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In my shareholder agreement, there is a very reasonable line that states:

Any hard landings to be reported immediately to [head instructor] or [club name]

The thing is, I'm not exactly sure where the line is, i.e. when does a non-great landing become a hard landing. The other day I flew into a challenging short-strip grass strip in moderate wind, bounced twice on the landing, added power, changed my mind, took power off, landed it just before the runway threshold, it was a mess. But the nose gear wasn't hit particularly hard.

How does one define a hard landing?

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    $\begingroup$ When you do it, you'll know :D $\endgroup$
    – Jamiec ♦
    Jun 9 at 8:55
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    $\begingroup$ Possible duplicate: aviation.stackexchange.com/questions/1613/… (Different aircraft, but answer likely to be the same) $\endgroup$
    – Jamiec ♦
    Jun 9 at 9:05
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    $\begingroup$ If you're rubbing the seat of your pants after you get out of the plane then it probably was one. $\endgroup$
    – GdD
    Jun 9 at 9:18
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    $\begingroup$ It's the sort of landing where your passengers ask if you landed or crashed $\endgroup$
    – Richard
    Jun 9 at 21:39

4 Answers 4

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In general aviation there isn't really a yes/no definition. It's a judgement call. As a newbie, and the owner of a shared aircraft, it's prudent to err on the side of caution and report anything more than minor bounces.

If it made you worry that you damaged it, it's hard enough to let someone know. Especially if the nose gear came down hard, or worse, first, the nose gear being the more delicate element.

Golden rule: You get in way less trouble with other shareholder partners and the person maintaining the airplane by reporting non-damage than by not reporting damage. You may find that you'll report something, they'll ask you to describe it in detail, and they may just say don't worry about it.

Or, you tell someone you had a bad bounce, they'll go out and give it a once over by eyeball, and if the thing looks like nothing's changed, like one wing tip a little low to the ground, that'll be it. Or they may start pulling cowlings and access panels, but you've covered your behind.

In any case, you'll get brownie points as someone they can trust not to hide your embarrassments (because it's the people that hide that stuff that other pilots fear the most).

The benefit is you can then observe the result if the airplane gets checked over and a thumbs up/thumbs down given, and you added some new data to your internal knowledge and experience database that helps you next time decide what to report and what not to.

As far as the airplane is concerned, all that matters is, is something permanently bent, or worse, fractured/cracked/torn. If nothing's bent out of its original shape, it's fine. The weak points are the gear leg roots and the socket structure the gear leg plugs into for cantilever gear (of the equivalent points at the fuselage for a strut based main gear), and the nose gear's attachments to the firewall or engine mount.

The decision to ground yourself if you landed really hard at some outlying airport is a little harder. If that was the case, I would inspect the airplane myself and stand back and look at it to see if everything was normal and if nothing stood out I'd fly back, but I'd still report the event.

Everybody bounces their airplanes, and over time you'll learn what's worth bothering with, and what's not.

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I would just add to the other answers to say that some aircraft have mechanical indicators showing that a hard landing has occurred. For example, the Eclipse 500 VLJ has split rings on the main landing gear that are displaced in a hard landing to reveal a red painted ring, and a tab on the nose gear that gets bent in the event of a hard landing. Either one indicates the need for an inspection prior to flying again.

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The threshold for "hard landing" is usually defined by the aircraft manufacturer in terms of either the load factor or the descent rate at touchdown.

For example, according to this video by Mentour Pilot, the threshold for the Boeing 737 is 2.1g (peak recorded load factor) at touchdown, whereas it is 2.6g for A320 according to this source.

Mentour Pilot also explained in his video that:

...There is nothing in the cockpit that indicates how many G's we have exerted during the landing unfortunately. (...) The reason for that is that we are supposed to be conservative, so if we have any kind of doubt, it is better for us to report it as a hard landing and get the maintenance inspection done.

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    $\begingroup$ I question how useful an answer about a B737 is, when the OP is clearly talking about flying light aircraft ("short-strip grass"). $\endgroup$
    – Jamiec ♦
    Jun 9 at 10:44
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    $\begingroup$ @Jamiec The first paragraph of my answer says: "The threshold for "hard landing" is usually defined by the aircraft manufacturer in terms of either the load factor or the descent rate at touchdown." - this is the answer, and is applicable to all aircraft, irrespective of weather it's a bush plane or a passenger jet. I only used Boeing 737 as an example, because I could easily find reliable information regarding its "hard landing limit". If you're able to find any reliable information regarding any light aircraft, feel free to inform me. $\endgroup$
    – Aditya Sharma
    Jun 9 at 11:13
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    $\begingroup$ @AdityaSharma that's an interesting point, but, respectfully, I think you need to justify your assertion that "hard landing" is defined by manufacturers. I would posit just the opposite, that manufacturers rarely publish this threshold. Perhaps in the case of defense and airline manufacturers this is not the case, but for typical light pistons and gliders I cannot recall seeing it in any POH or AFM I've read. Perhaps it's always been there and I've never noticed, but I remain skeptical until your assertion is supported. $\endgroup$
    – Kenn Sebesta
    Jun 9 at 12:24
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    $\begingroup$ @Jamiec Indeed, had OP done those two bounces and everything in a 737, there would have been no need to report it, it would have made the news. $\endgroup$
    – TooTea
    Jun 9 at 19:22
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As said in previous answers, there is not a real yes/no definition.

Let's use the Boeing 747 as an example:

When touching down on a Boeing 747, the pilot targets 60-180 FPM (Anything softer would be hard to aim). Mostly, according to my research, hard landings are usually landings above 250-300 FPM touchdown rate.

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  • $\begingroup$ incorrect. That's a dangerously low vertical speed that's very likely to lead to floating and bouncing, missed touchdown points, or worse. You're supposed to land "firmly". What that is depends on the aircraft type, but for a 747 it'd probably be in the 300-500fpm range. $\endgroup$
    – jwenting
    Jun 12 at 7:58
  • $\begingroup$ @jwenting: According to Raymer "anything above 4-5 fts would be considered a bad landing by most passengers". (240-300fpm). $\endgroup$
    – sophit
    Jun 12 at 9:32

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