Towards the end of Revelation, Jesus appears to approach earth twice (Rev 14:14-16; 19:11-14). Which one is His second coming?

Then I looked, and behold, a white cloud, and sitting on the cloud was one like a son of man, having a golden crown on His head and a sharp sickle in His hand. And another angel came out of the temple, crying out with a loud voice to Him who sat on the cloud, "Put in your sickle and reap, for the hour to reap has come, because the harvest of the earth is ripe." Then He who sat on the cloud swung His sickle over the earth, and the earth was reaped. (Rev 14:14-16)

And I saw heaven opened, and behold, a white horse, and He who sat on it is called Faithful and True, and in righteousness He judges and wages war. His eyes are a flame of fire, and on His head are many diadems; and He has a name written on Him which no one knows except Himself. He is clothed with a robe dipped in blood, and His name is called The Word of God. And the armies which are in heaven, clothed in fine linen, white and clean, were following Him on white horses. (Rev 19:11-14)

Jesus Himself defines His second coming to His disciples. He will come: 1) after the tribulation, 2) when both day and night is dark, 3) on the clouds, 4) with power and glory, 5) a trumpet sounds, and 6) His angels will gather Believers on earth and in heaven. Because the apostle John is recording Jesus' second coming from a heavenly perspective (Rev 14:1-20), he records all of the above heavenly elements except the earthly phenomena when both day and night are dark.

"But immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from the sky, and the powers of the heavens will be shaken. And then the sign of the Son of Man will appear in the sky, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of the sky with power and great glory. And He will send forth His angels with a great trumpet and they will gather together His elect from the four winds, from one end of the sky to the other." (Matt 24:29-31)

"But in those days, after that tribulation, the sun will be darkened and the moon will not give its light, and the stars will be falling from heaven, and the powers that are in the heavens will be shaken. Then they will see the Son of Man coming in clouds with great power and glory. And then He will send forth the angels, and will gather together His elect from the four winds, from the farthest end of the earth to the farthest end of heaven." (Mark 13:24-27)

"There will be signs in sun and moon and stars, and on the earth dismay among nations, in perplexity at the roaring of the sea and the waves, men fainting from fear and the expectation of the things which are coming upon the world; for the powers of the heavens will be shaken. Then they will see the Son of Man coming in a cloud with power and great glory. But when these things begin to take place, straighten up and lift up your heads, because your redemption is drawing near." (Luke 21:25-28)

The apostle Paul's accounts support the view that Jesus' second coming is associated with rapture (the gathering of Believers on earth and in heaven), which is the beginning of the process of resurrection (1 Cor 15:42-54)

Now I say this, brethren, that flesh and blood cannot inherit the kingdom of God; nor does the perishable inherit the imperishable. Behold, I tell you a mystery; we will not all sleep, but we will all be changed, in a moment, in the twinkling of an eye, at the last trumpet; for the trumpet will sound, and the dead will be raised imperishable, and we will be changed. For this perishable must put on the imperishable, and this mortal must put on immortality. (1 Cor 15:50-53)

For the Lord Himself will descend from heaven with a shout, with the voice of the archangel and with the trumpet of God, and the dead in Christ will rise first. Then we who are alive and remain will be caught up together with them in the clouds to meet the Lord in the air, and so we shall always be with the Lord. (1 Thes 4:16-17)

When Jesus spoke of His return, His second coming preceded the distribution and dispensation of God's bowls of wrath (Rev 15:5-8; 16:1-21). It is only after God's wrath is completely finished (Rev 15:1) and the marriage / wedding feast has taken place (Rev 19:7-9) that Jesus' second appearance (not Second Coming) is on a white horse leading a heavenly army to Armageddon. The apostle John makes a keen observation, he saw "heaven opened":

And I saw heaven opened, and behold, a white horse, and He who sat on it is called Faithful and True, and in righteousness He judges and wages war. His eyes are a flame of fire, and on His head are many diadems; and He has a name written on Him which no one knows except Himself. He is clothed with a robe dipped in blood, and His name is called The Word of God. And the armies which are in heaven, clothed in fine linen, white and clean, were following Him on white horses. (Rev 19:11-14)

Throughout the Bible, when "heaven opened," the heavenly vision was only witnessed by the individual for whom heaven opened. This suggests that the apostle John's vision of Jesus riding on a white horse, adorned for war, leading a heavenly army may not have been widely perceived by those on earth.

Now it came about in the thirtieth year, on the fifth day of the fourth month, while I was by the river Chebar among the exiles, the heavens were opened and I saw visions of God. (On the fifth of the month in the fifth year of King Jehoiachin's exile, the word of the Lord came expressly to Ezekiel the priest, son of Buzi, in the land of the Chaldeans by the river Chebar; and there the hand of the Lord came upon him.) (Ezek 1:1-3)

But Jesus answering said to him, "Permit it at this time; for in this way it is fitting for us to fulfill all righteousness." Then he *permitted Him. After being baptized, Jesus came up immediately from the water; and behold, the heavens were opened, and he saw the Spirit of God descending as a dove and lighting on Him, and behold, a voice out of the heavens said, "This is My beloved Son, in whom I am well-pleased." (Matt 3:15-17; Luke 3:20-22)

But being full of the Holy Spirit, he gazed intently into heaven and saw the glory of God, and Jesus standing at the right hand of God; and he said, "Behold, I see the heavens opened up and the Son of Man standing at the right hand of God." But they cried out with a loud voice, and covered their ears and rushed at him with one impulse. (Acts 7:55-57)

After these things I looked, and behold, a door standing open in heaven, and the first voice which I had heard, like the sound of a trumpet speaking with me, said, "Come up here, and I will show you what must take place after these things." Immediately I was in the Spirit; and behold, a throne was standing in heaven, and One sitting on the throne. And He who was sitting was like a jasper stone and a sardius in appearance; and there was a rainbow around the throne, like an emerald in appearance. (Rev 4:1-3)

While Jesus does not mention His leading of the heavenly army in the gospel accounts regarding His return nor John providing any details of the war at Armageddon, there is little doubt as to the outcome of Jesus' judgment.