Since his childhood, Randy Malmstrom has had a passion for aviation history and historic military aircraft in particular. He has a particular penchant for documenting specific airframes with a highly detailed series of walk-around images and an in-depth exploration of their history, which have proved to be popular with many of those who have seen them, and we thought our readers would be equally fascinated too. This installment of Randy’s Warbird Profiles takes a look at the Museum of Flight‘s Lockheed YO-3A Quiet Star, s/n 69-18005, Constr. No. 006.
The “Y” being a pre-production designation (which was never removed), and the “O” designation for observation aircraft. From what I have determined, this particular aircraft was one of three YO-3A’s assigned to the 220th Aviation Company “Catkillers” at Phu Bai Combat Base south of Huế, Vietnam, between 1970-72. After being struck off charge it went to the Special School District of St. Louis County at Rock Hill, Missouri, on February 15, 1973. The incomplete airframe was acquired by Harold and Vic Hansen of Seattle, Washington who rebuilt it using spare parts. Bruce Elliot of La Connor, Washington purchased it on December 10, 1987, and it spent many years in storage at Skagit Regional Airport, Burlington, Washington. He gifted it to the Museum of Flight in Seattle, Washington (MOF), and the MOF Restoration Center (on Paine Field in Everett, Washington) restored it and is now on static display at MOF – it has no engine. My photos and those courtesy of Don England and Craig Wall, thanks.
Designed in 1968 by engineers in the Advanced Programs Directorate at Lockheed Missiles & Space Company, Inc. (LSMC) to a Department of Defense specification for an observation/reconnaissance aircraft for the U.S. Army in Southeast Asia that would be acoustically undetectable from the ground when flying at an altitude of 1,200 feet at night. By accounts, only 14 production YO-3A’s were built and were sent to the 1st Army Security Agency (ASA) Company for action in Vietnam in early 1970 including the 73rd SAC (Surveillance Aircraft Company), 1st Aviation Brigade at Long Binh Post (“Long Binh Junction”). Records indicate that nine were sent to the 73rd at Long Thanh North (Bearcat Base, two to Binh Thuy Air Base, and three to Phu Bai Combat Base. In fourteen months during 1970-71, none were reportedly shot down or damaged by enemy fire. However, there are recorded crashes.
The powerplant was a single Continental IO-360D six-cylinder, air-cooled engine that powered a six-blade, fixed-pitch propeller that was operated by a 12-belt pulley drive and ran at a slow speed. The aircraft incorporated a number of noise reduction design features. In 1971, LMSC master craftsman Ole Fahlin designed a replacement custom-made three-blade constant speed wooden propeller (with a wider chord than a conventional propeller for a similarly sized airplane) made of polished and lacquered layers of Canadian Birch plywood one-sixteenth of an inch thick; and the low tip speed propeller aided in noise reduction. It had a seed reduction top speed of 138 mph and a cruising speed of 110 mph and flew as slow as 70 mph for maximum noise reduction – 60 decibels. It has been said the sound is something like a deck of cards being shuffled.
It had an “over-the-wing” asymmetrical “swirl chamber” exhaust system that ran the length of the fuselage reduced engine noise and which, for one thing, moved exhaust gases through an acoustical fairing and combustion air intake muffler that dissipated sound. Extra insulation, acoustic absorption treatment to the firewall, treated cooling air intake duct, and sealed valve covers (duct tape was also used in the field as needed!), smooth aerodynamic surfaces, and antennas that were either flush with the skin or internal, all helped reduce noise. I understand that the exhaust system (muffler) has been mistaken for side-looking airborne radar (SLAR) several times. Dr. Sherman M. Seltzer, Chief Engineer, was threatened with termination because of its asymmetrical design. But he convinced his Vice President that it was required to meet the noise specifications and survived.
Control surfaces were fabric and much of the aircraft was made of fiberglass. A trailing edge wing extension was added over the inner half of the span. The aircraft carried no armament and largely flew at night, although daylight missions (over rivers) took place. With a crew of two, the pilot sat in the rear seat and the observer sat in the front seat and operated the NVAP – Night Vision Aerial Periscope – with an infrared illuminator (developed by Xerox Electro-Optical in Pasadena) which could detect a 5-ft. person at one mile. Only 18 NVAP units were produced and it was an electro-optical system that amplified low level ambient light (stars, moon) to a visible level of illumination. The optics for the NVAP system, which included the Scanner Head under the fuselage with what is believed to be the largest single piece optical glass prism ever made, were provided by Carl Zeiss of Germany. One YO-3A was equipped with a laser target designator used to guide homing ordnance but it was never used.
While the aircraft was capable of being inaudible at 1,000 ft., pilots were known to fly undetected as low as 200 ft. After the Vietnam War, the U.S. Federal Bureau of Investigation acquired some YO-3A’s (for tracking kidnappers and extortionists for example); the State of Louisiana Fish and Wildlife used them to locate shrimp poachers; NASA took possession of one in the late 1970’s and used it for noise measurement tests; the U S. Customs and Border Protection operated them; as did the U.S. Coast Guard. As per D.E. Smith: The “YOYO” nickname the aircraft received disrespects most who produced, maintained and flew the aircraft. They were certainly not described as such while flying over “#10 Country” and some other places. They established significant aviation milestones in the ’70s. YouTube clip of its sound: https://youtu.be/x9W4guidKy4
About the author 
Randy Malmstrom grew up in a family steeped in aviation culture. His father, Bob, was still a cadet in training with the USAAF at the end of WWII, but did serve in Germany during the U.S. occupation in the immediate post-war period, where he had the opportunity to fly in a wide variety of types which flew in WWII. After returning to the States, Bob became a multi-engine aircraft sales manager and as such flew a wide variety of aircraft; Randy frequently accompanied him on these flights. Furthermore, Randy’s cousin, Einar Axel Malmstrom flew P-47 Thunderbolts with the 356th FG from RAF Martlesham Heath. He was commanding this unit at the time he was shot down over France on April 24th, 1944, spending the rest of the war as a prisoner of war. Following his repatriation at war’s end, Einar continued his military service, attaining the rank of Colonel. He was serving as Deputy Wing Commander of the 407th Strategic Fighter Wing at Great Falls AFB, MT at the time of his death in a T-33 training accident on August 21, 1954. The base was renamed in his honor in October 1955 and continues to serve in the present USAF as home to the 341st Missile Wing. Randy’s innate interest in history in general, and aviation history in particular, plus his educational background and passion for WWII warbirds, led him down his current path of capturing detailed aircraft walk-around photos and in-depth airframe histories, recording a precise description of a particular aircraft in all aspects.