Gap measurement tool assembly, system, and method for measuring a gap between mating parts of a structure

A gap measurement system for measuring a gap at a through hole between mating parts of a structure, the gap measurement system comprising:

• a gap measurement tool assembly configured for insertion into the through hole and for alignment with the gap between the mating parts, the gap measurement tool assembly comprising:
• a gap measurement tool comprising a first end, a second end, and a body formed between the first end and the second end, the body comprising:
• a hollow inner channel;
• an exterior annular crevice;
• a first exterior annular groove having a cross-hole intersected by the hollow inner channel;
• and
• a second exterior annular groove positioned distal to the first exterior annular groove;
• a first seal element fitted around the exterior annular crevice;
• a second seal element fitted around the second exterior annular groove;
• and
• a third seal element inserted into a portion of the hollow inner channel at the second end of the gap measurement tool;
• an air gage system coupled to the first end of the gap measurement tool;
• and
• an air supply source having compressed air, the air supply source coupled to the air gage system,
• wherein when the gap measurement tool assembly is inserted into the through hole and through the mating parts, so that the cross-hole is aligned with the gap, and an entry side and an exit side of the through hole are sealed, the compressed air is passed through the gap, via the hollow inner channel, and the air gage system takes a measurement of one of, a back pressure, an air flow, or a differential pressure, and correlates the measurement to a predetermined gap measurement, to determine a gap size of the gap at the through hole between the mating parts of the structure.

A method for measuring a gap at a through hole between mating parts of a structure, the method comprising the steps of:

• providing a gap measurement tool assembly comprising:
• a gap measurement tool comprising a first end, a second end, and a body formed between the first end and the second end, the body comprising:
• a hollow inner channel;
• an exterior annular crevice;
• a first exterior annular groove having a cross-hole intersected by the hollow inner channel;
• and
• a second exterior annular groove positioned distal to the first exterior annular groove;
• a first seal element fitted around the exterior annular crevice;
• a second seal element fitted around the second exterior annular groove;
• and
• a third seal element inserted into a portion of the hollow inner channel at the second end of the gap measurement tool;
• coupling the gap measurement tool assembly to an air gage system and an air supply source having compressed air, to obtain a gap measurement system;
• inserting the gap measurement tool assembly into the through hole and through the mating parts, so that the cross-hole of the gap measurement tool is aligned with the gap at the through hole between the mating parts, and an entry side and an exit side of the through hole are sealed;
• passing the compressed air through the hollow inner channel of the gap measurement tool and into the gap;
• using the air gage system to take a measurement of one of, a back pressure, an air flow, or a differential pressure;
• and
• correlating the measurement to a predetermined gap measurement, to determine a gap size of the gap at the through hole between the mating parts of the structure.