Congrats on accumulating the flight hours- this is an aspiration for
me, too.

I recommend using the SUMIF() function, which sums a range of numbers
if the criteria that you specify matches the data element in the row.
So the formula would sum all the hours for the 300 CB, Robinson 44,
etc.

However, this function requires exact typing: it would ignore 300CB,
for instance- note the missing space between 300 and CB. To avoid
problems, you could set up a dropdown box in the "aircraft" column.

The formula looks something like this:
=SUMIF($B$4:$B$4999,"300 CB",$H$4:$H$4999)
Note you can use a cell reference instead of the "300 CB".

Arrange a dropdown list in a cell by typing the list of aircraft
somewhere in your worksheet. From the menu click Data Validation.
In the Allow box click "List"; land the cursor in the Source box and
highlight the list of aircraft and click OK. (Tip: highlight one or
two extra spaces to in case you fly additional aircraft.) You can then
copy and paste the cell with the dropdown into B4:B4999.

Good luck- let us know if you run into any snags!