I really do not have the time to go back six weeks and check.
However going back 20 days, which is more readily available, we can see that the route has been on a tear the last few weeks with TK cycling through 15 different aircraft on that route, 3 times flying A330's for whatever capacity reasons, and the other 17 A321's, of which 2 were JR's, JMN was flown twice, which is NOT one with new Biz class. But I will give it to you, it would seem that they have flown several brand spanking new planes on the route over the last three weeks such as JTI which has only been in passenger service for about 8 weeks and JTL which has been in service for less than a month, and JSR which is about 10 months in Pax service and has done the route 3 times.... I assure you that this is frequency of decent biz class is a new happening and not something that was real as recently as the last flying season.
Heathrow (LHR) - Ataturk (IST) TC-JRI 2016-09-06 21:48:13
Heathrow (LHR) - Ataturk (IST) TC-JIV 2016-09-05 21:33:08
Heathrow (LHR) - Ataturk (IST) TC-JRA 2016-09-04 21:41:07
Heathrow (LHR) - Ataturk (IST) TC-JTN 2016-09-03 22:24:09
Heathrow (LHR) - Ataturk (IST) TC-JSU 2016-09-02 22:12:07
Heathrow (LHR) - Ataturk (IST) TC-JIM 2016-09-01 21:28:10
Heathrow (LHR) - Ataturk (IST) TC-JSR 2016-08-31 21:39:10
Heathrow (LHR) - Ataturk (IST) TC-JTL 2016-08-30 21:51:12
Heathrow (LHR) - Ataturk (IST) TC-JSO 2016-08-29 21:25:10
Heathrow (LHR) - Ataturk (IST) TC-JSR 2016-08-28 21:29:11
Heathrow (LHR) - Ataturk (IST) TC-JSN 2016-08-27 21:31:13
Heathrow (LHR) - Ataturk (IST) TC-JSV 2016-08-26 21:55:14
Heathrow (LHR) - Ataturk (IST) TC-JSZ 2016-08-25 21:25:41
Heathrow (LHR) - Ataturk (IST) TC-JSU 2016-08-24 22:09:08
Heathrow (LHR) - Ataturk (IST) TC-JTI 2016-08-23 20:57:09
Heathrow (LHR) - Ataturk (IST) TC-JMN 2016-08-22 21:21:11
Heathrow (LHR) - Ataturk (IST) TC-JTE 2016-08-21 21:14:09
Heathrow (LHR) - Ataturk (IST) TC-JMN 2016-08-20 22:46:07
Heathrow (LHR) - Ataturk (IST) TC-JSG 2016-08-19 21:55:09
Heathrow (LHR) - Ataturk (IST) TC-JSR 2016-08-18 21:49:06