- Trust drop.- Ramping of the other engines to balance the thrust loss.Suitable behavoiour: relevant to the situation "heavy engine failure". Consequences for the engine:- Destroying if the blading in the compressor and/or the turbine.- Heavy damages at the rotor spool and the labyrinths. (volume 2, Ill. 7.1.3-6)Misinterpretation:- Short term stuck after shut dow as consequence themally induced gap bridging. Engine separationCauses:Secondary failure of- extreme unbalances (volume 2, chapter 8.2).- Aggrieved mounting (Ill. 20.2-3).- Extrem turbulences (volume 1, chapter 5.1.6).- Assembly failure (Ill. 19.1-9 and Ill. 20.2-2)Typical operation condition:very seldom.- rather during start (high engine power) after primary failures like: bird strike, fracture of the rotor, mounting failure (Ill. 20.2-3).- After landing (ground contact, e.g., because of a landing gear failure.- During cruise at extreme turbulences (volume 1, chapter 5.1.6) Features/symptoms:- excursion of the airplane,- consequence of a damage of aggregates and the air frame. Suitable behaviour: relevant to the situation "heavy engine failure". Heavy engine failure(volume1, chapter 4.2)Causes:Different: Outer and innerprimary causes.(volume 2, chapter 8 and 9; volume 1, chapter 4.5)Typical operation condition: especially probably during start (takeoff, full power). (volume 3, chapter12.6) Features/symptoms:breakdown, mostly spontaneous withdrop of the speed ofall rotors/shafts. Fragment exit,(non contained: volume 2, chapter 8).Vibrations, fire, bang.Suitable behaviour: - A safe flight has highest priority before specific actions at the engine. - Shut down of the engine. Consequences for the engine:- No further operation possible.- Extensive repairs.Misinterpretation:- Wrong engine under suspicion.Separating of thfan rotorOil leak anf fireDisc fracture afterheavy axial rub.The position of the thrust bearing to the location of the shaft fracturedetermines in a particular degree the damage.Disk fracture or/andfreeing of the bladesdue to overspeed.Blade fracture due t0contact with the guide vanes. Oilleakand fireMögliche Folgen von Wellenbrüchen