The Embrs must be only at certain times of the day - or on certain days. In the good old days DC9's then B737's flew the route. Only last year I was on a BMI A321 on lunch time flight from LHR to GLA. I assume they still fly a mixture of Airbus on it - thats why i find it amazing they have gone to a commuter jet on Heathrow. Should bring back the hot breakfasts, lunch and dinners!!...when i think back now the cabin staff were great then!
Nivsy