Q400 Limits
Thread Starter
Join Date: Sep 2002
Location: uk
Posts: 49
Likes: 0
Received 0 Likes
on
0 Posts
Q400 Limits
Hi to all you pilot types 
A couple of Q's on the limits for the bonny new Q400 from a lowly engineer... Interested in limited/ short tarmac ops 
1. Crosswind limits for Ldg with avg load with any increments
2. Avg fuel burn per hr
3. Wet runway limits with avg load ldg/take off
Got a bit of a project going on and not knowing any Q engineers yet thought i'd ask you peeps. Any info sources i can research myself would be appreciated....
Bodjit
4.
A couple of Q's on the limits for the bonny new Q400 from a lowly engineer... Interested in limited/ short tarmac ops 1. Crosswind limits for Ldg with avg load with any increments
2. Avg fuel burn per hr
3. Wet runway limits with avg load ldg/take off
Got a bit of a project going on and not knowing any Q engineers yet thought i'd ask you peeps. Any info sources i can research myself would be appreciated....
Bodjit
4.
Supercharged PPRuNer
Join Date: Nov 2000
Location: Doon the watter, a million miles from the sandpit.
Posts: 1,183
Received 0 Likes
on
0 Posts
(1) 32kts X-wind limt, not dependent on traffic load.
(2) Give or take, 500kg per engine per hour. A bit more at max chat, a bit less on an economy run.
(3) Not sure what you mean by this, can you expand?
(2) Give or take, 500kg per engine per hour. A bit more at max chat, a bit less on an economy run.
(3) Not sure what you mean by this, can you expand?
Join Date: May 2003
Location: Somewhere In The South China Sea
Posts: 960
Likes: 0
Received 0 Likes
on
0 Posts
(3) Wet runway V1 reduced by 8kts, then for each 10kts headwind you can add 1kt back on to this. Calculation for Wet V1 taken from GWCs.
However, we take our V1/V2 from TOLD cards, but this Wet V1 will be used should there be a V1 split between the 2, the Wet V1 is normally limiting should we be reasonably heavy. Make sense? thought not
Basically if our T/O weight gives us a V1 of 120kts but the rwy is wet then this V1 is now 112kts, if we also have a 10kt headwind this V1 will be 113kts, we then check this against the TOLD cards for our weight, so if the TOLD card says a V1 of 116kts then the wet V1 is used as it's more limiting.
Bodjit, feel free to PM me should you need anything else.
However, we take our V1/V2 from TOLD cards, but this Wet V1 will be used should there be a V1 split between the 2, the Wet V1 is normally limiting should we be reasonably heavy. Make sense? thought not
Basically if our T/O weight gives us a V1 of 120kts but the rwy is wet then this V1 is now 112kts, if we also have a 10kt headwind this V1 will be 113kts, we then check this against the TOLD cards for our weight, so if the TOLD card says a V1 of 116kts then the wet V1 is used as it's more limiting.
Bodjit, feel free to PM me should you need anything else.
Join Date: Feb 2007
Location: Ask Screwing..
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Bodjit,
While your thinking about what to ask for question 4
.... heres some more detail regarding question 2 Fuel Burn;
In terms of fuel consumption in a typical UK environment max cruising at 25,000ft with the propellers at 850 rpm and the power levers in the rating detent total fuel flow is approximately 1100 kilos per hour.... yes I did say total i.e. both engines!!!
This figure is a typical summer fuel flow with temperatures being around ISA+10 at cruising altitude of 24,000/25,000ft. This would also mean that you are cruising just below VMO (red barbers pole). Thus indicated airspeed of around 250kts.
If however you were to bring the power levers back to maintain Indicated airspeed of 210kts in the cruise, then your TOTAL flow fuel can be improved significantly to approximately 730 kilos per hour!
The latter procedure is a great way to save fuel especially if your running early. It helps if the duration of the flight is greater than 1 hour so you can clearly see the benefit from this technique.
Mind you with such a good fuel burn already you may be more than happy with 1100kgs, but its great tool to have the ability to reduce that further. Of course this is relative, however if your planning to have a large fleet this can significantly reduce your fuel bill!
Please be advised that if the aircraft has drop down masks in the cabin then the max cruising altitude with be 28,000ft but I don't have figures for that level, perhaps someone else can help here.
Regards,
Aka
While your thinking about what to ask for question 4
.... heres some more detail regarding question 2 Fuel Burn;In terms of fuel consumption in a typical UK environment max cruising at 25,000ft with the propellers at 850 rpm and the power levers in the rating detent total fuel flow is approximately 1100 kilos per hour.... yes I did say total i.e. both engines!!!
This figure is a typical summer fuel flow with temperatures being around ISA+10 at cruising altitude of 24,000/25,000ft. This would also mean that you are cruising just below VMO (red barbers pole). Thus indicated airspeed of around 250kts.
If however you were to bring the power levers back to maintain Indicated airspeed of 210kts in the cruise, then your TOTAL flow fuel can be improved significantly to approximately 730 kilos per hour!
The latter procedure is a great way to save fuel especially if your running early. It helps if the duration of the flight is greater than 1 hour so you can clearly see the benefit from this technique.
Mind you with such a good fuel burn already you may be more than happy with 1100kgs, but its great tool to have the ability to reduce that further. Of course this is relative, however if your planning to have a large fleet this can significantly reduce your fuel bill!
Please be advised that if the aircraft has drop down masks in the cabin then the max cruising altitude with be 28,000ft but I don't have figures for that level, perhaps someone else can help here.
Regards,
Aka
Join Date: May 2003
Location: Somewhere In The South China Sea
Posts: 960
Likes: 0
Received 0 Likes
on
0 Posts
I have the AOM on my PC somewhere, I'll dig them out, but AKAfresh with the temperature being on average ISA+15 for the last couple of months it'll probably get to FL280 but it wont achieve VMO-10, more like VMO - 25/30, we struggle on some days to achieve VMO - 10 on hot days with the PLs in the detent. & who said it had bags of performance? 
Join Date: Feb 2007
Location: Ask Screwing..
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Deano777 I thought you were a company man and were leading the charge at Vmo -20 RFC (Reduced Fuel Cruise) don't tell me you were running late, surely not... tut tut hahaha
As for performance well I don't have a clue about that, go ask the 145 boys! lolll JK!
don't tell me you were running late, surely not... tut tut hahahaAs for performance well I don't have a clue about that, go ask the 145 boys! lolll JK!
Supercharged PPRuNer
Join Date: Nov 2000
Location: Doon the watter, a million miles from the sandpit.
Posts: 1,183
Received 0 Likes
on
0 Posts
Pah, you boy racers. Vmo -30 today in a vain attempt to avoid running ahead of schedule. Still ended up 10 mins early on both sectors.
Thread Starter
Join Date: Sep 2002
Location: uk
Posts: 49
Likes: 0
Received 0 Likes
on
0 Posts
Cheers everyone ... very enlightening.. especially the fuel burn. I can see why alot of people want them...seem to run on the smell of an oily rag
The runway limits were quite important in my project for such a fuel efficient Ac as the 400....... could it do short runways to take off and land and what during both would limit you... Could this Ac get into and out of lets say somewhere like London Cty with avg-full load and if not why not ????????? I'm assuming runway length would limit you being too short for t/o and or ldg.?
Was on one into and out of the IOM, both with brisk xwinds... Stopped reasonably quickly although theres plenty of tarmac at ronaldsway but I thought it was a little slow into the sky for such a light load....
Deano, G , AKA thanks for your time... very enlightening me thinks I may have to seek me a type course.... Your thoughts on City would be appreciated though
... very enlightening.. especially the fuel burn. I can see why alot of people want them...seem to run on the smell of an oily ragThe runway limits were quite important in my project for such a fuel efficient Ac as the 400....... could it do short runways to take off and land and what during both would limit you... Could this Ac get into and out of lets say somewhere like London Cty with avg-full load and if not why not ????????? I'm assuming runway length would limit you being too short for t/o and or ldg.?
Was on one into and out of the IOM, both with brisk xwinds... Stopped reasonably quickly although theres plenty of tarmac at ronaldsway but I thought it was a little slow into the sky for such a light load....
Deano, G , AKA thanks for your time... very enlightening me thinks I may have to seek me a type course.... Your thoughts on City would be appreciated though
Join Date: Feb 2007
Location: Ask Screwing..
Posts: 101
Likes: 0
Received 0 Likes
on
0 Posts
Bodjit,
The aircraft is designed for a regional market and often with regional airports you tend to have restrictions at these airports for example short runways, more noise abatement procedures, steep approach etc.
The aircraft does not have huge limitation when it comes to runway lengths provided its on 2 engines. The limitations really come become important when your single engine or say have a flap problem requiring you to either land flapless or with less the normal. Now runway length is more of a factor added further when the runway has other negative characteristics such as slope.
Note also if the runway is wet this will effectively double the required runway length! Not to mention if its Icing conditions too. Single engined worst case landing distance is about 1800m with max weight, wet runway and no wind. Anything with more than 2000m such be ok.
I believe the runway length at London City is 1,508 metres (4,984 ft), this should be ok to land and take off in normal conditions. The problem at city is not the runway length its the type of approach. The glide slope is 5.5 degrees well above the normal of 3 degrees. Therefore it is classified as a 'steep approach' and means all aircraft operating into London City must be certified to do such approaches.
For the airline I work for I know that the aircraft is NOT approved for such an approach. Perhaps others airlines have it approved but none that I know off and iv not seen a Q400 go into London City. But I may be proven wrong by the spotters out there.
The Q400 operates into Galway in Ireland which has a runway length of 1,220 m (4,003 ft) which is shorter than London City. Operating out of airports like Galway may require you to think about taking single leg fuel as apposed to round trip, if the passenger load is high/full, but this would be a conservative move, I really dont think your limited.
With regards to your comment about reverse and the taeoff at the IOM. There are a few points you need to note the Q400 has reverse available but our SOP is not to use it unless you are going to run out of runway and over run i.e in an emergency. I believe when the aircraft was first introduced reverse was used but it was found to bring up ground material which could inturn damage prop blades. So there is plenty more braking available if required.
The SOP on landing is to use DISC (lower than flight Idle) to slow the aircraft in-conjuction with the use of manual wheel brakes coupled with automatic spoiler deployment. Using DISC is more than enough to slow the aircraft down and you will certainly feel it, if you don't deploy it smoothly.
Oh also I might be wrong here, but I also thought it was airport policy that reverse thrust is NOT to be used when landing at City, maybe someone can confirm this.
The specific takeoff you mentioned in the IOM may have been slow due to certain factors such as head wind or even flap setting on the day. However its no Concorde so maybe it was just a typical Dash take off.
Regards,
AKA.
The aircraft is designed for a regional market and often with regional airports you tend to have restrictions at these airports for example short runways, more noise abatement procedures, steep approach etc.
The aircraft does not have huge limitation when it comes to runway lengths provided its on 2 engines. The limitations really come become important when your single engine or say have a flap problem requiring you to either land flapless or with less the normal. Now runway length is more of a factor added further when the runway has other negative characteristics such as slope.
Note also if the runway is wet this will effectively double the required runway length! Not to mention if its Icing conditions too. Single engined worst case landing distance is about 1800m with max weight, wet runway and no wind. Anything with more than 2000m such be ok.
I believe the runway length at London City is 1,508 metres (4,984 ft), this should be ok to land and take off in normal conditions. The problem at city is not the runway length its the type of approach. The glide slope is 5.5 degrees well above the normal of 3 degrees. Therefore it is classified as a 'steep approach' and means all aircraft operating into London City must be certified to do such approaches.
For the airline I work for I know that the aircraft is NOT approved for such an approach. Perhaps others airlines have it approved but none that I know off and iv not seen a Q400 go into London City. But I may be proven wrong by the spotters out there.
The Q400 operates into Galway in Ireland which has a runway length of 1,220 m (4,003 ft) which is shorter than London City. Operating out of airports like Galway may require you to think about taking single leg fuel as apposed to round trip, if the passenger load is high/full, but this would be a conservative move, I really dont think your limited.
With regards to your comment about reverse and the taeoff at the IOM. There are a few points you need to note the Q400 has reverse available but our SOP is not to use it unless you are going to run out of runway and over run i.e in an emergency. I believe when the aircraft was first introduced reverse was used but it was found to bring up ground material which could inturn damage prop blades. So there is plenty more braking available if required.
The SOP on landing is to use DISC (lower than flight Idle) to slow the aircraft in-conjuction with the use of manual wheel brakes coupled with automatic spoiler deployment. Using DISC is more than enough to slow the aircraft down and you will certainly feel it, if you don't deploy it smoothly.
Oh also I might be wrong here, but I also thought it was airport policy that reverse thrust is NOT to be used when landing at City, maybe someone can confirm this.
The specific takeoff you mentioned in the IOM may have been slow due to certain factors such as head wind or even flap setting on the day. However its no Concorde so maybe it was just a typical Dash take off.
Regards,
AKA.
Join Date: May 2003
Location: Somewhere In The South China Sea
Posts: 960
Likes: 0
Received 0 Likes
on
0 Posts
AKA
LCY runway is indeed 1500mtrs but the LDA is 1319m on both and the TORA is 1199m
Also regarding Q400s going in there I didn't think they did but I saw a photograph the other day of a Luthansa Regional Q400 landing so I guess they do but it's very very few operators.
LCY runway is indeed 1500mtrs but the LDA is 1319m on both and the TORA is 1199m
Also regarding Q400s going in there I didn't think they did but I saw a photograph the other day of a Luthansa Regional Q400 landing so I guess they do but it's very very few operators.
Join Date: Jul 2004
Location: UK
Posts: 849
Likes: 0
Received 0 Likes
on
0 Posts
Q400 used to operate into LCY quite regularly - SAS certainly used it on that route almost from the start. Think Flybe may have given it a crack, but wisely decided against it due to the increased risk of a tailstrike on what was then a new fleet, and crews who were finding it a real handful after life on the classic Dash.
