Tail strike, which occurs when the tail of an aircraft contacts the runway during takeoff or landing, is an event that can happen in virtually any aircraft. Some designs are far more susceptible to tail strike than others and, dependent upon the aircraft type and model, the relative frequency of tail strike on takeoff versus tail strike on landing can vary significantly. "Stretched" models of a given type are generally more likely to suffer a tail strike than the non-stretched version.
Intensive crew training is the single most critical preventive measure.
The frequency of tail strike is higher for some models on takeoff, and for other models on landing. The overall incident rate varies from one model to another as well as over time. For example, one model experienced a high incident rate upon entry into service, followed by a reduced rate and then an increased rate about six years after initial entry into service. Over the years, Boeing has taken a number of actions to reduce the rate of tail strike, including training, information, and system changes. Specific activities have included a tail strike avoidance video, a Flight Operations Review article, operations manual and technical bulletins, and airline presentations by Boeing instructor pilots. System changes included installation of tail skids on stretched models, revisions of automatic speed brake deployment logic to reduce pitchup on landing, and installation of a trailing edge flap seal to reduce airplane noseup attitude on approach and landing.
Though tail strike occurs in both daylight and darkness, and in both good and bad weather, the amount of flight crew experience with the model of airplane flown is a more significant factor. While tail strike may occur to pilots with abundant flight time in a model, most occur to pilots who are transitioning from one airplane model to another and have fewer than 100 hours of flight time in the new model. Incidents are greatest among pilots during their first heavy-weight operations in the new model, especially when the weather is marginal.
An unstabilized approach is the biggest single cause of tail strike. Flight crews try to set all the approach variables--on centerline, on approach path, on speed, and in the final landing configuration--by the time the airplane descends through 1,000 ft (305 m) above ground level (AGL). This is not always possible. If by the time the airplane descends through 500 ft (152 m) AGL with these approach variables not stabilized, a go-around should be considered.
Any tail strike can cause substantial damage to the aft fuselage of the aircraft which can be time consuming and expensive to repair. Beyond the cost of the repair itself, further expense will be incurred as a result of schedule disruption and the loss of the aircraft for the duration of the repair interval. A tail strike on landing tends to cause more serious damage than the same event during takeoff. In the worst case, the tail can strike the runway before the landing gear touches down, thus absorbing large amounts of energy for which it is not designed. The aft pressure bulkhead is often damaged as a result. There are several documented cases where improperly repaired tail strike damage has resulted in a catastrophic failure at a later point in time.