x. AIRCRAFT SYSTEMS,

This section is intended to identify the shortcomings of the aircraft systems installed on the accident aircraft and those system’s roles in the chain of events that led to the accident.

Conclusions: l The failure of the autopilot to adequately maintain aircraft attitude played a

significant role in this accident. l The failure of the autopilot to warn the flightcrew of an impending disconnect played a

significant role in this accident. l The lack of an ice detection system played a significant role in this accident. l The lack of adequate visual icing cues and the lack of adequate pneumatic ice

protection system operation guidance played a significant role in this accident. l The failure of the regulators philosophy regarding operation and certification of the

aircraft’s systems (i.e. anti-deicing equipment) in icing conditions played a significant role in this accident.

A. EMB-120 AIRCRAFT AND INSTALLED SYSTEMS

The aircraft involved within the accident was a standard EMB120RT and was equipped with a standard avionics suite (Collins Pro Line III) flight director system and autopilot (APS-65). It differed in no conceivable form from any other EMB 120 in the Comair Airlines fleet.

As far as ALPA can determine, all systems on the aircraft were operated properly by the crew as required by the Comair Flight Standards Manual (FSM) and all applicable Federal Aviation Regulations and yet the aircraft crashed. Therefore, it is imperative that we not only examine the operation of the aircraft, but also its systems. To do a factual analysis we must analyze data we have collected from the systems that affected the outcome of the accident. We will examine:

Autopilot system. Stall warning system. Pitch trim system. Ice detection system or lack thereof. De-ice/anti-ice system (ice/rain protection). A-56B conductive edge sealer. Recording systems FDR, CVR, and potentiometers. Fast/Slow indicator.

1. Autopilot System

The autopilot system on the EMB120 is the Collins APS-65 autopilot system. In this accident, it operated normally for its design parameters. The Collins APS-65 autopilot system met all the applicable certification standards when it was designed for commercial use. It was- approved and installed in the EMB-120 aircraft as a part of the aircraft’s initial certification.

45

FDR data showed that the autopilot was being operated by the flight crew with the following modes engaged: heading, pitch, altitude, preselect, (through the altitude alerter) and altitude hold (automatic A/p function after capture).

The A/p leveled the aircraft at 4,000 feet, as programmed. The autopilot was then commanded to turn left using the heading mode to achieve the turn the autopilot initiated a left wing down (LWD) roll angle to a maximum target of 25’ (the altitude hold mode was engaged). As the roll angle reached about 20’ LWD, the autopilot inputs started moving in a direction to command right wing down (RWD) to slow the LWD rate. The left roll angle gradually increased beyond the autopilot target of 25” LWD as the autopilot continued to increase RWD input. FDR data also showed that the autopilot was commanding nose-up trim at an increasing rate during the turn (pitch remained about 3”nose up) as the roll angle exceeded 45” LWD the autopilot disconnected and the stick shaker momentarily activated. .

At this point the control wheel abruptly deflected 20” right to 20” left (40’ total) and aircraft pitch went from 3” nose-up to 50’ nose down handing the flight crew an out of trim, uncontrolled aircraft in an unusual attitude close to the ground.

The autopilot, in this accident, did meet the FAA’s certification requirements. ALPA believes these certification requirements need to be changed to eliminate problems identified in this and previous accidents.

Autopilot systems need to be certified by the FAA with proper failure “warnings”. Currently there are no requirements for a “soft” failure or warning mode for autopilot systems. An aural or visual warning prior to reaching a servo or bank/pitch limit may have alerted the crew to a possible control problem or performance degradation of the aircraft prior to the upset. This problem does not just exist in the EMB-120 but is in ALPA’s opinion an industry wide problem that effects many aircraft that are equipped with “older” design autopilot systems.

Page 18 of the Embraer Operations Bulletin 120-002/96 (attached) refers to “Flight in Normal Icing Conditions”. Page 19 (attached) has a section titled “Climb/Cruise” which has multiple references to autopilot operations which are recommended for flying through normal icing conditions. Page 19 of the Operations Bulletin states:

i “Climb mode, mainly on those MOD 67G autopilots with 155 KIAS climb speed, is not recommended. Instead, use IAS mode at 170 KIAS. With AP engaged. Use HDG and % Bank mode. . Continuously monitor airspeed and autopilot operation. Be alert for mistrimmed condition that may be masked by the autopilot. Periodically disengage the autopilot and check trims - keep the aircraft trimmed all the time. With autopilot on or off, increase airspeed if buffet onsets.?

It is important to note that ATC predicates all handling in the terminal environment based on standard rate turns. It is curious that Embraer does not recommend manually flying the aircraft at a reduced bank angle limit (‘/z bank mode). Also there is no prohibition against operating the MOD

46

67G autopilot in “normal ice” in the climb mode, which will maintain 155 KIAS to Flight Level @X) 200 (20,000’) and decreases to 135 KIAS at FL320 (32,000’). ALPA believes the above statements show Embraer’s knowledge of autopilot deficiencies gleaned from information discussed in the incident section of this report along with Embraer internal documents.

On March 21,1997 ALPA requested that the NTSB consider making the following urgent safety recommendation affecting autopilot operation:

“The FAA should immediately require that all operators of the EMB-120prohibit autopilot operation while the aircraft is accreting ice of any intensity. ”

This ALPA recommendation was prompted by the documented incident history of roll upsets while operating in icing conditions with the autopilot engaged. ALPA believes that limiting the use of the autopilot in icing conditions is the most prudent course of action to take until the interactions between the aircraft and the autopilot are fully understood.

This ALPA recommendation went unanswered by the NTSB and was not addressed in the NTSB’s urgent safety recommendations of May 1997.

It is ALPA’s belief that Embraer is aware of the problems in the autopilot system. ALPA also believes that the FAA must certify autopilot systems with proper “warnings” built into the system. Currently there is not an autopilot “soft failure” or warning of impending failure/disconnect required for certification of the autopilot system. Had a aural/visual warning been available to the CMR 3272 crew to warn them of the impending autopilot disconnect due to a servo or bank angle limit being reached, the crew would have been alerted to the state of the autopilot operation prior to the abrupt, uncommanded disconnect. There are several simple modifications that could be made to provide such a warning.

2. Stall Warning System

The stall warning system on the EMB120 is designed to prevent the aircraft from attaining high angles-of-attack, which could result in high bank angles or potential loss of longitudinal control. It is ALPA’s belief that this system in its present configuration is inadequate for flight in 14 CFR Part

x 25, Appendix C icing conditions. Currently the system is unable to compensate for any aerodynamic degradation.

: Other aircraft currently use a “biased” stall system to reduce the triggering threshold when the de-ice /anti-ice system is engaged to account for aerodynamic changes, such as increased stall speed, that may occur when flying in icing conditions. The EMB 120 is currently not equipped which such a biasing system that would help to prevent a loss of aircraft control in icing conditions. ALPA believes a biased stall system would have been a beneficial tool in preventing this accident, and recommends the immediate installation of such a system all EMB-120 aircraft.

47

3. Pitch Trim System

Currently, the EMB-120 is not equipped with an aural trim-in-motion system. Therefore, it is not readily apparent to me flightcrew that the autopilot is applying pitch trim unless this information is acquired visually by purposely looking down and noticing the manual trim wheel to be rotating. Currently, many flightcrews, in an effort to adapt to the lack of an aural warning, place their leg against the manual trim wheel to assess when the system is in motion, which is inadequate.

It is ALPA’s contention that the addition of an aural trim-in-motion annunciation system would greatly enhance flightcrew situational awareness not only during normal operations, but in times of i

increased workload such as approaches, adverse weather, and trim system malfnnctions.

4. Ice Detection System *

The EMB 120 was not equipped with an ice detector system and relied solely on visual cues by the flight deck crew to determine when to operate the ice/rain protection systems of the aircraft.

ALPA believes Embraer determined during tanker testing that visual cues were no longer adequate for icing identification and detection, and in April of 1996 issued Operations Bulletin 120~002/96 entitled Operation in Icing Conditions. This document recommended changes to the operation of the ice/rain protection system from one of deicing to anti-icing due to the previous tanker testing. However, distribution of this document to flight crews was not mandatory. In fact, the accident crew never saw this information.

It is obvious from the aircraft’s previous icing encounter and roll-off history that techniques for detection and evaluation of ice accretion on this airplane were not effective. Records indicate that the EMB-120 has experienced difficulties in icing conditions as far back as June of 1989 (NTSB, FAA, NASA-ASRS). Control difficulties in icing conditions are by no means a recent development in the EMB-120 aircraft history. However, it took eight years since the first EMB-120 ice induced roll upset for the FAA to issue an NPRM to equip the EME-120 with an detector system (Reference docket No. 97-NM-46-AD). ALPA, having reviewed the NPRM, found that the proposed AD would not address changes to operators Flight Standards Manuals or their equivalent. The FAA subsequently issued the above referenced AD on January 23, 1998 with a compliance time of 10 months. ;

Changing the pneumatic ice protection system operation from a de-icing mechanism to an anti-icing mechanism raised several questions within the industry, one of which was the phenomenon of “ice i bridging”. In a review of ASRS reports for air carrier icing events, ALPA has been unable to find a report of ice bridging actually occurring. However, mere have been numerous reports of icing upset events occurring before flightcrews believed enough ice had accreted to warrant operation of the Ice Protection System (IPS). Among these reports are several of the previous EMB-120 events, and the British Aerospace ATP roll upset incident near Cowly, England, on August 11, 1991 (G-BMYK). There have been accidents as well, including:

l Fokker F-27/collision with terrain/l8 January 1987LEas.t Midlands

48

l Shorts SD360/roll upset, collision with terrain/31 January 1986/East Midlands

l Fokker F-27/Takeoff accident/21 December 1969/Ronne, Denmark

The Cowly incident led to the AAIB issuing the following recommendation:

“For UK registered aircraji certificated with approvalforflight into known icing conditions, the CAA require a reliable means of actively alerting the flight crew to all conditions where operation of the airframe de-icing system is necessary to maintain safe jlight. ”

L In May of 1997, the Board issued Safety Recommendation A-97-34, which stated:

“Require that all EMB-120 aircraf be equipped with automated ice detection and crew alerting systems for detecting airjirame ice accretion. ”

It is very important that the Board understand the difference between the two recommendations. A- 97-34 only requires a means for detecting airframe ice accretion. The UK recommendation requires detection of conditions where operation of the airframe de-icing system is necessary to maintain safe flight. In between falls the typical ‘/4” to L/2” procedure used with pneumatic ice protection systems.

The Boards recommendation is useful only when the Airplane Flight Manual requires the IPS to be operated continuously beginning with the first indication of ice accretion. Since Embraer requires this, the Boards recommendation is appropriate for the EMB-120...however, the concept cannot readily be exported to other types, as many manufacturers still require a minimum accretion prior to IPS operation. The UK recommendation gets more to the heart of the matter.

In the paper “Ice Detection for Turbourou Aircraft”, Peter Render has stated that pilots “who were flying aircraft without ice detectors did not see the need for fitting them, and felt that the addition of ice detectors would add nothing to their ability to detect ice.” The U.K. Civil Aviation Authority has reviewed icing accidents and determined that the flight crews involved typically were aware of the presence of icing conditions. Thus, industry, authorities and pilot associations have not

. identified the safety benefit provided by ice detection.

The argument misses the point by a wide margin, principally because it is tailored to existing, off-

r the-shelf technology. In reality, icing accidents do not result from a failed awareness of icing conditions. They result from a failed evaluation of icing accretion. The crew knows they are operating in icing conditions. They know that ice has accreted on the airframe. But their evaluation of the particular ice accretion is incorrect, and thus their evaluation of the aerodynamic effects of the accretion is incorrect. The UK recommendation has gone the extra step by requiring detection of conditions where operation of the airframe de-icing system is necessary.

With these issues in mind, IFALPA has developed the following draft policy regarding ice detection:

49

Proposed Draft Policy:

ICAO Annex 6

4.3.5.3.1 Flight in known or expected icing conditions shall not be commenced or continued unless the aeroplane is certificated and equipped to cope with such conditions.

4.3.5.3.2 A flight to be operated in known or expected icing conditions shall only be commenced if the crew are provided with a means to identify the earliest indication of ice accretion, to quantify the ice accretion on any critical flying surface, and to identify icing .J conditions or accretions which may degrade the handling qualities or performance of the aircraft.

ICAO Annex 8 I

2.4.1 Aircraft handling qualities and performance in certification icing conditions shall be essentially unchanged from the handling qualities and performance demonstrated in dry air.

2.4.2 An aircraft shall only be certificated for flight in icing conditions if it is equipped with a means to identify the earliest indication of ice accretion, to quantify the ice accretion on any critical flying surface, and to identify icing conditions or accretions which may degrade the handling qualities or performance of the aircraft.

2.4.3 An aircraft shall only be certificated for flight in icing conditions if the design insures that the failure of a primary flight control to function correctly and with reasonable control force, due to ice accretion in any icing environment, is extremely improbable.

2.4.4 Performance degradations resulting from ice accretion within the certification envelope, which exceed operationally significant thresholds, shall be reflected in airspeeds, limitations and warning systems so that essentially the same margins of safety are available in certification icing conditions as in non-icing conditions.

There is an open loop within the inflight icing operational paradigm. The flight crew must be given a certification envelope with defined edges, which are detectable from the cockpit. There must be clear, substantiated guidance for operating the airplane so as to remain within the certification I envelope. Such is hardly the case when the flight crew is peering out of the cockpit some twenty to thirty odd feet trying to assess the thickness of the ice accretion to within I%“, or trying to evaluate the propeller spinner for “unusual ice accretion”. ‘.

If the accident aircraft had in fact been equipped with an ice detection system, the crew would have had additional systems information available to detect the presence of ice on critical surfaces. This additional information may have led to operational changes in the conduct of the flight. Instead the crews training provided waiting for approximately %” of ice accumulation to build up before activating the pneumatic de-icers, or for a loss of 10 to 15 knots of airspeed to occur prior to boot activation (Comair EMB120 FSM 3A-33).

50

5. De-ice/Anti-ice System (Ice/Rain Protection)

The EMB 120 Ice/rain protections system has historically been operated in accordance with a pre- disposed notion of ice bridging and operators instructions. In this flight, it is inconclusive whether the pneumatic de-icers were operating at the time of the upset.

Filament analyses of the ice/rain protection system proved inconclusive. Cockpit crash damage made ice/rain protection system switch positions at the time of impact unreadable. However, we do know that the crew activated the windshield heat and prop heat in accordance with their cockpit flow and at 15:54: 10.9 on the CVR a “click” is heard and, to date, remains unidentified. Seconds later at 15:54:13.2 another click is heard. At 15:54:14.4 several unidentified “thumps” are heard to fade in and out.

The elapsed time from the first unidentified “click” until the “autopilot” aural warning is 13.2 seconds. ALPA believes that sound spectrum analysis is warranted, due to the fact that these sounds remain unidentified. Additionally these “clicks” and “thumps”, if analyzed, may be attributable to a system problem similar to the one listed in an entry in the aircraft maintenance record on January 1, 1997 (eight days prior to the accident) which shows mat the outboard leading edge deicing system failed in both timer one and two positions, 30 seconds into the de-icing cycle.

ALPA also believes that more information on the effects of inflight icing should be provided to flight crews. Embraer claims that the EMB-120, due to its multiple de-icer panels, smaller diameter tubing, higher pressure and more rapid inflation and deflation cycles does not produce ice bridging. EMB-120 pilots were never specifically informed of this claim and no documentation is available for general distribution and education other than AFM Revision No. 43.

The flight crew had no knowledge of Embraer Operations Bulletin 120-002/96 or the revised pneumatic de-ice system procedures of the AFM. Therefore, in this accident, there was no guidance for the flight crew to operate their deicing equipment at the first sign of ice accretion (assuming that the flightcrew could have detected the accretions).

ALPA is also concerned that the automatic feature of the ice/rain protection system, when selected OFF, will stop at that point and reset to the beginning of the cycle when selected to ON. All aircraft

i equipped with this type of system should be capable of completing an entire de-icing cycle after shutting off the ice /rain protection system. Without this type of protection, it is possible for portions of the aircraft to be partially free of ice or allow protected areas of the aircraft to effectively

i remain contaminated for periods upwards of 2 minutes on “heavy” cycle and 6 minutes on the “light” cycle.

Furthermore this brings us to ALPA’s concern that the pneumatic leading edge de-icer portion of the system may not provide the necessary deicer coverage for the airfoil, horizontal stabilizer, and vertical fin as stated in the” B.F. Goodrich Icing Impingement Analysis for the Embraer 120 Airfoils” Report no. SO-32-024A (Reference section IV of the ALPA submission). This issue when combined with the operating procedures for the pneumatic boot system cause ALPA great concern.

51

6. A-56B Conductive Edge Sealer

The A-56B conductive edge sealer is a brush-applied coating that helps static electrical charges move from the de-icing boot to the wing surface where they can dissipate. The Aircraft Systems Group examined the remaining wing sections from the wreckage and determined that this coating may not have been installed on the accident aircraft. However, it is ALPA’s belief that the absence of this sealer would not have caused any aerodynamic anomalies since the Aircraft Performance Group has determined that the surface texture differences between the surfaces was smooth and imperceptible.

Additionally, ALPA believes that this aircraft did not suffer from delamination aft of the leading edge as described in Embraer Alert Service Bulletin 120-51-004 dated Nov. 10, 1997.

7. Recording Systems .

This accident once again demonstrated problems with the aircraft’s recording systems,

The first problem is that the aircraft did not have FDR channels for the pneumatic de-ice system and power lever angle. The lack of both required a search for physical evidence. (Crush damage rendered both unusable.)

The second problem was the rudder potentiometer. As in the previous EMB 120 accidents investigated by the NTSB, (Carrolton Eagle Lake, Brunswick, etc.) the data was bad (noisy) and could not be used.

Both these recording systems if available would have aided the investigation.

8. Fast/Slow Indicator

The EMB-120 is equipped with a Fast/Slow AOA indicator which can be used as an aid to the pilots during the approach phase. This system is checked and calibrated every 4000-flight hours per the EMB-120 maintenance-planning guide. The stall warning computer that uses inputs from the AOA sensors and sideslip sensor generates the signals for the fast/slow indicator. These signals are presented pictorially on the left side of both me Captains and First Officers EADI display. The i indicator consists of a yellow center reference mark, the letters F (fast) and S (slow), a scale with 4 dots, and a diamond shaped green pointer. The pointer, when centered, indicates that the AOA is such that the airplane is flying at the correct airspeed regardless of gross weight. .

Currently, Comair Airlines is not required and does not train pilots in the specific use of this indicator. Nor is the use of AOA generally used as primary flight indication guidance for aircraft maneuvering. It is ALPA’s contention that the use of AOA should be used as a tool for airspeed control during aircraft maneuvering especially while in the approach configuration (low airspeed, high AOA, etc.). Currently, the EMB-120 Fast/Slow AOA indicator is calibrated for flaps position 0’ and 45” only. This equates to 1.3 V, in these configurations. Comair normally flies approaches using flaps at 25” thereby rendering the Fast/Slow Indicator unusable for critical portions of the

52

approach. ALPA believes that the fast/slow indicator on the Em-120 should also be calibrated for all aircraft configurations. This would provide crew guidance for these intermediate flap settings.

53

,8.0 INTERVIEW S-S

James Watson, COMAIR Captain, EMB-120

Mr. Bill McHugh, ALPA attorney was present

Captain Watson stated that he had been employed by COMAIR for 8 years. He had been a captain for 6 % years and had accrued about 14,000 hours of total flying time, which included about 4,800 hours in the BMB-120.

He had flown the accident airplane the previous 4 legs. The airplane was flown from CVG to Huntsville, AL (HSV), and the flight crew remained overnight with the airplane. The next morning, he ffew back to CVG, to Asheville, NC (AVL) and returned to CVG. The total flying time on the airplane was about 6 hours.

Most of the approaches were flown down to minimums and in IPR conditions. Wing deicing was used on 1 or 2 of the flight segments while enroute. The systems worked “tine.” Windshield heat and prop deice was also used.

The icing was mainly “light.” Prior to icing the ignitors were turned on. The ignitors were to be turned on for moderate to severe icing. Most everyone turns them on ifthere is any chance of going into icing conditions.

The approach into AVL was down to minimums; 200 feet. Everything worked tine. The two approaches he flew were using the auto-pilot. He used the auto-pilot on most approaches but turned it off occasionally, once he was established on the approach in order to hand fly it.

He stated that he would like to have kept the airplane. It was flying so good. The auto-pilot was used in all modes (heading lJ-IDG], NAV and approach [APP]).

The crew that brought the airplane in had already gone. He reported that the logbook was clean. It had one write up about a dent or something. He looked back several pages and there was nothing remarkable. There were no open write ups, only the one deferred item that he previously mentioned. There were no comments made to him by the flight attendant regarding cabin discrepancies.

The number 1 engine was about 2 seconds slower than normal until lightoff. It took 4-5 seconds. It was like this on all 4 starts. However, it was still within the time limit of 10 seconds for lightofF.

The airplane flew just like all the rest of COMAlR’s airplanes. The EMB-120 is easy to fly. It is extremely stable. You have to trim a lot in the airplane. Every time you change power, you trim. The rudder is highly effective.

13

Operation in king Conditions

The procaduros for operation in NORMI\L icing conditions are. specified in the approved AFM. The aircraft has demonstrated that flight In icing requires no special procedures beyond those already cktained in the manual. Such procedures sra re- stated and reinforcqd in this document to provide pilots with e clear understanding of the procrduraa and racommendations During the icing teat aerioa, the aircraft domonatrated nominal control response avwn when flying in SLD conditione. As ouch, tie procedures to be used under those conditiona do not differ significantly from that of the normal icing. The procedures are presented here in a checldlet form+ as a memory aid. XII proceduree and speeds presented herein must be applied aa long as ice is adhering to the aircrafL After the aircraft is free of ice, normal operation should be resumed.

Flight in Nonnal Icing Conditions

External Safety ln5pefdon Opwating’regulalions (FAR 91.209) dearly state that no pibt may takeoff an aircraft thst is contaminatad by frost, snow or ice. Regarding the air carriara (FAR 121.629), the ragulahons are vary specific about whether and how aircraft can operate in icing conditions. The ground &eck should follow the EXTERNAL SAFETY INSPECTION contained in :he approved AF M. with special emphasis on the surfaces that may collect ice; wing and reading edge, horizontal stabiliir upper af.d lower surfacea end leading edge, rudder and vertical stabiliier fuselage, Pi!otIAOWAT prober. staUc ports; antennas, all intakes and ?c;Uais. landing gear and whael well. and engine. When the aircraft ia contaminatid. application of deicing or anti-i&g fluid, JT both, ray be rguired. While deicing ramovaa the mntamination, an&icing prevents the aaumLlation fcr certain period of time. Tasfs were performed to aas~ra no performance or handSn9 dagndation due to fluid appiication. Approved dei&anti-ica fluids for the EM&l20 are stated in Oparational Bulletin 120-004/33. Ensure that Pa aim& is clean before takeoff, by dwcking that uitical areas have baM property deiced and an&iced. If any ice Or snow has accumulated, do not assume it wiil dew off during takeoff roH. Tly to minimize the time between fluid rppllation and the Rm of takeoff rolt. ‘Charted holdover limaa for da-ica and anti-icB pmducta ShOUkl ba viawaa conrWatively. Holdover timea can be significantly reduced due to many factors influenting fluid effectiveness. If contamination is building up, or the hoidover time sxpiraa, do 5 Pra- takeoff contamination check and ti necessary go Sack for one another fluid application.

Paga180f23

After Engine Starting/Takeoff If ice is foreast. kx protection systems must be tested according to the procedures prescribed in the approved AFM. After testing is concluded. leave the promotion systems on if the takeoff will be performed in icing conditions. Never leave me ground in known or forecast icing conditions with any ica protection system inoperative. Takeoff procedures and speeds contained in the approved AFM remain unchanged. To avoid the risk of engine malfunction during take&f run due to irgestion of contaminants, turn engina igMcm on prior to setting takeoff power. Takeoff should be performed using :na static takeoff tachnicque: appty takeoff power before releasing brakes. Check that engine limits are net exweded.

ClirnbENise Monitor ioe continwusly during ctimb/crJise. At the first sign of ice formation, tom all ica protection syemme on. Manual dib (autopilot off) is initined at a speed not lee.3 than 160 KIAS, at a constant pitch ang!e and climb power setting. When reach- 160 KIAS, pitoh shot&d be reduced in order to maintain mat speed. To climb with autopilot on, trim the airczaR wrth dimb power and at least 170 KIAS. The-r engage autopilot and select IAS mode to maintain the minimum required speed. Avoid the use of pitch hold for crib. CLIMB mode. mainly on those MOO 67G autopilots with- 155 KIAS clbnb speed. is not recommended. Instead. m IAS mode at 170 KlAS. Wrh AP engaged, use HDG and % 0 bank mode. Continuously monitor airspeed and autopilot operation. 60 alert for mistrimmed oondikion that may ba masked by the autopilot. Pertodicaliy disengage the autopilot and check trims - keep me airor& trimmed all the tima With autopilot on or off, increase l irepeed if buffet oqeete. Upon altahing the desired Eight altitude, accelerate with cfimb pcwer until the aircraft reaches the desired cruise spaed. Then set cruise power. During dimbloruire, maintain NH above 8C% for propar operation of the ice prottiion systems. Also oboe the NP aatablished by petfr~rmance requirements during climb, .wMch may be l tther 100 or 90%. Propeller vibration may ooour due to ice accumUlatlOn on the bladee. Cycting the propeller RPM may aid in shedding ice from the blades.

Page19of23