Peter William Bilsborough, a sergeant who served with the Royal Air Force Volunteer Reserve, was one of six fallen war heroes who had their headstones targeted at the burial ground in Shipley this week.
The damage was discovered as the world commemorated the 75th anniversary of the D-Day landings.
Now Peter's niece Julie Watson has spoken out, calling the vandalism "absolutely despicable".
Julie, a nurse who lives in Wakefield, said: "It's horrible that the people that are responsible for this are able to walk around freely, but those who died cannot because they sacrificed everything for us.
"It's absolutely despicable, and I'm disgusted."
The 63-year-old added: "My uncle died before I was born, but he has been in my life because I have put the time in to researching him and finding out about what he did in the Second World War."
Sgt Bilsborough, a rear bomber in the Force, was just 21 when he was killed as the Wellington Bomber he was flying suffered engine failure and he was forced to ditch, tragically drowning at sea.
Ms Watson said police suspect the graves were damaged on Monday or Tuesday, but that she didn't find out until the D-Day anniversary itself.
"I'm very pro-police, and I think they are going to catch whoever is responsible and bring them to justice.
"I think this must have been a targeted attack - the graves stand out because they are white, and whoever has done this clearly had some sort of equipment to help them."
Others graves targeted included First World War figures like Captain Crossley, of the West Yorkshire Regiment, who died in March 1919, gunner Henry Asquith Hardy, who died in January 1919, and Mr Stephenson, a sapper with the Royal Engineers.
Arthur Sheard, a driver with the Royal Field Artillery who died in May 1918 and was buried alongside his four-year-old daughter, who died two days after him, also had his grave damaged.
One woman who walks through the graveyard regularly, but did not wish to be named, said the incident was "shocking".
She said: "It's just awful to consider the lack of thought that has gone into this damage. The fact that it happened so close to D-Day is what I think has shocked people the most.
"It just makes you despair, really."