small jet down in London

[Vino Collapso]

One jet, a light plane and a helicopter crashing in the local area in the past three years or so, is making people a little jumpy around here. Personally I think that I have more chance of a bad car crash than being hit by a plane and yes I will be at the air display in June.

What still gives me a cold shudder from some 17 years ago, is seeing a 747 pull up over the tail of what looked like a DC9 (rear engine job). The 747 was in the Biggin stack and I think the DC9 was out of Heathrow, I have never told the wife.

I started to believe you until the last few sentences.

The helicopter was no where near Farnborough. What light plane are you talking about? And as for the rubbish about the B747 and the DC9!!!

Sorry but you just made yourself an 'unreliable' witness.

[NuName]

Dear SLF-Flyer

Please tell us the story of below, I'm on the edge of my seat.

"What still gives me a cold shudder from some 17 years ago, is seeing a 747 pull up over the tail of what looked like a DC9 (rear engine job). The 747 was in the Biggin stack and I think the DC9 was out of Heathrow, I have never told the wife."

[SLF-Flyer]

Vino Collapso

The pilot of the helicopter in question was asked to consider not taking off from Biggin as I recall, but crashed soon after taking off about 5 miles from the airport near Chelsfield, which is in the LB of Bromley. The light plane also came down also in the Chelsfield area and crashed onto a road killing the two pilots.

As for the near miss, I am not telling pokies.

[SLF-Flyer]

Planes crashes since 2000 out of Biggin.

January 2003


A flight instructor and his 15-year-old son, Simon, had just got the five-seater Bell 206 Jet Ranger back after a four-day maintenance check on January 17.
But the pair were killed when the private aircraft crashed into a field at Cudham Lane South and burst into flames at about 3.40pm.


The helicopter experienced problems soon after taking off from Biggin Hill Airport for a 15-minute journey to Southend Airport.

October 2005: A light aircraft, a Piper Cherokee, crashes into Victoria Gardens, less than half a mile from Biggin Hill airport, narrowly missing several houses.

The helicopter pilot is hailed a hero after swerving his stricken craft away from houses before it plunges to the ground, killing him and his passenger, his son.

I rest my case.

[vancouv]

It appears from the report that the plane passed through the overhead. I'm a PPL who flies a PA28 and if I was in the overhead I would expect to be able to glide in, even with no engine.

Can someone tell me if this is not possible in something like a Citation? Do you need to extend so far out from the field that gliding onto the runway is not an option?

Apologies if this is a stupid question, but I have no experience of flying anything bigger than a PA28.

[Feathers McGraw]

Would someone with the requisite knowledge care to explain the process of getting fuel from the tanks to the engines in a Citation 500 please.

Is there a common feed mechanism to both engines?

[Chilli Monster]

Vancouv - yes, you can glide the aircraft. Flight manual quotes 125 Kts @8500 lbs. This aircraft would have been considerable heavier, so glide speed would have been higher. As you have to put the nose down to increase speed I suspect the glide would have turned into a very fast, semi controlled impact on the airfield from the height it was at. You need to be quite a bit higher to think about the glide option.

Feathers - LH fuel supplies the Left engine, RH fuel supplies the Right Engine. Separate systems, via a series of pumps and injectors. Cross feed is an option if required to keep the tanks in balance (Single Engine Ops).

[Feathers McGraw]

Thanks for the explanation Chilli Monster, I didn't expect anyone to say that there was a common path for fuel to engines.

So, engines apparently very short of thrust and vibrating (possible misdiagnosis of the latter), but whatever caused that seems to require both engines to be in a similar situation as the s/e performance is described as adequate.

Fuel starvation, again? They clearly had more than enough on board as evinced by the post crash fire. And only 700ft to play with.

What sort of glide angle could you achieve at 10k pounds weight?

[roljoe]

Hi,

you don't fly an angle, you fly a speed with a jet in a glide condition..

anyhow,..700ft is really to low..to come back..go strait and look for a road or a flat field, and prepare to land on the belly..

[Feathers McGraw]

Yes, I know about the speed rather than angle, I was asking to get some idea of how far you can glide from 700ft agl.

[Chilli Monster]

Depends how fast you're going. If you have to accelerate then you nose down, so that's more height lost. You're probably looking at 1/2 to 3/4 of a mile - no more.

[roljoe]

So for Feathers, if you know about the speed , you should also know that this a/c was in a post take-off segment, meaning that the speed was not in excess...this to say that you get only a few seconds to take proper action to save the day...which is not a piece of cake...

just remember the "Concorde" in the vicinity of Paris

[hedgehopper]

"roljoe: you don't fly an angle, you fly a speed with a jet in a glide condition.."

From EMERGENCY/ABNORMAL PROCEDURES Citation I/ISP Revision 1 sep 1996

Tab 10A MAXIMUM GLIDE-EMERGENCY LANDING

"Maximun Glide Speed........AOA .35"

Then speeds: flap 0
7,500 114
8,500 120
9,500 126
10,500 132
11,350 137
11,850 140

VREF......... AOA .6"

"AOA" Angle of Attack is displayed on a gauge above the electrical panel to the top left of the P1 panel " (can't find a picture) but there is a triangle at .35 AOA for best Climb/Glide. There is also a slow(Red "^")/On speed (Green "O")/fast indicator (Amber down cheveron) available only to the P1 for "normal approaches" above the panel, displayed by lights.

The AAIB in S02/2008 state " The aircraft then manoeuvred to overhead the airfield at approximately 1,200 ft aal"

Regards

Hedgehopper

[pilotbear]

roljoe, please explain what you mean by remember Concorde?

[Vino Collapso]

A flight instructor and his 15-year-old son, Simon, had just got the five-seater Bell 206 Jet Ranger back after a four-day maintenance check on January 17.
But the pair were killed when the private aircraft crashed into a field at Cudham Lane South and burst into flames at about 3.40pm.


The helicopter experienced problems soon after taking off from Biggin Hill Airport for a 15-minute journey to Southend Airport.

October 2005: A light aircraft, a Piper Cherokee, crashes into Victoria Gardens, less than half a mile from Biggin Hill airport, narrowly missing several houses.

The helicopter pilot is hailed a hero after swerving his stricken craft away from houses before it plunges to the ground, killing him and his passenger, his son.

I rest my case.

This is not really the thread to be batting this subject to and fro but one last response.

Correct the helicopter came down in Cudham Lane South. The clue is in the name Cudham not Chelsham. Bearing approx 110 degrees from the airport.

The light aircraft was a PA38 ending up in Victoria Gardens, Biggin Hill not Chelsham. Bearing from the airport approx. 200 degrees.

The C501 came down near Farnborough Village, Kent. Bearing from the airport approx. 020 degrees.

Pretty widespread pattern with only one common denominator. They were all within 3 miles of an airport.

You must be part of the 'Flightpath' alliance or quoting from a mis-informed local newspaper article?

[ChrisGr31]

Its not the right thread, but to the best of my knowledge no aircraft have crashed within 3 miles of my house in the 30 years I have lived there, let alone 3.

Therefore it might be that there is a greater chance of an aircraft crashing on your house if you are near an airport, but its still a pretty small chance.

[G-SPOTs Lost]

AOA indexer only works on the 500 with the gear down - so no donuts

[Feathers McGraw]

Roljoe and Chilli Monster

Thanks for the info, my own calculation based on a rough 7 degree descent angle said about 3/4 mile or so, allowing a little height for a flare and landing.

I quite agree that they had very little margin to play with and in fact looking at where they eventually ran out of options I'd say they did an exceptional job of getting as far as they did.

Knowing the area somewhat, it's a fairly hilly area too, so terrain clearance would have been at a premium whichever direction they were from Biggin.

I wonder if the recent maintenance activities on the jet might have had a bearing?

[om15]

The aircraft was maintained to AMM Chapters 4 and 5 of CESCOM, all maintenance was up to date and carried out by Approved Part 145 Organisations.
Prelim statement from AAIB indicated that there is no evidence to indicate an engine failure, nor indication of starter generator bearing failure which could cause engine vibration.

Any speculation regarding maintenance is purely that, speculation, so unless you have specific information regarding this aircraft which may be of value to the AAIB, best not muse on this on a public forum.

Best regards,
om15

[moggiee]

vancouv:

Gliding is not something that would normally enter the equation as the aeroplane in question has two engines, unlike a PA28. Because of this, there should be no need to consider gliding as the statistical probability of losing both engines is tiny. In short, lose an engine on a PA28 and you have to glide - lose an engine on a twin and you SHOULD still be able to fly on the remaining engine.

As a result, following an engine failure, the intention would be to return to the airfield for a single engine approach. The approach would normally be flown with a lesser flap setting than for two engines, and a slightly higher approach speed to compensate (typically 5-10kts faster). The lesser flap setting means less drag, requiring less power (and therefore creating less asymmetry) but also gives less lift, hence the higher approach speed. The higher speed also gives better control authority, meaning (in theory) better control response.

They would aim to fly the approach at a 3 degree descent angle - the same as for an ILS approach or visual approach. A 3 degree descent will bring you down at a rate of 320' per nautical mile and so if they were 2500' above ground level, they would take an approximate 8nm approach (plus about 2nm for getting settled in final approach track and configuring for approach).

However, when manoeuvring with an engine out, care must be taken to avoid letting the speed get too low as there is less thrust available to recover. If speed is allowed to get too low then the rudder/fin lose control authority and due to the asymmetric thrust caused by one engine, it will become increasingly difficult to maintain directional control. In extreme cases, the aeroplane will yaw and then roll, ultimately entering a spiral dive or stall.

Turning increases drag and therefore will tend to cause IAS to reduce. If IAS reduces far enough, directional control will be compromised and, if the speed drops far enough, drag will increase dramatically as the aeroplane finds itself on the "wrong side of the drag curve".

Some twin engined aeroplanes are a little short on power following an engine failure and may struggle to maintain airspeed when turning - especially if they are heavy (as this Citation was). In such cases, it may be very difficult to avoid a significant speed loss in a sustained turn - such as a base turn onto final approach.

My suspicion, for what it's worth, is that the most likely cause of the crash was that, following a loss of power, the speed dropped too low whilst manoeuvring and directional control was compromised. However, we may never know for sure.