Малая авиация России. Обучение на Пилота-любителя. Обсуждение самолётов. Регистрация.

lt.ak писал(а):летал на разных автопилотах, включая S-TEC-и, такого не было не разу ... в чём именно выражается ? ...

502 писал(а):У меня, к сожалению, мух не обнаружено,

su27 писал(а):Встречался с такой проблемой, не помню какой автопилот. Думается мне проблема в алгоритме работы, передаточные числа может не совсем удачно подобраны.

ЛОДОЧНИК писал(а):...При включении режима удержания высоты...

Helimobil писал(а):Решили проблему? И что это было?
И еще вопрос.

ЛОДОЧНИК писал(а):...При включении режима удержания высоты...

А как вы его включаете? VNAV, если таковая есть, при этом активна?

These autopilots are really not good in aircraft larger than a Warrior ... I have not encountered a 55 that did not have pitch issues.

The majority of problems ... are caused by the primary cable tensions or the static system. Usually the elevator primary cable has to be set on the high end of the spec ... We recommend checking the static system to 18000' with no more than 100fpm leak.

Troubleshooting Pitch Porpoise

When dealing with a pitch porpoise squawk, there are several different approaches that can be used. We recommend that the first step be to reduce the variables involved. By asking yourself a few questions you can save yourself a lot of time.

In a new installation, is the altitude transducer mounted correctly? If the hose bib is vertical, gravity will affect the sensor. The hose bib must be mounted horizontally.

Is the pitch bridle cable tension set properly? If the bridle cable tension in not set correctly the autopilot will be working harder to maintain selected altitude hold. It is also important to check bridle cable tension in an older installation.

Is the computer mounted securely? In some installations (ie, 60-2, 60PSS, 65), if the remote mounted computer is not mounted securely, vibrations from the aircraft will affect the accelerometer possibly causing pitch porpoise.

Control system friction is another factor that needs to be considered when autopilots exhibit poor performance in one axis or another. Excessive friction in the primary control surface causes the autopilot to work harder and slows its overall response time leaving the pilot and technician to think the problem is in the autopilot system when in fact it is not.

Control system friction is something that should be checked any time the flight control system appears to respond slowly in one axis or another. Consult the aircraft manufacturer’s manual for procedures to determine acceptable system friction limits.

For an existing installation, the first suspect should be the pitch servo. High start up voltage is the indicator and it can be checked two ways. First, measure the resistance across the motor leads (Pins 3 & 4). 12 Volt motors should read 3 to 4 Ohms. 24 Volt motors should read 8-10 Ohms. If you see a reading fifty percent higher than these, that would indicate a high start up voltage. The second way to check high start up is by applying voltage to the motor. A 12 Volt motor should start by 1.5 Volts or less and a 24 Volt motor should start by 2 Volts or less. Unfortunately, the pitch servo is often the hardest component in the system to remove and therefore the most neglected in servicing.

The static system needs to be checked for leaks and any moisture in the system.

We hope these suggestions will help you find and eliminate system problems before you decide the pitch computer is at fault.