Twice the double European champions have travelled to Belfast and both times they have come home with their tails between their legs. Now Flood is planning to turn the tide of history and ensure his side get off to a better start than they managed last year, when they were turned over in Toulouse.
"Games in this tournament don't come much harder than having to face Ulster at Ravenhill on a Friday night and we know it is going to be a difficult start. It is as hard a place to go as any in Europe," said Flood.
"But while we know what lies ahead of us, no team can afford to take Leicester Tigers lightly. We have a great pedigree in the Heineken Cup and, even though we haven't won it since 2002, we have been in two more finals since then.
"We've had two very bad nights at Ravenhill down the years. We lost 41-7 in a Pool match in 2012 and I believe it was even worse back in 2003 when Martin Johnson's side were beaten 33-0. They were battered by all accounts in that first game, but turned it around with a comprehensive 49-7 win six days later back at Welford Road.
"I didn't go to Belfast two seasons ago, but it was very disappointing. They played very well and we were poor. We can't afford for that to happen again."
As much as Flood is aware of the strength of the Johan Muller inspired pack that propelled Ulster into the Heineken Cup final in 2012 and the RaboDirect PRO2 final earlier in the year, he also knows there is plenty of potential behind the scrum.
Andrew Trimble, Tommy Bowe and Craig Gilroy provide real cutting edge, while Luke Marshall and Jared Payne add further threat. But Flood believes it is the home half-backs that will be the ones to watch.
"Ulster have a strong pack and have great tacticians behind to dictate their game. Ruan Pienaar will be coming into the tournament off the back of another strong performance with South Africa in the Rugby Championships and Paddy Jackson is a player who is simply going to get stronger and stronger over time," said Flood.
"We know all about tough away games because we had to travel to Toulouse first up last season and lost 23-9. We had to come home and make amends for that defeat by beating the Ospreys at Welford Road in Round 2."
Last season the Tigers were drawn in the 'Pool of Death' with Toulouse and the Ospreys, and this season is not much better with 2003 quarter-finalists Montpellier also in the mix. That's why a good start is going to be crucial to Flood's hopes to reach a sixth final.
"We know from their recent results, including massive wins over Toulouse and Clermont and a draw with Toulon, how strong Montpellier are going to be this season and nobody can afford to take Benetton Treviso lightly. We've had some close shaves against them in the past," said Flood
"There is certainly a burning desire within the squad to reach the final again. It has been a frustrating 11 years waiting to bring the Heineken Cup back to Welford Road after those back to back triumphs in 2001 and 2002.
"Last year we had to go to Toulon in the quarter-finals, but we all felt we could have come away with a result there. We are a club that is capable of winning on the road in the big games.
"When you look at this season then you'd expect Clermont to be up there again having been one of the best teams in Europe in recent years. Toulon have built on the squad that won the title last year and they look like they will attack it again.
"There are two or three good English clubs who will be pressing and the Ospreys will be a threat. Then you have to start thinking about the Irish provinces who have such a rich history in this tournament.
"That's what makes the Heineken Cup so good - you simply can't pick a winner."