·便民百宝箱·社区工具·查看新帖·设为首页·保存桌面·手机版
中美洲际直升机

飞行总动员航空网—Flight Story aviation network—领先的飞行主题社区—航空业界动态—飞机资讯—飞行论坛中心

 找回密码
 立即注册

QQ登录

只需一步,快速开始

长三角无人机
中国航空金融发展东疆国际论坛西联航空航天咨询服务中心西北通用航空协会
欢迎加入飞行总动员航空会飞行总动员航空商城淘宝店
搜索
查看: 704|回复: 0

IS&S Autothrottle For The PT6A Is Significant Safety Advancement [复制链接]

Rank: 7Rank: 7Rank: 7

UID
62577
帖子
462
精华
0
积分
2178
威望
0
金钱
1716
贡献
0
注册时间
2014-7-16
最后登录
2018-4-11
在线时间
257 小时
发表于 2018-1-9 10:32:08 |显示全部楼层
本帖最后由 XLC 于 2018-1-9 10:37 编辑

Innovative Solutions & Support’s autothrottle (A/T) system, now approved for first-generation Pilatus PC-12 turboprops, virtually is a takeoff-to-touchdown power management system for the Pratt & Whitney Canada PT6A. It finally relieves pilots of having to babysit the engine, to prevent exceeding its torque and temperature limits. In October, we hitched a ride in IS&S’s PC-12 to see firsthand the new A/T system’s full envelope capabilities.

At San Diego’s Montgomery-Gibbs Airport (MYF), IS&S company pilot Eric Smedberg belted into the left seat of Serial Number 306. We took notes from the right seat and ran the radios. The system includes a left-side integrated standby display that hosts the autothrottle computer, an engine data concentrator and a throttle lever servo in the center console.



The autothrottle can be adapted to virtually all PT6-powered aircraft with the IS&S Integrated Standby Unit (ISU).

The entire A/T package weighs 7.2 lb. and costs about $60,000 installed. Currently, it’s approved as an add-on for IS&S’s PC-12 flat-panel avionics system, but STCs are in the works for other avionics packages. Expect the next approval to be for PC-12NG aircraft fitted with Honeywell Apex avionics. At the same time, IS&S is pursuing approvals of twin A/T systems for Beech King Airs. A/T packages for the PC-12NG and King Air will require additional hardware and software to link the IS&S autothrottles to other manufacturers’ avionics systems.


There are two basic modes of operation: torque mode and airspeed mode. Torque mode normally is used to set takeoff and climb power. For cruise, the pilot manually can dial in the appropriate torque using flight manual data for maximum and long-range cruise, plus max endurance. Airspeed mode supports commanded airspeed and turbulence speed modes. Envelope protection includes torque, temperature, overspeed and underspeed protections.


Pre-start and start checks remain unchanged. Once cleared for takeoff on Runway 28R, Smedberg engaged the A/T. The servo advanced the throttle smoothly to prevent torque or temperature overshoot, precisely setting the Airplane Flight Manual published takeoff torque limit for airport elevation and outside air temperature.



The $60,000 IS&S autothrottle, seen here on a PT6A-powered Pilatus PC-12, can help pilots avoid torque and temperature limits that can bedevil older engines.





The Flight Deck integrates Primary Flight Display (PFD) and Multi-Function Display (MFD) information including: charts, maps, airspace depiction with low and high vector routes, SVS, EVS, patented zooming feature, satellite weather, engine instruments, electronic checklists, RAIM capability and dual SBAS GPS receivers in support of the FMS with LPV appraoch capability.



As we climbed out toward Julian VOR, Smedberg switched to airspeed hold, causing the A/T to hold 160 KIAS during the ascent. We noticed that engine torque frequently bumped up against maximum limits, rather than setting the more conservative AFM normal climb torque setting.


After leveling off at 13,500 ft. over Julian, Smedberg dialed down the selected airspeed to the minimum allowable for the aircraft, payload and fuel weights entered into the system. Fuel consumption is tracked by the computer, so minimum allowable airspeed is dynamic with weight change.


Smedberg allowed the aircraft to decelerate. As it approached minimum speed, the A/T advanced the throttle lever to prevent the aircraft from slowing below a safe airspeed. As he maneuvered the aircraft, the A/T kept the aircraft well below the angle of attack where the stick shaker or stick pusher would have been triggered.


While most pilots will never test such envelope protection limits, they’re likely to use the A/T system for flying approaches quite routinely. We called SOCAL approach and asked for clearance to fly the RNAV (RNP) Z Runway 24 procedure into Carlsbad’s McClellan-Palomar Airport (CRQ).


Smedberg coupled the autopilot, programmed the IS&S flat-panel display system’s internal FMS and dialed in 150 KIAS as the desired speed. We flew directly to Julian VOR and descended progressively to step-down fixes. While the IS&S FMS VNAV isn’t capable of flying directly between vertical waypoints, it will maintain a fixed-rate descent to final and missed approach fixes while respecting intermediate crossing restrictions.


The FMS also is fully capable of flying radius-to-fix curved legs, but our entry from Julian, 35 mi. east of the airport, essentially was a straight-in on a track of 257 deg. with one turn to the 245-deg. final approach course 5.8 mi. from the threshold.


On the missed approach, Smedberg pressed the TOGA button on the throttle. This initiated go-around on the flight director and caused the A/T system to advance the throttle to maximum allowable takeoff torque.


In typically CAVU conditions in early October in San Diego, we canceled our instrument clearance and climbed southwest to 3,500 ft. We joined V-23 to fly down to Mount Soledad en route to Montgomery-Gibbs Airport for landing.


Our observations? IS&S autothrottles are a significant safety advancement for aircraft powered by PT6A turboprop engines. The PT6A A/T is the next best thing to a FADEC because it slashes pilot workload from takeoff to short final. It also provides flight envelope protections as well as guarding against engine exceedances. We’ll have more to say about the system when we have a chance to fly it.




使用道具 举报

关闭

飞行总动员推荐

飞行总动员®航空俱乐部(FSAC)服务项目
诚邀您加入飞行总动员®航空俱乐部(FSAC) 首家国际国内连锁航空会员俱乐部 加入会员享有的权益:

查看 »

飞行总动员航空qq群微信号

Copyright ©2011 fxzdy.com All Right Reserved.  Powered by Discuz! (网站已备案)

本站信息均由会员发表,不代表本网站立场,如侵犯了您的权利请发帖投诉   安全联盟 关注

平平安安
TOP
回顶部