Command blocks weren't added until Release 1.4.2 though (note that the OP is talking about Beta 1.7 (probably Beta 1.7.3 to be specific), not Release 1.7), so mods are the only way (note that the mods TileEntity mentions are for Release 1.7); you can't even use ender pearls for temporary "flight". If any such mods exist they are probably very obscure by now (all I could find for Beta 1.7 was singleplayer commands but that basically just gives you Creative flight).
However, you may be able to find a mod that does what you want in this archive, which is a massive (1000+) collection of mods for Beta 1.7.3, I can't say what mods it contains though or which ones would do what you want (there is no separate listing of what it contains, I also found it on this Reddit for old versions so somebody there may be able to help):
So no slime blocks, honey blocks or observers.
“Bees are the best addition to the game”
- TotallyNotThomas, 2021
I don't thing there is a way to create flying machines in 1.7
For this versions there are some mods like MCHeli or DavincisVessels to create flying machines
With the default content of 1.7 is it not possible
You can but only with command blocks
Command blocks weren't added until Release 1.4.2 though (note that the OP is talking about Beta 1.7 (probably Beta 1.7.3 to be specific), not Release 1.7), so mods are the only way (note that the mods TileEntity mentions are for Release 1.7); you can't even use ender pearls for temporary "flight". If any such mods exist they are probably very obscure by now (all I could find for Beta 1.7 was singleplayer commands but that basically just gives you Creative flight).
However, you may be able to find a mod that does what you want in this archive, which is a massive (1000+) collection of mods for Beta 1.7.3, I can't say what mods it contains though or which ones would do what you want (there is no separate listing of what it contains, I also found it on this Reddit for old versions so somebody there may be able to help):
TheMasterCaver's First World - possibly the most caved-out world in Minecraft history - includes world download.
TheMasterCaver's World - my own version of Minecraft largely based on my views of how the game should have evolved since 1.6.4.
Why do I still play in 1.6.4?