Aerobatics and Gates

[ExRAFRadar]

Hi all,

In the Shoreham thread there is talk of 'hitting Gates' with respect to flight manoeuvres.

Can I ask those in the know what are these Gates?

I assume they are a planned altitude/attitude for a certain manoeuvre but could not find anything online after an admittedly quick search.

Thanks in advance.

[Pure Pursuit]

Gates

Gates are predefined positions on the display route that are used as safety checks prior to certain manoeuvres in order to ensure that the pilot has sufficient height (based on QFE) and speed. For example, the top of a loop would have a gate, which the pilot would have to achieve prior to completing the second half of the loop. If the gate parameters are not met, the manoeuvre is aborted.

[ShyTorque]

They are a combination of height above the surface, airspeed and rate of climb or descent, depending on the manoeuvre being flown.

Essentially, it's a way of assessing the energy in the aircraft.

[Courtney Mil]

I'm not a display pilot, never have been. You are pretty much on the money. A gate is a position in space (top of a loop, for example) with associated parameters (height and speed, most usually). So, at the top of a loop the pilot/crew will need to check that they meet those parameters to know if they have sufficient room to complete the manoeuvre before committing nose low. Other manoeuvres may simply require an adjustment (heading, bank, pitch, throttle).

Layman's explanation. I'm sure they'll be another along in a minute.

[ExRAFRadar]

One thing I did not anticipate.
I assumed you had entry requirements for the start of a manoeuvre but did not think about gates at certain points during the manoeuvre.
Bit obvious really, just not to me.
Excellent, thanks all.

[factanonverba]

Got to post, the gate is at entry point to the manoeuvre - position, height, speed, power and then if using the vertical the same "g". The gate in a looping manoeuvre at the top, involves height and speed checks, min and max, and confirms what you have checked before you start the loop/vertical manoeuvre. To commit into the vertical without any of those parameters is asking for something different each time.

[Exrigger]

Don't know if this document is of interest, it explains a lot more than gates but I reckon the responses so far have covered it off as well:


https://www.caa.co.uk/docs/33/CivilAirDisplaysAGuideforPilots.pdf

[jayteeto]

An excellent video was available a while back. A blue Angels? Jet doing a solo, set the wrong pressure setting on the altimeter. He thought he had the gate, but hit the runway. Luckily he ejected in time

[KenV]

An excellent video was available a while back. A blue Angels? Jet doing a solo, set the wrong pressure setting on the altimeter. He thought he had the gate, but hit the runway. Luckily he ejected in time

Link to the video is below. LOTS of people thought (and repeatedly stated) he missed his gate while performing a loop. This is incorrect.

https://www.youtube.com/watch?v=alo_XWCqNUQ

[GlobalNav]

It's always SOMETHING!

[Shaft109]

A further question...

Having read the above I understand gates a little more but what effect (or lack of) does the thrust in a jet have on the radius of a loop?

e.g. if the aircraft was a glider in a loop the QFE height and airspeed would give an indication of energy in the aircraft at various points but like the Typhoon near miss or now the Hunter accident does having full thrust have much effect on this?


Or indeed do you modulate the throttle settings as you perform the manoeuvres?

Meant in a technical / respectful was not speculating on any causes of said crash.

[Lonewolf_50]

Originally Posted by jayteeto

An excellent video was available a while back. A blue Angels? Jet doing a solo, set the wrong pressure setting on the altimeter. He thought he had the gate, but hit the runway. Luckily he ejected in time

From the paint scheme, and the fact that it is F-16 versus F-18, it was a US Air Force Thunderbird.

[Mach the Knife]

The Thunderbird solo made his gate, unfortunately he had the wrong altimeter setting, fortunately he had a good bang seat.

There is a big difference between entry parameters and gates during aerobatics to a base height (be that agl or a nominated height). Entry parameters are what you planned and aim for and they should, in a rehearsed routine, always be the same. A gate is a MUST achieve and the manoeuvre can be adjusted to make the gate. If you don't make ALL of the gate parameters you need to fly the escape manoeuvre. The gate in a looping type of manoeuvre (which includes the 1/4 clover) is a height AND speed. You can hit the height but if you are faster than planned at that gate the height required to pull through will be much greater depending on the ac you are flying and how much excess performance you have.

[KenV]

The Thunderbird solo made his gate, unfortunately he had the wrong altimeter setting, fortunately he had a good bang seat.

Actually, no. That is not correct. He did miss his gate, and NOT because he had the wrong altimeter setting.

[Fareastdriver]

He would have checked his altimeter setting before take off; i.e. airfield altitude.

[Radix]

............

[KenV]

Want some time to make up your mind?

The point is moot. His pre-calculated gate had an incorrect number (altitude).

Capt Stricklin did not miscalculate the gate altitude. According to the accident report he had the correct altitude and the correct altimeter setting. But he had flown the maneuver hundreds of times at a lower altitude (Nellis), and while flying at a higher altitude (Mountain Home) "the pilot reverted back to his Nellis habit pattern for a split second." In this case the "instinct" ingrained during his training failed him.

But that is NOT what I was actually getting at. I was making an entirely different point. People have made and continue to make assumptions about the maneuver he was performing, just as people are making assumptions about the maneuver the Hunter pilot was performing. Look at the video. What is wrong with this loop maneuver?
https://www.youtube.com/watch?v=alo_XWCqNUQ

[Above The Clouds]

KenV
But that is NOT what I was actually getting at. I was making an entirely different point. People have made and continue to make assumptions about the maneuver he was performing, just as people are making assumptions about the maneuver the Hunter pilot was performing. Look at the video. What is wrong with this loop maneuver?

FFS you have been banging on about this for the last hour or two on the other thread and they all got deleted, instead of beating around the bush why don't you just explain what it is you are trying to achieve without all the waste of bandwidth, for a start the F16 didn't do a loop he attempted a reverse half cuban after take-off is that what you are getting at because people interpret a video wrongly ?

[O-P]

There were two things wrong with his "loop".

1. It wasn't one.

2. He hit the ground.

[KenV]

FFS you have been banging on about this for the last hour or two on the other thread....

Finally! Tons of people ASSUMED this was a failed loop when it was not a loop at all. It was a split S. The same thing is happening in the Hunter accident. Many people ASSUME the pilot was attempting a loop, while many others ASSUME the pilot was attempting 1/4 clover. The fact is, no one knows what the pilot was attempting and comments about him executing the maneuver poorly and then failing to abort the maneuver after a gate was missed are wild speculation based on wild assumptions.

And what's interesting is that after "banging on about this for the last hour or two" no one caught the fact that it was not a loop until I pointed it out. Despite obvious visual evidence to the contrary, everyone assumed it was a loop because that was what it was called. The same thing is happening in the Hunter accident. Someone called the maneuver a 1/4 clover and thus it must certainly be a 1/4 clover. The point is no one but the pilot knows and he is in no condition to speak.