Part 83, page 315

Transcript

The scan is the source; the transcript is machine-generated from it.

MULTI-SPEED SWITCH OPERATION AND MAINTENANCE

by W. H. Zarling P. A. Greco Analysts, Electrical-Electronics Field Service Department

When starting the engine in most helicopters, it is necessary to press and then hold the start button until the engine is in operation. In the H-43B HUSKIE, however, the start is made by merely pushing the button momentarily and then releasing it, thus setting the automatic engine starting system in operation. This allows the pilot time to prepare for flight while the engine is starting and also minimizes the time required to get the helicopter airborne and on the way to perform its rescue mission.

Once the engine is started, the automatic starting system is deenergized by the multi-speed switch. This switch, P/N AE47-2 and -3, is preset to deenergize the starting system at 28 to 30 percent of N1 (gas turbine) RPM. Comprised of a normally closed micro switch and an actuating mechanism which operates by centrifugal force, the multi-speed switch is located on the engine between the N1 tachometer mounting pad and the N1 tachometer. The multi-speed switch and N1 tachometer are mechanically driven by the N1 reduction accessory gear box.

The electrical location of the speed switch is shown in figure 1, which represents the latest production configuration of the engine starting system. The switch operation in relation to the other components in the system is as follows: When the aircraft's start button is depressed, circuit connections for current flow are provided from the D. C. essential bus to the junction of the speed switch and ignition system. At this point the current divides into two paths, one to the ignition system and the other to the speed switch. Since the speed switch contacts are normally closed, current flows through to the prime fuel solenoid, the starting relay and the starter relay. This action opens the prime fuel valve allowing prime fuel to flow into the engine; energizes the starter relay, allowing APU or battery current to flow to the starter; and energizes the starting relay. The starting relay contacts are connected in parallel across the start switch, functioning as a "latching" switch, and provides a path for current flow into the starting system. At this time the start button can be released and the starting system remains self energized.

A normal engine start should be accomplished when N1 RPM reaches 28 to 30%. The speed switch actuating mechanism is adjusted to actuate the micro switch between these percentages. When this occurs, the path for current flow through the speed switch is opened, deenergizing the prime fuel solenoid, the starter and starting relays. This action opens the paralleled contacts of the starting relay, connected across the

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MISSION REPORT FROM LUKE AFB

by 1st Lt. Carroll L. Wright Information Officer, Det. 15

crashed aircraft was only about 300 yards off the end of the runway. It took the fire trucks approximately thirty minutes to rig a fire hose long enough to reach the scene. During all this time, the helicopter was the only fire suppression vehicle that could reach the scene.

This Detachment has flown a total of 1104 missions during the above mentioned period. These missions cover all types such as bailouts, military crashes, civilian crashes, military evacuations, civilian evacuations, search and recovery, and scrambles with the fire suppression kit. There have been eighteen bailouts of which one had to be picked up with the hoist because of the rough terrain the pilot had landed in. Out of thirty-four evacuations, twenty-eight were civilians. The hoist was used to pick up fifteen of these evacuations and the Stokes litter had to be used on two occasions because of the extreme injuries involved. Thirty-two aircraft have crashed within our area and eleven have been within fifteen miles of the base. The H-43B has aided greatly in the recovery of eighteen deceased persons. The majority of these individuals were in extremely rough terrain which made their recovery next to impossible by any other means. These missions were flown all over the State of Arizona. They cover an area from a few miles next to the Mexican border to the depths of the Grand Canyon.

This detachment has flown 1020:30 hours in the H-43B as of 5 July 1962. We have found the H-43B requires relatively little maintenance once it is placed in commission. There have been times when parts were on shortage and the aircraft would be AOCP for a short period of time.

These missions combined with the professional attitude of the members of this Detachment speak for themselves. Both the civilian and the military populace have grown to depend on the professional ability of this Detachment and its members have tried to meet the obligation both day and night. The H-43B has played the largest part in the mission accomplishment. It has definitely proven itself to be an extremely versatile vehicle for both fire suppression and rescue. K

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Detachment 15, WARC (MATS), Luke AFB, Arizona; offers the following record of mission accomplishment as a record of interest to see if any other LBR can top it.

On 24 April 1960, Capt. Walter C. McMeen, Det. 15 Commander, flew the first rescue mission with the H-43B in the field. This mission appeared in the July, 1960, Rotor Tips which is published monthly by the Kaman Aircraft Corp. Captain McMeen was placed on the Scroll of Honor for his accomplishment. This one mission proved the outstanding capability of the H-43B "Huskie" as a rescue vehicle and thus was the begining of a long list of mission accomplishment in the H-43B. All missions that will be mentioned were flown in the H-43B and cover the period from 24 April 1960, to 5 July 1962.

The most outstanding mission accomplishment developed on 5 July 1962. On this date, this detachment accomplished the one thousandth (1000th) actual scramble mission with the fire suppression kit. The fire suppression kit is carried when an aircraft declares an emergency inflight with intentions of landing at Luke. It is also carried to any aircraft accident which may occur within 15 miles of the base to furnish fire suppression and rescue coverage. The 1000th emergency developed when a T-33 pilot, Capt. James R. McCulloch, 4512 CCRTRARON, declared an emergency and was inbound to Luke for landing. The helicopter was airborne in less than two minutes with the fire suppression kit. The T-33 pilot landed his aircraft safely and the helicopter returned to the alert parking area. Once again the every-day routine had been acted out uneventfully. Not all of the emergencies have ended this way though, because the fire suppression kit has had to be used on eight (8) occasions. On one occasion, after the fire kit was used, the helicopter returned the kit to the ramp to be recharged. After the kit was recharged, the helicopter returned to the crash scene to continue the firefighting operation. The fire trucks from the base had not reached the scene yet. The aircraft had crashed in a freshly irrigated field and the fire trucks could not reach it because of the mud. The interesting thing about this mission was the fact that the

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1000th SCRAMBLE—Crew of the H-43B which carried fire suppression kit for the 1000th time in support of an aircraft with an inflight emergency. Front row, left to right, are A1C Robert J. Stone, fireman; S/Sgt. George S. Edwards, crew chief; A1C Frank E. Hill, fireman. Rear, Capt. Harold D. Salero, co-pilot; 1st Lt. Carroll L. Wright, pilot and rescue crew commander. (USAF photos)

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12 KAMAN ROTOR TIPS AUGUST, 1962 DB Cooper-36788 9