Forgot to say in my earlier post that really the geodetic construction technique was not very suitable for aircraft!it was similar to the structure which worked very well on the R100 .Even the Wellington had some idiosynchratic behaviour caused by geodetics although it was probably as good overall as anything else available at the time (not necessarily a recommendation!!)Most WW2 aircraft of course are viewed with affection by their crews and enthusiasts and I am not trying to upset anybody!!but really the Wellesley was big enough to point to flexing problems and I think it was a big mistake by Vickers to persevere with geodetics.