The CH-46 Phrog
WHEN MARINE CORPS squadron HMM-265 deployed ashore at Marble Mountain in South Vietnam 49 years ago, it achieved a major milestone in airmobile warfare. The unit was flying the Boeing Vertol CH-46A Sea Knight, known almost universally as the “Phrog” for the way it squats on its back gear and for its tendency to bounce when beginning to taxi. With the Phrog’s introduction, the Corps became the first military service to adopt “vertical envelopment,” a tactic to bypass enemy strongpoints with helicopters and restore the initiative to the attackers.
A succession of pioneering reciprocating-engine helicopters—the HRP-1, HUS-1 (UH-34), and HR2S-1 (Ch-37)—proved the validity of the vertical envelopment doctrine, but by 1958 those aircraft had reached the limits of their capability, and turbines offered the best opportunity for improvement. The Corps settled on a variant of Vertol Corporation’s Model 107, begun in response to a French request for improved performance in the helicopters the French military flew in the Algerian insurgency. At first glance, what would become the CH-46 did not seem to be a great improvement over the HUS and HR2S, but the realities of Southeast Asia’s high-density altitudes and the helicopter’s simple, utilitarian design enabled it to significantly outperform its predecessors in nearly every conceivable category. The Corps ultimately acquired more than 400 CH-46S, which went on to serve as the mainstay of Marine medium-lift capability through virtually every conflict the United States has engaged in since the mid-1960s.
With the impending conversion of HMM-74 to the Bell-boeing MV-22 Osprey, the Phrog has reached the sunset of its operational career. To celebrate its legacy, the National Air and Space Museum will host the farewell to one of the great workhorses of Marine Corps aviation. On August 1, Buno 153369, appearing in a polished version of its Vietnamera paint scheme, will arrive at the Museum’s Steven F. Udvar-hazy Center in northern Virginia for a ceremony commemorating its service. After the event, the aircraft, on loan from the National Museum of the Marine Corps, will go on display at the Udvar-hazy Center.
Having extensive Vietnam service with HMM-364 “Purple Foxes,” number 153369 is a worthy airframe for the honor. One of its pilots, First Lieutenant Joseph Donovan, was awarded a Navy Cross for a hazardous rescue flown on April 21, 1969. Exactly 41 years later, his daughter, Captain Eileen Donovan, also assigned to -364, flew 153369. She is now flying the Osprey and helping to usher the Corps into a remarkable new era of vertical envelopment capability, as notable as that heralded by the arrival of the Phrog.
J.R. DAILEY IS THE JOHN AND ADRIENNE
MARS DIRECTOR OF THE NATIONAL AIR AND
Washington, DCChantilly, VA