Boeing Vertol Model 147 tilt-wing VTOL project (AAFSS)

My dears,

the Boeing-Vertol Model-147 was for AX competition,see also:
www.hitechweb.szm.sk/fightersAP10.htm

Sorry,

I missunderstand about the BV-147, it was just VTOL project.

Regarding to Model 147, its here at the bottom of the page:
http://www.hitechweb.szm.sk/helicopters1.htm

It was derived from Vertol Model 76 (VZ-2) and if I remember correctly, was proposed to the AAFSS competition and ended at the last place. I downloaded its picture somewhere from net many years ago (maybe prototypes.fr ??).


[Attachement] Model 147 (from : Aviation Week 1965 9-17)

Hello Friends !

I find in my archives this drawing of the Boeing Model 147 (it was published in 2000 on my article on the AH-56 Cheyenne).

I search information on the Sikorsky S66 for AAFSS program.


Cordialement

Let me get this straight- Boeing entered a tiltwing design in to AAFSS competition? Did the specifications not call for a helicopter? I'd think on the basis of the 1947 Key West agreement the Army would have called for a helicopter to avoid a turf war with the USAF.

Sentinel Chicken said:

Let me get this straight- Boeing entered a tiltwing design in to AAFSS competition? Did the specifications not call for a helicopter? I'd think on the basis of the 1947 Key West agreement the Army would have called for a helicopter to avoid a turf war with the USAF.

Click to expand...

Good point here. This exactly what happened, and Mr Mirage 4000 article explain very well how this problem plagued the cheyenne program... and also how the A-X program (A-9/A-10) grown from that.

Canadair also proposed an armed CL-84 variant.

The AAFSS program asked for superlatives performances (for an helicopter).
As a result, only compound machines (fixed-wing / helicopter mix) could fulfill those performances... but their wings, propellers or jet engines made USAF furious...

Actually even the Cobra helicopter made the USAF furious, but because it met all of the weight and "rotor" measures agreed to by the USAF in the Key West Agreement they really could do nothing about it. They saw ANY aircraft that conducted fire support to troops in direct combat as an infringement on their close air support mission. A debate that rages on even today in the age of attack helicopters as a integral part of many land combat forces. An interesting note; the USAF conducts Close Air Support for ground forces, while US Army attack helicopters conduct Close Combat Attack in support of troops.

Interestingly while the AH-56 had problems with high speed flight rotor stability and flutter issues, they were not insurmountable and fixes were in the works. Amongst the Army types around at the time of the cancellation it is generally agreed that the decision was made behind large oak doors at the Pentagon and in Congress, giving the USAF less threat to on of its core missions while the Army would not get push back on several other programs.

Interestingly several years later when the USAF decided that the A-10 was redundant in a WWIII scenario they agreed to allow the Army to have the aircraft. It is rumored (although I suspect it is urban legend) that it was within one signature when the fact that the USAF was not going to give the Army personnel slots to go with the aircraft that the deal fell through.

Interestingly while the AH-56 had problems with high speed flight rotor stability and flutter issues, they were not insurmountable and fixes were in the works

Click to expand...

Jack Real agree on this fact. Problems of rotor stability had been cured after 1969 crashes.
In fact they had found three solutions to this problem!
- an improved variant of the original rotor (interim solution)
- a new rotor with a mecanical control
- another solution was electronic control
(I'm not specialist, I've to check the article).


In fact from 1971 there was no problems with the rotor... the machine reached
447 kph (after a 4300 hp engine was mounted). Long flights at 370 kph and treetops were made.
Seems that the program was definitevely buried after a demo "failed" : one TOW missile (over 10!) missed its target at Yuma in front of Army officials. This was used as pretext. ..

Murky Vertol 147 model images from AW&ST March 8, 1965.

Dear Boys and Girls, here are some pictures with a caption in French of the Boeing-Vertol model 147 "project"......

The pictures come from the 15th May 1965 issue of Aviation Magazine International......

Terry (Caravellarella)

..

Boeing Vertol Model 147

Source:
http://cs.finescale.com/fsm/modeling_subjects/f/16/t/46989.aspx?sort=ASC&pi240=17

Hi,


here is a Boeing Vertol tilt-wing project in a model for wind tunnel,I think it was BV.147,
and there is a version with low-tail (new for me).


http://www.dtic.mil/dtic/tr/fulltext/u2/712645.pdf