OH-23 Stuck Throttle & Autorotation
Tom Fleming- 1967 (Pat Eastes also remembers)
The story of the (almost disastrous) OH-23 autorotation at Cu Chi.
In October the Troop received a new Warrant Officer WO1 straight out of flight school. He was assigned to the Light Scout Section to fly the OH-23G and was checked out by the unit OH-23 Instructor Pilot, CPT Sanders. During his tactical check outs it was observed that he was not able to perform the duties of an Aero Scout wingman within any of the Scout teams and therefore he was relegated to fly “ass and trash” missions in support of the squadron.
On his last mission with the troop he was assigned the mission of flying to the squadron lager area about 20 kilometers west of Cu Chi and pick up the Squadron Commander, LTC Shea and the S-3, MAJ Kelly, and fly them back to Chu Chi. He landed successfully in the LZ, which was rather tight, and got the two passengers onboard. Due to the restricted nature of the LZ, heavy load and warm temperatures he correctly elected to do a maximum performance take off. This technique calls for twisting the throttle to full on and climbing out at full power.
This part of the take off was successfully completed, however when he attempted to level off, lower the collective and roll the throttle back to reduce power he discovered that he could not move the throttle. It was stuck full on. This required him to continue to climb in order to keep the RPM of the rotor blades within the safe operating range. His first call was to the Troop Flight Operation, Centaur 65, and in a panicky transmission explained that the throttle was stuck full on and he was climbing higher and higher. He even claimed if something wasn’t done he would be an Angel soon. The unit OH-23 IP CPT Sanders was called to Flight Operations and got on the radio with the young pilot and told him to calm down, continue as shallow a climb as possible with increased RPM, at the Maximum allowable, the air speed at VNE (Velocity Not to Exceed -Maximum Allowable Airspeed) and to continue to Cu Chi Airfield for an autorotation to the main 10.000 foot long runway. Applying this technique the pilot was able to slow his assent and became a bit calmer.
CPT Sanders talked the pilot through the autorotation procedures and made him repeat them to him to ensure that he had them committed to memory. All Army aviators make numerous practice autorotations throughout their training and must be proficient doing them to pass through each phase of flight school. Additionally, an autorotation is a standard part of any check out with an instructor pilot to be qualified to fly that model helicopter. The pilot arrived at Cu Chi aligned with the main runway from the southeast at 3000 feet altitude. Because he was higher than one would normally initiate an autorotation CPT Sanders reminded him that he would have a longer glide path than he was used too and not to over shoot the runway (10,000 feet long).
Our nervous pilot was apparently so anxious to get the whole thing over with that he instructed LTC Shea to turn the magneto off (thereby shutting off the engine) as soon as he crossed the perimeter of the base camp. That point was at least one quarter of a mile from the approach end of the runway and far too early to shut off the engine and commence autorotation. His glide path took him to the maintenance shop of E Company 25th Maintenance BN (Aircraft Maintenance). As he approached the top of the maintenance shop building he pulled pitch and flared, bounced off the roof and slammed into the PSP covered area in front of the shop where damaged helicopters awaiting maintenance were parked. It came to rest in a line of damaged D Troop OH-23s. LTC Shea and MAJ Kelly got out and remarked to the D Troop Commander who had raced to the crash site, “That was a hard landing.” and that was all that was said about the whole thing by the Squadron Commander.
Thankfully no one was hurt, but we were minus another OH-23 and another pilot who was immediately transferred to some other 25th Infantry Division aviation unit.
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Pat Eastes
Talking about -23s, remember the infamous flight of one of my classmates in WORWAC 67-11. He had, I believe, the Squadron XO on board when he had a frozen throttle on his OH-23?
He planted it on the runway at Cu Chi, and the passenger exited quickly, shouting "Good landing, Good landing!" Don't remember what happened to the pilot, and I don't know if the passenger ever flew again. - Charles "Juaquin' Eastes