+ or - 30 seconds: why so hard?

[DylanVille01]

I am new to the world of rotary wing aviation so I couldn’t quite give an adequate rebuttal to my friends accusation. I was discussing army aviation with a few buddies (just received their wings to fly jets). The 160th and their emphasis on “on target plus or minus 30 seconds” came up and the jet guys didn’t think that is very challenging as they explained “the aircraft can tell you what time you will be at a location and do that work for you.” I am not sure I buy that as some of the best pilots in the world seem to put a lot of emphasis on that ability. Can someone help explain why hitting a target within such a close time frame is much more difficult in a rotary wing aircraft? 

[Thedude]

Your friends don't have any idea what they're talking about because they've likely never flown close to the ground except for takeoff and landing. Once they're at 35000' they simply fly in a straight line and then descend to land. Super simple, boring sh*t. We fly under 50' while maneuvering over and around obstacles and using the terrain to help us or hinder the enemy. We fly constantly changing headings, airspeeds and altitudes from takeoff to landing. Our flight profile is a whole lot more demanding and deadly and the consequences for missing a specific time at a specific location can be the difference between life and death, not just a customer who is angry. 

Use winds as a simple, single example they should understand. When flying at a constant 180* heading and 350kts at 35000' they might have relatively constant wind of 60kts/180*. That's easy to calculate for and your ground speed essentially remains the same 290kts for the duration. If a helicopter is flying a heading of 180* at 120kts at 50' with a 20kt headwind we are only doing 100kts ground. When we make a turn to 090* to continue flying along the terrain we want we now have a roughly 118kt ground speed. The heading changes a minute later to 125*, we now have a 107* ground speed, etc etc all the way to the destination. 

[SBuzzkill]

LoL, FNGs...

Edited July 2, 2021 by SBuzzkill

[SemperGumby]

To add to Thedude's example, if you're in Attack Aviation, you'd have to account for setting up at the attack by fire or support by fire position, get positive ID of the target, and launch the munition. So, all that takes time, including the munition time of flight. Sometimes, what you planned isn't what how it is when you get there and you can't see the target from that angle. There are a lot more variables when you go from thousands of feet above ground level to dozens of feet or less.

Yes, there are systems that can get you there and a TOT with munitions impact (+/- 5 Seconds) is possible with the systems on board but it takes a lot of training and luck to pull it off in training but is much more difficult when it's a two-way range.

[jkray]

Yes they are correct that the aircraft systems will tell you how long it will take to get there, but they are assuming that you have the luxury of telling someone when you’ll be there. On an air assault the ground force commander will tell you when you need to be at the LZ with boots hitting the ground, then you need to back plan from that time to the exact second you need to take off from the airfield taking into account and planning for everything that was said by thedude. Not to mention you have 5+ aircraft all flying 1 rotor disk apart from each other and all of you need to hit the LZ at the same time. Also don’t forget to plan the route so you land with favorable winds and in the correct direction for the guys in the back to get out on the correct side for their mission.

[StockTrader]

Ask your fixed wing friend if he has the skills to still get the mission done without the help of his aircraft.  Stopwatch, compass, and a map.  Then we can talk.

[SBuzzkill]

I feel kind of guilty about my useless post earlier, so here's my real thoughts.

While very useful tools that make the job a lot easier, ETAs given to you by an aircraft are very simple calculations.  They do not compensate for acceleration/deceleration, turns, changing topography, changing wind conditions, detours, etc. +/- 30 seconds isn't an incredible feat in itself, but depending on the operation it can be very difficult to achieve.

There are techniques you can use to increase the accuracy of GPS based ETAs but they still aren't perfect and they wont give you anything until you're up and flying.  So you still need to accurately plan in order to calculate and time your starting point, as well as backwards plan in order to make sure that you are ready to take off in order to meet that timeline.  

Additionally, any truly contested environment is going to render GPS based navigation useless.  It's going to be jammed.  Take a look through the NOTAMS and you'll see it's a frequent occurrence in training events around the United States.  INS is only so good, so you better be sh*t hot with a map, stopwatch and compass.

There's so much more to meeting an ETA than simply adjusting airspeed.  Your friends will learn that as they gain experience in more and more complex operations.

As an aside, we've all heard the phrase "no plan survives first contact with the enemy."  Don't fall into the trap of thinking that means we shouldn't extensively plan.  It simply means keep your mind flexible and learn to adjust the plan to fit the unfolding events.

[twinhueyman]

In assessment for the 160th, you have to navigate a complex route to arrive TOT +/- 30 seconds using only dead reckoning (compass, clock, and map), manually adjusting for all of the variables in-flight.  That skill is maintained as a capability in the unit and practiced, and has been used on actual operations surprisingly recently in the past when GPS, INS, etc are unavailable or unreliable.  That’s where the motto comes from.

In more routine operations, the coordination of multiple elements on a complex assault to result in a TOT (or multiple TOTs) is one of the skills of 160th crews that we did better and more reliably than anyone else.  Nobody performs the symphony of a timed assault nearly as well.  Hence the pride.

Mike