To create a new data frame that includes flights headed to SFO in February, we first need to filter the flights data frame using the following criteria:

$-$ Destination airport is SFO

$-$ Flights take place in February

We can use the filter$()$ function from the dplyr package to achieve this.

The code would look like this:

$```$r

library$($dplyr$)$

sfo$\_$feb$\_$flights $<-$ filter$($flights$,$ month $==2,$ dest $==$ "SFO"$)$

$```$

This code creates a new data frame called sfo$\_$feb$\_$flights that includes flights headed to SFO in February.

To determine how many flights meet these criteria, we can use the nrow$()$ function to count the number of rows in sfo$\_$feb$\_$flights:

$```$r

nrow$($sfo$\_$feb$\_$flights$)$

$```$

This returns the number of rows $($i$.$e$.,$ the number of flights$)$ in sfo$\_$feb$\_$flights, which is $**2286**.$