Some of this posted elsewhere but generally helpful.
A plan of the revelation.
The revelation can be divided into 7 sections :
- The prologue or introduction. | 1:1 ~ 1:3
- The messages to the seven churches.
The things that were seen.
Introduction | 1:4 ~ 1:20
Seven Messages | 2:1 ~ 3:22
- Activity in heaven.
The things that are.
Jesus as Messenger | 4:1 ~ 5:14
- The prophetic section.
The things that will be.
Seal 1 ~ 6 | 6:1 ~ 6:17
The Reedemed | 7:1 ~ 7:17
Seal 7 | 8:1 ~ 8:6
Trumpet 1 ~ 4 | 8:7 ~ 8:12
Warning of 3 Woes | 8:13
Trumpet 5 | Woe 1 | 9:1 ~ 9:12
Trumpet 6 | 9:13 ~ 9:21
7 Thunders | 10:1 ~ 10:11
Woe 2 | 11:1 ~ 11:14
Trumpet 7 | 11:15 ~ 11:19
Woman & Son & Dragon | Woe 3 | 12:1 ~ 12:17
Sea Beast | 13:1 ~ 13:10
Earth Beast | 13:11 ~ 13:18
The Redemed & Judgement | 14:1 ~ 14:20
Introduction to 7 Plagues | 15:1 ~ 16:1
Vial 1 ~ 6 | 16:2 ~ 16:12
3 Frogs & Armageddon | 16:13 ~ 16:16
Vial 7 | 16:17 ~ 16:21
Beast Punished | 17:1 ~ 19:21
- The 1000 Years | 20:1 ~ 20:15
- The New Jerusalem | 21:1 ~ 22:5
- Warning & Promise | 22:6 ~ 22:21
A chronological progression.
There is a chronological progression with the important caveat that the 7th seal contains all 7 trumpets and the 7th trumpet contains all 7 vials.
Visually :
<----- Seal 1 - 6 -----><-------------------- Seal 7 -------------------->
<----- Trumpet 1 - 6 -----><----- Trumpet 7 ----->
<----- Vial 1 - 7 ----->
Reoccurrence of events.
The overlaying of these 3 schemes allows for a repetition of certain events.
For instance, the 7th Vial contains these :
The seventh angel poured out his bowl into the air ... “It is done!”
Then there came flashes of lightning, rumblings, peals of thunder and a severe earthquake. No earthquake like it has ever occurred since mankind has been on earth, so tremendous was the quake.
Revelation 16:17, 18 NIV
This 7th Vial being the culmination of all things at the return of christ - the “It is done!” and prepatory verses 16-17 - being signal events are also described in the 7th Trumpet :
The seventh angel sounded his trumpet, and there were loud voices in heaven ...
And there came flashes of lightning, rumblings, peals of thunder, an earthquake ...
Revelation 11:15, 19 NIV
This 7th Vial and 7th Trumpet also being noted in the 7th Seal :
When he opened the seventh seal ...
... there came peals of thunder, rumblings, flashes of lightning and an earthquake.
Revelation 8:1, 5 NIV
This in effect causes a severe time compression and expansion in the narrative which can be disconcerting when not understood.
Duplication of descriptions.
It should also be noted that disparate events often share similar descriptors.
For instance, the 7th Vial - the return of christ - contains this :
Every island fled away and the mountains could not be found.
Revelation 16:20 NIV
A similar descriptor being found in the 6th Seal :
The heavens receded like a scroll being rolled up, and every mountain and island was removed from its place.
Revelation 6:14 NIV
This "receding like a scroll" being the events relating to the disappearance of the pagan Roman empire (the dragon) and eventual appearance of "the beast" under Constantine. The "heavens" signifying action in authority systems.
The mountains and islands normally being somewhat protected from events in the Roman polity by either their prominence or isolation. The events of the "christianizing" of Rome were so significant as to effect all corners of the empire.
Likewise the global effect of the return of christ.
The Seals.
No doubt a significant issue with the Revelation is a failure to walk through the events in the prophetic section systematically. Taken in isolation, without an awareness of biblical symbols generally, and without regard to other concomitant prophecy - especially Daniel chapters 2 and 7 - will inevitably lead nowhere.
The example from the question turning locusts into attack helicopters. A reasonable guess, considering Revelation describing future events in the language of its day, but wrong.
The solution being to start from the start and walk systematically through the symbols.
Fortunately we are provided with as clear an indication as to the timespan of the Revelation as we are Nebuchadnezzars image.
The Revelation ... the things which must needs come to pass with speed,––and he shewed them by signs ...
Revelation 1:1 Rotherham
The events to be looked for being necessarily relevant to all faithful from the withdrawal of the spirit gifts until the return of Jesus.
Amos 3:7 and John 16:13 and Acts 2:38-39 and 1 Corinthians 8:9 and 2 Peter 1:19 etcetera.
Four Horses of the Apocalypse.
The shared symbology of the four horses being the horse as representive of the Roman body politic, a.k.a. the Roman empire, and the rider signifying the events extant at that point, ultimately affecting the colour, or state, of that empire.
The white horse.
"I looked, and there before me was a white horse! Its rider held a bow, and he was given a crown, and he rode out as a conqueror bent on conquest." (verse 2 NIV)
White being symbolic of peace within the Roman empire generally. The bow without arrows symbolic of the non-militant spread of christianity. The crown being στέφανος as presented at the crucifixion. This "conquest" of christianity being at the price of much persecution.
Five Good Emperors.
"... that their rule was a time when "the Roman Empire was governed by absolute power, under the guidance of wisdom and virtue" ... these benevolent monarchs and their moderate policies were unusual and contrasted with their more tyrannical and oppressive successors.'
https://en.m.wikipedia.org/wiki/Nerva%E2%80%93Antonine_dynasty
The red horse.
"Then another horse came out, a fiery red one. Its rider was given power to take peace from the earth and to make people kill each other. To him was given a large sword." (verse 4 NIV)
Red being symbolic of bloodshed. The "large sword" being properly "great dagger" - μάχαιρα - an instrument for assasination.
Year of the Five Emperors.
https://en.m.wikipedia.org/wiki/Year_of_the_Five_Emperors
The black horse.
"I looked, and there before me was a black horse! Its rider was holding a pair of scales in his hand." (verse 5 NIV)
Black symbolic of grief and mourning. The scales - elaborated in the subsequent verse - representing the decline of the Roman economy following excess and severe taxation and the crippling effects on food production.
Five emporers of excess and taxation.
"All land, including imperial estates, which was not under cultivation in Italy and the provinces, was to be given over to private individuals to work, with security of tenure and a ten-year tax exemption."
https://www.cambridge.org/core/books/abs/cambridge-ancient-history/severan-dynasty/E77FF1B3F3C5B7D9EDC0109D5B74EE8B
"... around 20,000 men and women were killed or proscribed on this charge during this time."
https://en.m.wikipedia.org/wiki/Geta_(emperor)
"Domestically, Caracalla became known ... for the introduction of a new Roman currency named the antoninianus, a sort of double denarius; and for the massacres he ordered, both in Rome and elsewhere in the empire."
https://en.m.wikipedia.org/wiki/Caracalla
https://en.m.wikipedia.org/wiki/Antoninianus
https://en.m.wikipedia.org/wiki/Constitutio_Antoniniana
"This shortfall left Rome in a dire fiscal situation that Macrinus needed to address."
https://en.m.wikipedia.org/wiki/Macrinus
"... he suffered one of the worst reputations among Roman emperors."
"Elagabalus was not a tyrant, but he was an incompetent, probably the least able emperor Rome had ever had."
"Under Elagabalus, the gradual devaluation of Roman aurei and denarii continued ..."
https://en.m.wikipedia.org/wiki/Elagabalus
"Alexander's reign was also characterized by a significant breakdown of military discipline."
https://en.m.wikipedia.org/wiki/Severus_Alexander
The pale horse.
"I looked, and there before me was a pale horse! Its rider was named Death, and Hades was following close behind him. They were given power over a fourth of the earth to kill by sword, famine and plague, and by the wild beasts of the earth." (verse 8 NIV)
The pale horse - χλωρός - being the colour of death. The sword in this instance being ῥομφαίᾳ as used in war. The "wild beasts" being the barbarians who for the first time directly threatened Rome - the fourth part of the empire, hitherto untouched.
See summary here :
https://www.cambridge.org/core/books/abs/cambridge-ancient-history/maximinus-to-diocletian-and-the-crisis/E05D7B1DEAD0E01B17972C0636743DF5
https://en.m.wikipedia.org/wiki/Year_of_the_Six_Emperors
https://en.m.wikipedia.org/wiki/Crisis_of_the_Third_Century
https://en.m.wikipedia.org/wiki/Tetrarchy
The fifth seal.
"When he opened the fifth seal ..." (verse 9 NIV)
"The Diocletianic or Great Persecution was the last and most severe persecution of Christians in the Roman Empire."
https://en.m.wikipedia.org/wiki/Diocletianic_Persecution
The sixth seal.
"I watched as he opened the sixth seal. There was a great earthquake. The sun turned black like sackcloth made of goat hair, the whole moon turned blood red, and the stars in the sky fell to earth ... The heavens receded like a scroll being rolled up, and every mountain and island was removed from its place."
Revelation 6:12-14 NIV
The earthquake signifying the massive shift from pagan Rome to "christianized" Rome under Constantine.
https://en.m.wikipedia.org/wiki/Constantine_the_Great_and_Christianity
The sun representing the embodiment of imperial power, until that time pagan, disappears.
This disappearing of the sun or imperial authority, eclipsed by theocracy or "christianity" again being found in Constantine :
'... a vision that Constantine had while marching at midday in which "he saw with his own eyes the trophy of a cross of light in the heavens, above the sun, and bearing the inscription, In Hoc Signo Vinces" ("In this sign thou shalt conquer").'
https://en.m.wikipedia.org/wiki/Constantine_the_Great
The moon, representing the ecclesiastical systems of that pagan system are stained through war and violence. The stars, or "leading lights" that received power from that pagan system and its emporer and ecclesiastical systems "fall to the earth".
These heavens in their entirety "receded like a scroll being rolled up". All mountains and islands, nominally protected from upheaval by prominence and isolation, affected.
This description forming the backdrop to the introduction in chapter 12 of Constantine and the beast of chapter 13.
The seventh seal.
"When he opened the seventh seal, there was silence in heaven for about half an hour." (8:1 NIV)
The events of the 6th Seal culminating in :
'... the great civil war of 324 ... the war as a battle between Christianity and paganism ...'
'Thus Constantine became the sole emperor of the Roman Empire.'
https://en.m.wikipedia.org/wiki/Constantine_the_Great
There following a period of great stability and elevation of "christianity" in the empire until shortly after the death of Constantine some 15 or so years later.
A day for a year being 360 divided by 12 (in this case the day being the hours of the sun) or 15, and ὡς being "about".
The Four Trumpets.
Thus begins the barbarian predations on the western empire. These four trumpets each describing events against a third of that empire.
The earth being the central Italian division centred in Rome. The sea being the Mediterranean. The rivers being the European heartland where the major rivers are found. The heavens again being the Italian third but in this instance there being a final blow to the authority of the western Empire.
Trumpet first.
"The first angel sounded his trumpet, and there came hail and fire mixed with blood, and it was hurled down on the earth. A third of the earth was burned up, a third of the trees were burned up, and all the green grass was burned up." (8:7 NIV)
Alaric's efforts concentrated toward the Italian third. The grass representing the people and the trees the rulers, both decimated by his invasion.
'Alaric ... marched into Italy ... He is responsible for the sack of Rome in 410; one of several notable events in the Western Roman Empire's eventual decline.'
https://en.m.wikipedia.org/wiki/Alaric_I
And not co-incidentally :
'... the envoys boasted to him that the Roman people were trained to fight and ready for war, Alaric laughed at them and said, "The thickest grass is easier to cut than the thinnest."'
https://en.m.wikipedia.org/wiki/Sack_of_Rome_(410)
Trumpet second.
"The second angel sounded his trumpet, and something like a huge mountain, all ablaze, was thrown into the sea. A third of the sea turned into blood, a third of the living creatures in the sea died, and a third of the ships were destroyed." (8:8-9 NIV)
'The Vandals under Gaiseric invaded Africa in 429 ... to seize Carthage, the once most treasured province of Rome.'
This Carthagian "mountain" becoming a base of operations and being effectively "thrown into the sea" :
'Once in power ... naval raids were routinely launched on Romans in the Mediterranean.'
https://en.m.wikipedia.org/wiki/Carthage
'... a large fleet ... exerting effective control over much of the western Mediterranean.'
'Gaiseric moved a large seaborne force from Carthage to Italy and sacked the city in a more thorough manner than even Alaric's Goths had ...'
https://en.m.wikipedia.org/wiki/Gaiseric
Trumpet third.
"The third angel sounded his trumpet, and a great star, blazing like a torch, fell from the sky on a third of the rivers and on the springs of water— the name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter." (8:10-11 NIV)
Attila the Hun coming from outside the western empire having geatest effect against the barbarian third.
'... he was one of the most feared enemies of the Western and Eastern Roman Empires. He crossed the Danube twice ...'
'... He also attempted to conquer Roman Gaul (modern France), crossing the Rhine in 451 ...'
https://en.m.wikipedia.org/wiki/Attila
Trumpet fourth.
"The fourth angel sounded his trumpet, and a third of the sun was struck, a third of the moon, and a third of the stars, so that a third of them turned dark. A third of the day was without light, and also a third of the night." (8:12 NIV)
Until this point the incursions had been against the people of the Italian peninsula, upon the Mediterranean, into the heart of riverine Europe, now the "heavens" or ruling sytems of the western empire were displaced.
'Odoacer ... a barbarian soldier and statesman ... deposed the Western Roman ... emperor ... and became the ruler of Italy (476–493).'
'The Eastern Emperor then conferred upon Odoacer the title of Patrician and granted him legal authority to govern Italy in the name of Rome, as dux Italiae.'
https://en.m.wikipedia.org/wiki/Odoacer
The First Woe Fifth Trumpet.
The fifth angel sounded his trumpet ... (9:1 NIV)
Now that the western empire has been largely subdued by the barbarians attention shifts in the 5th Trumpet (and 6th) to the eastern empire centred in Constantinople.
... and I saw a star that had fallen from the sky to the earth. (verse 1)
The "star" indicating much as it does today, a personage of significant prominence.
The πεπτωκότα is in the past tense - at the time of the vision, this person had already fallen.
'... when Abu Talib, his uncle who supported him ... died, Muhammed was left with no protection. The repercussions of the death of Abu Talib were in the political sphere.'
https://en.m.wikipedia.org/wiki/Persecution_of_Muslims_by_Meccans
After the death of Abu Talib Muhammad was forced to flee the political atmosphere - "the sky" - of Mecca in exchange for the company of the people - "the earth" - in Medina.
https://en.m.wikipedia.org/wiki/Hijrah
The star was given the key to the shaft of the Abyss. (verse 1)
The abyss - ἀβύσσου - being the "depths of the sea" (Luke 8:31) out of which the beast arises.
'The beast, which you saw, once was, now is not, and yet will come up out of the Abyss ...' Revelation 17:8
'The waters which thou sawest, where the whore sitteth, are peoples, and multitudes, and nations, and tongues.' Revelation 17:15
In that case the "sea" being the literal and figurative "sea" of Mediterranean people, from which arises catholic Europe, the ultimate object of destruction.
In the current case the abyss being the peoples of the levant which would succumb to Mahomet and become his "locusts".
The "pit" or shaft being of necessity the eastern empire centred in Constantinople.
The control or "key" of which would ultimately fall to the Ottomans, but not the abyss itself, that honour being reserved for Napoleon (Vials 1 through 5).
When he opened the Abyss, smoke rose from it like the smoke from a gigantic furnace. The sun and sky were darkened by the smoke from the Abyss. (verse 2)
https://en.m.wikipedia.org/wiki/Muslim_conquest_of_the_Levant
The "smoke" from these conquests being visible to all the Roman empire.
'And out of the smoke locusts came down on the earth and were given power like that of scorpions of the earth.' (verse 3)
The caliphates while having a centralized system of authority were not monarchies in the ususal sense (Proverbs 30:27).
The scorpion being a natural symbol for the power of these vast united Arab armies.
They were told not to harm the grass of the earth or any plant or tree, but only those people who did not have the seal of God on their foreheads. (verse 4)
The caliphates were incredibly tolerant of subjugated populations preferring the destruction of catholics.
'At its greatest extent, the Umayyad Caliphate ... the largest empire the world had yet seen and the sixth largest ever to exist in history.'
https://en.m.wikipedia.org/wiki/Caliphate
'The Umayyad Caliphate ruled over a vast multiethnic and multicultural population. Christians, who still constituted a majority of the caliphate's population, and Jews were allowed to practice their own religion ...'
https://en.m.wikipedia.org/wiki/Umayyad_Caliphate
They were not allowed to kill them but only to torture them for five months. And the agony they suffered was like that of the sting of a scorpion when it strikes. (verse 5)
Although the action of the Saracens was significant against the eastern and western empires, they made little inroad and had no lasting effect.
The locusts looked like horses prepared for battle. On their heads they wore something like crowns of gold, and their faces resembled human faces. Their hair was like women’s hair ... (verses 7 and 8)
Unlike the clean shaven Romans, the Saracens wore beards, "faces of men" - ἀνθρώπων - but with long flowing hair "like women".
Italians (apparently) call the locust cavaletta or "little horse" due to its horse like head.
'The Arabian or Arab horse is a breed of horse that originated on the Arabian Peninsula. With a distinctive head shape ...'
https://en.m.wikipedia.org/wiki/Arabian_horse
The appearance when armoured no doubt adding to a resemblance to scorpions.
They had tails with stingers, like scorpions, and in their tails they had power to torment people for five months. (verse 10)
'The heavy engines, siege machines ... were carried on camels behind the army.'
https://en.m.wikipedia.org/wiki/Umayyad_Caliphate
These 5 months and the earlier 5 (in verse 5) corresponding to 300 years and possibly related to the rise of the Umayyad Caliphate and the Abbasid Caliphate during which time the empire declined.
https://en.m.wikipedia.org/wiki/Umayyad_Caliphate
https://en.m.wikipedia.org/wiki/Abbasid_Caliphate
They had as king over them the angel of the Abyss, whose name in Hebrew is Abaddon and in Greek is Apollyon (that is, Destroyer). (verse 11)
Both these labels being "destroyer". The Caliphs - the messenger of the eastern abyss - having two distinct functions, to subjugate the hebrew world first and then to rage against the greek Byzantine empire.
And many other items of note.
Understanding the purpose of the Revelation being critcal to its examination.
That purpose being an unrolling scroll of prophesy for all believers between the time of the partial knowledge and prophesy in the period after the ascension of Jesus and the spirit gifts until his return and the “It is done!”.
