All the known internal codes for mainline aircraft
 

Going to Venice this week, it started out as a 737 and we chose our seats, then it changed to an A319 and we re-picked seats again, now its at T-72 and I went online to check seats and is shows "M9A".

Do you think this could be a Titan operated flight?

I Googled it and "M9A" is "Airbus A319 – Former BMI Airframe (G-DBC*)".

It came from this intriguing site!

Good effort - cheers!

Was looking at the cheap upgrade but if it is a BMi aircraft then there is little point because it will have the recaro seats.

I believe this is the full list with credit to baw217:

18A - Airbus A318
19B - Airbus A319 (G-EU**). Can also be 19C.
M9A - Airbus A319 (G-DBC*)
M0A - Airbus A320 (G-MID*)
B0A - Airbus A320 (G-MEDK)
20D - Airbus A320 (G-EU**/G-TT**)
21A - Airbus A321 (G-EUX*)
M1A - Airbus A321 (G-MED*)

73A - Boeing 737-400
74C - Boeing 747-400 (Mid-J). Can also be 74D, 74I or 74J.
74G - Boeing 747-400 (High-J). Can also be 74A
47A - Boeing 747-400 (High-J Lite). Can also be 47B, 74E or 74K.
76B - Boeing 767-300 (Short Haul)
76Z - Boeing 767-300 (Long Haul)
77X - Boeing 777-200 (G-ZZZ*)
77A - Boeing 777-200IGW (G-VII* 3 Class Configuration)
77C - Boeing 777-200IGW (G-VII* or G-RAES 4 Class Configuration) Can also be 77D or 77E.
77F - Boeing 777-200ER (G-YMM* 4 Class Configuration)
77S - Boeing 777-200ER (G-YMM* 3 Class Configuration)
77N - Boeing 777-300ER

ER7 - Embraer 170
ER9 - Embraer 190
S20 - SAAB 2000

75V - Boeing 757-200 (F-HAV*)
75X - Boeing 757-200 (F-GPEK)

I've got 73A and 734 operating my LGW-ALC return this weekend, so presumably there's a further differentiation between 737-400s as well?

Flights a long way out will typically show the normal aircraft identifier (734, 744, etc) and then a few days before it will change to the specific configuration (73A, 74C, 74G, etc).

You will likely see your inbound change to 73A between now and OLCI.

In god knows how many years of flying BA I have never noticed the aircraft designator change. Thanks for the info! ^

This is the kind of stuff FT is great for. Thanks for the info, nux and Dave_C!

I think that this has only started happening recently.

I've seen it on ExpertFlyer a fair bit within t-72 of a flight. Really only ever paid attention to the 777 designators though.

It's been on EF for a long time, but it's only recently started showing on ba.com.

The change seems to occur at the time when the flight is edited on the day three days before the flight (eg Monday for a Thursday flight). All of the other T-3d things seem to happen at this time.

discovered it on my flight to PFO last Sat....

It was on an airbus (ex BMI as we had the middle seat in CE covered with the drinks shelf contraption......)

Great stuff! I am on M0A - Airbus A320 on Friday, and there's a distinct B-seat on the front row of economy. Is this a feature of the ex-BMI aircaft?

There is a bassinet at the front attached to the bulhead but that's all I can think of. I personally think the interior of the BMi airbus looked much nicer, I don't know if they stripped the brown recaros out yet though as haven't flown on one since they fully merged

If you mean at the front of ET, then yes there is! With their convertible seats in CE the B and E seats are squished leaving the aisle in-line, so no need to alter the first row of ET.