In the late 1960s Boeing modified a Chinook to test a few new concepts. It was designated the Boeing Vertol 347. One thing they did was add a wing to each side. It had two four blade rotors and was much quieter in flight. The idea was it could be used in Vietnam to sneak up on the enemy. One bad thing was it could not auto rotate.

Photo here https://www.helis.com/database/model/Boeing-Vertol-347/

My instrument flight instructor for the upgrade from tactical instrument ticket to VOR/ILS and standard instrument ticket was CW2 Joe Stokes. He had been a maintenance officer in a Chinook unit in Vietnam. He was such a good story teller he always had an audience at "stand around stand" before weekend warrior formations. His best story was of Mike, a guard Chinook pilot in West Texas who though he was hot stuff and could fly under a high wire. Early in the story, Joe started another big story about putting his own Huey together off the books in Vietnam. Someone stopped him to ask, "What happened to Mike?" "Oh, he crashed and burned," Joe answered and quickly went on with the other story. His timing was professional.

Bell Model 533 (High Performance Helicopter)
Experimental / Research Helicopter (1962)

https://www.militaryfactory.com/aircraf ... ft_id=1931

How about 316 mph in a Huey!

The problem is it shakes like hell over ninety when old and tired.

Johntoo wrote:Bell Model 533 (High Performance Helicopter)
Experimental / Research Helicopter (1962)

https://www.militaryfactory.com/aircraf ... ft_id=1931

How about 316 mph in a Huey!

This aircraft is on static display where I work.

Hi,
I saw this when I was passing through Ft. Eustis, VA, many years ago. Glad to see it has a permanent home, quite impressive for what it accomplished. Amen to all who had the cojones to work the program.