Now you can do dinner in Nairobi and have breakfast in New York

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

10 October 2018

Still on Kenya Airways…our national flag carrier is scheduled to start direct flights to the United States of America starting from 28 October this year. During a dinner party hosted by the airline in New York last month, the Cabinet Secretary for foreign affairs, Monica Juma, stated that “you shall be able to take break fast in New York and do dinner in Nairobi”.

Will that really be possible?

The air distance from Nairobi to New York is 11,840km. Kenya Airways plans to use the Boeing 787-8 Dreamliner aircraft which cruises at about 900km/h. Therefore, the flight time will be 11,840/900 = 13 hours. Allowing one hour at each airport for taxiing, queuing etc. brings the total flight time to 15 hours.

So, if you have breakfast in New York at, say, 7am, then start off at 10am; what time will you get to Nairobi?

The first step in this solving this problem is to find out what time it will be in Nairobi when you start your journey at 10am in New York. That depends on the season, but, right now (October) New York is 7 hours behind Nairobi.

Therefore, at 10am in New York, it is 17:00h in Nairobi; that is, 5pm. In other words; it is almost dinner time in Kenya and you haven’t started your 15-hour journey!

Adding 15 hours to 5pm takes us to 8am the following day. So, it turns out that you will have breakfast in New York on one day, and another breakfast in Nairobi the next day.

Without doing any further calculations, it is easy to see that if you start the journey after dinner in New York, you will arrive in Nairobi in time for dinner the following day.

Perhaps the Cabinet Secretary was remembering the days of the supersonic jet – the Concorde. This aircraft had a cruising speed of about 2,100km/h. So, this trip would last just 7.5h (after adding the usual two hours of taxiing and queuing).

If the journey started at 10am in New York, you would arrive in Nairobi at 1:30am that night. So, if we adjusted departure time to 6am, the arrival would be 8.30pm – just in time for dinner.

But there is one big problem with the Concorde: it can’t fly direct from New York to Nairobi! Its range is only 7,200km; that is 5,000km short of the journey. It would need to stop somewhere on the West African coast to add fuel.

But you might think that all this is just academic calculations: the timetable for the New York flight is already out. Flights from the USA are scheduled to take off at 12pm and arrive Nairobi at 10:30am the following day. The journey from Kenya starts at 11:25pm and arrives at 6:25am the following day.

Perhaps the CS should have said “you shall be able to have dinner in Nairobi and take breakfast in New York”.