# Tag Info

2

To add to the disadvantage of a drag chute. The now retired USCG HU-25 Guardian (military version of Dassault Falcon 20) had a drag chute attached to the tail cone for emergency landings or short runways. This was because the engines the coast guard used did not have reverse thrust capability. This drag chute was only effective to about 60 knots. It was ...

0

Treat the bird strike question and the engine fail question as separate issues. Like a previous poster said, most bird strikes do not cause engine failure. I have personally seen one bird strike and participated in another bird strike. Neither stopped the engine. For our Class D airfield, the SOP would be to notify ATC (or, CTAF after hours) to warn ...

11

Your $v_\mathrm{ref}$ does not depend on density altitude since it is given in Indicated Airspeed, which already accounts for density effects. However, the True Airspeed and therefore also Groundspeed will be higher at a higher density altitude, resulting in more runway required to stop. The Flight Safety Foundation has a nice summary of factors influencing ...

4

Depends on how bad is the sea state, but the general technique for seaplanes is to land parallel to the swell, preferably on top of a wave: When landing on a swell system with large, widely spaced crests more than four times the length of the floats, the best landing heading parallels the crests and has the most favorable headwind component. In this ...

-2

How high are the waves? Timing into the wind, proper flare and try not to capsized I reckon. Never sideways to the waves.

3

Transport aircraft are certificated to a maximum operating temperature for departure that is related to International Standard Atmosphere (ISA), typically 35 deg C above ISA (there may be airplanes certified to ISA +40), ISA being 15C at sea level and dropping from there at the standard adiabatic lapse rate . ISA temperature at Phoenix airport at 1135 ft ...

4

The Eurocontrol Lexicon can help here as well. The Estimated In-Block Time is defined as: The estimated time that an aircraft will arrive in-block. (Eurocontrol) This is not very helpful, but the definition for Actual In-Block Time is: The actual date and time when the parking brakes have been engaged at the parking position. (Eurocontrol) This ...

4

Definitions provided by the FAA can be found in AC 120-28D - Criteria for Approval of Category III Weather Minima for Takeoff, Landing, and Rollout. From the document we find for Fail Operational: 4.3.2. Fail Operational Category III Operations. A Fail Operational System is a system which after failure of any single component, is capable of completing ...

2

I don't think the quote you gave is correct. This might be the case for some aircraft (like the Boeing 777 with 3 autopilots), but not in general. A more general definition is: Autoland systems are normally designated Fail Operational or Fail Passive. A Fail Operational system must have at least two autopilots engaged for the approach. The failure ...

10

The quoted explanation about "fail operational" and "fail passive" is correct, in that "fail operational" means the system will continue to function after an failure, and "fail passive" means the system will not misbehave after an failure. The exact number of autopilots required to make this work, however, is debatable; and much depends on how you define it....

17

Maximum landing weight (MLW) limit exists primarily to cater for approach climb performance requirements (i.e. go-around requirement). As per 14CFR 25.1001: if the aircraft does not have a fuel dumping system, it must meet the all-engine-operating and one-engine-inoperative climb in the approach climb configuration at maximum takeoff weight. Otherwise, ...

27

At the instant of touchdown, any vertical kinetic energy the plane possesses must be absorbed by the landing gear, which thereafter must bear the entire weight of the plane. That kinetic energy depends on the sink rate and the plane's weight. The sink rate ideally will be zero at wheels down in a perfect world, but the gear is designed to accomodate a ...

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