2.  
For Frankfurt Airport, a calculation was carried out for all landing directions, and the results are presented in the chart enclosed.

The runway occupancy time is defined as the elapsed time a landing aircraft is on a runway, from crossing of threshold until vacating the runway by reaching a distance of 30 m from the runway centre line.
The runway occupancy time is composed of different phases;
-Time from crossing the threshold to touchdown;
-Time from touchdown to the runway turn-off point (braking time), including, if necessary, time for transition or a transition route after touchdown without run-up;
-Time from the turn-off point to vacating the runway until reaching a distance of 30 m from the runway centre line.
3.  In order to determine the runway occupancy time, the following assumptions were taken as a basis.
-In order to calculate the turn-off time from the runway to vacating the runway, an approach speed of 120 kt is assumed for a B 727, for an A 300 an approach speed of 130 kt, and for a B 747 an approach speed of 140 kt. These assumptions are important for the determination of the roll-out distance.
-The touchdown point is the location of the glide path transmitter;
-After touchdown and roll-out, the aircraft takes the nearest (rapid) exit taxiway.
4.  The results have shown that under the above-mentioned circumstances and assumptions runway occupancy times of 50 seconds and less can be achieved.
The table also includes the following details:
-The delay values b which were arithmetically calculated for the braking distance after touchdown; and
-The distance of the following aircraft from the threshold in NM or km when the preceding aircraft has vacated the runway by reaching a distance of 30 m.

Runway Occupancy Time Airport Frankfurt
Runway Heading  Taxiway  Approach speed  Runway Occupancy Time  Decel-aration factor (b)  Distance of following aircraft to touchdown (Initial separation 2,5 NM) 
KT  sec  m/sec.2  NM  km 
25 R  Gto Ato Ato Ato  120 120 130 140  39,2 44,3 1) 47,5 1) 49,8  - 2,3 - 1,8 - 2,3 - 1,8  1,19 1,02 0,78 0,56  2,210 1,895 1,450 1,045 
25 L  G Hto Hto Hto  120 120 130 140  41,0 48,9 1) 50,0 1) 49,0 1)  - 2,4 - 1,5 - 2,4 - 2,5  1,13 0,87 0,69 0,59  2,100 1,610 1,290 1,100 
07 R  Cto Cto Cto  120 130 140  44,8 1) 48,1 1) 50,0  - 1,8 - 2,3 - 1,7  1,00 0,76 0,56  1,850 1,410 1,045 
07 L  Mto Mto Mto  120 130 140  47,1 1) 50,0 1) 49,2 1)  - 1,6 - 2,1 - 2,1  0,93 0,69 0,59  1,720 1,290 1,085 
Hto (07) planned  120  42,7  - 1,9  1,08  2,000 

1) transition zone calculated without braking