Boeing 767 collides with truck and highway streetlight as it lands at Newark airport
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buffnut453
Captain
OUCH!!! That's an expensive mistake. Aircraft clearly too low on approach, something both the crew and ATC should have picked up on.
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MiTasol
Major
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Not guaranteed to be a mistake. Unfortunately, aircraft do sometimes descend lower than required on short final, there is a "scatter" in the accuracy of the threshold crossing height and the point of touchdown. Usually Autoland in equipped aircraft is very accurate, but there can be greater variation in the accuracy of hand-flown approaches. Pilots have visual and electronic aids to achieve the required accuracy but sometimes they fail to achieve the required standard. The layout of the busy commercial runway is designed to be safe with landings within the normal accuracy, in detail, the touchdown point has to be far enough down the runway that the aircraft is safely high enough for obstacles in the undershoot. In this respect, some runways have no obstacles in large distances before the runway starts and so there is little problem. However, runways that have roads or other obstacles close to the ends of the runway are problematic if an aircraft fails to maintain the safe flightpath.
The aircraft here must have been too low as it hit a vehicle and a lightstand, the reason for being too low might have been due to a problem. The investigation will find the cause.
Cheers
Eng
Yikes! Could have been a lot worse.
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MiTasol
Major
The truck involved appears to be an airline catering truck.
OK for a little humour?
So, I have the cause sorted-out. The aircraft saw the catering-truck was vulnerable there on the road and took its chance to get it's own back for all the damages catering trucks do to aircraft!
Cheers
Eng
The approved method is to fly the glidepath all the way down to the flare point, which should guarantee 50' of clearance at the threshold. It is, however, fairly common practice to "duck under" the glidepath right at the end, especially on a short runway, to allow more room to flare without using up too much runway. Done properly, you get a smooth landing in the zone and nobody notices you fudged the safety margin. Done improperly . . . well, it looks a lot like this.
The main risk factors are: heavy aircraft, short runway, and pilot fatigue. I'd note this one was reportedly on the short runway at EWR (Rwy29--6726'), after a nine hour flight from Venice, with (presumably) international fuel reserves. I know we're not supposed to speculate, but a betting man would probably guess . . .
The main risk factors are: heavy aircraft, short runway, and pilot fatigue. I'd note this one was reportedly on the short runway at EWR (Rwy29--6726'), after a nine hour flight from Venice, with (presumably) international fuel reserves. I know we're not supposed to speculate, but a betting man would probably guess . . .
There are some points here:
The PAPI's can and do give guidance for certain types of aircraft. Common widebody settings do give a 3 degree eyeline that gives about 50' pilots eye height over the Threshold.
Pilot's have to realise that the U/C is way below that, in my old type we had to allow 33' for the Gear low point, which gave about 17' above the Threshold in a perfect stable short final.
Airfield approach plates state the TCH (Threshold Crossing Height) and PAPI details.
(See correction by Retattack in his post #11. The PAPI eye height at the Threshold is frigged in classes to give 50' above the lowest point (usually gear). However, pilots are left to allow for this if their aircraft is outside the setting of the PAPI. I had to check for the setting with reference to our 33', not just subtract it.)
The Rwy 29 details seem to show a 224' displaced Threshold, so the 50' eye height should be above that displaced Threshold, giving about another 11' height @ the start of the Rwy.
Pilots should normally touchdown in the Touchdown Zone that starts 150m after the Threshold or Displaced Threshold. However, you must not touchdown before the marked Threshold or displaced Threshold.
Landing Distance Required allows for the normal approach criteria and technique (unless otherwise stated) and equates directly to Landing Distance Available so that a safe landing can be calculated and performed.
Cheers
Eng
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The 50' threshold clearance is a certification requirement, not a PAPI setting, it's measured at the bottom of the landing gear, and results in the landing distance calculated in the AFM.
PAPIs are required to be sited to provide proper threshold crossing height (TCH) for "the most critical aircraft that normally operates on the runway" and while that doesn't exactly match the AFM, it's pretty close.
Per table 5.1 of the pertinent order ( https://www.faa.gov/documentLibrary/media/Order/FAA_Order_6850.2C.pdf ), the minimum PAPI TCH for most major airports coincides with "Height group 4" (which includes 767s) and equates to 75' (+5/-15).
Yes, you are correct about the group setting for 50', my bad! We had to correct for the difference, not the total as I said. I will add a note on my post!
Cheers
Eng
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