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LHR has published a table ranking the noise and pollution levels of the different airlines using the airport. At the bottom of the list is Israel's El Al.

El Al, in their official statement, say that this is because they are using older 747-400 planes which are due to be replaced by Dreamliners. However, somebody was trying to explain to me that the extra noise was due to particular flight methods and manoeuvres which they implement for purposes of security and defence, being a high risk airline.

I'm not sure what they could do differently, especially as they should be under UK ATC control.

Does anyone have any concrete knowledge (obviously not classified info) or an educated guess whether this guy's theory is rational or not.

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    $\begingroup$ Sounds like nonsense to me $\endgroup$ – J. Hougaard Jun 19 '17 at 16:20
  • $\begingroup$ Quite happy for it to be nonsense or urban myth. It has more weight if professionals say so than if I say it myself. $\endgroup$ – David Glickman Jun 19 '17 at 16:29
  • $\begingroup$ The only credibility I can give is if the airline does a quick climb-out or a steep descent to reduce surface-to-air vulnerabilities, however even hand-held SAMs can shoot down aircraft at cruising altitude. I guess they could also be trying to avoid small arms fire or RPGs. $\endgroup$ – Ron Beyer Jun 19 '17 at 17:09
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    $\begingroup$ There are a limited number of "standard departures" from Heathrow and the corridors are incredibly tight with 8 busy fields nearby who routes need to co-ordinate with Heathrows. No way would dispensation be given to a particular airline, regardless of being "high risk". And all this talk about manpads, small arms fire and RPGs. We're talking London, not Baghdad. You have no chance of bringing down an airliner in flight with an RPG or small arms and deviating a bit isn't going to help with manpads and guided weapons. $\endgroup$ – Simon Jun 19 '17 at 18:08
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    $\begingroup$ Having read a ton on ElAl's security measures, of which they have many, I don't recall anything along the lines of this. Most of their security is on the ground against the possibility of a bombing or hijacking of the plane (those people that ask you questions before check-in are amazing at what they do, and read every time your eyebrow moves to see if you're suspicious). They are usually not afraid of SAMs and the like, and if they are, they wouldn't fly to the airport where there is a threat of it. $\endgroup$ – Mennyg Jun 20 '17 at 7:00
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Being familiar with neither El Al nor LHR, what follows is entirely in the category of "educated guesses".

There are two broad ranges where noise levels can be affected by operations, those being on approach and on departure. The things that tend to make aircraft noisy on approach would be configuring early and flying down final with lots of drag (i.e. full flaps) and lots of power (i.e. lots of engine noise). On departure, using maximum thrust instead of a reduced thrust takeoff tends to be more noise close-in to the airport, but it results in a steeper climbout, which makes for less noise farther away.

Would "standard operating procedures" for a "high risk" airline tend to require either of these? Hard to say. As far as survivability, configuring early means that if you take a missile close in, you're already in a landing configuration, so losing a hydraulic system or two doesn't affect your ability to get configured for landing. On the other hand, being at full flaps makes performance on a go-around worse if you take the missile and can't change configuration (but need to go around rather than land). Plus, engines running at the higher power setting would tend to be more of a target for an IR (heat-seeking) missile. If you thought you were coming in to a high-threat airfield, you'd probably want a steep approach, meaning lots of drag but a LOW power setting. I have a hard time envisioning a 747 doing this coming into LHR, but maybe they do, spooling the power WAY up to arrest the steep descent at some point close-in. Maybe.

On departure, the max-thrust takeoff DOES get you out of some threat envelopes more quickly than the reduced thrust takeoff, so that's fairly believable. Get as high as you can before you depart the airport perimeter (which is presumably more secure than the areas outside the airport fence). If "always fly a max thrust takeoff" is part of the El Al S.O.P., then it wouldn't be surprising that this would result in higher noise levels close in.

Still in the "educated guess" category, I would wonder if some element of the noise ratings may have to do with how they're calculated. If the rating for British Airways averages out the 747's departing at heavy weights to destinations far away (four engines at very high power settings putting out lots of noise) with smaller, lighter airplanes departing to closer destinations (two engines at reduced thrust, putting out less noise), then their average would be lower than a carrier which is always flying heavy 4-engine jets to a fairly distant destination. Not that El Al would be the only airline in this situation, I'd suspect, but not having smaller & less noisy aircraft to reduce the average may be at least one factor in the ratings.

Without seeing the actual ratings and at least some of the methodology as to how they're calculated (near/far, approach/departure/both, weighted by time of day, whatever else), it's very hard to know what's really going on there. Plus, taking a look at the procedures into LHR & seeing if there is any difference in how El Al flies them and how "everybody else" does. A lot of questions there in order to get a true high-quality answer to what's really driving those results.

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  • $\begingroup$ Something tells me, that for an average airliner, taking a single missile in any configuration would spell disaster. They aren't designed to evade, or confuse any incoming missile (be it IR, RADAR, or other)... and the structure isn't designed with partial breakup survivability in mind. My guess would be, any "security" measures being taken are for reducing damages caused by small arms fire. $\endgroup$ – SnakeDoc Jun 19 '17 at 22:30
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    $\begingroup$ @SnakeDoc Stratfor quotes 30% survival rate for civilian aircraft hit by a MANPAD, and notes that El Al aircraft actually do have some sort of countermeasures installed. $\endgroup$ – Ralph J Jun 19 '17 at 23:02

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