This series of tapes were defective.
I had purchased "America-By-Air" - Vol #3 when it first was offered on VHS. I was unable to find the first 2 volumes. This was pre-internet. (1983) Jump ahead 25 years and; lo & behold, Amazon had a vendor offering the complete 3-volume set (Used) for sale. I ordered same. When the set arrived and attempted to play -- the tapes would NOT track properly; skipped through tracks; sound track would be garbled or not play at all. I contacted the vendor and relayed the problems I was experiencing. The vendor stated he had bought the set from a "GOODWILL Industries " outlet. Sorry 'bout that!!!I located the original producer of the series and he was willing to transfer the Master Tapes onto DVDs. And included all the original inserts.Cost me approximately $65, but worth every cent.