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piratepete
11th Oct 2010, 19:16
The airline im with has a very very high rate of hard landing events showing up on the QAR for the 737-800.This is not the case on my fleet, 767/757.Maybe an experience issue.However the other evening going in to HKG, nil wind nice WX etc, I had no reason to have any doubts about the FOs landing ability.I have 11,000 hours of IP time on type including base training etc.At 50 feet things looked good, I was already thinking of the turnoff options.At 20 feet nothing was happening with the flare activities, but my guard was certainly down.As is my custom from lots of instructing my left hand quietly slid to close to the control column.What happened next took me by surprise, and I believe but cant be sure, that the FO actually lowered the nose slightly, however the flare did not take place, and it was too late for me to save the very hard arrival.I had no choice but to comment in the Logbook "suspected hard landing.....".The FO was grounded for re-training as a result.My question is this.Have any of you experienced a technically defi ned hard landing and if so, what does it feel like, because this is a first for me in 36 years of flying heavy jets.The QAR said a g force of 1:8 for my event.

fantom
11th Oct 2010, 19:34
How could it have been 1G? That's straight and level, remember?

Aviophage
11th Oct 2010, 20:08
This thread is a load of cock and bull I'm afraid. I smell b/s from the OP.

Denti
11th Oct 2010, 20:30
Have seen landing reports from the QAR that state a touch-down g-load of 0.8g. In the outfits i worked for a hard landing check was mandatory if someone wrote up a suspected hard landing. However, retraining was not usually done on first offence, only if someone did it repeatedly and showed other landing problems.

IRRenewal
11th Oct 2010, 20:31
Capt to F/O: "Why did you do that?"

F/O to Capt: "Why did you allow me to do that?"

GlueBall
11th Oct 2010, 21:31
In your case, a no-flare, level-flight-1G-touchdown would not normally qualify as a "hard landing." Typically, a "hard landing" as such would usually include a bounce.

Here's what Boeing says:
"For landing at or below the maximum design landing weight on
airplanes with flight data recording systems capable of at
least least eight (8) samples per second, the following can be
used: An indication of a hard landing on the main landing gear
is a peak recorded vertical acceleration that exceeds 1.7 G
(incremental 0.7 G). This vertical accelerometer data must be
measured by the flight data recorder accelerometer at a data
sampling rate of at least eight (8) samples per second. This
vertical acceleration G-level threshold is valid for a
conventional landing with impact with no more than two (2)
degrees of airplane roll, main landing gear touchdown first and
normal rotation onto the nose gear. For a hard landing that is
a hard nose landing or is accompanied by more than two (2)
degrees of roll at the time of main landing gear impact, The
recorded peak acceleration can be significantly less than 1.7
G, but a hard landing inspection may still be necessary.

(b) For landing at or below the maximum design landing weight on
airplanes with flight data recording systems capable of at
least least sixteen (16) samples per second, the following can
be used: An indication of a hard landing on the main landing
gear is a peak recorded vertical acceleration that exceeds 1.8
G (incremental 0.8 G). This vertical accelerometer data must
be measured by the flight data recorder accelerometer at a data
sampling rate of at least sixteen (16) samples per second.
This vertical acceleration G-level threshold is valid for a
conventional landing with impact with no more than two (2)
degrees of airplane roll, main landing gear touchdown first and
normal rotation onto the nose gear. For a hard landing that is
a hard nose landing or is accompanied by more than two (2)
degrees of roll at the time of main landing gear impact, The
recorded peak acceleration can be significantly less than 1.8
G, but a hard landing inspection may still be necessary."

Checkboard
11th Oct 2010, 21:36
Have any of you considered what the code for :8 is?

I think that the OP meant 1.8 G - which is a hard landing. :8

Tom355uk
12th Oct 2010, 17:31
Aviophage This thread is a load of cock and bull I'm afraid. I smell b/s from the OP.

Ohhh the irony........ :rolleyes:

Anyway, from a (currently) SLF perspective, I have experienced a confirmed 3.15g bounce followed by a 2.75g second touchdown - it was hard. Very, very hard indeed. Quite unlike anything else in the world, and difficult to describe. I was looking out of the window at the moment of touchdown, and you could really tell that the VS was much higher than usual. For a split second, you expect the aircraft to disintegrate underneath you with the real loud bang that accompanies it. I actually thought we had crashed (again, for a second or two) and it is not something I'd like to experience again if I'm honest. :ouch:

B777Heavy
12th Oct 2010, 18:07
Try flare at 10 feet and should help reduce hard landings....

Capt Claret
12th Oct 2010, 21:31
QAR data is not a good determiner of hard landing exceedence because most QAR do not continuously record the G but record it at intervals.

PA38-Pilot
13th Oct 2010, 20:13
I have felt a 1.98G landing once. It hurt, but the aircraft was still in one piece (hard landing check performed, but everything was fine).

PJ2
13th Oct 2010, 20:42
Capt Claret;

Although there are no regulatory requirments for QAR parameter definitions, the FOQA QAR is just fine for determining hard landings. In fact, often the QAR sample rates are higher than the DFDR for some parameters depending upon the DFDAU LFL, (logical frame layout, or data frame).

If the IVSI is recorded at a sufficently high rate, maintenance can and do determine the touchdown 'g' using the rate of descent for the purposes of assessing the requirement for a hard landing check. This would done on the B777 as the vertical accelerometer, which is located in the ADIRU bay near the cockpit and is not reliable. It can be spikey and can trigger false hard landing FOQA events.

[Load 15 info deleted - thanks]

PJ2

Safety Concerns
13th Oct 2010, 20:53
PJ2, you need to be somewhat careful in what you are implying. I am sure some may read into your post that no "load 15" report = no hard landing on an A320.

This is not the case. A load 15 report cannot detect every hard landing permutation. Therefore for the A320 at least, once a pilot makes a tech log entry the landing parameters must be determined. That means you either read the DFDR data or maintenance perform a hard landing inspection.

The load 15 report may in some cases speed up the confirmation process nothing more.

bcgallacher
14th Oct 2010, 13:55
Some years ago I was flt mech on a 747-100 that suffered a hard landing in Miami - the impact noise was unbelievable followed by the sound of the upper deck oven door which had been torn off clattering down the spiral staircase into the first class area!Inspection showed no problem - 747 is a tough bird.

toby320
14th Oct 2010, 14:23
HI, PRUNERS

A hard landing is defined as a landing with a vertical acceleration of more than 2.6 g at the center of gravity or:
-a vertical speed (v/s) of more than 600 ft/min.

An overweight landin is defined as a landing at more tha the maximum landing weight with a vertical acceleration of more then 1.7 g at center of gravity or:
-a vertical speed (v/s) of more then 360 ft/min.

On A-320 if the aircraft has DMU/FDIMU with an enhanced load report 15, do the "inspection after hard/overweight landing for aircraft with enhanced DMU/FDIMU load repot 15".

It is responsability of the flight crew to make a report if THEY THINK THERE WAS A HARD/OVERWEIGHT LANDING.

I hope this helps. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

toby.

Safety Concerns
14th Oct 2010, 17:49
On A-320 if the aircraft has DMU/FDIMU with an enhanced load report 15, do the "inspection after hard/overweight landing for aircraft with enhanced DMU/FDIMU load repot 15".

The above doesn't make sense. Once an entry has been made the landing parameters as posted must be confirmed to be within limits to avoid an inspection.

An aircraft fitted with enhanced DMU's may just save the work involved in confirming those parameters. For example if a Captain makes an entry "suspected hard landing" then if no load 15 report available the second option is DFDR readout. If that isn't possible then you must perform the inspection.

If however a load 15 report is available then you will very quickly be able to determine whether an inspection is necessary or not.

It is that simple. If you believe that because there is no load 15 report the landing wasn't "hard" you are very much mistaken

shortfuel
14th Oct 2010, 20:13
If you believe that because there is no load 15 report the landing wasn't "hard" you are very much mistaken

So true.
Even if a parameter exceedance generates a LOAD REPORT, that report does not automatically produce a printout at the end of the flight.
This auto-print facility has to be configured by the operator.

I recommend the following AAIB report:
http://www.aaib.gov.uk/cms_resources.cfm?file=/Bulletin%206-2009.pdf

AerocatS2A
14th Oct 2010, 22:48
QAR data is not a good determiner of hard landing excellence because most QAR do not continuously record the G but record it at intervals.
I hear that misalignment of the rear fuselage with associated ripples in the skin is a good indicator of a hard landing ;).

Capt Claret
15th Oct 2010, 04:07
I hear that misalignment of the rear fuselage with associated ripples in the skin is a good indicator of a hard landing .;)

Nah, I think that just confirmed the crew's suspicions. :\