JACKSONVILLE, Fla., May 31— Herbert Spencer Duckworth, a retired vice admiral who commanded the aircraft carrier Cowpens in World War II, died at St. Luke's Hospital on Tuesday. He was 90 years old.
He was air officer on the aircraft carrier Lexington at the battle of Coral Sea in 1942. In 1947 and 1948 he commanded the Jacksonville Naval Air Station.
After retiring to Jacksonville in 1952 he served as president of the Jacksonville Art Museum.
His survivors include his wife, Myrtle, two sons and two daughters
Lieutenant General Lemuel C . Shepherd, Jr. Commanding General, FMFPac, after an inspection trip to the war zone during which he was briefed on and viewed the operations of the brigade and of VMO—6, echoed General Craig's praise of helicopters and repeated his call for more of them:
There are no superlatives adequate to describe the general reaction to the helicopter. Almost any individual questioned could offer some personal story to emphasize the valuable part played by the five H03S planes available .* Reconnaissance, liaison, visual flank security, movement of security patrols from one key locality to the next, posting and supply of security detachments and many more . There is no doubt that the enthusiasm voiced by the brigade is entirely warranted . Moreover the usefulness of the helicopter is not by any means confined to a situation such as encountered in Korea . No effort should be spared to get helicopters—larger than the H03S-ls if possible —but helicopters in any form, to the theater at once —and on a priority higher than any other weapon.
 Cited in BGen Clayton C . Jerome memo to VAdm Cassady, RAdms Soucek, Duckworth, Pride, and Goe, dtd 19Sep50, no Subj, hereafter cited as Jerome memo.
In view of General Shepherd ' s statement pertaining to the helicopter in Korea, Brigadier General Clayton C. Jerome, who relieved Major General Wallace as the Director of Aviation on 1 September 1950, sent a memorandum to Admiral Cassady in which he included General Shepherd' s statement. General Jerome said
"this emphasizes the
[remark] I made the other day in connection with the requirements for helicopters, more helicopters, and more helicopters in the Korea Area. "
 Jerome memo .
Major General Lamson-Scribner
recalled the period: Just prior to the receipt of General Shepherd's
letter, General Jerome and I attended a conference
[at] which Admiral Cassady, was chairman of the Navy Aircraft Procurement Program for Fiscal 51 . The program was for only a relatively few helicopters . We insisted that we needed more than programed for purchase . Admiral Mel Pride, Chief of BuAir, remarked in essence
`If you know as little about helicopters as we do you would not get into one .' Admiral Cassady said ,
`Mel, the Marines want them . Make some changes in the program to provide more helicopters for the Marines .'
 MajGen F. H. Lamson-Scribner (Ret.) ltr to Dir MCHist&Mus, dtd 23Mar75 . Comment file, "Developmental History of the Helicopter in the USMC 1946 — 1962 . "
General Jerome's memo was only the latest of many attempts to convince the Department of the Navy to increase the Marine Corps ' inventory of aircraft for the Korean buildup . On 19 July, General Cates submitted a request to the Secretary of the Navy for an additional four Marine fighter squadrons in an effort to increase the total to 12 .