Takeoff and landing on snowy and icy airfields, airports

 Passenger planes are exploited on the runway, cleared of snow and ice. However, in some cases, the aircraft operated on specially prepared lanes with snow cover. Takeoffs from the runway, covered with ice or a layer of thawed snow (slush), can be performed only in case of special need (special, expeditionary, rescue work, etc.). Landing on icy or snow-covered runways can be allowed only for small values ​​of the lateral component of the wind. The decision to land on an icy lane can only be made if absolutely necessary if it is not possible to land at another airfield. Specific instructions on the performance of take-off and landing in the above conditions and additional restrictions are given in official documents.

The data on the change characteristics of the takeoff and landing aircraft passenger, depending on the surface state VPP1.

The takeoff run on the runway covered with rolled snow, longer than the run-up of the concrete runway 15%, if the strength of the snow cover is sufficient for take-off of this type of aircraft and the snow cover during takeoff is not exposed to significant destruction (depth gauge to 40-50 mm). If the snow cover during take-off is subject to considerable damage (depth gauge more 40- 50 mm), the length of the runway the aircraft is increased by a large amount.

Gidroglissirovanie. In the presence of water on the runway, mud or slush in some cases may cause gidroglissirovaniya. Nature gidroglissirovaniya complicated. The reason for its occurrence is that when the rotating wheel of the stationary liquid layer forces arising in this fluid hydrodynamic pressure wedge separates the contact surface of the tire from the runway surface. As a result, there is a reduction or even complete loss of the brake clutch. The angular velocity of rotation of the wheel at the same drops.

Occurrence gidroglissirovaniya dangerous for two main reasons. Firstly, significantly reduced directional stability of the aircraft. Secondly, take off characteristics deteriorate. The most significant increases stop distance. Small random perturbations in the presence gidroglissirovaniya could lead to rolling out the aircraft with the runway.

Occurrence gidroglissirovaniya influenced by a number of factors. In particular, the higher the tire pressure and the relief pattern on its surface and at a higher speed arises gidroglissirovanie.

To prevent gidroglissirovaniya necessary to avoid take-off and landing runway, a state which does not correspond to the instructions. If you want to fly to the runway covered with water, melting snow or mud (within limits), you should carefully check the condition of the tires of the wheels of the chassis. Availability VG1P oil promotes the aforementioned complicating phenomena.

Using the automatic release of the wheels. Automatic release wheels should be included in all cases, except for runs and taxiing aircraft on the smooth ice surface. This automatic release on the run need to turn off at a speed of no more than 40-50 km / h. In all other cases, disabling automatic brake release does not give a positive effect and can lead to the destruction of tire wheels.