I dont think it will work in a query then.  The only way it would work
in a query is if you had a field specifying it as inbound or outbound
and then a single numeric field for number of flights.

you could create a report with groupings and subtotals though.

What are the datatypes of those fields?
I woud have used a single field myself ...

ok it is more than possible but it is not simple there may be a more
simple way but i cannot be bothered thinking of it

you need to do a query in three stages

i am presuming you are using the yes/no data type for the inbound
outbound fields and a date for the mission date

you need to build seven queries (i know it sounds like alot but it
breaks down each section and allows you to summarise the data for use

first using this sql

create (this will summarise all your inbound flights where there is an
inbound flight on that date)

SELECT mission.missiondate, Count(mission.inbound) AS inbound
FROM mission
WHERE (((mission.inbound)=True))
GROUP BY mission.missiondate;

and save it as qryinbound

next create (this will summarise all your outbound flights where there
is an outbound flight on that date)

SELECT mission.missiondate, Count(mission.outbound) AS outbound
FROM mission
WHERE (((mission.outbound)=True))
GROUP BY mission.missiondate;

and satve it as qryoutbound

next create (this will summarise all your outbound flights where there
is an outbound flight not on that date)

SELECT mission.missiondate, 0 AS outbound
FROM mission
GROUP BY mission.missiondate
HAVING (((Sum(mission.outbound))=0));

and save it as qrynotoutbound

next create (this will summarise all your inbound flights where there
is an inbound flight not on that date)

SELECT mission.missiondate, 0 AS inbound
FROM mission
GROUP BY mission.missiondate
HAVING (((Sum(mission.inbound))=0));

and save it as qrynotinbound

next create (this will combine the inbound and not inbound query into
one ready for the final query)

SELECT qryinbound.missiondate, qryinbound.inbound
FROM qryinbound
UNION SELECT qrynotinbound.missiondate, qrynotinbound.inbound
FROM qrynotinbound;

and save it as qryallinbound

next create (this will combine the outbound and not outbound query
into one ready for the final query)

SELECT qryoutbound.missiondate, qryoutbound.outbound
FROM qryoutbound
UNION SELECT qrynotoutbound.missiondate, qrynotoutbound.outbound
FROM qrynotoutbound;

and save it as qryalloutbound

and finnally create (this will summarise the data and give it to you
in the form i believe you are looking for

SELECT qryallinbound.missiondate, qryallinbound.inbound,
qryalloutbound.outbound
FROM qryallinbound INNER JOIN qryalloutbound ON
qryallinbound.missiondate = qryalloutbound.missiondate;

and save it as whatever and this query will give you the required data
this will of course only give you data

and of course name the fields and tables in my sql queries as that
ever you have named them i have just used obvious names such as
mission and inbound outbound and missiondate so you will understand

the test data i used was
id    missiondate    inbound    outbound
1    1/01/2008                   Yes    No
2    1/01/2008                   Yes    No
3    1/01/2008                   No    Yes
4    1/01/2008                   No    Yes
5    1/01/2008                   No    Yes
6    1/02/2008                   Yes    No
7    1/03/2008                   No    Yes

the results i got was

missiondate    inbound    outbound
1/01/2008                   2    3
1/02/2008                   1    0
1/03/2008                   0    1

i do hope this helps

regards
kelvan

SELECT [Date], Abs(Sum(Len(Trim(MissionIN & "")>0))) as Inbound
, Abs(Sum(Len(Trim(MissionOut & "")>0))) as OutBound
FROM YourTable
Group BY [Date]

I am making the assumption that you fields can contain zero-length
strings or that you are hooked to another data source that stores spaces
in a field by definition (char fields in SQL for instance).

'====================================================
 John Spencer
 Access MVP 2002-2005, 2007-2008
 The Hilltop Institute
 University of Maryland Baltimore County
'====================================================

tell me is this an example of what you are looking for
missiondate    actype    outbound    inbound
1/01/2008                   747    1    2
1/01/2008                   767    2    0
1/02/2008                   767    0    1
1/03/2008                   747    1    0