C++/g++ cygwin_exception::open_stackdumpfile: Dumping stack trace to *.exe.stackdump

Here's my main in Airport.cpp:

#include <iostream>
#include "Airport_Queue.h"
#include "Airplane.h"
#include <stdlib.h>

int main(){

    Airplane *b = new Airplane(true);
    (*b).come();
    (*b).go();
    std::cout << "........." << std::endl;
    Airport_Queue *landing_queue = new Airport_Queue(5);
    Airplane *a0 = new Airplane(true);
    (*landing_queue).enqueue(a0); //error here
    //(*landing_queue).dequeue();

return 0;

This is my Airport_Queue.cpp

#include "Airport_Queue.h"
Airport_Queue::Airport_Queue(unsigned size){
    Airplane** a = new Airplane*[size];
    size = 0;
    head = tail = 0;
}
Airport_Queue::~Airport_Queue(){
    for (size_t i = 0; i < sizeof(a); i++){
        delete a[i];
    }
    delete [] a;
}
void Airport_Queue::enqueue(Airplane* airplane){
    if (!(*this).isFull()){
        a[tail] = airplane;
        (*a[tail]).come();
        tail = (tail+1) % sizeof(a);
        size++;
    }
    else{
        std::cerr << "Queue is full." << std::endl;
    }
}
Airplane* Airport_Queue::dequeue(){ 
    if (!(*this).isEmpty()){
        size_t x = head;
        (*a[head]).go();
        head = (head+1) % sizeof(a);
        size--;
        return a[x];
    }
    else{
        std::cerr << "Queue is empty." << std::endl;
        return NULL;
    }   
}
bool Airport_Queue::isEmpty(){
    if (size == 0)
        return true;
    else
        return false;
}
bool Airport_Queue::isFull(){
    if (size == sizeof(a))
        return true;
    else
        return false;
}
int Airport_Queue::getSize(){
    return size;
}

I also have a class called Airplane. The command I use to compile and link is g++ -std=c+11 -Wall -g -o airport Airport.cpp Airplane.cpp Airport_Queue.cpp How can I fix this run-time error? The error is when I call enqueue. Then I get

4 [main] airport 3796 cygwin_exception::open_stackdumpfile: Dumping stack trace to airport.exe.stackdump

Please. And thank you.