american eagle erj

alan cottrill · Post by **alan cottrill** » 03 Jul 2007, 12:15

Just read in todays flight mag,about an erj of american eagle,who started to land at boston logan intl on 20/06/07,when they realised the u/c was still up,pic in the flight mag shows sparks coming from the flaps,as they made contact with the runway,and the aircraft managed to lift off,and do a go around.
On reading the article,it transpires that it was not the fault of the crew,they had 3 greens,it was as they started to touch down,they noticed an u/c lever disagree light,and did a go around,on investigation it looks like an u/c electronic box that was at fault,thankfully no injurys,and the aircraft flew past the tower after a manual lowering of the gear,to confirm it was down before they landed safely.
regards alan. :shock:

Prop Jockey · Post by **Prop Jockey** » 03 Jul 2007, 18:19

Hi Alan,

There's a couple of pics here http://community.myfoxboston.com/blogs/Maria_Stephanos

Scroll down a bit to get to them................

Cheers

Rich

Kevin Farnell · Post by **Kevin Farnell** » 03 Jul 2007, 19:15

If you look closely at the pics, the nosegear doors are open, and possibly the maingear doors as well.

Kevin

Chris Trott · Post by **Chris Trott** » 03 Jul 2007, 20:01

The ERJ (like the 737) doesn't have any doors on the mains. It has covers that are linked directly to the landing gear strut, but the wheels retract flush with the underside of the aircraft.

It will be interesting to see the NTSB final on this incident since it'll get extra investigation (since it was covered on the media) and a full report.

Docket # is - DCA07IFA050

Motormouse · Post by **Motormouse** » 07 Jul 2007, 10:05

Kevin Farnell wrote:If you look closely at the pics, the nosegear doors are open, and possibly the maingear doors as well.

Kevin

Yep, the erj don't have maingear doors, the nosewheel doors on t'other hand are sequenced by a logic circuit in the Landing Gear Electronic Unit
(LGEU) the 'black box' which was faulty on this occasion.

I'm guessing here that there was also at least two (of the six) gear 'up' proximity switches faulty too----to give 'three greens' or 'reds' a logic
voting system is used, however the crew should have noticed the
'LG Lever Disagree' message on EICAS before they got to that situation.

BTW, to put your minds at rest, in UK (and EASA member states) a test of
landing gear prox switches and LGEU logic is mandatory every 300 hrs....whereas our transatlantic cousins can do it every 600 hrs.

ttfn

Pete

alan cottrill · Post by **alan cottrill** » 07 Jul 2007, 13:00

From the flight mag article,it looks as if there was a short in the electronic box,they did not give full details,as the investigation is still ongoing,and i agree they should have seen the u/c diagree warning sooner than they did,they also took a very geat risk,when they elected to do a go-around,they must have herd the scrapeing noise,from the flaps dragging along the runway,if any other controls had been damage,they could so easily have lost control,with a posible loss of life,i would have thought a belly landing at this stage,would have been the safer option.
regards alan.

Chris Trott · Post by **Chris Trott** » 07 Jul 2007, 15:11

Alan, the scrape happened after go-around was initiated. All aircraft settle some while the power comes up. Even if they initiated go-around at 200 feet it is still possible to have the aircraft touch down while making an normal go-around. It's not supposed to, but if certain aircraft will depending on how fast the speed starts to build because of tight tolerances in the approach configuration (i.e. little margin from flying to stalling). Also, we do not know when the disagree light came on. The fact that it showed 3-green means that for at least part of the approach after the gear was selected down, the disagree light did not illuminate initially. Until we get the final report I would not make and judgements on if the disagree light was on the whole time or not and I would also not make any judgements as to how they handled the situation without first getting the FDR data out that shows exactly when they initiated the go-around and what altitude they were at when they did so.

alan cottrill · Post by **alan cottrill** » 07 Jul 2007, 21:23

Hi Cris.
I have just been reading the article at this link below.
Aircrew Health - Aircraft Accident News
then click on the line titled.
NTSB Takes Closer Look At ERJ-135 Landing Gear Incident -
Going by this article,they started the go around after the flaps contacted the ground,,but like you said,only time will tell what did happen,and in what order,the flight data is still under investigation,as is the cvr data.
It makes for an interesting read.
regards alan.

Chris Trott · Post by **Chris Trott** » 07 Jul 2007, 21:40

Hrm... wonder if that's the NTSB saying that or whom because people on site during the incident reported hearing the engines begin to spool up before ground contact. Had the crew not reacted until after the flaps started scraping then they would not have been able to depart because the airplane would have fully impacted the ground, something that (thankfully) it did not.

One thing I always try to remember is that incident timelines tend to change quite a bit during the investigation, even after the CVR and FDR data's been pulled because there's stuff not reported on those items that interpretation from the Radar Recordings and various video and photographic evidence will reveal and cause the CVR and FDR timeline to be adjusted in relation to external activities (i.e. ground contact).

Motormouse · Post by **Motormouse** » 08 Jul 2007, 11:57

Hi Alan, Chris is correct, once below 'Decision Height', any go-around initiated stands the chance of the aeroplane still making ground contact, this is due to the time the engines take to make power, coupled with the rate of descent when go-around is initiated, you can't just 'pull up';
or you're likely to stall.

Design of the ERJ series does take into account a possible wheels-up,
the aircraft has a fairly hefty underbelly 'skid' and is designed to settle on the flaps (which are largely of a composite carbon fibre) and therefore
not likely to leave large debris.

ttfn

Pete